cmd/compile: optimize 386's assembly generator

The ADDconstmodify has similar logic with other constmodify like instructions. This CL optimize them to share code via fallthrough. And the size of pkg/linux_386/cmd/compile/internal/x86.a decreases about 0.3KB. Change-Id: Ibdf06228afde875e8fe8e30851b50ca2be513dd9 Reviewed-on: https://go-review.googlesource.com/136398 Run-TryBot: Ben Shi <[email protected]> TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: Keith Randall <[email protected]>
cloudflare · Sep 20, 2018 · 9a033bf · 9a033bf
1 parent 048c766
commit 9a033bf
Showing 1 changed file with 13 additions and 13 deletions.
diff --git a/src/cmd/compile/internal/x86/ssa.go b/src/cmd/compile/internal/x86/ssa.go
@@ -547,22 +547,22 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) {
  p.To.Reg = v.Args[0].Reg()
  gc.AddAux(&p.To, v)
  case ssa.Op386ADDLconstmodify:
- var p *obj.Prog = nil
  sc := v.AuxValAndOff()
- off := sc.Off()
  val := sc.Val()
- if val == 1 {
- p = s.Prog(x86.AINCL)
- } else if val == -1 {
- p = s.Prog(x86.ADECL)
- } else {
- p = s.Prog(v.Op.Asm())
- p.From.Type = obj.TYPE_CONST
- p.From.Offset = val
+ if val == 1 || val == -1 {
+ var p *obj.Prog
+ if val == 1 {
+ p = s.Prog(x86.AINCL)
+ } else {
+ p = s.Prog(x86.ADECL)
+ }
+ off := sc.Off()
+ p.To.Type = obj.TYPE_MEM
+ p.To.Reg = v.Args[0].Reg()
+ gc.AddAux2(&p.To, v, off)
+ break
  }
- p.To.Type = obj.TYPE_MEM
- p.To.Reg = v.Args[0].Reg()
- gc.AddAux2(&p.To, v, off)
+ fallthrough
  case ssa.Op386ANDLconstmodify, ssa.Op386ORLconstmodify, ssa.Op386XORLconstmodify:
  sc := v.AuxValAndOff()
  off := sc.Off()