cmd/compile: better check for single live memory
Enhance the one-live-memory-at-a-time check to run during many
more phases of the SSA backend. Also make it work in an interblock
fashion.
Change types.IsMemory to return true for tuples containing a memory type.
Fix trim pass to build the merged phi correctly. Doesn't affect
code but allows the check to pass after trim runs.
Switch the AddTuple* ops to take the memory-containing tuple argument second.
Update #20335
Change-Id: I5b03ef3606b75a9e4f765276bb8b183cdc172b43
Reviewed-on: https://go-review.googlesource.com/43495
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/src/cmd/compile/internal/ssa/check.go b/src/cmd/compile/internal/ssa/check.go
index 82d7b76..82aa9f1 100644
--- a/src/cmd/compile/internal/ssa/check.go
+++ b/src/cmd/compile/internal/ssa/check.go
@@ -310,6 +310,10 @@
}
}
+ memCheck(f)
+}
+
+func memCheck(f *Func) {
// Check that if a tuple has a memory type, it is second.
for _, b := range f.Blocks {
for _, v := range b.Values {
@@ -319,24 +323,122 @@
}
}
- // Check that only one memory is live at any point.
- // TODO: make this check examine interblock.
- if f.scheduled {
- for _, b := range f.Blocks {
- var mem *Value // the live memory
+ // Single live memory checks.
+ // These checks only work if there are no memory copies.
+ // (Memory copies introduce ambiguity about which mem value is really live.
+ // probably fixable, but it's easier to avoid the problem.)
+ // For the same reason, disable this check if some memory ops are unused.
+ for _, b := range f.Blocks {
+ for _, v := range b.Values {
+ if (v.Op == OpCopy || v.Uses == 0) && v.Type.IsMemory() {
+ return
+ }
+ }
+ if b != f.Entry && len(b.Preds) == 0 {
+ return
+ }
+ }
+
+ // Compute live memory at the end of each block.
+ lastmem := make([]*Value, f.NumBlocks())
+ ss := newSparseSet(f.NumValues())
+ for _, b := range f.Blocks {
+ // Mark overwritten memory values. Those are args of other
+ // ops that generate memory values.
+ ss.clear()
+ for _, v := range b.Values {
+ if v.Op == OpPhi || !v.Type.IsMemory() {
+ continue
+ }
+ if m := v.MemoryArg(); m != nil {
+ ss.add(m.ID)
+ }
+ }
+ // There should be at most one remaining unoverwritten memory value.
+ for _, v := range b.Values {
+ if !v.Type.IsMemory() {
+ continue
+ }
+ if ss.contains(v.ID) {
+ continue
+ }
+ if lastmem[b.ID] != nil {
+ f.Fatalf("two live memory values in %s: %s and %s", b, lastmem[b.ID], v)
+ }
+ lastmem[b.ID] = v
+ }
+ // If there is no remaining memory value, that means there was no memory update.
+ // Take any memory arg.
+ if lastmem[b.ID] == nil {
for _, v := range b.Values {
- if v.Op != OpPhi {
- for _, a := range v.Args {
- if a.Type.IsMemory() || a.Type.IsTuple() && a.Type.FieldType(1).IsMemory() {
- if mem == nil {
- mem = a
- } else if mem != a {
- f.Fatalf("two live mems @ %s: %s and %s", v, mem, a)
- }
- }
+ if v.Op == OpPhi {
+ continue
+ }
+ m := v.MemoryArg()
+ if m == nil {
+ continue
+ }
+ if lastmem[b.ID] != nil && lastmem[b.ID] != m {
+ f.Fatalf("two live memory values in %s: %s and %s", b, lastmem[b.ID], m)
+ }
+ lastmem[b.ID] = m
+ }
+ }
+ }
+ // Propagate last live memory through storeless blocks.
+ for {
+ changed := false
+ for _, b := range f.Blocks {
+ if lastmem[b.ID] != nil {
+ continue
+ }
+ for _, e := range b.Preds {
+ p := e.b
+ if lastmem[p.ID] != nil {
+ lastmem[b.ID] = lastmem[p.ID]
+ changed = true
+ break
+ }
+ }
+ }
+ if !changed {
+ break
+ }
+ }
+ // Check merge points.
