From a68e93791d978c51f242445678d3580b39737f5a Mon Sep 17 00:00:00 2001 From: Keith Randall Date: Wed, 14 Feb 2018 14:21:31 -0800 Subject: [PATCH] [release-branch.go1.10] cmd/compile: fix constant folding of right shifts on s390x Repeat previous fix on amd64 for s390x. Sub-word right shifts should sign extend before shifting. Update #23812 Change-Id: I2d770190c7d8a22310b0dbd9facb3fb05afa362a Reviewed-on: https://go-review.googlesource.com/94028 Run-TryBot: Keith Randall TryBot-Result: Gobot Gobot Reviewed-by: Brad Fitzpatrick (cherry picked from commit 1566bf90253097dfec83f621a48e761ded4d2144) Reviewed-on: https://go-review.googlesource.com/94216 --- src/cmd/compile/internal/ssa/gen/S390X.rules | 2 +- src/cmd/compile/internal/ssa/gen/S390XOps.go | 8 ++++---- src/cmd/compile/internal/ssa/rewriteS390X.go | 4 ++-- 3 files changed, 7 insertions(+), 7 deletions(-) diff --git a/src/cmd/compile/internal/ssa/gen/S390X.rules b/src/cmd/compile/internal/ssa/gen/S390X.rules index 6b997bd46d..366fcc2b2a 100644 --- a/src/cmd/compile/internal/ssa/gen/S390X.rules +++ b/src/cmd/compile/internal/ssa/gen/S390X.rules @@ -1088,7 +1088,7 @@ (SUBconst (MOVDconst [d]) [c]) -> (MOVDconst [d-c]) (SUBconst (SUBconst x [d]) [c]) && is32Bit(-c-d) -> (ADDconst [-c-d] x) (SRADconst [c] (MOVDconst [d])) -> (MOVDconst [d>>uint64(c)]) -(SRAWconst [c] (MOVDconst [d])) -> (MOVDconst [d>>uint64(c)]) +(SRAWconst [c] (MOVDconst [d])) -> (MOVDconst [int64(int32(d))>>uint64(c)]) (NEG (MOVDconst [c])) -> (MOVDconst [-c]) (NEGW (MOVDconst [c])) -> (MOVDconst [int64(int32(-c))]) (MULLDconst [c] (MOVDconst [d])) -> (MOVDconst [c*d]) diff --git a/src/cmd/compile/internal/ssa/gen/S390XOps.go b/src/cmd/compile/internal/ssa/gen/S390XOps.go index ab781cee90..d12dfe78bb 100644 --- a/src/cmd/compile/internal/ssa/gen/S390XOps.go +++ b/src/cmd/compile/internal/ssa/gen/S390XOps.go @@ -309,15 +309,15 @@ func init() { {name: "SLWconst", argLength: 1, reg: gp11, asm: "SLW", aux: "Int8"}, // arg0 << auxint, shift amount 0-31 {name: "SRD", argLength: 2, reg: sh21, asm: "SRD"}, // unsigned arg0 >> arg1, shift amount is mod 64 - {name: "SRW", argLength: 2, reg: sh21, asm: "SRW"}, // unsigned arg0 >> arg1, shift amount is mod 32 + {name: "SRW", argLength: 2, reg: sh21, asm: "SRW"}, // unsigned uint32(arg0) >> arg1, shift amount is mod 32 {name: "SRDconst", argLength: 1, reg: gp11, asm: "SRD", aux: "Int8"}, // unsigned arg0 >> auxint, shift amount 0-63 - {name: "SRWconst", argLength: 1, reg: gp11, asm: "SRW", aux: "Int8"}, // unsigned arg0 >> auxint, shift amount 0-31 + {name: "SRWconst", argLength: 1, reg: gp11, asm: "SRW", aux: "Int8"}, // unsigned uint32(arg0) >> auxint, shift amount 0-31 // Arithmetic shifts clobber flags. {name: "SRAD", argLength: 2, reg: sh21, asm: "SRAD", clobberFlags: true}, // signed arg0 >> arg1, shift amount is mod 64 - {name: "SRAW", argLength: 2, reg: sh21, asm: "SRAW", clobberFlags: true}, // signed arg0 >> arg1, shift amount is mod 32 + {name: "SRAW", argLength: 2, reg: sh21, asm: "SRAW", clobberFlags: true}, // signed int32(arg0) >> arg1, shift amount is mod 32 {name: "SRADconst", argLength: 1, reg: gp11, asm: "SRAD", aux: "Int8", clobberFlags: true}, // signed arg0 >> auxint, shift amount 0-63 - {name: "SRAWconst", argLength: 1, reg: gp11, asm: "SRAW", aux: "Int8", clobberFlags: true}, // signed arg0 >> auxint, shift amount 0-31 + {name: "SRAWconst", argLength: 1, reg: gp11, asm: "SRAW", aux: "Int8", clobberFlags: true}, // signed int32(arg0) >> auxint, shift amount 0-31 {name: "RLLGconst", argLength: 1, reg: gp11, asm: "RLLG", aux: "Int8"}, // arg0 rotate left auxint, rotate amount 0-63 {name: "RLLconst", argLength: 1, reg: gp11, asm: "RLL", aux: "Int8"}, // arg0 rotate left auxint, rotate amount 0-31 diff --git a/src/cmd/compile/internal/ssa/rewriteS390X.go b/src/cmd/compile/internal/ssa/rewriteS390X.go index fe9b2bd001..5f25e9d279 100644 --- a/src/cmd/compile/internal/ssa/rewriteS390X.go +++ b/src/cmd/compile/internal/ssa/rewriteS390X.go @@ -37197,7 +37197,7 @@ func rewriteValueS390X_OpS390XSRAW_0(v *Value) bool { func rewriteValueS390X_OpS390XSRAWconst_0(v *Value) bool { // match: (SRAWconst [c] (MOVDconst [d])) // cond: - // result: (MOVDconst [d>>uint64(c)]) + // result: (MOVDconst [int64(int32(d))>>uint64(c)]) for { c := v.AuxInt v_0 := v.Args[0] @@ -37206,7 +37206,7 @@ func rewriteValueS390X_OpS390XSRAWconst_0(v *Value) bool { } d := v_0.AuxInt v.reset(OpS390XMOVDconst) - v.AuxInt = d >> uint64(c) + v.AuxInt = int64(int32(d)) >> uint64(c) return true } return false -- 2.48.1