From 59f1579956f07efe2611f6892a923764a0778ab2 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Thu, 6 Apr 2023 13:26:20 +0100 Subject: [PATCH] add power_decode_svp64_rm.py capability for new LD/ST format https://bugs.libre-soc.org/show_bug.cgi?id=1047 --- src/openpower/consts.py | 4 + src/openpower/decoder/isa/caller.py | 6 +- src/openpower/decoder/power_svp64_rm.py | 203 +++++++++++++++++++----- 3 files changed, 168 insertions(+), 45 deletions(-) diff --git a/src/openpower/consts.py b/src/openpower/consts.py index 0bdfb333..f31ab561 100644 --- a/src/openpower/consts.py +++ b/src/openpower/consts.py @@ -271,6 +271,10 @@ class SVP64MODEb(_Const): LDI_POST = 2 # LD-Immediate Post/FF Mode LDI_PI = 3 # LD-Immediate Post-Increment LDI_FF = 4 # LD-Immediate Fault-First + # LDST Indexed + LDIDX_ELS = 0 # Indexed element-strided + # LDST VLI for ffirst is in bit 0 + LDST_VLI = 0 # BO bits BO_MSB = 2 BO_LSB = 4 diff --git a/src/openpower/decoder/isa/caller.py b/src/openpower/decoder/isa/caller.py index b3c680f3..7e656d83 100644 --- a/src/openpower/decoder/isa/caller.py +++ b/src/openpower/decoder/isa/caller.py @@ -2234,14 +2234,14 @@ 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 diff --git a/src/openpower/decoder/power_svp64_rm.py b/src/openpower/decoder/power_svp64_rm.py index f2b40576..b88b9a38 100644 --- a/src/openpower/decoder/power_svp64_rm.py +++ b/src/openpower/decoder/power_svp64_rm.py @@ -1,6 +1,11 @@ # SPDX-License-Identifier: LGPLv3+ # Copyright (C) 2021 Luke Kenneth Casson Leighton # Funded by NLnet http://nlnet.nl + +# sigh this entire module is a laborious mess. it really should be +# auto-generated from the power_insn.py database but a technique +# for doing so (similar to python HTML/XML-node-walking) is needed + """SVP64 RM (Remap) Record. https://libre-soc.org/openpower/sv/svp64/ @@ -50,6 +55,14 @@ https://libre-soc.org/openpower/sv/ldst/ https://libre-soc.org/openpower/sv/branches/ LD/ST immed: +| 0 | 1 | 2 | 3 4 | description | +|---|---| --- |---------|--------------------------- | +| 0 | 0 | 0 | zz els | simple mode | +| 0 | 0 | 1 | PI LF | post-increment and Fault-First | +| 1 | 0 | N | zz els | sat mode: N=0/1 u/s | +|VLi| 1 | inv | CR-bit | Rc=1: ffirst CR sel | +|VLi| 1 | inv | els RC1 | Rc=0: ffirst z/nonz | + 00 0 zz els normal mode (with element-stride option) 01 inv CR-bit Rc=1: ffirst CR sel 01 inv els RC1 Rc=0: ffirst z/nonz @@ -58,6 +71,13 @@ LD/ST immed: 11 inv els RC1 Rc=0: pred-result z/nonz LD/ST indexed: + +| 0 | 1 | 2 | 3 4 | description | +|---|---| --- |---------|--------------------------- | +|els| 0 | SEA | dz sz | simple mode | +|VLi| 1 | inv | CR-bit | Rc=1: ffirst CR sel | +|VLi| 1 | inv | els RC1 | Rc=0: ffirst z/nonz | + 00 0 sz dz normal mode 00 1 rsvd reserved 01 inv CR-bit Rc=1: ffirst CR sel @@ -161,8 +181,10 @@ class SVP64RMModeDecode(Elaboratable): mode2 = sel(m, mode, SVP64MODE.MOD2) cr = sel(m, mode, SVP64MODE.CR) + ##################### + # Branch-Conditional decoding + ##################### with m.If(is_bc): - # Branch-Conditional is completely different # Counter-Test Mode. with m.If(mode[SVP64MODE.BC_CTRTEST]): with m.If(self.rm_in.ewsrc[1]): @@ -176,6 +198,9 @@ class SVP64RMModeDecode(Elaboratable): comb += self.bc_lru.eq(self.rm_in.elwidth[0]) comb += self.bc_vsb.eq(self.rm_in.ewsrc[0]) + ##################### + # CRops decoding + ##################### with m.Elif(is_cr): with m.Switch(mode2): with m.Case(0, 1): # needs further decoding (LDST no mapreduce) @@ -195,8 +220,10 @@ class SVP64RMModeDecode(Elaboratable): with m.Else(): comb += self.cr_sel.eq(cr) - with m.Else(): - # combined arith / ldst decoding due to similarity + ##################### + # LDST decoding (both Idx and Imm - should be separate) + ##################### + with