[dev.ssa] cmd/compile: make sure we don't move loads between blocks
This can lead to multiple stores being live at once.
Do OINDEX and ODOT using addresses & loads instead of specific ops.
This keeps SSA values from containing unSSAable types.
Change-Id: I79567e9d43cdee09084eb89ea0bd7aa3aad48ada
Reviewed-on: https://go-review.googlesource.com/15654
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: David Chase <drchase@google.com>
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index 45ae132..b568c58 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -1732,8 +1732,9 @@
return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
case ODOT:
- v := s.expr(n.Left)
- return s.newValue1I(ssa.OpStructSelect, n.Type, n.Xoffset, v)
+ // TODO: fix when we can SSA struct types.
+ p := s.addr(n)
+ return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
case ODOTPTR:
p := s.expr(n.Left)
@@ -1742,29 +1743,29 @@
return s.newValue2(ssa.OpLoad, n.Type, p, s.mem())
case OINDEX:
- if n.Left.Type.Bound >= 0 { // array or string
+ switch {
+ case n.Left.Type.IsString():
a := s.expr(n.Left)
i := s.expr(n.Right)
i = s.extendIndex(i)
- if n.Left.Type.IsString() {
- if !n.Bounded {
- len := s.newValue1(ssa.OpStringLen, Types[TINT], a)
- s.boundsCheck(i, len)
- }
- ptrtyp := Ptrto(Types[TUINT8])
- ptr := s.newValue1(ssa.OpStringPtr, ptrtyp, a)
- ptr = s.newValue2(ssa.OpAddPtr, ptrtyp, ptr, i)
- return s.newValue2(ssa.OpLoad, Types[TUINT8], ptr, s.mem())
- } else {
- if !n.Bounded {
- len := s.constInt(Types[TINT], n.Left.Type.Bound)
- s.boundsCheck(i, len)
- }
- return s.newValue2(ssa.OpArrayIndex, n.Left.Type.Type, a, i)
+ if !n.Bounded {
+ len := s.newValue1(ssa.OpStringLen, Types[TINT], a)
+ s.boundsCheck(i, len)
}
- } else { // slice
+ ptrtyp := Ptrto(Types[TUINT8])
+ ptr := s.newValue1(ssa.OpStringPtr, ptrtyp, a)
+ ptr = s.newValue2(ssa.OpAddPtr, ptrtyp, ptr, i)
+ return s.newValue2(ssa.OpLoad, Types[TUINT8], ptr, s.mem())
+ case n.Left.Type.IsSlice():
p := s.addr(n)
return s.newValue2(ssa.OpLoad, n.Left.Type.Type, p, s.mem())
+ case n.Left.Type.IsArray():
+ // TODO: fix when we can SSA arrays of length 1.
+ p := s.addr(n)
+ return s.newValue2(ssa.OpLoad, n.Left.Type.Type, p, s.mem())
+ default:
+ s.Fatalf("bad type for index %v", n.Left.Type)
+ return nil
}
case OLEN, OCAP:
