have to now add LD/ST-update instructions to list of explicit-allowed
[openpower-isa.git] / src / openpower / decoder / isa / caller.py
index 7a27d12e2426613c09f73c6ed8857fbacc73bf27..5d8498857e7ee95b1f621f25cbc8f05d14694236 100644 (file)
@@ -13,46 +13,39 @@ related bugs:
 * https://bugs.libre-soc.org/show_bug.cgi?id=424
 """
 
-import re
-from nmigen.sim import Settle, Delay
+from collections import namedtuple
+from copy import deepcopy
 from functools import wraps
-from copy import copy, deepcopy
-from openpower.decoder.orderedset import OrderedSet
-from openpower.decoder.selectable_int import (
-    FieldSelectableInt,
-    SelectableInt,
-    selectconcat,
-)
-from openpower.decoder.power_insn import SVP64Instruction
-from openpower.decoder.power_enums import (spr_dict, spr_byname, XER_bits,
-                                           insns, MicrOp,
-                                           In1Sel, In2Sel, In3Sel,
-                                           OutSel, CRInSel, CROutSel, LDSTMode,
-                                           SVP64RMMode, SVP64PredMode,
-                                           SVP64PredInt, SVP64PredCR,
-                                           SVP64LDSTmode, FPTRANS_INSNS)
-
-from openpower.decoder.power_enums import SVPtype
-
-from openpower.decoder.helpers import (exts, gtu, ltu, undefined,
-                                       ISACallerHelper, ISAFPHelpers)
-from openpower.consts import PIb, MSRb  # big-endian (PowerISA versions)
-from openpower.consts import (SVP64MODE,
-                              SVP64CROffs,
-                              )
-from openpower.decoder.power_svp64 import SVP64RM, decode_extra
 
+from nmigen.sim import Settle
+from openpower.consts import (MSRb, PIb,  # big-endian (PowerISA versions)
+                              SVP64CROffs, SVP64MODEb)
+from openpower.decoder.helpers import (ISACallerHelper, ISAFPHelpers, exts,
+                                       gtu, undefined)
+from openpower.decoder.isa.mem import Mem, MemException
 from openpower.decoder.isa.radixmmu import RADIX
-from openpower.decoder.isa.mem import Mem, swap_order, MemException
 from openpower.decoder.isa.svshape import SVSHAPE
 from openpower.decoder.isa.svstate import SVP64State
-
-
+from openpower.decoder.orderedset import OrderedSet
+from openpower.decoder.power_enums import (FPTRANS_INSNS, CRInSel, CROutSel,
+                                           In1Sel, In2Sel, In3Sel, LDSTMode,
+                                           MicrOp, OutSel, SVMode,
+                                           SVP64LDSTmode, SVP64PredCR,
+                                           SVP64PredInt, SVP64PredMode,
+                                           SVP64RMMode, SVPType, XER_bits,
+                                           insns, spr_byname, spr_dict,
+                                           BFP_FLAG_NAMES)
+from openpower.decoder.power_insn import SVP64Instruction
+from openpower.decoder.power_svp64 import SVP64RM, decode_extra
+from openpower.decoder.selectable_int import (FieldSelectableInt,
+                                              SelectableInt, selectconcat,
+                                              EFFECTIVELY_UNLIMITED)
+from openpower.fpscr import FPSCRState
+from openpower.xer import XERState
 from openpower.util import LogKind, log
 
-from collections import namedtuple
-import math
-import sys
+LDST_UPDATE_INSNS = ['ldu', 'lwzu', 'lbzu', 'lhzu', 'lhau', 'lfsu', 'lfdu',
+                    ]
 
 instruction_info = namedtuple('instruction_info',
                               'func read_regs uninit_regs write_regs ' +
@@ -66,6 +59,9 @@ special_sprs = {
     'VRSAVE': 256}
 
 
+# rrright.  this is here basically because the compiler pywriter returns
+# results in a specific priority order.  to make sure regs match up they
+# need partial sorting. sigh.
 REG_SORT_ORDER = {
     # TODO (lkcl): adjust other registers that should be in a particular order
     # probably CA, CA32, and CR
@@ -85,6 +81,7 @@ REG_SORT_ORDER = {
     "CTR": 0,
     "TAR": 0,
     "MSR": 0,
+    "FPSCR": 0,
     "SVSTATE": 0,
     "SVSHAPE0": 0,
     "SVSHAPE1": 0,
@@ -95,11 +92,43 @@ REG_SORT_ORDER = {
     "CA32": 0,
 
     "overflow": 7,  # should definitely be last
+    "CR0": 8,       # likewise
 }
 
 fregs = ['FRA', 'FRB', 'FRC', 'FRS', 'FRT']
 
 
+def get_masked_reg(regs, base, offs, ew_bits):
+    # rrrright.  start by breaking down into row/col, based on elwidth
+    gpr_offs = offs // (64 // ew_bits)
+    gpr_col = offs % (64 // ew_bits)
+    # compute the mask based on ew_bits
+    mask = (1 << ew_bits) - 1
+    # now select the 64-bit register, but get its value (easier)
+    val = regs[base + gpr_offs]
+    # shift down so element we want is at LSB
+    val >>= gpr_col * ew_bits
+    # mask so we only return the LSB element
+    return val & mask
+
+
+def set_masked_reg(regs, base, offs, ew_bits, value):
+    # rrrright.  start by breaking down into row/col, based on elwidth
+    gpr_offs = offs // (64//ew_bits)
+    gpr_col = offs % (64//ew_bits)
+    # compute the mask based on ew_bits
+    mask = (1 << ew_bits)-1
+    # now select the 64-bit register, but get its value (easier)
+    val = regs[base+gpr_offs]
+    # now mask out the bit we don't want
+    val = val & ~(mask << (gpr_col*ew_bits))
+    # then wipe the bit we don't want from the value
+    value = value & mask
+    # OR the new value in, shifted up
+    val |= value << (gpr_col*ew_bits)
+    regs[base+gpr_offs] = val
+
+
 def create_args(reglist, extra=None):
     retval = list(OrderedSet(reglist))
     retval.sort(key=lambda reg: REG_SORT_ORDER.get(reg, 0))
@@ -117,14 +146,56 @@ class GPR(dict):
         for i in range(len(regfile)):
             self[i] = SelectableInt(regfile[i], 64)
 
-    def __call__(self, ridx):
+    def __call__(self, ridx, is_vec=False, offs=0, elwidth=64):
         if isinstance(ridx, SelectableInt):
             ridx = ridx.value
-        return self[ridx]
+        if elwidth == 64:
+            return self[ridx+offs]
+        # rrrright.  start by breaking down into row/col, based on elwidth
+        gpr_offs = offs // (64//elwidth)
+        gpr_col = offs % (64//elwidth)
+        # now select the 64-bit register, but get its value (easier)
+        val = self[ridx+gpr_offs].value
+        # now shift down and mask out
+        val = val >> (gpr_col*elwidth) & ((1 << elwidth)-1)
+        # finally, return a SelectableInt at the required elwidth
+        log("GPR call", ridx, "isvec", is_vec, "offs", offs,
+            "elwid", elwidth, "offs/col", gpr_offs, gpr_col, "val", hex(val))
+        return SelectableInt(val, elwidth)
 
     def set_form(self, form):
         self.form = form
 
+    def write(self, rnum, value, is_vec=False, elwidth=64):
+        # get internal value
+        if isinstance(rnum, SelectableInt):
+            rnum = rnum.value
+        if isinstance(value, SelectableInt):
+            value = value.value
+        # compatibility...
+        if isinstance(rnum, tuple):
+            rnum, base, offs = rnum
+        else:
+            base, offs = rnum, 0
+        # rrrright.  start by breaking down into row/col, based on elwidth
+        gpr_offs = offs // (64//elwidth)
+        gpr_col = offs % (64//elwidth)
+        # compute the mask based on elwidth
+        mask = (1 << elwidth)-1
+        # now select the 64-bit register, but get its value (easier)
+        val = self[base+gpr_offs].value
+        # now mask out the bit we don't want
+        val = val & ~(mask << (gpr_col*elwidth))
+        # then wipe the bit we don't want from the value
+        value = value & mask
+        # OR the new value in, shifted up
+        val |= value << (gpr_col*elwidth)
+        # finally put the damn value into the regfile
+        log("GPR write", base, "isvec", is_vec, "offs", offs,
+            "elwid", elwidth, "offs/col", gpr_offs, gpr_col, "val", hex(val),
+            "@", base+gpr_offs)
+        dict.__setitem__(self, base+gpr_offs, SelectableInt(val, 64))
+
     def __setitem__(self, rnum, value):
         # rnum = rnum.value # only SelectableInt allowed
         log("GPR setitem", rnum, value)
@@ -201,7 +272,7 @@ class SPR(dict):
                 info = spr_dict[key]
             else:
                 info = spr_byname[key]
-            dict.__setitem__(self, key, SelectableInt(0, info.length))
+            self[key] = SelectableInt(0, info.length)
             res = dict.__getitem__(self, key)
         log("spr returning", key, res)
         return res
@@ -217,6 +288,8 @@ class SPR(dict):
             self.__setitem__('SRR0', value)
         if key == 'HSRR1':  # HACK!
             self.__setitem__('SRR1', value)
+        if key == 1:
+            value = XERState(value)
         log("setting spr", key, value)
         dict.__setitem__(self, key, value)
 
@@ -278,33 +351,32 @@ class CRFields:
             _cr = FieldSelectableInt(self.cr, bits)
             self.crl.append(_cr)
 
-# decode SVP64 predicate integer to reg number and invert
-
 
+# decode SVP64 predicate integer to reg number and invert
 def get_predint(gpr, mask):
+    r3 = gpr(3)
     r10 = gpr(10)
     r30 = gpr(30)
     log("get_predint", mask, SVP64PredInt.ALWAYS.value)
     if mask == SVP64PredInt.ALWAYS.value:
         return 0xffff_ffff_ffff_ffff  # 64 bits of 1
     if mask == SVP64PredInt.R3_UNARY.value:
-        return 1 << (gpr(3).value & 0b111111)
+        return 1 << (r3.value & 0b111111)
     if mask == SVP64PredInt.R3.value:
-        return gpr(3).value
+        return r3.value
     if mask == SVP64PredInt.R3_N.value:
-        return ~gpr(3).value
+        return ~r3.value
     if mask == SVP64PredInt.R10.value:
-        return gpr(10).value
+        return r10.value
     if mask == SVP64PredInt.R10_N.value:
-        return ~gpr(10).value
+        return ~r10.value
     if mask == SVP64PredInt.R30.value:
-        return gpr(30).value
+        return r30.value
     if mask == SVP64PredInt.R30_N.value:
-        return ~gpr(30).value
-
-# decode SVP64 predicate CR to reg number and invert status
+        return ~r30.value
 
 
+# decode SVP64 predicate CR to reg number and invert status
 def _get_predcr(mask):
     if mask == SVP64PredCR.LT.value:
         return 0, 1
@@ -323,10 +395,9 @@ def _get_predcr(mask):
     if mask == SVP64PredCR.NS.value:
         return 3, 0
 
+
 # read individual CR fields (0..VL-1), extract the required bit
 # and construct the mask
-
-
 def get_predcr(crl, mask, vl):
     idx, noninv = _get_predcr(mask)
     mask = 0
@@ -338,71 +409,110 @@ def get_predcr(crl, mask, vl):
 
