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[dev.ssa] cmd/compile: fix phi floats

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The code previously always used AX causing errors.  For now, just
switch off the type in order to at least generate valid code.

Change-Id: Iaf13120a24b62456b9b33c04ab31f2d5104b381b
Reviewed-on: https://go-review.googlesource.com/13943
Reviewed-by: David Chase <drchase@google.com>
This commit is contained in:
Todd Neal 2015-08-25 22:49:59 -05:00 • committed by David Chase
parent 752fe4dcb5
commit 7cadf23afb
2 changed files with 62 additions and 4 deletions
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20
src/cmd/compile/internal/ssa/regalloc.go
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@ -550,6 +550,16 @@ func (s *regAllocState) setState(state []regState) {
}
}
// compatReg returns a register compatible with the a value and is used when
// spilling/loading.
// TODO: choose a better default register (set of reg by type?).
func compatReg(v *Value) regMask {
if v.Type.IsFloat() {
return 1 << 16 // X0
}
return 1 << 0 // AX
}
func (s *regAllocState) regalloc(f *Func) {
liveset := newSparseSet(f.NumValues())
argset := newSparseSet(f.NumValues())
@ -836,10 +846,11 @@ func (s *regAllocState) regalloc(f *Func) {
if !argset.contains(v.ID) {
continue
}
// This stack-based phi is the argument of some other
// phi in this block. We must make a copy of its
// value so that we don't clobber it prematurely.
c := s.allocValToReg(v, s.values[v.ID].regs|1<<0, false)
c := s.allocValToReg(v, s.values[v.ID].regs|compatReg(v), false)
d := p.NewValue1(v.Line, OpStoreReg, v.Type, c)
s.values[v.ID].spill2 = d
}
@ -848,9 +859,10 @@ func (s *regAllocState) regalloc(f *Func) {
// we might need a register to do the assignment.
for _, v := range stackPhis {
// Load phi arg into a register, then store it with a StoreReg.
// If already in a register, use that. If not, use register 0.
// TODO: choose a better default register (set of reg by type?).
c := s.allocValToReg(v.Args[i], s.values[v.Args[i].ID].regs|1<<0, false)
// If already in a register, use that. If not, pick a compatible
// register.
w := v.Args[i]
c := s.allocValToReg(w, s.values[w.ID].regs|compatReg(w), false)
v.Args[i] = p.NewValue1(v.Line, OpStoreReg, v.Type, c)
}
// Figure out what value goes in each register.