diff options
| -rw-r--r-- | src/cmd/compile/internal/ssa/regalloc.go | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/cmd/compile/internal/ssa/regalloc.go b/src/cmd/compile/internal/ssa/regalloc.go index 291ca91c61..abfdfc1b24 100644 --- a/src/cmd/compile/internal/ssa/regalloc.go +++ b/src/cmd/compile/internal/ssa/regalloc.go @@ -963,7 +963,10 @@ func (s *regAllocState) regalloc(f *Func) { } // Save the starting state for use by merge edges. - var regList []startReg + // We append to a stack allocated variable that we'll + // later copy into s.startRegs in one fell swoop, to save + // on allocations. + regList := make([]startReg, 0, 32) for r := register(0); r < s.numRegs; r++ { v := s.regs[r].v if v == nil { @@ -976,7 +979,8 @@ func (s *regAllocState) regalloc(f *Func) { } regList = append(regList, startReg{r, v, s.regs[r].c, s.values[v.ID].uses.pos}) } - s.startRegs[b.ID] = regList + s.startRegs[b.ID] = make([]startReg, len(regList)) + copy(s.startRegs[b.ID], regList) if s.f.pass.debug > regDebug { fmt.Printf("after phis\n") |