+ for _, b := range f.Blocks {
+ for _, v := range b.Values {
+ if v.Op == OpPhi && v.Type.IsMemory() {
+ for i, a := range v.Args {
+ if a != lastmem[b.Preds[i].b.ID] {
+ f.Fatalf("inconsistent memory phi %s %d %s %s", v.LongString(), i, a, lastmem[b.Preds[i].b.ID])
}
}
- if v.Type.IsMemory() || v.Type.IsTuple() && v.Type.FieldType(1).IsMemory() {
+ }
+ }
+ }
+
+ // Check that only one memory is live at any point.
+ if f.scheduled {
+ for _, b := range f.Blocks {
+ var mem *Value // the current live memory in the block
+ for _, v := range b.Values {
+ if v.Op == OpPhi {
+ if v.Type.IsMemory() {
+ mem = v
+ }
+ continue
+ }
+ if mem == nil && len(b.Preds) > 0 {
+ // If no mem phi, take mem of any predecessor.
+ mem = lastmem[b.Preds[0].b.ID]
+ }
+ for _, a := range v.Args {
+ if a.Type.IsMemory() && a != mem {
+ f.Fatalf("two live mems @ %s: %s and %s", v, mem, a)
+ }
+ }
+ if v.Type.IsMemory() {
mem = v
}
}
diff --git a/src/cmd/compile/internal/ssa/deadstore.go b/src/cmd/compile/internal/ssa/deadstore.go
index de3c6ae..bac4930 100644
--- a/src/cmd/compile/internal/ssa/deadstore.go
+++ b/src/cmd/compile/internal/ssa/deadstore.go
@@ -34,10 +34,6 @@
}
if v.Type.IsMemory() {
stores = append(stores, v)
- if v.Op == OpSelect1 {
- // Use the args of the tuple-generating op.
- v = v.Args[0]
- }
for _, a := range v.Args {
if a.Block == b && a.Type.IsMemory() {
storeUse.add(a.ID)
diff --git a/src/cmd/compile/internal/ssa/gen/AMD64.rules b/src/cmd/compile/internal/ssa/gen/AMD64.rules
index 5543395..711373a 100644
--- a/src/cmd/compile/internal/ssa/gen/AMD64.rules
+++ b/src/cmd/compile/internal/ssa/gen/AMD64.rules
@@ -487,12 +487,12 @@
(AtomicExchange64 ptr val mem) -> (XCHGQ val ptr mem)
// Atomic adds.
-(AtomicAdd32 ptr val mem) -> (AddTupleFirst32 (XADDLlock val ptr mem) val)
-(AtomicAdd64 ptr val mem) -> (AddTupleFirst64 (XADDQlock val ptr mem) val)
-(Select0 <t> (AddTupleFirst32 tuple val)) -> (ADDL val (Select0 <t> tuple))
-(Select1 (AddTupleFirst32 tuple _ )) -> (Select1 tuple)
-(Select0 <t> (AddTupleFirst64 tuple val)) -> (ADDQ val (Select0 <t> tuple))
-(Select1 (AddTupleFirst64 tuple _ )) -> (Select1 tuple)
+(AtomicAdd32 ptr val mem) -> (AddTupleFirst32 val (XADDLlock val ptr mem))
+(AtomicAdd64 ptr val mem) -> (AddTupleFirst64 val (XADDQlock val ptr mem))
+(Select0 <t> (AddTupleFirst32 val tuple)) -> (ADDL val (Select0 <t> tuple))
+(Select1 (AddTupleFirst32 _ tuple)) -> (Select1 tuple)
+(Select0 <t> (AddTupleFirst64 val tuple)) -> (ADDQ val (Select0 <t> tuple))
+(Select1 (AddTupleFirst64 _ tuple)) -> (Select1 tuple)
// Atomic compare and swap.
(AtomicCompareAndSwap32 ptr old new_ mem) -> (CMPXCHGLlock ptr old new_ mem)
diff --git a/src/cmd/compile/internal/ssa/gen/AMD64Ops.go b/src/cmd/compile/internal/ssa/gen/AMD64Ops.go
index ed77bb0..28131db 100644
--- a/src/cmd/compile/internal/ssa/gen/AMD64Ops.go
+++ b/src/cmd/compile/internal/ssa/gen/AMD64Ops.go
@@ -572,8 +572,8 @@
// Note: arg0 and arg1 are backwards compared to MOVLstore (to facilitate resultInArg0)!
