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| author | Keith Randall <khr@golang.org> | 2020-12-09 14:59:40 -0800 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2021-02-23 20:05:01 +0000 |
| commit | d2911d76127deaa08644979cec7d990559f0aa54 (patch) | |
| tree | bbb8f48fbcbdebc660deb24f83d0961d4d2caa03 /src/cmd/compile/internal/ssa/rewriteMIPS64.go | |
| parent | d434c2338b11b9ecf19865e8ec3f2721706f29cf (diff) | |
| download | go-d2911d76127deaa08644979cec7d990559f0aa54.tar.gz go-d2911d76127deaa08644979cec7d990559f0aa54.zip | |
cmd/compile: fold MOV*nop and MOV*const
MOV*nop and MOV*reg seem superfluous. They are there to keep type
information around that would otherwise get thrown away. Not sure
what we need it for. I think our compiler needs a normalization of
how types are represented in SSA, especially after lowering.
MOV*nop gets in the way of some optimization rules firing, like for
load combining.
For now, just fold MOV*nop and MOV*const. It's certainly safe to
do that, as the type info on the MOV*const isn't ever useful.
R=go1.17
Change-Id: I3630a80afc2455a8e9cd9fde10c7abe05ddc3767
Reviewed-on: https://go-review.googlesource.com/c/go/+/276792
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Diffstat (limited to 'src/cmd/compile/internal/ssa/rewriteMIPS64.go')
| -rw-r--r-- | src/cmd/compile/internal/ssa/rewriteMIPS64.go | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/ssa/rewriteMIPS64.go b/src/cmd/compile/internal/ssa/rewriteMIPS64.go index d78f6089af..073cf8726c 100644 --- a/src/cmd/compile/internal/ssa/rewriteMIPS64.go +++ b/src/cmd/compile/internal/ssa/rewriteMIPS64.go @@ -339,6 +339,8 @@ func rewriteValueMIPS64(v *Value) bool { return rewriteValueMIPS64_OpMIPS64MOVHstorezero(v) case OpMIPS64MOVVload: return rewriteValueMIPS64_OpMIPS64MOVVload(v) + case OpMIPS64MOVVnop: + return rewriteValueMIPS64_OpMIPS64MOVVnop(v) case OpMIPS64MOVVreg: return rewriteValueMIPS64_OpMIPS64MOVVreg(v) case OpMIPS64MOVVstore: @@ -3584,6 +3586,21 @@ func rewriteValueMIPS64_OpMIPS64MOVVload(v *Value) bool { } return false } +func rewriteValueMIPS64_OpMIPS64MOVVnop(v *Value) bool { + v_0 := v.Args[0] + // match: (MOVVnop (MOVVconst [c])) + // result: (MOVVconst [c]) + for { + if v_0.Op != OpMIPS64MOVVconst { + break + } + c := auxIntToInt64(v_0.AuxInt) + v.reset(OpMIPS64MOVVconst) + v.AuxInt = int64ToAuxInt(c) + return true + } + return false +} func rewriteValueMIPS64_OpMIPS64MOVVreg(v *Value) bool { v_0 := v.Args[0] // match: (MOVVreg x) |