 
 # TODO, really should just be using PowerDecoder2
-def get_pdecode_idx_in(dec2, name):
+def get_idx_map(dec2, name):
     op = dec2.dec.op
     in1_sel = yield op.in1_sel
     in2_sel = yield op.in2_sel
     in3_sel = yield op.in3_sel
-    # get the IN1/2/3 from the decoder (includes SVP64 remap and isvec)
     in1 = yield dec2.e.read_reg1.data
-    in2 = yield dec2.e.read_reg2.data
-    in3 = yield dec2.e.read_reg3.data
-    in1_isvec = yield dec2.in1_isvec
-    in2_isvec = yield dec2.in2_isvec
-    in3_isvec = yield dec2.in3_isvec
-    log("get_pdecode_idx_in in1", name, in1_sel, In1Sel.RA.value,
-        in1, in1_isvec)
-    log("get_pdecode_idx_in in2", name, in2_sel, In2Sel.RB.value,
-        in2, in2_isvec)
-    log("get_pdecode_idx_in in3", name, in3_sel, In3Sel.RS.value,
-        in3, in3_isvec)
-    log("get_pdecode_idx_in FRS in3", name, in3_sel, In3Sel.FRS.value,
-        in3, in3_isvec)
-    log("get_pdecode_idx_in FRB in2", name, in2_sel, In2Sel.FRB.value,
-        in2, in2_isvec)
-    log("get_pdecode_idx_in FRC in3", name, in3_sel, In3Sel.FRC.value,
-        in3, in3_isvec)
     # identify which regnames map to in1/2/3
     if name == 'RA' or name == 'RA_OR_ZERO':
         if (in1_sel == In1Sel.RA.value or
                 (in1_sel == In1Sel.RA_OR_ZERO.value and in1 != 0)):
-            return in1, in1_isvec
+            return 1
         if in1_sel == In1Sel.RA_OR_ZERO.value:
-            return in1, in1_isvec
+            return 1
     elif name == 'RB':
         if in2_sel == In2Sel.RB.value:
-            return in2, in2_isvec
+            return 2
         if in3_sel == In3Sel.RB.value:
-            return in3, in3_isvec
+            return 3
     # XXX TODO, RC doesn't exist yet!
     elif name == 'RC':
-        assert False, "RC does not exist yet"
-    elif name == 'RS':
+        if in3_sel == In3Sel.RC.value:
+            return 3
+    elif name in ['EA', 'RS']:
         if in1_sel == In1Sel.RS.value:
-            return in1, in1_isvec
+            return 1
         if in2_sel == In2Sel.RS.value:
-            return in2, in2_isvec
+            return 2
         if in3_sel == In3Sel.RS.value:
-            return in3, in3_isvec
+            return 3
     elif name == 'FRA':
         if in1_sel == In1Sel.FRA.value:
-            return in1, in1_isvec
+            return 1
+        if in3_sel == In3Sel.FRA.value:
+            return 3
     elif name == 'FRB':
         if in2_sel == In2Sel.FRB.value:
-            return in2, in2_isvec
+            return 2
     elif name == 'FRC':
         if in3_sel == In3Sel.FRC.value:
-            return in3, in3_isvec
+            return 3
     elif name == 'FRS':
         if in1_sel == In1Sel.FRS.value:
-            return in1, in1_isvec
+            return 1
         if in3_sel == In3Sel.FRS.value:
-            return in3, in3_isvec
+            return 3
+    elif name == 'FRT':
+        if in1_sel == In1Sel.FRT.value:
+            return 1
+    elif name == 'RT':
+        if in1_sel == In1Sel.RT.value:
+            return 1
+    return None
+
+
+# TODO, really should just be using PowerDecoder2
+def get_idx_in(dec2, name, ewmode=False):
+    idx = yield from get_idx_map(dec2, name)
+    if idx is None:
+        return None, False
+    op = dec2.dec.op
+    in1_sel = yield op.in1_sel
+    in2_sel = yield op.in2_sel
+    in3_sel = yield op.in3_sel
+    # get the IN1/2/3 from the decoder (includes SVP64 remap and isvec)
+    in1 = yield dec2.e.read_reg1.data
+    in2 = yield dec2.e.read_reg2.data
+    in3 = yield dec2.e.read_reg3.data
+    if ewmode:
+        in1_base = yield dec2.e.read_reg1.base
+        in2_base = yield dec2.e.read_reg2.base
+        in3_base = yield dec2.e.read_reg3.base
+        in1_offs = yield dec2.e.read_reg1.offs
+        in2_offs = yield dec2.e.read_reg2.offs
+        in3_offs = yield dec2.e.read_reg3.offs
+        in1 = (in1, in1_base, in1_offs)
+        in2 = (in2, in2_base, in2_offs)
+        in3 = (in3, in3_base, in3_offs)
+
+    in1_isvec = yield dec2.in1_isvec
+    in2_isvec = yield dec2.in2_isvec
+    in3_isvec = yield dec2.in3_isvec
+    log("get_idx_in in1", name, in1_sel, In1Sel.RA.value,
+        in1, in1_isvec)
+    log("get_idx_in in2", name, in2_sel, In2Sel.RB.value,
+        in2, in2_isvec)
+    log("get_idx_in in3", name, in3_sel, In3Sel.RS.value,
+        in3, in3_isvec)
+    log("get_idx_in FRS in3", name, in3_sel, In3Sel.FRS.value,
+        in3, in3_isvec)
+    log("get_idx_in FRB in2", name, in2_sel, In2Sel.FRB.value,
+        in2, in2_isvec)
+    log("get_idx_in FRC in3", name, in3_sel, In3Sel.FRC.value,
+        in3, in3_isvec)
+    if idx == 1:
+        return in1, in1_isvec
+    if idx == 2:
+        return in2, in2_isvec
+    if idx == 3:
+        return in3, in3_isvec
     return None, False
 
 
 # TODO, really should just be using PowerDecoder2
-def get_pdecode_cr_in(dec2, name):
+def get_cr_in(dec2, name):
     op = dec2.dec.op
     in_sel = yield op.cr_in
     in_bitfield = yield dec2.dec_cr_in.cr_bitfield.data
@@ -412,7 +522,7 @@ def get_pdecode_cr_in(dec2, name):
     # get the IN1/2/3 from the decoder (includes SVP64 remap and isvec)
     in1 = yield dec2.e.read_cr1.data
     cr_isvec = yield dec2.cr_in_isvec
-    log("get_pdecode_cr_in", in_sel, CROutSel.CR0.value, in1, cr_isvec)
+    log("get_cr_in", in_sel, CROutSel.CR0.value, in1, cr_isvec)
     log("    sv_cr_in", sv_cr_in)
     log("    cr_bf", in_bitfield)
     log("    spec", spec)
@@ -421,12 +531,12 @@ def get_pdecode_cr_in(dec2, name):
     if name == 'BI':
         if in_sel == CRInSel.BI.value:
             return in1, cr_isvec
-    log("get_pdecode_cr_in not found", name)
+    log("get_cr_in not found", name)
     return None, False
 
 
 # TODO, really should just be using PowerDecoder2
-def get_pdecode_cr_out(dec2, name):
+def get_cr_out(dec2, name):
     op = dec2.dec.op
     out_sel = yield op.cr_out
     out_bitfield = yield dec2.dec_cr_out.cr_bitfield.data
@@ -435,91 +545,134 @@ def get_pdecode_cr_out(dec2, name):
     sv_override = yield dec2.dec_cr_out.sv_override
     # get the IN1/2/3 from the decoder (includes SVP64 remap and isvec)
     out = yield dec2.e.write_cr.data
-    o_isvec = yield dec2.o_isvec
-    log("get_pdecode_cr_out", out_sel, CROutSel.CR0.value, out, o_isvec)
+    o_isvec = yield dec2.cr_out_isvec
+    log("get_cr_out", out_sel, CROutSel.CR0.value, out, o_isvec)
     log("    sv_cr_out", sv_cr_out)
     log("    cr_bf", out_bitfield)
     log("    spec", spec)
     log("    override", sv_override)
     # identify which regnames map to out / o2
+    if name == 'BF':
+        if out_sel == CROutSel.BF.value:
+            return out, o_isvec
     if name == 'CR0':
         if out_sel == CROutSel.CR0.value:
             return out, o_isvec
-    if name == 'CR1': # these are not actually calculated correctly
+    if name == 'CR1':  # these are not actually calculated correctly
         if out_sel == CROutSel.CR1.value:
             return out, o_isvec
-    log("get_pdecode_cr_out not found", name)
+    # check RC1 set? if so return implicit vector, this is a REAL bad hack
+    RC1 = yield dec2.rm_dec.RC1
+    if RC1:
+        log("get_cr_out RC1 mode")
+        if name == 'CR0':
+            return 0, True # XXX TODO: offset CR0 from SVSTATE SPR
+        if name == 'CR1':
+            return 1, True # XXX TODO: offset CR1 from SVSTATE SPR
+    # nope - not found.
+    log("get_cr_out not found", name)
     return None, False
 
 
 # TODO, really should just be using PowerDecoder2
-def get_pdecode_idx_out(dec2, name):
+def get_out_map(dec2, name):
     op = dec2.dec.op
     out_sel = yield op.out_sel
     # get the IN1/2/3 from the decoder (includes SVP64 remap and isvec)
     out = yield dec2.e.write_reg.data
-    o_isvec = yield dec2.o_isvec
     # identify which regnames map to out / o2
     if name == 'RA':
-        log("get_pdecode_idx_out", out_sel, OutSel.RA.value, out, o_isvec)
         if out_sel == OutSel.RA.value:
-            return out, o_isvec
+            return True
     elif name == 'RT':
-        log("get_pdecode_idx_out", out_sel, OutSel.RT.value,
-            OutSel.RT_OR_ZERO.value, out, o_isvec,
-            dec2.dec.RT)
         if out_sel == OutSel.RT.value:
-            return out, o_isvec
+            return True
         if out_sel == OutSel.RT_OR_ZERO.value and out != 0:
-            return out, o_isvec
+            return True
     elif name == 'RT_OR_ZERO':
-        log("get_pdecode_idx_out", out_sel, OutSel.RT.value,
-            OutSel.RT_OR_ZERO.value, out, o_isvec,
-            dec2.dec.RT)
         if out_sel == OutSel.RT_OR_ZERO.value:
-            return out, o_isvec
+            return True
     elif name == 'FRA':
-        log("get_pdecode_idx_out", out_sel, OutSel.FRA.value, out, o_isvec)
         if out_sel == OutSel.FRA.value:
-            return out, o_isvec
+            return True
+    elif name == 'FRS':
+        if out_sel == OutSel.FRS.value:
+            return True
     elif name == 'FRT':
-        log("get_pdecode_idx_out", out_sel, OutSel.FRT.value,
-            OutSel.FRT.value, out, o_isvec)
         if out_sel == OutSel.FRT.value:
-            return out, o_isvec
-    log("get_pdecode_idx_out not found", name, out_sel, out, o_isvec)
+            return True
+    return False
+
+
+# TODO, really should just be using PowerDecoder2
+def get_idx_out(dec2, name, ewmode=False):
+    op = dec2.dec.op
+    out_sel = yield op.out_sel
+    # get the IN1/2/3 from the decoder (includes SVP64 remap and isvec)
+    out = yield dec2.e.write_reg.data
+    o_isvec = yield dec2.o_isvec
+    if ewmode:
+        offs = yield dec2.e.write_reg.offs
+        base = yield dec2.e.write_reg.base
+        out = (out, base, offs)
+    # identify which regnames map to out / o2
+    ismap = yield from get_out_map(dec2, name)
+    if ismap:
+        log("get_idx_out", name, out_sel, out, o_isvec)
+        return out, o_isvec
+    log("get_idx_out not found", name, out_sel, out, o_isvec)
     return None, False
 
 
 # TODO, really should just be using PowerDecoder2
-def get_pdecode_idx_out2(dec2, name):
+def get_out2_map(dec2, name):
     # check first if register is activated for write
     op = dec2.dec.op
     out_sel = yield op.out_sel
     out = yield dec2.e.write_ea.data
-    o_isvec = yield dec2.o2_isvec
     out_ok = yield dec2.e.write_ea.ok
-    log("get_pdecode_idx_out2", name, out_sel, out, out_ok, o_isvec)
     if not out_ok:
-        return None, False
+        return False
 