{name: "XADDLlock", argLength: 3, reg: gpstorexchg, asm: "XADDL", typ: "(UInt32,Mem)", aux: "SymOff", resultInArg0: true, clobberFlags: true, faultOnNilArg1: true, hasSideEffects: true, symEffect: "RdWr"},
{name: "XADDQlock", argLength: 3, reg: gpstorexchg, asm: "XADDQ", typ: "(UInt64,Mem)", aux: "SymOff", resultInArg0: true, clobberFlags: true, faultOnNilArg1: true, hasSideEffects: true, symEffect: "RdWr"},
- {name: "AddTupleFirst32", argLength: 2}, // arg0=tuple <x,y>. Returns <x+arg1,y>.
- {name: "AddTupleFirst64", argLength: 2}, // arg0=tuple <x,y>. Returns <x+arg1,y>.
+ {name: "AddTupleFirst32", argLength: 2}, // arg1=tuple <x,y>. Returns <x+arg0,y>.
+ {name: "AddTupleFirst64", argLength: 2}, // arg1=tuple <x,y>. Returns <x+arg0,y>.
// Compare and swap.
// arg0 = pointer, arg1 = old value, arg2 = new value, arg3 = memory.
diff --git a/src/cmd/compile/internal/ssa/gen/S390X.rules b/src/cmd/compile/internal/ssa/gen/S390X.rules
index aed4f5c..4ae21cd 100644
--- a/src/cmd/compile/internal/ssa/gen/S390X.rules
+++ b/src/cmd/compile/internal/ssa/gen/S390X.rules
@@ -120,12 +120,12 @@
(AtomicStorePtrNoWB ptr val mem) -> (MOVDatomicstore ptr val mem)
// Atomic adds.
-(AtomicAdd32 ptr val mem) -> (AddTupleFirst32 (LAA ptr val mem) val)
-(AtomicAdd64 ptr val mem) -> (AddTupleFirst64 (LAAG ptr val mem) val)
-(Select0 <t> (AddTupleFirst32 tuple val)) -> (ADDW val (Select0 <t> tuple))
-(Select1 (AddTupleFirst32 tuple _ )) -> (Select1 tuple)
-(Select0 <t> (AddTupleFirst64 tuple val)) -> (ADD val (Select0 <t> tuple))
-(Select1 (AddTupleFirst64 tuple _ )) -> (Select1 tuple)
+(AtomicAdd32 ptr val mem) -> (AddTupleFirst32 val (LAA ptr val mem))
+(AtomicAdd64 ptr val mem) -> (AddTupleFirst64 val (LAAG ptr val mem))
+(Select0 <t> (AddTupleFirst32 val tuple)) -> (ADDW val (Select0 <t> tuple))
+(Select1 (AddTupleFirst32 _ tuple)) -> (Select1 tuple)
+(Select0 <t> (AddTupleFirst64 val tuple)) -> (ADD val (Select0 <t> tuple))
+(Select1 (AddTupleFirst64 _ tuple)) -> (Select1 tuple)
// Atomic exchanges.
(AtomicExchange32 ptr val mem) -> (LoweredAtomicExchange32 ptr val mem)
diff --git a/src/cmd/compile/internal/ssa/gen/S390XOps.go b/src/cmd/compile/internal/ssa/gen/S390XOps.go
index c3edb93..2a08a27 100644
--- a/src/cmd/compile/internal/ssa/gen/S390XOps.go
+++ b/src/cmd/compile/internal/ssa/gen/S390XOps.go
@@ -467,8 +467,8 @@
// Returns a tuple of <old contents of *(arg0+auxint+aux), memory>.
{name: "LAA", argLength: 3, reg: gpstorelaa, asm: "LAA", typ: "(UInt32,Mem)", aux: "SymOff", faultOnNilArg0: true, hasSideEffects: true, symEffect: "RdWr"},
{name: "LAAG", argLength: 3, reg: gpstorelaa, asm: "LAAG", typ: "(UInt64,Mem)", aux: "SymOff", faultOnNilArg0: true, hasSideEffects: true, symEffect: "RdWr"},
- {name: "AddTupleFirst32", argLength: 2}, // arg0=tuple <x,y>. Returns <x+arg1,y>.
- {name: "AddTupleFirst64", argLength: 2}, // arg0=tuple <x,y>. Returns <x+arg1,y>.
+ {name: "AddTupleFirst32", argLength: 2}, // arg1=tuple <x,y>. Returns <x+arg0,y>.
+ {name: "AddTupleFirst64", argLength: 2}, // arg1=tuple <x,y>. Returns <x+arg0,y>.
