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cmd/compile/internal/ssa: combine load + op on AMD64

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On AMD64 Most operation can have one operand in memory.
Combine load and dependand operation into one new operation,
where possible. I've seen no significant performance changes on go1,
but this allows to remove ~1.8kb code from go tool. And in math package
I see e. g.:

Remainder-6            70.0ns ± 0%   64.6ns ± 0%   -7.76%  (p=0.000 n=9+1
Change-Id: I88b8602b1d55da8ba548a34eb7da4b25d59a297e
Reviewed-on: https://go-review.googlesource.com/36793
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Ilya Tocar 2017-02-10 13:17:20 -06:00
parent a9292b833b
commit 21c71d7788
5 changed files with 1160 additions and 0 deletions
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13
src/cmd/compile/internal/amd64/ssa.go
View file

@ -645,6 +645,19 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
// Break false dependency on destination register.
opregreg(x86.AXORPS, r, r)
opregreg(v.Op.Asm(), r, v.Args[0].Reg())
case ssa.OpAMD64ADDQmem, ssa.OpAMD64ADDLmem, ssa.OpAMD64SUBQmem, ssa.OpAMD64SUBLmem,
ssa.OpAMD64ANDQmem, ssa.OpAMD64ANDLmem, ssa.OpAMD64ORQmem, ssa.OpAMD64ORLmem,
ssa.OpAMD64XORQmem, ssa.OpAMD64XORLmem, ssa.OpAMD64ADDSDmem, ssa.OpAMD64ADDSSmem,
ssa.OpAMD64SUBSDmem, ssa.OpAMD64SUBSSmem, ssa.OpAMD64MULSDmem, ssa.OpAMD64MULSSmem:
p := gc.Prog(v.Op.Asm())
p.From.Type = obj.TYPE_MEM
p.From.Reg = v.Args[1].Reg()
gc.AddAux(&p.From, v)
p.To.Type = obj.TYPE_REG
p.To.Reg = v.Reg()
if v.Reg() != v.Args[0].Reg() {
v.Fatalf("input[0] and output not in same register %s", v.LongString())
}
case ssa.OpAMD64DUFFZERO:
off := duffStart(v.AuxInt)
adj := duffAdj(v.AuxInt)