-    if name == 'RA':
+    if name in ['EA', 'RA']:
         if hasattr(op, "upd"):
             # update mode LD/ST uses read-reg A also as an output
             upd = yield op.upd
-            log("get_pdecode_idx_out2", upd, LDSTMode.update.value,
+            log("get_idx_out2", upd, LDSTMode.update.value,
                 out_sel, OutSel.RA.value,
-                out, o_isvec)
+                out)
             if upd == LDSTMode.update.value:
-                return out, o_isvec
+                return True
+    if name == 'RS':
+        fft_en = yield dec2.implicit_rs
+        if fft_en:
+            log("get_idx_out2", out_sel, OutSel.RS.value,
+                out)
+            return True
     if name == 'FRS':
-        int_op = yield dec2.dec.op.internal_op
-        fft_en = yield dec2.use_svp64_fft
-        # if int_op == MicrOp.OP_FP_MADD.value and fft_en:
+        fft_en = yield dec2.implicit_rs
         if fft_en:
-            log("get_pdecode_idx_out2", out_sel, OutSel.FRS.value,
-                out, o_isvec)
-            return out, o_isvec
+            log("get_idx_out2", out_sel, OutSel.FRS.value,
+                out)
+            return True
+    return False
+
+
+# TODO, really should just be using PowerDecoder2
+def get_idx_out2(dec2, name, ewmode=False):
+    # check first if register is activated for write
+    op = dec2.dec.op
+    out_sel = yield op.out_sel
+    out = yield dec2.e.write_ea.data
+    if ewmode:
+        offs = yield dec2.e.write_ea.offs
+        base = yield dec2.e.write_ea.base
+        out = (out, base, offs)
+    o_isvec = yield dec2.o2_isvec
+    ismap = yield from get_out2_map(dec2, name)
+    if ismap:
+        log("get_idx_out2", name, out_sel, out, o_isvec)
+        return out, o_isvec
     return None, False
 
 
@@ -529,10 +682,18 @@ class StepLoop:
 
     def __init__(self, svstate):
         self.svstate = svstate
+        self.new_iterators()
 
-    def get_iterators(self):
+    def new_iterators(self):
         self.src_it = self.src_iterator()
         self.dst_it = self.dst_iterator()
+        self.loopend = False
+        self.new_srcstep = 0
+        self.new_dststep = 0
+        self.new_ssubstep = 0
+        self.new_dsubstep = 0
+        self.pred_dst_zero = 0
+        self.pred_src_zero = 0
 
     def src_iterator(self):
         """source-stepping iterator
@@ -542,36 +703,68 @@ class StepLoop:
         # source step
         if pack:
             # pack advances subvl in *outer* loop
-            if end_src:
-                if not end_ssub:
-                    self.svstate.ssubstep += SelectableInt(1, 2)
-                self.svstate.srcstep = SelectableInt(0, 7)  # reset
-            else:
-                self.svstate.srcstep += SelectableInt(1, 7) # advance srcstep
+            while True:  # outer subvl loop
+                while True:  # inner vl loop
+                    vl = self.svstate.vl
+                    subvl = self.subvl
+                    srcmask = self.srcmask
+                    srcstep = self.svstate.srcstep
+                    pred_src_zero = ((1 << srcstep) & srcmask) != 0
+                    if self.pred_sz or pred_src_zero:
+                        self.pred_src_zero = not pred_src_zero
+                        log("    advance src", srcstep, vl,
+                            self.svstate.ssubstep, subvl)
+                        # yield actual substep/srcstep
+                        yield (self.svstate.ssubstep, srcstep)
+                    # the way yield works these could have been modified.
+                    vl = self.svstate.vl
+                    subvl = self.subvl
+                    srcstep = self.svstate.srcstep
+                    log("    advance src check", srcstep, vl,
+                        self.svstate.ssubstep, subvl, srcstep == vl-1,
+                        self.svstate.ssubstep == subvl)
+                    if srcstep == vl-1:  # end-point
+                        self.svstate.srcstep = SelectableInt(0, 7)  # reset
+                        if self.svstate.ssubstep == subvl:  # end-point
+                            log("    advance pack stop")
+                            return
+                        break  # exit inner loop
+                    self.svstate.srcstep += SelectableInt(1, 7)  # advance ss
+                subvl = self.subvl
+                if self.svstate.ssubstep == subvl:  # end-point
+                    self.svstate.ssubstep = SelectableInt(0, 2)  # reset
+                    log("    advance pack stop")
+                    return
+                self.svstate.ssubstep += SelectableInt(1, 2)
+
         else:
             # these cannot be done as for-loops because SVSTATE may change
             # (srcstep/substep may be modified, interrupted, subvl/vl change)
             # but they *can* be done as while-loops as long as every SVSTATE
             # "thing" is re-read every single time a yield gives indices
-            while True: # outer vl loop
-                while True: # inner subvl loop
+            while True:  # outer vl loop
+                while True:  # inner subvl loop
+                    vl = self.svstate.vl
                     subvl = self.subvl
                     srcmask = self.srcmask
                     srcstep = self.svstate.srcstep
-                    if self.pred_sz or ((1 << srcstep) & srcmask) != 0:
-                        log("    advance src", srcstep, self.svstate.vl,
-                                               self.svstate.ssubstep, subvl)
+                    pred_src_zero = ((1 << srcstep) & srcmask) != 0
+                    if self.pred_sz or pred_src_zero:
+                        self.pred_src_zero = not pred_src_zero
+                        log("    advance src", srcstep, vl,
+                            self.svstate.ssubstep, subvl)
                         # yield actual substep/srcstep
                         yield (self.svstate.ssubstep, srcstep)
-                    if self.svstate.ssubstep == subvl: # end-point
+                    if self.svstate.ssubstep == subvl:  # end-point
                         self.svstate.ssubstep = SelectableInt(0, 2)  # reset
-                        break
+                        break  # exit inner loop
                     self.svstate.ssubstep += SelectableInt(1, 2)
                 vl = self.svstate.vl
-                if srcstep == vl-1: # end-point
+                if srcstep == vl-1:  # end-point
                     self.svstate.srcstep = SelectableInt(0, 7)  # reset
-                    break # trigger StopIteration
-                self.svstate.srcstep += SelectableInt(1, 7) # advance srcstep
+                    self.loopend = True
+                    return
+                self.svstate.srcstep += SelectableInt(1, 7)  # advance srcstep
 
     def dst_iterator(self):
         """dest-stepping iterator
@@ -581,103 +774,214 @@ class StepLoop:
         # dest step
         if unpack:
             # pack advances subvl in *outer* loop
-            pass # TODO
+            while True:  # outer subvl loop
+                while True:  # inner vl loop
+                    vl = self.svstate.vl
+                    subvl = self.subvl
+                    dstmask = self.dstmask
+                    dststep = self.svstate.dststep
+                    pred_dst_zero = ((1 << dststep) & dstmask) != 0
+                    if self.pred_dz or pred_dst_zero:
+                        self.pred_dst_zero = not pred_dst_zero
+                        log("    advance dst", dststep, vl,
+                            self.svstate.dsubstep, subvl)
+                        # yield actual substep/dststep
+                        yield (self.svstate.dsubstep, dststep)
+                    # the way yield works these could have been modified.
+                    vl = self.svstate.vl
+                    dststep = self.svstate.dststep
+                    log("    advance dst check", dststep, vl,
+                        self.svstate.ssubstep, subvl)
+                    if dststep == vl-1:  # end-point
+                        self.svstate.dststep = SelectableInt(0, 7)  # reset
+                        if self.svstate.dsubstep == subvl:  # end-point
+                            log("    advance unpack stop")
+                            return
+                        break
+                    self.svstate.dststep += SelectableInt(1, 7)  # advance ds
+                subvl = self.subvl
+                if self.svstate.dsubstep == subvl:  # end-point
+                    self.svstate.dsubstep = SelectableInt(0, 2)  # reset
+                    log("    advance unpack stop")
+                    return
+                self.svstate.dsubstep += SelectableInt(1, 2)
         else:
             # these cannot be done as for-loops because SVSTATE may change
             # (dststep/substep may be modified, interrupted, subvl/vl change)
             # but they *can* be done as while-loops as long as every SVSTATE
             # "thing" is re-read every single time a yield gives indices
-            while True: # outer vl loop
-                while True: # inner subvl loop
+            while True:  # outer vl loop
+                while True:  # inner subvl loop
                     subvl = self.subvl
                     dstmask = self.dstmask
                     dststep = self.svstate.dststep
-                    if self.pred_dz or ((1 << dststep) & dstmask) != 0:
+                    pred_dst_zero = ((1 << dststep) & dstmask) != 0
+                    if self.pred_dz or pred_dst_zero:
+                        self.pred_dst_zero = not pred_dst_zero
                         log("    advance dst", dststep, self.svstate.vl,
-                                               self.svstate.dsubstep, subvl)
+                            self.svstate.dsubstep, subvl)
                         # yield actual substep/dststep
                         yield (self.svstate.dsubstep, dststep)
-                    if self.svstate.dsubstep == subvl: # end-point
+                    if self.svstate.dsubstep == subvl:  # end-point
                         self.svstate.dsubstep = SelectableInt(0, 2)  # reset
                         break
                     self.svstate.dsubstep += SelectableInt(1, 2)
+                subvl = self.subvl
                 vl = self.svstate.vl
-                if dststep == vl-1: # end-point
+                if dststep == vl-1:  # end-point
                     self.svstate.dststep = SelectableInt(0, 7)  # reset
-                    break # trigger StopIteration
-                self.svstate.dststep += SelectableInt(1, 7) # advance dststep
+                    return
+                self.svstate.dststep += SelectableInt(1, 7)  # advance dststep
 
     def src_iterate(self):
         """source-stepping iterator
         """
-        end_src = self.end_src
         subvl = self.subvl
+        vl = self.svstate.vl
         pack = self.svstate.pack
         unpack = self.svstate.unpack
         ssubstep = self.svstate.ssubstep
         end_ssub = ssubstep == subvl
+        end_src = self.svstate.srcstep == vl-1
         log("    pack/unpack/subvl", pack, unpack, subvl,
-                                     "end", end_src,
-                                     "sub", end_ssub)
+            "end", end_src,
+            "sub", end_ssub)
         # first source step
         srcstep = self.svstate.srcstep
+        srcmask = self.srcmask
         if pack:
             # pack advances subvl in *outer* loop
-            if end_src:
-                if not end_ssub:
-                    self.svstate.ssubstep += SelectableInt(1, 2)
-                self.svstate.srcstep = SelectableInt(0, 7)  # reset
-            else:
-                self.svstate.srcstep += SelectableInt(1, 7) # advance srcstep
+            while True:
+                assert srcstep <= vl-1
+                end_src = srcstep == vl-1
+                if end_src:
+                    if end_ssub:
+                        self.loopend = True
+                    else:
+                        self.svstate.ssubstep += SelectableInt(1, 2)
+                    srcstep = 0  # reset
+                    break
+                else:
+                    srcstep += 1  # advance srcstep
+                    if not self.srcstep_skip:
+                        break
+                    if ((1 << srcstep) & srcmask) != 0:
+                        break
+                    else:
+                        log("      sskip", bin(srcmask), bin(1 << srcstep))
         else:
             # advance subvl in *inner* loop
             if end_ssub:
-                if not end_src:
-                    self.svstate.srcstep += SelectableInt(1, 7)
+                while True:
+                    assert srcstep <= vl-1
+                    end_src = srcstep == vl-1
+                    if end_src:  # end-point
+                        self.loopend = True
+                        srcstep = 0
+                        break
+                    else:
+                        srcstep += 1
+                    if not self.srcstep_skip:
+                        break
+                    if ((1 << srcstep) & srcmask) != 0:
+                        break
+                    else:
+                        log("      sskip", bin(srcmask), bin(1 << srcstep))
                 self.svstate.ssubstep = SelectableInt(0, 2)  # reset
             else:
-                self.svstate.ssubstep += SelectableInt(1, 2) # advance ssubstep
+                # advance ssubstep
+                self.svstate.ssubstep += SelectableInt(1, 2)
 
