[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:
diff --git a/src/cmd/compile/internal/ssa/gen/generic.rules b/src/cmd/compile/internal/ssa/gen/generic.rules
index 8195d6b..1de7a6b 100644
--- a/src/cmd/compile/internal/ssa/gen/generic.rules
+++ b/src/cmd/compile/internal/ssa/gen/generic.rules
@@ -75,9 +75,9 @@
// indexing operations
// Note: bounds check has already been done
-(ArrayIndex (Load ptr mem) idx) -> (Load (PtrIndex <v.Type.PtrTo()> ptr idx) mem)
+(ArrayIndex (Load ptr mem) idx) && b == v.Args[0].Block -> (Load (PtrIndex <v.Type.PtrTo()> ptr idx) mem)
(PtrIndex <t> ptr idx) -> (AddPtr ptr (MulPtr idx (ConstPtr [t.Elem().Size()])))
-(StructSelect [idx] (Load ptr mem)) -> (Load (OffPtr <v.Type.PtrTo()> [idx] ptr) mem)
+(StructSelect [idx] (Load ptr mem)) && b == v.Args[0].Block -> (Load (OffPtr <v.Type.PtrTo()> [idx] ptr) mem)
// complex ops
(ComplexReal (ComplexMake real _ )) -> real
diff --git a/src/cmd/compile/internal/ssa/rewritegeneric.go b/src/cmd/compile/internal/ssa/rewritegeneric.go
index 8534e2a..99c49a8 100644
--- a/src/cmd/compile/internal/ssa/rewritegeneric.go
+++ b/src/cmd/compile/internal/ssa/rewritegeneric.go
@@ -136,15 +136,18 @@
;
case OpArrayIndex:
// match: (ArrayIndex (Load ptr mem) idx)
- // cond:
+ // cond: b == v.Args[0].Block
// result: (Load (PtrIndex <v.Type.PtrTo()> ptr idx) mem)
{
if v.Args[0].Op != OpLoad {
- goto end4894dd7b58383fee5f8a92be08437c33
+ goto end68b373270d9d605c420497edefaa71df
}
ptr := v.Args[0].Args[0]
mem := v.Args[0].Args[1]
idx := v.Args[1]
+ if !(b == v.Args[0].Block) {
+ goto end68b373270d9d605c420497edefaa71df
+ }
v.Op = OpLoad
v.AuxInt = 0
v.Aux = nil
@@ -157,8 +160,8 @@
v.AddArg(mem)
return true
}
- goto end4894dd7b58383fee5f8a92be08437c33
- end4894dd7b58383fee5f8a92be08437c33:
+ goto end68b373270d9d605c420497edefaa71df
+ end68b373270d9d605c420497edefaa71df:
;
case OpCom16:
// match: (Com16 (Com16 x))
@@ -1510,15 +1513,18 @@
;
case OpStructSelect:
// match: (StructSelect [idx] (Load ptr mem))
- // cond:
+ // cond: b == v.Args[0].Block
// result: (Load (OffPtr <v.Type.PtrTo()> [idx] ptr) mem)
{
idx := v.AuxInt
if v.Args[0].Op != OpLoad {
- goto end16fdb45e1dd08feb36e3cc3fb5ed8935
+ goto endd1a92da3e00c16a8f5bd3bd30deca298
}
ptr := v.Args[0].Args[0]
mem := v.Args[0].Args[1]
+ if !(b == v.Args[0].Block) {
+ goto endd1a92da3e00c16a8f5bd3bd30deca298
+ }
v.Op = OpLoad
v.AuxInt = 0
v.Aux = nil
@@ -1531,8 +1537,8 @@
v.AddArg(mem)
return true
}
- goto end16fdb45e1dd08feb36e3cc3fb5ed8935
- end16fdb45e1dd08feb36e3cc3fb5ed8935:
+ goto endd1a92da3e00c16a8f5bd3bd30deca298
+ endd1a92da3e00c16a8f5bd3bd30deca298:
;
case OpSub16:
// match: (Sub16 x x)
