minor cleanup in ISACaller on result handling
[openpower-isa.git] / src / openpower / decoder / isa / caller.py
index a0bd9678244b99c37ac943a92a4f2ded7ddaf031..94ac7c008366d5edc9a7fadd34e8033e135084df 100644 (file)
@@ -37,7 +37,7 @@ 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,
+from openpower.consts import (SVP64MODE, SVP64MODEb,
                               SVP64CROffs,
                               )
 from openpower.decoder.power_svp64 import SVP64RM, decode_extra
@@ -66,6 +66,9 @@ 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
@@ -279,33 +282,32 @@ 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
@@ -324,10 +326,9 @@ 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
@@ -536,14 +537,12 @@ class StepLoop:
 
     def __init__(self, svstate):
         self.svstate = svstate
-        self.loopend = False
         self.new_iterators()
 
     def new_iterators(self):
         self.src_it = self.src_iterator()
         self.dst_it = self.dst_iterator()
-        self.end_src = False
-        self.end_dst = False
+        self.loopend = False
         self.new_srcstep = 0
         self.new_dststep = 0
         self.new_ssubstep = 0
@@ -559,12 +558,40 @@ 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)
@@ -572,22 +599,26 @@ class StepLoop:
             # "thing" is re-read every single time a yield gives indices
             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,
+                    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
                         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
                     self.svstate.srcstep = SelectableInt(0, 7)  # reset
-                    break  # trigger StopIteration
+                    self.loopend = True
+                    return
                 self.svstate.srcstep += SelectableInt(1, 7)  # advance srcstep
 
     def dst_iterator(self):
@@ -598,7 +629,37 @@ 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)
@@ -609,7 +670,9 @@ class StepLoop:
                     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)
                         # yield actual substep/dststep
@@ -618,10 +681,11 @@ class StepLoop:
                         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
                     self.svstate.dststep = SelectableInt(0, 7)  # reset
-                    break  # trigger StopIteration
+                    return
                 self.svstate.dststep += SelectableInt(1, 7)  # advance dststep
 
     def src_iterate(self):
@@ -668,6 +732,7 @@ class StepLoop:
                     end_src = srcstep == vl-1
                     if end_src:  # end-point
                         self.loopend = True
+                        srcstep = 0
                         break
                     else:
                         srcstep += 1
@@ -730,6 +795,7 @@ class StepLoop:
                     end_dst = dststep == vl-1
                     if end_dst:  # end-point
                         self.loopend = True
+                        dststep = 0
                         break
                     else:
                         dststep += 1
@@ -986,10 +1052,7 @@ 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
@@ -1161,13 +1224,15 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         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
+            mode = SelectableInt(mode, 5) # convert to SelectableInt before test
+            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)
@@ -1176,7 +1241,7 @@ 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 handle_carry_(self, inputs, output, ca, ca32):
         inv_a = yield self.dec2.e.do.invert_in
         if inv_a:
             inputs[0] = ~inputs[0]
@@ -1185,12 +1250,6 @@ 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)
@@ -1199,10 +1258,9 @@ 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
@@ -1225,10 +1283,10 @@ 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):
         if hasattr(self.dec2.e.do, "invert_in"):
             inv_a = yield self.dec2.e.do.invert_in
             if inv_a:
@@ -1238,8 +1296,7 @@ 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
 
@@ -1249,8 +1306,6 @@ 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
@@ -1271,8 +1326,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         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))
@@ -1367,18 +1421,14 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         """execute one 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)
         opname = code.split(' ')[0]
         try:
             yield from self.call(opname)         # execute the instruction
@@ -1730,7 +1780,11 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # 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)
@@ -1751,34 +1805,18 @@ 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), output_names)
+        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)
 
         # 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
-
+        overflow = outs.get('overflow')
         # and one called CR0
-        cr0 = None
-        if info.write_regs:
-            for name, output in zip(output_names, results):
-                if name == 'CR0':
-                    cr0 = output
+        cr0 = outs.get('CR0')
 
         if not self.is_svp64_mode:  # yeah just no. not in parallel processing
             # detect if overflow was in return result
@@ -1786,7 +1824,7 @@ 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)
 
         # only do SVP64 dest predicated Rc=1 if dest-pred is not enabled
         rc_en = False
@@ -1797,7 +1835,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         # 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, cr0)
+            yield from self.do_rc_ov(ins_name, results[0], overflow, cr0)
 
         # check failfirst
         ffirst_hit = False
@@ -1805,8 +1843,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
             ffirst_hit = (yield from self.check_ffirst(rc_en, srcstep))
 
         # any modified return results?
-        yield from self.do_outregs_nia(asmop, ins_name, info,
-                                       output_names, results,
+        yield from self.do_outregs_nia(asmop, ins_name, info, outs,
                                        carry_en, rc_en, ffirst_hit)
 
     def check_ffirst(self, rc_en, srcstep):
@@ -1835,42 +1872,39 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         yield Settle()  # let decoder update
         return True
 
-    def do_rc_ov(self, ins_name, results, overflow, cr0):
+    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)
         else:
             rc_reg = "CR0"
         regnum, is_vec = yield from get_pdecode_cr_out(self.dec2, rc_reg)
-        cmps = results
         # hang on... for `setvl` actually you want to test SVSTATE.VL
         is_setvl = ins_name == '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(cmps, regnum, overflow, no_so=is_setvl)
+            self.handle_comparison(result, regnum, overflow, no_so=is_setvl)
         else:
             # 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, output_names, results,
+    def do_outregs_nia(self, asmop, ins_name, info, outs,
                        carry_en, rc_en, ffirst_hit):
         # 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)
+        for name, output in outs.items():
+            yield from self.check_write(info, name, output, carry_en)
 
         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(results, rc_en,
+            nia_update = (yield from self.check_step_increment(rc_en,
                                                            asmop, ins_name))
         if nia_update:
             self.update_pc_next()
@@ -2054,7 +2088,7 @@ class ISACaller(ISACallerHelper, ISAFPHelpers, StepLoop):
         else:
             self.gpr[regnum] = output
 
-    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:
@@ -2086,8 +2120,7 @@ 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")