-        log("    advance src", self.svstate.srcstep, self.svstate.ssubstep)
+        self.svstate.srcstep = SelectableInt(srcstep, 7)
+        log("    advance src", self.svstate.srcstep, self.svstate.ssubstep,
+            self.loopend)
 
     def dst_iterate(self):
         """dest step iterator
         """
-        end_dst = self.end_dst
+        vl = self.svstate.vl
         subvl = self.subvl
         pack = self.svstate.pack
         unpack = self.svstate.unpack
         dsubstep = self.svstate.dsubstep
         end_dsub = dsubstep == subvl
+        dststep = self.svstate.dststep
+        end_dst = dststep == vl-1
+        dstmask = self.dstmask
         log("    pack/unpack/subvl", pack, unpack, subvl,
-                                     "end", end_dst,
-                                     "sub", end_dsub)
+            "end", end_dst,
+            "sub", end_dsub)
         # now dest step
         if unpack:
             # unpack advances subvl in *outer* loop
-            if end_dst:
-                if not end_dsub:
-                    self.svstate.dsubstep += SelectableInt(1, 2)
-                self.svstate.dststep = SelectableInt(0, 7)  # reset
-            else:
-                self.svstate.dststep += SelectableInt(1, 7) # advance dststep
+            while True:
+                assert dststep <= vl-1
+                end_dst = dststep == vl-1
+                if end_dst:
+                    if end_dsub:
+                        self.loopend = True
+                    else:
+                        self.svstate.dsubstep += SelectableInt(1, 2)
+                    dststep = 0  # reset
+                    break
+                else:
+                    dststep += 1  # advance dststep
+                    if not self.dststep_skip:
+                        break
+                    if ((1 << dststep) & dstmask) != 0:
+                        break
+                    else:
+                        log("      dskip", bin(dstmask), bin(1 << dststep))
         else:
             # advance subvl in *inner* loop
             if end_dsub:
-                if not end_dst:
-                    self.svstate.dststep += SelectableInt(1, 7)
+                while True:
+                    assert dststep <= vl-1
+                    end_dst = dststep == vl-1
+                    if end_dst:  # end-point
+                        self.loopend = True
+                        dststep = 0
+                        break
+                    else:
+                        dststep += 1
+                    if not self.dststep_skip:
+                        break
+                    if ((1 << dststep) & dstmask) != 0:
+                        break
+                    else:
+                        log("      dskip", bin(dstmask), bin(1 << dststep))
                 self.svstate.dsubstep = SelectableInt(0, 2)  # reset
             else:
-                self.svstate.dsubstep += SelectableInt(1, 2) # advance ssubstep
-        log("    advance dst", self.svstate.dststep, self.svstate.dsubstep)
+                # advance ssubstep
+                self.svstate.dsubstep += SelectableInt(1, 2)
+
+        self.svstate.dststep = SelectableInt(dststep, 7)
+        log("    advance dst", self.svstate.dststep, self.svstate.dsubstep,
+            self.loopend)
+
+    def at_loopend(self):
+        """tells if this is the last possible element.  uses the cached values
+        for src/dst-step and sub-steps
+        """
+        subvl = self.subvl
+        vl = self.svstate.vl
+        srcstep, dststep = self.new_srcstep, self.new_dststep
+        ssubstep, dsubstep = self.new_ssubstep, self.new_dsubstep
+        end_ssub = ssubstep == subvl
+        end_dsub = dsubstep == subvl
+        if srcstep == vl-1 and end_ssub:
+            return True
+        if dststep == vl-1 and end_dsub:
+            return True
+        return False
 
-    def advance_svstate_steps(self, end_src=False, end_dst=False):
+    def advance_svstate_steps(self):
         """ advance sub/steps. note that Pack/Unpack *INVERTS* the order.
         TODO when Pack/Unpack is set, substep becomes the *outer* loop
         """
         self.subvl = yield self.dec2.rm_dec.rm_in.subvl
-        self.end_src = end_src
-        self.end_dst = end_dst
+        if self.loopend:  # huhn??
+            return
         self.src_iterate()
         self.dst_iterate()
 
@@ -699,11 +1003,11 @@ class StepLoop:
         pred_sz = yield self.dec2.rm_dec.pred_sz
         if pmode == SVP64PredMode.INT.value:
             srcmask = dstmask = get_predint(self.gpr, dstpred)
-            if sv_ptype == SVPtype.P2.value:
+            if sv_ptype == SVPType.P2.value:
                 srcmask = get_predint(self.gpr, srcpred)
         elif pmode == SVP64PredMode.CR.value:
             srcmask = dstmask = get_predcr(self.crl, dstpred, vl)
-            if sv_ptype == SVPtype.P2.value:
+            if sv_ptype == SVPType.P2.value:
                 srcmask = get_predcr(self.crl, srcpred, vl)
         # work out if the ssubsteps are completed
         ssubstart = ssubstep == 0
@@ -720,11 +1024,10 @@ class StepLoop:
         self.pred_sz = pred_sz
         self.new_ssubstep = ssubstep
         log("    new ssubstep", ssubstep)
-        if ssubstart:
-            # until the predicate mask has a "1" bit... or we run out of VL
-            # let srcstep==VL be the indicator to move to next instruction
-            if not pred_sz:
-                self.srcstep_skip = True
+        # until the predicate mask has a "1" bit... or we run out of VL
+        # let srcstep==VL be the indicator to move to next instruction
+        if not pred_sz:
+            self.srcstep_skip = True
 
     def read_dst_mask(self):
         """same as read_src_mask - check and record everything needed
@@ -761,9 +1064,8 @@ class StepLoop:
         self.pred_dz = pred_dz
         self.new_dsubstep = dsubstep
         log("    new dsubstep", dsubstep)
-        if dsubstart:
-            if not pred_dz:
-                self.dststep_skip = True
+        if not pred_dz:
+            self.dststep_skip = True
 
     def svstate_pre_inc(self):
         """check if srcstep/dststep need to skip over masked-out predicate bits
@@ -771,6 +1073,7 @@ class StepLoop:
         it is purely for skipping masked-out bits
         """
 
+        self.subvl = yield self.dec2.rm_dec.rm_in.subvl
         yield from self.read_src_mask()
         yield from self.read_dst_mask()
 
@@ -785,6 +1088,9 @@ class StepLoop:
         vl = self.svstate.vl
         # srcstep-skipping opportunity identified
         if self.srcstep_skip:
+            # cannot do this with sv.bc - XXX TODO
+            if srcmask == 0:
+                self.loopend = True
             while (((1 << srcstep) & srcmask) == 0) and (srcstep != vl):
                 log("      sskip", bin(1 << srcstep))
                 srcstep += 1
@@ -805,6 +1111,9 @@ class StepLoop:
         pred_dst_zero = self.pred_dz
         vl = self.svstate.vl
         if self.dststep_skip:
+            # cannot do this with sv.bc - XXX TODO
+            if dstmask == 0:
+                self.loopend = True
             while (((1 << dststep) & dstmask) == 0) and (dststep != vl):
                 log("      dskip", bin(1 << dststep))
                 dststep += 1
@@ -834,7 +1143,8 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
                  initial_pc=0,
                  bigendian=False,
                  mmu=False,
-                 icachemmu=False):
+                 icachemmu=False,
+                 initial_fpscr=0):
 
         self.bigendian = bigendian
         self.halted = False
@@ -888,16 +1198,13 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # set up 4 dummy SVSHAPEs if they aren't already set up
         for i in range(4):
             sname = 'SVSHAPE%d' % i
-            if sname not in self.spr:
-                val = 0
-            else:
-                val = self.spr[sname].value
+            val = self.spr.get(sname, 0)
             # make sure it's an SVSHAPE
             self.spr[sname] = SVSHAPE(val, self.gpr)
         self.last_op_svshape = False
 
         # "raw" memory
-        self.mem = Mem(row_bytes=8, initial_mem=initial_mem)
+        self.mem = Mem(row_bytes=8, initial_mem=initial_mem, misaligned_ok=True)
         self.mem.log_fancy(kind=LogKind.InstrInOuts)
         self.imem = Mem(row_bytes=4, initial_mem=initial_insns)
         # MMU mode, redirect underlying Mem through RADIX
@@ -910,6 +1217,8 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # FPR (same as GPR except for FP nums)
         # 4.2.2 p124 FPSCR (definitely "separate" - not in SPR)
         #            note that mffs, mcrfs, mtfsf "manage" this FPSCR
+        self.fpscr = FPSCRState(initial_fpscr)
+
         # 2.3.1 CR (and sub-fields CR0..CR6 - CR0 SO comes from XER.SO)
         #         note that mfocrf, mfcr, mtcr, mtocrf, mcrxrx "manage" CRs
         #         -- Done
@@ -922,9 +1231,10 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # create CR then allow portions of it to be "selectable" (below)
         self.cr_fields = CRFields(initial_cr)
         self.cr = self.cr_fields.cr
+        self.cr_backup = 0  # sigh, dreadful hack: for fail-first (VLi)
 
         # "undefined", just set to variable-bit-width int (use exts "max")
-        # self.undefined = SelectableInt(0, 256)  # TODO, not hard-code 256!
+        # self.undefined = SelectableInt(0, EFFECTIVELY_UNLIMITED)
 
         self.namespace = {}
         self.namespace.update(self.spr)
@@ -942,12 +1252,16 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
                                'SVSHAPE3': self.spr['SVSHAPE3'],
                                'CR': self.cr,
                                'MSR': self.msr,
+                               'FPSCR': self.fpscr,
                                'undefined': undefined,
                                'mode_is_64bit': True,
                                'SO': XER_bits['SO'],
-                               'XLEN': 64  # elwidth overrides, later
+                               'XLEN': 64  # elwidth overrides
                                })
 
+        for name in BFP_FLAG_NAMES:
+            setattr(self, name, 0)
+
         # update pc to requested start point
         self.set_pc(initial_pc)
 
@@ -959,12 +1273,16 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         self.decoder = decoder2.dec
         self.dec2 = decoder2
 
-        super().__init__(XLEN=self.namespace["XLEN"])
+        super().__init__(XLEN=self.namespace["XLEN"], FPSCR=self.fpscr)
 
     @property
     def XLEN(self):
         return self.namespace["XLEN"]
 
+    @property
+    def FPSCR(self):
+        return self.fpscr
+
     def call_trap(self, trap_addr, trap_bit):
         """calls TRAP and sets up NIA to the new execution location.
         next instruction will begin at trap_addr.
@@ -991,7 +1309,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         self.spr['SRR1'].value = msr
         if self.is_svp64_mode:
             self.spr['SVSRR0'] = self.namespace['SVSTATE'].value
-        self.trap_nia = SelectableInt(trap_addr | (kaivb&~0x1fff), 64)
+        self.trap_nia = SelectableInt(trap_addr | (kaivb & ~0x1fff), 64)
         self.spr['SRR1'][trap_bit] = 1  # change *copy* of MSR in SRR1
 
         # set exception bits.  TODO: this should, based on the address
@@ -1019,7 +1337,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
     def memassign(self, ea, sz, val):
         self.mem.memassign(ea, sz, val)
 