m.Elif(is_ldst): with m.Switch(mode2): with m.Case(0): # needs further decoding (LDST no mapreduce) with m.If(is_ldstimm & mode[SVP64MODE.LDI_POST]): @@ -205,15 +232,111 @@ class SVP64RMModeDecode(Elaboratable): comb += self.ldst_ffirst.eq(mode[SVP64MODE.LDI_FF]) with m.Elif(is_ldst): comb += self.mode.eq(SVP64RMMode.NORMAL) - with m.Elif(mode[SVP64MODE.REDUCE]): + with m.Case(1, 3): + comb += self.mode.eq(SVP64RMMode.FFIRST) # ffirst + with m.Case(2): + with m.If(is_ldstimm): + comb += self.mode.eq(SVP64RMMode.SATURATE) # saturate + with m.Else(): + comb += self.mode.eq(SVP64RMMode.NORMAL) # els-bit + + # extract zeroing + with m.If(is_ldst & ~is_ldstimm): # LDST-Indexed + with m.Switch(mode2): + with m.Case(0,2): + # sz/dz only when mode2[0] = 0 + comb += self.pred_sz.eq(mode[SVP64MODE.DZ]) + comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) + + with m.Elif(is_ldstimm): # LDST-Immediate + with m.Switch(mode2): + with m.Case(0): # simple mode + with m.If(~mode[2]): # (but not PI/LF) + # [MSB0-numbered] bits 0,1,2 of mode zero, use zz + comb += self.pred_sz.eq(mode[SVP64MODE.ZZ]) + comb += self.pred_dz.eq(mode[SVP64MODE.ZZ]) + with m.Case(2): # saturated mode + # saturated-mode also uses zz + comb += self.pred_sz.eq(mode[SVP64MODE.ZZ]) + comb += self.pred_dz.eq(mode[SVP64MODE.ZZ]) + + # extract failfirst + with m.If(self.mode == SVP64RMMode.FFIRST): # fail-first + comb += self.inv.eq(mode[SVP64MODE.INV]) + with m.If(is_ldst): + comb += self.vli.eq(mode[SVP64MODE.LDST_VLI]) + with m.If(self.rc_in): + comb += self.cr_sel.eq(cr) + with m.Else(): + # only when Rc=0 + comb += self.RC1.eq(mode[SVP64MODE.RC1]) + with m.If(~is_ldst): + comb += self.vli.eq(mode[SVP64MODE.VLI]) + comb += self.cr_sel.eq(0b10) # EQ bit index is implicit + + # extract saturate + with m.Switch(mode2): + with m.Case(2): + with m.If(mode[SVP64MODE.N]): + comb += self.saturate.eq(SVP64Sat.UNSIGNED) + with m.Else(): + comb += self.saturate.eq(SVP64Sat.SIGNED) + with m.Default(): + comb += self.saturate.eq(SVP64Sat.NONE) + + # do elwidth/elwidth_src extract + comb += self.ew_src.eq(self.rm_in.ewsrc) + comb += self.ew_dst.eq(self.rm_in.elwidth) + comb += self.subvl.eq(self.rm_in.subvl) + + # extract els (element strided mode bit) + # see https://libre-soc.org/openpower/sv/ldst/ + els = Signal() + with m.If(is_ldstimm): # LD/ST-immediate + with m.Switch(mode2): + with m.Case(0): + with m.If(~mode[2]): # (but not PI/LF) + comb += els.eq(mode[SVP64MODE.ELS_NORMAL]) + with m.Case(2): + comb += els.eq(mode[SVP64MODE.ELS_SAT]) + with m.Case(1, 3): + with m.If(self.rc_in): + comb += els.eq(mode[SVP64MODE.ELS_FFIRST_PRED]) + with m.Else(): # LD/ST-Indexed + with m.Switch(mode2): + with m.Case(0, 2): + comb += els.eq(mode[SVP64MODE.LDIDX_ELS]) + with m.Case(1, 3): + with m.If(self.rc_in): + comb += els.eq(mode[SVP64MODE.ELS_FFIRST_PRED]) + + # RA is vectorised + with m.If(self.ldst_ra_vec): + comb += self.ldstmode.eq(SVP64LDSTmode.INDEXED) + # not element-strided, therefore unit... + with m.Elif(~els): + comb += self.ldstmode.eq(SVP64LDSTmode.UNITSTRIDE) + # but if the LD/ST immediate is zero, allow cache-inhibited + # loads from same location, therefore don't do element-striding + with m.Elif(~self.ldst_imz_in): + comb += self.ldstmode.eq(SVP64LDSTmode.ELSTRIDE) + + ###################### + # arith decoding + ###################### + with m.Else(): + with m.Switch(mode2): + with m.Case(0): # needs further decoding (LDST no mapreduce) + with m.If(mode[SVP64MODE.REDUCE]): comb += self.mode.eq(SVP64RMMode.MAPREDUCE) with m.Else(): comb += self.mode.eq(SVP64RMMode.NORMAL) with m.Case(1): - comb += self.mode.eq(SVP64RMMode.FFIRST) # fail-first + comb += self.mode.eq(SVP64RMMode.FFIRST) # ffirst with m.Case(2): comb += self.mode.eq(SVP64RMMode.SATURATE) # saturate with m.Case(3): + # mode = 0b11: arithmetic predicate-result comb += self.mode.eq(SVP64RMMode.PREDRES) # pred result # extract "reverse gear" for mapreduce mode @@ -225,35 +348,20 @@ class SVP64RMModeDecode(Elaboratable): # extract zeroing with m.Switch(mode2): - with m.Case(0): # needs further decoding (LDST no mapreduce) - with m.If(is_ldstimm & - ~(self.ldst_postinc | self.ldst_ffirst)): - # no predicate-zeroing in fail-first or postinc - pass - with m.If(is_ldst): - # XXX TODO, work out which of these is most - # appropriate set both? or just the one? - # or one if LD, the other if ST? - comb += self.pred_sz.eq(mode[SVP64MODE.DZ]) - comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) - with m.Elif(mode[SVP64MODE.REDUCE]): - with m.If(self.rm_in.subvl == Const(0, 2)): # no SUBVL - comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) - with m.Else(): + with m.Case(0): + # normal-mode only active in simple mode + with m.If(~mode[SVP64MODE.REDUCE]): # bit 2 is zero? comb += self.pred_sz.eq(mode[SVP64MODE.SZ]) comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) - with m.Case(1, 3): - with m.If(is_ldst): - with m.If(~self.ldst_ra_vec): - comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) - with m.Elif(self.rc_in): - comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) with m.Case(2): - with m.If(is_ldst & ~self.ldst_ra_vec): - comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) - with m.Else(): - comb += self.pred_sz.eq(mode[SVP64MODE.SZ]) - comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) + # sat-mode all good... + comb += self.pred_sz.eq(mode[SVP64MODE.SZ]) + comb += self.pred_dz.eq(mode[SVP64MODE.DZ]) + with m.Case(3): + # predicate-result has ZZ + with m.If(self.rc_in): + comb += self.pred_sz.eq(mode[SVP64MODE.ZZ]) + comb += self.pred_dz.eq(mode[SVP64MODE.ZZ]) # extract failfirst with m.If(self.mode == SVP64RMMode.FFIRST): # fail-first @@ -263,7 +371,8 @@ class SVP64RMModeDecode(Elaboratable): with m.Else(): # only when Rc=0 comb += self.RC1.eq(mode[SVP64MODE.RC1]) - comb += self.vli.eq(mode[SVP64MODE.VLI]) + with m.If(~is_ldst): + comb += self.vli.eq(mode[SVP64MODE.VLI]) comb += self.cr_sel.eq(0b10) # EQ bit index is implicit # extract saturate @@ -285,14 +394,22 @@ class SVP64RMModeDecode(Elaboratable): # see https://libre-soc.org/openpower/sv/ldst/ els = Signal() with m.If(is_ldst): - with m.Switch(mode2): - with m.Case(0): - comb += els.eq(mode[SVP64MODE.ELS_NORMAL]) - with m.Case(2): - comb += els.eq(mode[SVP64MODE.ELS_SAT]) - with m.Case(1, 3): - with m.If(self.rc_in): - comb += els.eq(mode[SVP64MODE.ELS_FFIRST_PRED]) + with m.If(is_ldstimm): + with m.Switch(mode2): + with m.Case(0): + comb += els.eq(mode[SVP64MODE.ELS_NORMAL]) + with m.Case(2): + comb += els.eq(mode[SVP64MODE.ELS_SAT]) + with m.Case(1, 3): + with m.If(self.rc_in): + comb += els.eq(mode[SVP64MODE.ELS_FFIRST_PRED]) + with m.Else(): + with m.Switch(mode2): + with m.Case(0, 2): + comb += els.eq(mode[SVP64MODE.LDIDX_ELS]) + with m.Case(1, 3): + with m.If(self.rc_in): + comb += els.eq(mode[SVP64MODE.ELS_FFIRST_PRED]) # RA is vectorised with m.If(self.ldst_ra_vec): @@ -305,6 +422,10 @@ class SVP64RMModeDecode(Elaboratable): with m.Elif(~self.ldst_imz_in): comb += self.ldstmode.eq(SVP64LDSTmode.ELSTRIDE) + ###################### + # Common fields (not many, sigh) + ###################### + # extract src/dest predicate. use EXTRA3.MASK because EXTRA2.MASK # is in exactly the same bits srcmask = sel(m, self.rm_in.extra, EXTRA3.MASK) @@ -323,7 +444,5 @@ class SVP64RMModeDecode(Elaboratable): with m.Else(): comb += self.predmode.eq(SVP64PredMode.INT) # non-zero src: INT - # TODO: detect zeroing mode, saturation mode, a few more. - return m -- 2.30.2