// Compare and swap.
// arg0 = pointer, arg1 = old value, arg2 = new value, arg3 = memory.
diff --git a/src/cmd/compile/internal/ssa/loopreschedchecks.go b/src/cmd/compile/internal/ssa/loopreschedchecks.go
index 8ffca82..98b6e92 100644
--- a/src/cmd/compile/internal/ssa/loopreschedchecks.go
+++ b/src/cmd/compile/internal/ssa/loopreschedchecks.go
@@ -391,10 +391,6 @@
}
if v.Type.IsMemory() {
stores = append(stores, v)
- if v.Op == OpSelect1 {
- // Use the arg of the tuple-generating op.
- v = v.Args[0]
- }
for _, a := range v.Args {
if a.Block == b && a.Type.IsMemory() {
storeUse.add(a.ID)
diff --git a/src/cmd/compile/internal/ssa/rewriteAMD64.go b/src/cmd/compile/internal/ssa/rewriteAMD64.go
index ff24103..9a69a31 100644
--- a/src/cmd/compile/internal/ssa/rewriteAMD64.go
+++ b/src/cmd/compile/internal/ssa/rewriteAMD64.go
@@ -35902,18 +35902,18 @@
_ = typ
// match: (AtomicAdd32 ptr val mem)
// cond:
- // result: (AddTupleFirst32 (XADDLlock val ptr mem) val)
+ // result: (AddTupleFirst32 val (XADDLlock val ptr mem))
for {
ptr := v.Args[0]
val := v.Args[1]
mem := v.Args[2]
v.reset(OpAMD64AddTupleFirst32)
+ v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpAMD64XADDLlock, types.NewTuple(typ.UInt32, types.TypeMem))
v0.AddArg(val)
v0.AddArg(ptr)
v0.AddArg(mem)
v.AddArg(v0)
- v.AddArg(val)
return true
}
}
@@ -35924,18 +35924,18 @@
_ = typ
// match: (AtomicAdd64 ptr val mem)
// cond:
- // result: (AddTupleFirst64 (XADDQlock val ptr mem) val)
+ // result: (AddTupleFirst64 val (XADDQlock val ptr mem))
for {
ptr := v.Args[0]
val := v.Args[1]
mem := v.Args[2]
v.reset(OpAMD64AddTupleFirst64)
+ v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpAMD64XADDQlock, types.NewTuple(typ.UInt64, types.TypeMem))
v0.AddArg(val)
v0.AddArg(ptr)
v0.AddArg(mem)
v.AddArg(v0)
- v.AddArg(val)
return true
}
}
@@ -40216,7 +40216,7 @@
func rewriteValueAMD64_OpSelect0_0(v *Value) bool {
b := v.Block
_ = b
- // match: (Select0 <t> (AddTupleFirst32 tuple val))
+ // match: (Select0 <t> (AddTupleFirst32 val tuple))
// cond:
// result: (ADDL val (Select0 <t> tuple))
for {
@@ -40225,8 +40225,8 @@
if v_0.Op != OpAMD64AddTupleFirst32 {
break
}
- tuple := v_0.Args[0]
- val := v_0.Args[1]
+ val := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpAMD64ADDL)
v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpSelect0, t)
@@ -40234,7 +40234,7 @@
v.AddArg(v0)
return true
}
- // match: (Select0 <t> (AddTupleFirst64 tuple val))
+ // match: (Select0 <t> (AddTupleFirst64 val tuple))
// cond:
// result: (ADDQ val (Select0 <t> tuple))
for {
@@ -40243,8 +40243,8 @@
if v_0.Op != OpAMD64AddTupleFirst64 {
break
}
- tuple := v_0.Args[0]
- val := v_0.Args[1]
+ val := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpAMD64ADDQ)
v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpSelect0, t)
@@ -40255,7 +40255,7 @@
return false
}
func rewriteValueAMD64_OpSelect1_0(v *Value) bool {
- // match: (Select1 (AddTupleFirst32 tuple _))
+ // match: (Select1 (AddTupleFirst32 _ tuple))
// cond:
// result: (Select1 tuple)
for {
@@ -40263,12 +40263,12 @@
if v_0.Op != OpAMD64AddTupleFirst32 {
break
}
- tuple := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpSelect1)
v.AddArg(tuple)
return true
}
- // match: (Select1 (AddTupleFirst64 tuple _))