-    def prep_namespace(self, insn_name, formname, op_fields):
+    def prep_namespace(self, insn_name, formname, op_fields, xlen):
         # TODO: get field names from form in decoder*1* (not decoder2)
         # decoder2 is hand-created, and decoder1.sigform is auto-generated
         # from spec
@@ -1032,12 +1350,16 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             # pseudocode
             if self.is_svp64_mode and name in ['BI']:  # TODO, more CRs
                 # BI is a 5-bit, must reconstruct the value
-                regnum, is_vec = yield from get_pdecode_cr_in(self.dec2, name)
+                regnum, is_vec = yield from get_cr_in(self.dec2, name)
                 sig = getattr(fields, name)
                 val = yield sig
                 # low 2 LSBs (CR field selector) remain same, CR num extended
                 assert regnum <= 7, "sigh, TODO, 128 CR fields"
                 val = (val & 0b11) | (regnum << 2)
+            elif self.is_svp64_mode and name in ['BF']:  # TODO, more CRs
+                regnum, is_vec = yield from get_cr_out(self.dec2, "BF")
+                log('hack %s' % name, regnum, is_vec)
+                val = regnum
             else:
                 sig = getattr(fields, name)
                 val = yield sig
@@ -1052,6 +1374,9 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         self.namespace['XER'] = self.spr['XER']
         self.namespace['CA'] = self.spr['XER'][XER_bits['CA']].value
         self.namespace['CA32'] = self.spr['XER'][XER_bits['CA32']].value
+        self.namespace['OV'] = self.spr['XER'][XER_bits['OV']].value
+        self.namespace['OV32'] = self.spr['XER'][XER_bits['OV32']].value
+        self.namespace['XLEN'] = xlen
 
         # add some SVSTATE convenience variables
         vl = self.svstate.vl
@@ -1059,17 +1384,24 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         self.namespace['VL'] = vl
         self.namespace['srcstep'] = srcstep
 
+        # take a copy of the CR field value: if non-VLi fail-first fails
+        # this is because the pseudocode writes *directly* to CR. sigh
+        self.cr_backup = self.cr.value
+
         # sv.bc* need some extra fields
         if self.is_svp64_mode and insn_name.startswith("sv.bc"):
             # blegh grab bits manually
             mode = yield self.dec2.rm_dec.rm_in.mode
-            bc_vlset = (mode & SVP64MODE.BC_VLSET) != 0
-            bc_vli = (mode & SVP64MODE.BC_VLI) != 0
-            bc_snz = (mode & SVP64MODE.BC_SNZ) != 0
+            # convert to SelectableInt before test
+            mode = SelectableInt(mode, 5)
+            bc_vlset = mode[SVP64MODEb.BC_VLSET] != 0
+            bc_vli = mode[SVP64MODEb.BC_VLI] != 0
+            bc_snz = mode[SVP64MODEb.BC_SNZ] != 0
             bc_vsb = yield self.dec2.rm_dec.bc_vsb
             bc_lru = yield self.dec2.rm_dec.bc_lru
             bc_gate = yield self.dec2.rm_dec.bc_gate
             sz = yield self.dec2.rm_dec.pred_sz
+            self.namespace['mode'] = SelectableInt(mode, 5)
             self.namespace['ALL'] = SelectableInt(bc_gate, 1)
             self.namespace['VSb'] = SelectableInt(bc_vsb, 1)
             self.namespace['LRu'] = SelectableInt(bc_lru, 1)
@@ -1078,7 +1410,112 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             self.namespace['sz'] = SelectableInt(sz, 1)
             self.namespace['SNZ'] = SelectableInt(bc_snz, 1)
 
-    def handle_carry_(self, inputs, outputs, already_done):
+    def get_kludged_op_add_ca_ov(self, inputs, inp_ca_ov):
+        """ this was not at all necessary to do.  this function massively
+        duplicates - in a laborious and complex fashion - the contents of
+        the CSV files that were extracted two years ago from microwatt's
+        source code.  A-inversion is the "inv A" column, output inversion
+        is the "inv out" column, carry-in equal to 0 or 1 or CA is the
+        "cry in" column
+
+        all of that information is available in
+            self.instrs[ins_name].op_fields
+        where info is usually assigned to self.instrs[ins_name]
+
+        https://git.libre-soc.org/?p=openpower-isa.git;a=blob;f=openpower/isatables/minor_31.csv;hb=HEAD
+
+        the immediate constants are *also* decoded correctly and placed
+        usually by DecodeIn2Imm into operand2, as part of power_decoder2.py
+        """
+        def ca(a, b, ca_in, width):
+            mask = (1 << width) - 1
+            y = (a & mask) + (b & mask) + ca_in
+            return y >> width
+
+        asmcode = yield self.dec2.dec.op.asmcode
+        insn = insns.get(asmcode)
+        SI = yield self.dec2.dec.SI
+        SI &= 0xFFFF
+        CA, OV = inp_ca_ov
+        inputs = [i.value for i in inputs]
+        if SI & 0x8000:
+            SI -= 0x10000
+        if insn in ("add", "addo", "addc", "addco"):
+            a = inputs[0]
+            b = inputs[1]
+            ca_in = 0
+        elif insn == "addic" or insn == "addic.":
+            a = inputs[0]
+            b = SI
+            ca_in = 0
+        elif insn in ("subf", "subfo", "subfc", "subfco"):
+            a = ~inputs[0]
+            b = inputs[1]
+            ca_in = 1
+        elif insn == "subfic":
+            a = ~inputs[0]
+            b = SI
+            ca_in = 1
+        elif insn == "adde" or insn == "addeo":
+            a = inputs[0]
+            b = inputs[1]
+            ca_in = CA
+        elif insn == "subfe" or insn == "subfeo":
+            a = ~inputs[0]
+            b = inputs[1]
+            ca_in = CA
+        elif insn == "addme" or insn == "addmeo":
+            a = inputs[0]
+            b = ~0
+            ca_in = CA
+        elif insn == "addze" or insn == "addzeo":
+            a = inputs[0]
+            b = 0
+            ca_in = CA
+        elif insn == "subfme" or insn == "subfmeo":
+            a = ~inputs[0]
+            b = ~0
+            ca_in = CA
+        elif insn == "subfze" or insn == "subfzeo":
+            a = ~inputs[0]
+            b = 0
+            ca_in = CA
+        elif insn == "addex":
+            # CA[32] aren't actually written, just generate so we have
+            # something to return
+            ca64 = ov64 = ca(inputs[0], inputs[1], OV, 64)
+            ca32 = ov32 = ca(inputs[0], inputs[1], OV, 32)
+            return ca64, ca32, ov64, ov32
+        elif insn == "neg" or insn == "nego":
+            a = ~inputs[0]
+            b = 0
+            ca_in = 1
+        else:
+            raise NotImplementedError(
+                "op_add kludge unimplemented instruction: ", asmcode, insn)
+
+        ca64 = ca(a, b, ca_in, 64)
+        ca32 = ca(a, b, ca_in, 32)
+        ov64 = ca64 != ca(a, b, ca_in, 63)
+        ov32 = ca32 != ca(a, b, ca_in, 31)
+        return ca64, ca32, ov64, ov32
+
+    def handle_carry_(self, inputs, output, ca, ca32, inp_ca_ov):
+        op = yield self.dec2.e.do.insn_type
+        if op == MicrOp.OP_ADD.value and ca is None and ca32 is None:
+            retval = yield from self.get_kludged_op_add_ca_ov(
+                inputs, inp_ca_ov)
+            ca, ca32, ov, ov32 = retval
+            asmcode = yield self.dec2.dec.op.asmcode
+            if insns.get(asmcode) == 'addex':
+                # TODO: if 32-bit mode, set ov to ov32
+                self.spr['XER'][XER_bits['OV']] = ov
+                self.spr['XER'][XER_bits['OV32']] = ov32
+            else:
+                # TODO: if 32-bit mode, set ca to ca32
+                self.spr['XER'][XER_bits['CA']] = ca
+                self.spr['XER'][XER_bits['CA32']] = ca32
+            return
         inv_a = yield self.dec2.e.do.invert_in
         if inv_a:
             inputs[0] = ~inputs[0]
@@ -1087,12 +1524,6 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         if imm_ok:
             imm = yield self.dec2.e.do.imm_data.data
             inputs.append(SelectableInt(imm, 64))
-        assert len(outputs) >= 1
-        log("outputs", repr(outputs))
-        if isinstance(outputs, list) or isinstance(outputs, tuple):
-            output = outputs[0]
-        else:
-            output = outputs
         gts = []
         for x in inputs:
             log("gt input", x, output)
@@ -1101,10 +1532,9 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         log(gts)
         cy = 1 if any(gts) else 0
         log("CA", cy, gts)
-        if not (1 & already_done):
+        if ca is None:  # already written
             self.spr['XER'][XER_bits['CA']] = cy
 
-        log("inputs", already_done, inputs)
         # 32 bit carry
         # ARGH... different for OP_ADD... *sigh*...
         op = yield self.dec2.e.do.insn_type
@@ -1127,10 +1557,20 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
                 gts.append(gt)
             cy32 = 1 if any(gts) else 0
             log("CA32", cy32, gts)
-        if not (2 & already_done):
+        if ca32 is None:  # already written
             self.spr['XER'][XER_bits['CA32']] = cy32
 
-    def handle_overflow(self, inputs, outputs, div_overflow):
+    def handle_overflow(self, inputs, output, div_overflow, inp_ca_ov):
+        op = yield self.dec2.e.do.insn_type
+        if op == MicrOp.OP_ADD.value:
+            retval = yield from self.get_kludged_op_add_ca_ov(
+                inputs, inp_ca_ov)
+            ca, ca32, ov, ov32 = retval
+            # TODO: if 32-bit mode, set ov to ov32
+            self.spr['XER'][XER_bits['OV']] = ov
+            self.spr['XER'][XER_bits['OV32']] = ov32
+            self.spr['XER'][XER_bits['SO']] |= ov
+            return
         if hasattr(self.dec2.e.do, "invert_in"):
             inv_a = yield self.dec2.e.do.invert_in
             if inv_a:
@@ -1140,8 +1580,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         if imm_ok:
             imm = yield self.dec2.e.do.imm_data.data
             inputs.append(SelectableInt(imm, 64))
-        assert len(outputs) >= 1
-        log("handle_overflow", inputs, outputs, div_overflow)
+        log("handle_overflow", inputs, output, div_overflow)
         if len(inputs) < 2 and div_overflow is None:
             return
 
@@ -1151,8 +1590,6 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             ov, ov32 = div_overflow, div_overflow
         # arithmetic overflow can be done by analysing the input and output
         elif len(inputs) >= 2:
-            output = outputs[0]
-
             # OV (64-bit)
             input_sgn = [exts(x.value, x.bits) < 0 for x in inputs]
             output_sgn = exts(output.value, output.bits) < 0
@@ -1167,14 +1604,13 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
 
         # now update XER OV/OV32/SO
         so = self.spr['XER'][XER_bits['SO']]
-        new_so = so | ov # sticky overflow ORs in old with new
+        new_so = so | ov  # sticky overflow ORs in old with new
         self.spr['XER'][XER_bits['OV']] = ov
         self.spr['XER'][XER_bits['OV32']] = ov32
         self.spr['XER'][XER_bits['SO']] = new_so
         log("    set overflow", ov, ov32, so, new_so)
 
