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| author | Joel Sing <joel@sing.id.au> | 2020-02-26 04:00:10 +1100 |
|---|---|---|
| committer | Joel Sing <joel@sing.id.au> | 2020-02-28 14:33:28 +0000 |
| commit | 8955a56da015890f317d5f6919391503b854d93a (patch) | |
| tree | 59483143777c46d5d25fe01103dd9f3c1b1ffd0f /src/cmd/compile/internal/ssa/rewriteRISCV64.go | |
| parent | 44286d09c5fcdb703624fad6ce24306294cab1fe (diff) | |
| download | go-8955a56da015890f317d5f6919391503b854d93a.tar.gz go-8955a56da015890f317d5f6919391503b854d93a.zip | |
cmd/compile: improve SignExt32to64 on riscv64
SignExt32to64 can be implemented with a single ADDIW instruction, rather than
the two shifts that are in use currently.
Change-Id: Ie1bbaef4018f1ba5162773fc64fa5a887457cfc9
Reviewed-on: https://go-review.googlesource.com/c/go/+/220922
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/cmd/compile/internal/ssa/rewriteRISCV64.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteRISCV64.go | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/src/cmd/compile/internal/ssa/rewriteRISCV64.go b/src/cmd/compile/internal/ssa/rewriteRISCV64.go index e25f80c5ca0..e4480dc3669 100644 --- a/src/cmd/compile/internal/ssa/rewriteRISCV64.go +++ b/src/cmd/compile/internal/ssa/rewriteRISCV64.go @@ -4109,18 +4109,13 @@ func rewriteValueRISCV64_OpSignExt16to64(v *Value) bool { } func rewriteValueRISCV64_OpSignExt32to64(v *Value) bool { v_0 := v.Args[0] - b := v.Block // match: (SignExt32to64 <t> x) - // result: (SRAI [32] (SLLI <t> [32] x)) + // result: (ADDIW [0] x) for { - t := v.Type x := v_0 - v.reset(OpRISCV64SRAI) - v.AuxInt = 32 - v0 := b.NewValue0(v.Pos, OpRISCV64SLLI, t) - v0.AuxInt = 32 - v0.AddArg(x) - v.AddArg(v0) + v.reset(OpRISCV64ADDIW) + v.AuxInt = 0 + v.AddArg(x) return true } } |