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[dev.ssa] cmd/compile: make sure we don't move loads between blocks

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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>
This commit is contained in:
Keith Randall 2015-10-09 09:33:29 -07:00
parent 32ffbf7e0f
commit 9703564c9a
3 changed files with 36 additions and 29 deletions
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39
src/cmd/compile/internal/gc/ssa.go
View File

@ -1732,8 +1732,9 @@ func (s *state) expr(n *Node) *ssa.Value {
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 @@ func (s *state) expr(n *Node) *ssa.Value {
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:

4
src/cmd/compile/internal/ssa/gen/generic.rules
View File

@ -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

22
src/cmd/compile/internal/ssa/rewritegeneric.go
View File

@ -136,15 +136,18 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
;
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 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
v.AddArg(mem)
return true
}
goto end4894dd7b58383fee5f8a92be08437c33
end4894dd7b58383fee5f8a92be08437c33:
goto end68b373270d9d605c420497edefaa71df
end68b373270d9d605c420497edefaa71df:
;
case OpCom16:
// match: (Com16 (Com16 x))
@ -1510,15 +1513,18 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
;
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 @@ func rewriteValuegeneric(v *Value, config *Config) bool {
v.AddArg(mem)
return true
}
goto end16fdb45e1dd08feb36e3cc3fb5ed8935
end16fdb45e1dd08feb36e3cc3fb5ed8935:
goto endd1a92da3e00c16a8f5bd3bd30deca298
endd1a92da3e00c16a8f5bd3bd30deca298:
;
case OpSub16:
// match: (Sub16 x x)