-    def handle_comparison(self, outputs, cr_idx=0, overflow=None, no_so=False):
-        out = outputs[0]
+    def handle_comparison(self, out, cr_idx=0, overflow=None, no_so=False):
         assert isinstance(out, SelectableInt), \
             "out zero not a SelectableInt %s" % repr(outputs)
         log("handle_comparison", out.bits, hex(out.value))
@@ -1194,7 +1630,11 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             SO = SelectableInt(1, 0)
         else:
             SO = self.spr['XER'][XER_bits['SO']]
-        log("handle_comparison SO overflow", SO, overflow)
+        log("handle_comparison SO", SO.value,
+                    "overflow", overflow,
+                    "zero", zero.value,
+                    "+ve", positive.value,
+                     "-ve", negative.value)
         # alternative overflow checking (setvl mainly at the moment)
         if overflow is not None and overflow == 1:
             SO = SelectableInt(1, 1)
@@ -1245,8 +1685,8 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         opcode = yield self.dec2.dec.opcode_in
         opcode = SelectableInt(value=opcode, bits=32)
         pfx = SVP64Instruction.Prefix(opcode)
-        log("prefix test: opcode:", pfx.po, bin(pfx.po), pfx.id)
-        self.is_svp64_mode = bool((pfx.po == 0b000001) and (pfx.id == 0b11))
+        log("prefix test: opcode:", pfx.PO, bin(pfx.PO), pfx.id)
+        self.is_svp64_mode = bool((pfx.PO == 0b000001) and (pfx.id == 0b11))
         self.pc.update_nia(self.is_svp64_mode)
         # set SVP64 decode
         yield self.dec2.is_svp64_mode.eq(self.is_svp64_mode)
@@ -1268,31 +1708,29 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
     def execute_one(self):
         """execute one instruction
         """
+        self.insnlog = [] # log the instruction
         # get the disassembly code for this instruction
-        if self.is_svp64_mode:
-            if not self.disassembly:
-                code = yield from self.get_assembly_name()
-            else:
-                code = self.disassembly[self._pc+4]
-            log("    svp64 sim-execute", hex(self._pc), code)
+        if not self.disassembly:
+            code = yield from self.get_assembly_name()
         else:
-            if not self.disassembly:
-                code = yield from self.get_assembly_name()
-            else:
-                code = self.disassembly[self._pc]
-            log("sim-execute", hex(self._pc), code)
+            offs, dbg = 0, ""
+            if self.is_svp64_mode:
+                offs, dbg = 4, "svp64 "
+            code = self.disassembly[self._pc+offs]
+            log("    %s sim-execute" % dbg, hex(self._pc), code)
+            self.insnlog.append(code)
         opname = code.split(' ')[0]
         try:
             yield from self.call(opname)         # execute the instruction
         except MemException as e:                # check for memory errors
             if e.args[0] == 'unaligned':         # alignment error
-               # run a Trap but set DAR first
-                print("memory unaligned exception, DAR", e.dar)
+                # run a Trap but set DAR first
+                print("memory unaligned exception, DAR", e.dar, repr(e))
                 self.spr['DAR'] = SelectableInt(e.dar, 64)
                 self.call_trap(0x600, PIb.PRIV)    # 0x600, privileged
                 return
             elif e.args[0] == 'invalid':         # invalid
-               # run a Trap but set DAR first
+                # run a Trap but set DAR first
                 log("RADIX MMU memory invalid error, mode %s" % e.mode)
                 if e.mode == 'EXECUTE':
                     # XXX TODO: must set a few bits in SRR1,
@@ -1312,6 +1750,18 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             # not supported yet:
             raise e                          # ... re-raise
 
+        # append the log file
+        with open("/tmp/insnlog.txt", "a+") as f:
+            f.write(" ".join(self.insnlog)+"\n")
+
+        log("gprs after code", code)
+        self.gpr.dump()
+        crs = []
+        for i in range(len(self.crl)):
+            crs.append(bin(self.crl[i].asint()))
+        log("crs", " ".join(crs))
+        log("vl,maxvl", self.svstate.vl, self.svstate.maxvl)
+
         # don't use this except in special circumstances
         if not self.respect_pc:
             self.fake_pc += 4
@@ -1343,6 +1793,11 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         else:
             rc_en = False
             rc_ok = False
+        # annoying: ignore rc_ok if RC1 is set (for creating *assembly name*)
+        RC1 = yield self.dec2.rm_dec.RC1
+        if RC1:
+            rc_en = False
+            rc_ok = False
         # grrrr have to special-case MUL op (see DecodeOE)
         log("ov %d en %d rc %d en %d op %d" %
             (ov_ok, ov_en, rc_ok, rc_en, int_op))
@@ -1379,6 +1834,10 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
                 asmop = 'mtcrf'
         return asmop
 
+    def reset_remaps(self):
+        self.remap_loopends = [0] * 4
+        self.remap_idxs = [0, 1, 2, 3]
+
     def get_remap_indices(self):
         """WARNING, this function stores remap_idxs and remap_loopends
         in the class for later use.  this to avoid problems with yield
@@ -1386,6 +1845,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # go through all iterators in lock-step, advance to next remap_idx
         srcstep, dststep, ssubstep, dsubstep = self.get_src_dststeps()
         # get four SVSHAPEs. here we are hard-coding
+        self.reset_remaps()
         SVSHAPE0 = self.spr['SVSHAPE0']
         SVSHAPE1 = self.spr['SVSHAPE1']
         SVSHAPE2 = self.spr['SVSHAPE2']
@@ -1397,8 +1857,6 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
                   (SVSHAPE3, SVSHAPE3.get_iterator()),
                   ]
 
-        self.remap_loopends = [0] * 4
-        self.remap_idxs = [0, 1, 2, 3]
         dbg = []
         for i, (shape, remap) in enumerate(remaps):
             # zero is "disabled"
@@ -1476,14 +1934,22 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # list of instructions not being supported by binutils (.long)
         dotstrp = asmop[:-1] if asmop[-1] == '.' else asmop
         if dotstrp in [*FPTRANS_INSNS,
-                    'ffmadds', 'fdmadds', 'ffadds',
-                     'mins', 'maxs', 'minu', 'maxu',
-                    'setvl', 'svindex', 'svremap', 'svstep',
-                    'svshape', 'svshape2',
-                    'grev', 'ternlogi', 'bmask', 'cprop',
-                    'absdu', 'absds', 'absdacs', 'absdacu', 'avgadd',
-                    'fmvis', 'fishmv',
-                    ]:
+                       *LDST_UPDATE_INSNS,
+                       'ffmadds', 'fdmadds', 'ffadds',
+                       'minmax',
+                       'setvl', 'svindex', 'svremap', 'svstep',
+                       'svshape', 'svshape2',
+                       'grev', 'ternlogi', 'bmask', 'cprop',
+                       'absdu', 'absds', 'absdacs', 'absdacu', 'avgadd',
+                       'fmvis', 'fishmv', 'pcdec', "maddedu", "divmod2du",
+                       "dsld", "dsrd", "maddedus",
+                       "shadd", "shaddw", "shadduw",
+                       "fcvttg", "fcvttgo", "fcvttgs", "fcvttgso",
+                       "fmvtg", "fmvtgs",
+                       "fcvtfg", "fcvtfgs",
+                       "fmvfg", "fmvfgs",
+                       "maddsubrs", "maddrs"
+                       ]:
             illegal = False
             ins_name = dotstrp
 
@@ -1491,6 +1957,15 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         if asmop.startswith('bc') and self.is_svp64_mode:
             ins_name = 'sv.%s' % ins_name
 
+        # ld-immediate-with-pi mode redirects to ld-with-postinc
+        ldst_imm_postinc = False
+        if 'u' in ins_name and self.is_svp64_mode:
+            ldst_pi = yield self.dec2.rm_dec.ldst_postinc
+            if ldst_pi:
+                ins_name = ins_name.replace("u", "up")
+                ldst_imm_postinc = True
+                log("   enable ld/st postinc", ins_name)
+
         log("   post-processed name", dotstrp, ins_name, asmop)
 
         # illegal instructions call TRAP at 0x700
@@ -1513,9 +1988,28 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             self.update_pc_next()
             return
 
+        # get elwidths, defaults to 64
+        xlen = 64
+        ew_src = 64
+        ew_dst = 64
+        if self.is_svp64_mode:
+            ew_src = yield self.dec2.rm_dec.ew_src
+            ew_dst = yield self.dec2.rm_dec.ew_dst
+            ew_src = 8 << (3-int(ew_src))  # convert to bitlength
+            ew_dst = 8 << (3-int(ew_dst))  # convert to bitlength
+            xlen = max(ew_src, ew_dst)
+            log("elwdith", ew_src, ew_dst)
+        log("XLEN:", self.is_svp64_mode, xlen)
+
         # look up instruction in ISA.instrs, prepare namespace
-        info = self.instrs[ins_name]
-        yield from self.prep_namespace(ins_name, info.form, info.op_fields)
+        if ins_name == 'pcdec':  # grrrr yes there are others ("stbcx." etc.)
+            info = self.instrs[ins_name+"."]
+        elif asmop[-1] == '.' and asmop in self.instrs:
+            info = self.instrs[asmop]
+        else:
+            info = self.instrs[ins_name]
+        yield from self.prep_namespace(ins_name, info.form, info.op_fields,
+                                       xlen)
 
         # preserve order of register names
         input_names = create_args(list(info.read_regs) +
@@ -1531,7 +2025,13 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         log("sv rm", sv_rm, dest_cr, src_cr, src_byname, dest_byname)
 
         # see if srcstep/dststep need skipping over masked-out predicate bits
-        if (self.is_svp64_mode or ins_name in ['setvl', 'svremap', 'svstate']):
+        # svstep also needs advancement because it calls SVSTATE_NEXT.
+        # bit the remaps get computed just after pre_inc moves them on
+        # with remap_set_steps substituting for PowerDecider2 not doing it,
+        # and SVSTATE_NEXT not being able to.use yield, the preinc on
+        # svstep is necessary for now.
+        self.reset_remaps()
+        if (self.is_svp64_mode or ins_name in ['svstep']):
             yield from self.svstate_pre_inc()
         if self.is_svp64_mode:
             pre = yield from self.update_new_svstate_steps()
@@ -1577,9 +2077,8 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # main input registers (RT, RA ...)
         inputs = []
         for name in input_names:
-            log("name", name)
-            regval = (yield from self.get_input(name))
-            log("regval", regval)
+            regval = (yield from self.get_input(name, ew_src))
+            log("regval name", name, regval)
             inputs.append(regval)
 
         # arrrrgh, awful hack, to get _RT into namespace
@@ -1589,13 +2088,13 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             self.namespace[regname] = SelectableInt(RT, 5)
             if RT == 0:
                 self.namespace["RT"] = SelectableInt(0, 5)
-            regnum, is_vec = yield from get_pdecode_idx_out(self.dec2, "RT")
+            regnum, is_vec = yield from get_idx_out(self.dec2, "RT")
             log('hack input reg %s %s' % (name, str(regnum)), is_vec)
 
         # in SVP64 mode for LD/ST work out immediate
         # XXX TODO: replace_ds for DS-Form rather than D-Form.
         # use info.form to detect
-        if self.is_svp64_mode:
+        if self.is_svp64_mode and not ldst_imm_postinc:
             yield from self.check_replace_d(info, remap_active)
 
         # "special" registers
@@ -1613,14 +2112,20 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # the ALL/ANY mode we can early-exit
         if self.is_svp64_mode and ins_name.startswith("sv.bc"):
             no_in_vec = yield self.dec2.no_in_vec  # BI is scalar
-            # XXX TODO - pack/unpack here
             end_loop = no_in_vec or srcstep == vl-1 or dststep == vl-1
             self.namespace['end_loop'] = SelectableInt(end_loop, 1)
 
+        inp_ca_ov = (self.spr['XER'][XER_bits['CA']].value,
+                     self.spr['XER'][XER_bits['OV']].value)
+
         # execute actual instruction here (finally)
         log("inputs", inputs)
         results = info.func(self, *inputs)
-        log("results", results)
+        output_names = create_args(info.write_regs)
+        outs = {}
+        for out, n in zip(results or [], output_names):
+            outs[n] = out
+        log("results", outs)
 
         # "inject" decorator takes namespace from function locals: we need to
         # overwrite NIA being overwritten (sigh)
@@ -1641,27 +2146,18 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             self.last_st_addr, self.last_ld_addr)
 
         # detect if CA/CA32 already in outputs (sra*, basically)
-        already_done = 0
-        output_names = []
-        if info.write_regs:
-            output_names = create_args(info.write_regs)
-            for name in output_names:
-                if name == 'CA':
-                    already_done |= 1
-                if name == 'CA32':
-                    already_done |= 2
-
-        log("carry already done?", bin(already_done))
+        ca = outs.get("CA")
+        ca32 = outs.get("CA32")
+
+        log("carry already done?", ca, ca32, output_names)
         carry_en = yield self.dec2.e.do.output_carry
         if carry_en:
-            yield from self.handle_carry_(inputs, results, already_done)
+            yield from self.handle_carry_(
+                inputs, results[0], ca, ca32, inp_ca_ov=inp_ca_ov)
 
-        # check if one of the regs was named "overflow"
-        overflow = None
-        if info.write_regs:
-            for name, output in zip(output_names, results):
-                if name == 'overflow':
-                    overflow = output
+        # get outout named "overflow" and "CR0"
+        overflow = outs.get('overflow')
+        cr0 = outs.get('CR0')
 
         if not self.is_svp64_mode:  # yeah just no. not in parallel processing
             # detect if overflow was in return result
@@ -1669,47 +2165,108 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             ov_ok = yield self.dec2.e.do.oe.ok
             log("internal overflow", ins_name, overflow, "en?", ov_en, ov_ok)
             if ov_en & ov_ok:
-                yield from self.handle_overflow(inputs, results, overflow)
+                yield from self.handle_overflow(
+                    inputs, results[0], overflow, inp_ca_ov=inp_ca_ov)
 
         # only do SVP64 dest predicated Rc=1 if dest-pred is not enabled
         rc_en = False
         if not self.is_svp64_mode or not pred_dst_zero:
             if hasattr(self.dec2.e.do, "rc"):
                 rc_en = yield self.dec2.e.do.rc.rc
+        # don't do Rc=1 for svstep it is handled explicitly.
+        # XXX TODO: now that CR0 is supported, sort out svstep's pseudocode
+        # to write directly to CR0 instead of in ISACaller. hooyahh.
         if rc_en and ins_name not in ['svstep']:
-            yield from self.do_rc_ov(ins_name, results, overflow)
+            yield from self.do_rc_ov(ins_name, results[0], overflow, cr0)
+
+        # check failfirst
+        ffirst_hit = False, False
+        if self.is_svp64_mode:
+            sv_mode = yield self.dec2.rm_dec.sv_mode
+            is_cr = sv_mode == SVMode.CROP.value
+            chk = rc_en or is_cr
+            ffirst_hit = (yield from self.check_ffirst(info, chk, srcstep))
 
         # any modified return results?
-        yield from self.do_outregs_nia(asmop, ins_name, info,
-                                       output_names, results,
-                                       carry_en, rc_en)
+        yield from self.do_outregs_nia(asmop, ins_name, info, outs,
+                                       carry_en, rc_en, ffirst_hit, ew_dst)
+
+    def check_ffirst(self, info, rc_en, srcstep):
+        """fail-first mode: checks a bit of Rc Vector, truncates VL
+        """
+        rm_mode = yield self.dec2.rm_dec.mode
+        ff_inv = yield self.dec2.rm_dec.inv
+        cr_bit = yield self.dec2.rm_dec.cr_sel
+        RC1 = yield self.dec2.rm_dec.RC1
+        vli_ = yield self.dec2.rm_dec.vli  # VL inclusive if truncated
+        log(" ff rm_mode", rc_en, rm_mode, SVP64RMMode.FFIRST.value)
+        log("        inv", ff_inv)
+        log("        RC1", RC1)
+        log("        vli", vli_)
+        log("     cr_bit", cr_bit)
+        log("      rc_en", rc_en)
+        if not rc_en or rm_mode != SVP64RMMode.FFIRST.value:
+            return False, False
+        # get the CR vevtor, do BO-test
+        crf = "CR0"
+        log("asmregs", info.asmregs[0], info.write_regs)
+        if 'CR' in info.write_regs and 'BF' in info.asmregs[0]:
+            crf = 'BF'
+        regnum, is_vec = yield from get_cr_out(self.dec2, crf)
+        crtest = self.crl[regnum]
+        ffirst_hit = crtest[cr_bit] != ff_inv
+        log("cr test", crf, regnum, int(crtest), crtest, cr_bit, ff_inv)
+        log("cr test?", ffirst_hit)
+        if not ffirst_hit:
+            return False, False
+        # Fail-first activated, truncate VL
+        vli = SelectableInt(int(vli_), 7)
+        self.svstate.vl = srcstep + vli
+        yield self.dec2.state.svstate.eq(self.svstate.value)
+        yield Settle()  # let decoder update
+        return True, vli_
 
-    def do_rc_ov(self, ins_name, results, overflow):
+    def do_rc_ov(self, ins_name, result, overflow, cr0):
         if ins_name.startswith("f"):
-            rc_reg = "CR1" # not calculated correctly yet (not FP compares)
+            rc_reg = "CR1"  # not calculated correctly yet (not FP compares)
         else:
             rc_reg = "CR0"
-        regnum, is_vec = yield from get_pdecode_cr_out(self.dec2, rc_reg)
-        cmps = results
+        regnum, is_vec = yield from get_cr_out(self.dec2, rc_reg)
         # hang on... for `setvl` actually you want to test SVSTATE.VL
-        is_setvl = ins_name == 'setvl'
+        is_setvl = ins_name in ('svstep', 'setvl')
         if is_setvl:
-            vl = results[0].vl
-            cmps = (SelectableInt(vl, 64), overflow,)
+            result = SelectableInt(result.vl, 64)
+        #else:
+        #    overflow = None  # do not override overflow except in setvl
+
+        # if there was not an explicit CR0 in the pseudocode, do implicit Rc=1
+        if cr0 is None:
+            self.handle_comparison(result, regnum, overflow, no_so=is_setvl)
         else:
-            overflow = None # do not override overflow except in setvl
-        self.handle_comparison(cmps, regnum, overflow, no_so=is_setvl)
-
-    def do_outregs_nia(self, asmop, ins_name, info, output_names, results,
-                       carry_en, rc_en):
-        # write out any regs for this instruction
-        if info.write_regs:
-            for name, output in zip(output_names, results):
-                yield from self.check_write(info, name, output, carry_en)
-
-        # check advancement of src/dst/sub-steps and if PC needs updating
-        nia_update = (yield from self.check_step_increment(results, rc_en,
-                                                           asmop, ins_name))
+            # otherwise we just blat CR0 into the required regnum
+            log("explicit rc0", cr0)
+            self.crl[regnum].eq(cr0)
+
+    def do_outregs_nia(self, asmop, ins_name, info, outs,
+                       ca_en, rc_en, ffirst_hit, ew_dst):
+        ffirst_hit, vli = ffirst_hit
+        # write out any regs for this instruction, but only if fail-first is ok
+        # XXX TODO: allow CR-vector to be written out even if ffirst fails
+        if not ffirst_hit or vli:
+            for name, output in outs.items():
+                yield from self.check_write(info, name, output, ca_en, ew_dst)
+        # restore the CR value on non-VLI failfirst (from sv.cmp and others
+        # which write directly to CR in the pseudocode (gah, what a mess)
+        # if ffirst_hit and not vli:
+        #    self.cr.value = self.cr_backup
+
+        if ffirst_hit:
+            self.svp64_reset_loop()
+            nia_update = True
+        else:
+            # check advancement of src/dst/sub-steps and if PC needs updating
+            nia_update = (yield from self.check_step_increment(rc_en,
+                                                               asmop, ins_name))
         if nia_update:
             self.update_pc_next()
 
@@ -1732,14 +2289,14 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         if op == MicrOp.OP_LOAD.value:
             if remap_active:
                 offsmul = yield self.dec2.in1_step
-                log("D-field REMAP src", imm, offsmul)
+                log("D-field REMAP src", imm, offsmul, ldstmode)
             else:
                 offsmul = (srcstep * (subvl+1)) + ssubstep
-                log("D-field src", imm, offsmul)
+                log("D-field src", imm, offsmul, ldstmode)
         elif op == MicrOp.OP_STORE.value:
             # XXX NOTE! no bit-reversed STORE! this should not ever be used
             offsmul = (dststep * (subvl+1)) + dsubstep
-            log("D-field dst", imm, offsmul)
+            log("D-field dst", imm, offsmul, ldstmode)
         # Unit-Strided LD/ST adds offset*width to immediate
         if ldstmode == SVP64LDSTmode.UNITSTRIDE.value:
             ldst_len = yield self.dec2.e.do.data_len
@@ -1764,31 +2321,43 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             else:
                 self.namespace['D'] = imm
 
-    def get_input(self, name):
+    def get_input(self, name, ew_src):
         # using PowerDecoder2, first, find the decoder index.
         # (mapping name RA RB RC RS to in1, in2, in3)
-        regnum, is_vec = yield from get_pdecode_idx_in(self.dec2, name)
+        regnum, is_vec = yield from get_idx_in(self.dec2, name, True)
         if regnum is None:
             # doing this is not part of svp64, it's because output
             # registers, to be modified, need to be in the namespace.
-            regnum, is_vec = yield from get_pdecode_idx_out(self.dec2, name)
+            regnum, is_vec = yield from get_idx_out(self.dec2, name, True)
         if regnum is None:
-            regnum, is_vec = yield from get_pdecode_idx_out2(self.dec2, name)
+            regnum, is_vec = yield from get_idx_out2(self.dec2, name, True)
+
+        if isinstance(regnum, tuple):
+            (regnum, base, offs) = regnum
+        else:
+            base, offs = regnum, 0  # temporary HACK
 
         # in case getting the register number is needed, _RA, _RB
+        # (HACK: only in straight non-svp64-mode for now, or elwidth == 64)
         regname = "_" + name
-        self.namespace[regname] = regnum
+        if not self.is_svp64_mode or ew_src == 64:
+            self.namespace[regname] = regnum
+        elif regname in self.namespace:
+            del self.namespace[regname]
+
         if not self.is_svp64_mode or not self.pred_src_zero:
             log('reading reg %s %s' % (name, str(regnum)), is_vec)
             if name in fregs:
-                reg_val = SelectableInt(self.fpr(regnum))
-                log("read reg %d: 0x%x" % (regnum, reg_val.value))
+                reg_val = SelectableInt(self.fpr(base, is_vec, offs, ew_src))
+                log("read reg %d/%d: 0x%x" % (base, offs, reg_val.value))
+                self.insnlog.append("rFPR:%d.%d/%d" % (base, offs, ew_src))
             elif name is not None:
-                reg_val = SelectableInt(self.gpr(regnum))
-                log("read reg %d: 0x%x" % (regnum, reg_val.value))
+                reg_val = SelectableInt(self.gpr(base, is_vec, offs, ew_src))
+                self.insnlog.append("rGPR:%d.%d/%d" % (base, offs, ew_src))
+                log("read reg %d/%d: 0x%x" % (base, offs, reg_val.value))
         else:
             log('zero input reg %s %s' % (name, str(regnum)), is_vec)
-            reg_val = 0
+            reg_val = SelectableInt(0, ew_src)
         return reg_val
 
     def remap_set_steps(self, remaps):
@@ -1814,12 +2383,25 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         mi2 = self.svstate.mi2
         mo0 = self.svstate.mo0
         mo1 = self.svstate.mo1
-        steps = [(self.dec2.in1_step, mi0),  # RA
-                 (self.dec2.in2_step, mi1),  # RB
-                 (self.dec2.in3_step, mi2),  # RC
-                 (self.dec2.o_step, mo0),   # RT
-                 (self.dec2.o2_step, mo1),   # EA
+        steps = [[self.dec2.in1_step,  mi0],  # RA
+                 [self.dec2.in2_step,  mi1],  # RB
+                 [self.dec2.in3_step,  mi2],  # RC
+                 [self.dec2.o_step,  mo0],   # RT
+                 [self.dec2.o2_step,  mo1],   # EA
                  ]
+        if False:  # TODO
+            rnames = ['RA', 'RB', 'RC', 'RT', 'RS']
+            for i, reg in enumerate(rnames):
+                idx = yield from get_idx_map(self.dec2, reg)
+                if idx is None:
+                    idx = yield from get_idx_map(self.dec2, "F"+reg)
+                if idx == 1:  # RA
+                    steps[i][0] = self.dec2.in1_step
+                elif idx == 2:  # RB
+                    steps[i][0] = self.dec2.in2_step
+                elif idx == 3:  # RC
+                    steps[i][0] = self.dec2.in3_step
+                log("remap step", i, reg, idx, steps[i][1])
         remap_idxs = self.remap_idxs
         rremaps = []
         # now cross-index the required SHAPE for each of 3-in 2-out regs
@@ -1831,18 +2413,22 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             if shape.value == 0x0:
                 continue
             # now set the actual requested step to the current index
-            yield dstep.eq(remap_idx)
+            if dstep is not None:
+                yield dstep.eq(remap_idx)
 
             # debug printout info
-            rremaps.append((shape.mode, i, rnames[i], shape_idx, remap_idx))
+            rremaps.append((shape.mode, hex(shape.value), dstep,
+                            i, rnames[i], shape_idx, remap_idx))
         for x in rremaps:
             log("shape remap", x)
 
-    def check_write(self, info, name, output, carry_en):
+    def check_write(self, info, name, output, carry_en, ew_dst):
         if name == 'overflow':  # ignore, done already (above)
             return
+        if name == 'CR0':  # ignore, done already (above)
+            return
         if isinstance(output, int):
-            output = SelectableInt(output, 256)
+            output = SelectableInt(output, EFFECTIVELY_UNLIMITED)
         # write carry flafs
         if name in ['CA', 'CA32']:
             if carry_en:
@@ -1864,9 +2450,9 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
                 log('msr written', hex(self.msr.value))
             return
         # find out1/out2 PR/FPR
-        regnum, is_vec = yield from get_pdecode_idx_out(self.dec2, name)
+        regnum, is_vec = yield from get_idx_out(self.dec2, name, True)
         if regnum is None:
-            regnum, is_vec = yield from get_pdecode_idx_out2(self.dec2, name)
+            regnum, is_vec = yield from get_idx_out2(self.dec2, name, True)
         if regnum is None:
             # temporary hack for not having 2nd output
             regnum = yield getattr(self.decoder, name)
@@ -1878,18 +2464,23 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             reg_prefix = 'r'
         # check zeroing due to predicate bit being zero
         if self.is_svp64_mode and self.pred_dst_zero:
-            log('zeroing reg %d %s' % (regnum, str(output)), is_vec)
-            output = SelectableInt(0, 256)
-        log("write reg %s%d %0xx" % (reg_prefix, regnum, output.value))
+            log('zeroing reg %s %s' % (str(regnum), str(output)), is_vec)
+            output = SelectableInt(0, EFFECTIVELY_UNLIMITED)
+        log("write reg %s%s 0x%x ew %d" % (reg_prefix, str(regnum),
+                                           output.value, ew_dst),
+            kind=LogKind.InstrInOuts)
         # zero-extend tov64 bit begore storing (should use EXT oh well)
         if output.bits > 64:
             output = SelectableInt(output.value, 64)
+        rnum, base, offset = regnum
         if name in fregs:
-            self.fpr[regnum] = output
+            self.fpr.write(regnum, output, is_vec, ew_dst)
+            self.insnlog.append("wFPR:%d.%d/%d" % (rnum, offset, ew_dst))
         else:
-            self.gpr[regnum] = output
+            self.gpr.write(regnum, output, is_vec, ew_dst)
+            self.insnlog.append("wGPR:%d.%d/%d" % (rnum, offset, ew_dst))
 
-    def check_step_increment(self, results, rc_en, asmop, ins_name):
+    def check_step_increment(self, rc_en, asmop, ins_name):
         # check if it is the SVSTATE.src/dest step that needs incrementing
         # this is our Sub-Program-Counter loop from 0 to VL-1
         if not self.allow_next_step_inc:
@@ -1921,30 +2512,24 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             self.update_nia()
             if not rc_en:
                 return True
-            results = [SelectableInt(0, 64)]
-            self.handle_comparison(results)  # CR0
+            self.handle_comparison(SelectableInt(0, 64))  # CR0
             return True
         if self.allow_next_step_inc == 2:
             log("SVSTATE_NEXT: read")
             nia_update = (yield from self.svstate_post_inc(ins_name))
         else:
             log("SVSTATE_NEXT: post-inc")
-        # use actual src/dst-step here to check end, do NOT
-        # use bit-reversed version
-        srcstep, dststep = self.new_srcstep, self.new_dststep
-        ssubstep, dsubstep = self.new_ssubstep, self.new_dsubstep
+        # use actual (cached) src/dst-step here to check end
         remaps = self.get_remap_indices()
         remap_idxs = self.remap_idxs
         vl = self.svstate.vl
         subvl = yield self.dec2.rm_dec.rm_in.subvl
-        end_src = srcstep == vl-1
-        end_dst = dststep == vl-1
         if self.allow_next_step_inc != 2:
-            yield from self.advance_svstate_steps(end_src, end_dst)
+            yield from self.advance_svstate_steps()
         #self.namespace['SVSTATE'] = self.svstate.spr
         # set CR0 (if Rc=1) based on end
+        endtest = 1 if self.at_loopend() else 0
         if rc_en:
-            endtest = 1 if (end_src or end_dst) else 0
             #results = [SelectableInt(endtest, 64)]
             # self.handle_comparison(results) # CR0
 
@@ -1954,9 +2539,9 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
                 shape_idx = self.svstate_next_mode.value-1
                 endings = self.remap_loopends[shape_idx]
             cr_field = SelectableInt((~endings) << 1 | endtest, 4)
-            log("svstep Rc=1, CR0", cr_field)
+            log("svstep Rc=1, CR0", cr_field, endtest)
             self.crl[0].eq(cr_field)  # CR0
-        if end_src or end_dst:
+        if endtest:
             # reset at end of loop including exit Vertical Mode
             log("SVSTATE_NEXT: after increments, reset")
             self.svp64_reset_loop()
@@ -1984,6 +2569,12 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         if self.svstate_next_mode == 6:
             self.svstate_next_mode = 0
             return SelectableInt(self.svstate.dststep, 7)
+        if self.svstate_next_mode == 7:
+            self.svstate_next_mode = 0
+            return SelectableInt(self.svstate.ssubstep, 7)
+        if self.svstate_next_mode == 8:
+            self.svstate_next_mode = 0
+            return SelectableInt(self.svstate.dsubstep, 7)
         return SelectableInt(0, 7)
 
     def get_src_dststeps(self):
@@ -1992,19 +2583,23 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         return (self.new_srcstep, self.new_dststep,
                 self.new_ssubstep, self.new_dsubstep)
 
-    def update_new_svstate_steps(self):
-        # note, do not get the bit-reversed srcstep here!
-        srcstep, dststep = self.new_srcstep, self.new_dststep
-        ssubstep, dsubstep = self.new_ssubstep, self.new_dsubstep
-
-        # update SVSTATE with new srcstep
-        self.svstate.srcstep = srcstep
-        self.svstate.dststep = dststep
-        self.svstate.ssubstep = ssubstep
-        self.svstate.dsubstep = dsubstep
+    def update_svstate_namespace(self, overwrite_svstate=True):
+        if overwrite_svstate:
+            # note, do not get the bit-reversed srcstep here!
+            srcstep, dststep = self.new_srcstep, self.new_dststep
+            ssubstep, dsubstep = self.new_ssubstep, self.new_dsubstep
+
+            # update SVSTATE with new srcstep
+            self.svstate.srcstep = srcstep
+            self.svstate.dststep = dststep
+            self.svstate.ssubstep = ssubstep
+            self.svstate.dsubstep = dsubstep
         self.namespace['SVSTATE'] = self.svstate
         yield self.dec2.state.svstate.eq(self.svstate.value)
         yield Settle()  # let decoder update
+
+    def update_new_svstate_steps(self, overwrite_svstate=True):
+        yield from self.update_svstate_namespace(overwrite_svstate)
         srcstep = self.svstate.srcstep
         dststep = self.svstate.dststep
         ssubstep = self.svstate.ssubstep
@@ -2012,7 +2607,11 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         pack = self.svstate.pack
         unpack = self.svstate.unpack
         vl = self.svstate.vl
+        sv_mode = yield self.dec2.rm_dec.sv_mode
         subvl = yield self.dec2.rm_dec.rm_in.subvl
+        rm_mode = yield self.dec2.rm_dec.mode
+        ff_inv = yield self.dec2.rm_dec.inv
+        cr_bit = yield self.dec2.rm_dec.cr_sel
         log("    srcstep", srcstep)
         log("    dststep", dststep)
         log("        pack", pack)
@@ -2021,9 +2620,15 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         log("    dsubstep", dsubstep)
         log("         vl", vl)
         log("      subvl", subvl)
+        log("    rm_mode", rm_mode)
+        log("    sv_mode", sv_mode)
+        log("        inv", ff_inv)
+        log("     cr_bit", cr_bit)
 
         # check if end reached (we let srcstep overrun, above)
         # nothing needs doing (TODO zeroing): just do next instruction
+        if self.loopend:
+            return True
         return ((ssubstep == subvl and srcstep == vl) or
                 (dsubstep == subvl and dststep == vl))
 
@@ -2065,7 +2670,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         log("    reverse", reverse_gear)
         log("    out_vec", out_vec)
         log("    in_vec", in_vec)
-        log("    sv_ptype", sv_ptype, sv_ptype == SVPtype.P2.value)
+        log("    sv_ptype", sv_ptype, sv_ptype == SVPType.P2.value)
         # check if this was an sv.bc* and if so did it succeed
         if self.is_svp64_mode and insn_name.startswith("sv.bc"):
             end_loop = self.namespace['end_loop']
@@ -2077,17 +2682,14 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # check if srcstep needs incrementing by one, stop PC advancing
         # but for 2-pred both src/dest have to be checked.
         # XXX this might not be true! it may just be LD/ST
-        if sv_ptype == SVPtype.P2.value:
+        if sv_ptype == SVPType.P2.value:
             svp64_is_vector = (out_vec or in_vec)
         else:
             svp64_is_vector = out_vec
         # loops end at the first "hit" (source or dest)
-        end_src = srcstep == vl-1
-        end_dst = dststep == vl-1
-        loopend = ((end_src and ssubstep == subvl) or
-                   (end_dst and dsubstep == subvl))
-        log("loopend", svp64_is_vector, loopend, end_src, end_dst,
-                                ssubstep == subvl, dsubstep == subvl)
+        yield from self.advance_svstate_steps()
+        loopend = self.loopend
+        log("loopend", svp64_is_vector, loopend)
         if not svp64_is_vector or loopend:
             # reset loop to zero and update NIA
             self.svp64_reset_loop()
@@ -2096,7 +2698,6 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             return True
 
         # still looping, advance and update NIA
-        yield from self.advance_svstate_steps(end_src, end_dst)
         self.namespace['SVSTATE'] = self.svstate
 
         # not an SVP64 branch, so fix PC (NIA==CIA) for next loop
@@ -2120,6 +2721,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         self.svstate.dststep = 0
         self.svstate.ssubstep = 0
         self.svstate.dsubstep = 0
+        self.loopend = False
         log("    svstate.srcstep loop end (PC to update)")
         self.namespace['SVSTATE'] = self.svstate