+ // match: (Select1 (AddTupleFirst64 _ tuple))
// cond:
// result: (Select1 tuple)
for {
@@ -40276,7 +40276,7 @@
if v_0.Op != OpAMD64AddTupleFirst64 {
break
}
- tuple := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpSelect1)
v.AddArg(tuple)
return true
diff --git a/src/cmd/compile/internal/ssa/rewriteS390X.go b/src/cmd/compile/internal/ssa/rewriteS390X.go
index 1929f54..f07ca9a 100644
--- a/src/cmd/compile/internal/ssa/rewriteS390X.go
+++ b/src/cmd/compile/internal/ssa/rewriteS390X.go
@@ -898,18 +898,18 @@
_ = typ
// match: (AtomicAdd32 ptr val mem)
// cond:
- // result: (AddTupleFirst32 (LAA ptr val mem) val)
+ // result: (AddTupleFirst32 val (LAA ptr val mem))
for {
ptr := v.Args[0]
val := v.Args[1]
mem := v.Args[2]
v.reset(OpS390XAddTupleFirst32)
+ v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpS390XLAA, types.NewTuple(typ.UInt32, types.TypeMem))
v0.AddArg(ptr)
v0.AddArg(val)
v0.AddArg(mem)
v.AddArg(v0)
- v.AddArg(val)
return true
}
}
@@ -920,18 +920,18 @@
_ = typ
// match: (AtomicAdd64 ptr val mem)
// cond:
- // result: (AddTupleFirst64 (LAAG ptr val mem) val)
+ // result: (AddTupleFirst64 val (LAAG ptr val mem))
for {
ptr := v.Args[0]
val := v.Args[1]
mem := v.Args[2]
v.reset(OpS390XAddTupleFirst64)
+ v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpS390XLAAG, types.NewTuple(typ.UInt64, types.TypeMem))
v0.AddArg(ptr)
v0.AddArg(val)
v0.AddArg(mem)
v.AddArg(v0)
- v.AddArg(val)
return true
}
}
@@ -34159,7 +34159,7 @@
func rewriteValueS390X_OpSelect0_0(v *Value) bool {
b := v.Block
_ = b
- // match: (Select0 <t> (AddTupleFirst32 tuple val))
+ // match: (Select0 <t> (AddTupleFirst32 val tuple))
// cond:
// result: (ADDW val (Select0 <t> tuple))
for {
@@ -34168,8 +34168,8 @@
if v_0.Op != OpS390XAddTupleFirst32 {
break
}
- tuple := v_0.Args[0]
- val := v_0.Args[1]
+ val := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpS390XADDW)
v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpSelect0, t)
@@ -34177,7 +34177,7 @@
v.AddArg(v0)
return true
}
- // match: (Select0 <t> (AddTupleFirst64 tuple val))
+ // match: (Select0 <t> (AddTupleFirst64 val tuple))
// cond:
// result: (ADD val (Select0 <t> tuple))
for {
@@ -34186,8 +34186,8 @@
if v_0.Op != OpS390XAddTupleFirst64 {
break
}
- tuple := v_0.Args[0]
- val := v_0.Args[1]
+ val := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpS390XADD)
v.AddArg(val)
v0 := b.NewValue0(v.Pos, OpSelect0, t)
@@ -34198,7 +34198,7 @@
return false
}
func rewriteValueS390X_OpSelect1_0(v *Value) bool {
- // match: (Select1 (AddTupleFirst32 tuple _))
+ // match: (Select1 (AddTupleFirst32 _ tuple))
// cond:
// result: (Select1 tuple)
for {
@@ -34206,12 +34206,12 @@
if v_0.Op != OpS390XAddTupleFirst32 {
break
}
- tuple := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpSelect1)
v.AddArg(tuple)
return true
}
- // match: (Select1 (AddTupleFirst64 tuple _))
+ // match: (Select1 (AddTupleFirst64 _ tuple))
// cond:
// result: (Select1 tuple)
for {
@@ -34219,7 +34219,7 @@
if v_0.Op != OpS390XAddTupleFirst64 {
break
}
- tuple := v_0.Args[0]
+ tuple := v_0.Args[1]
v.reset(OpSelect1)
v.AddArg(tuple)
return true
diff --git a/src/cmd/compile/internal/ssa/schedule.go b/src/cmd/compile/internal/ssa/schedule.go
index 2e9464e..c44c243 100644
--- a/src/cmd/compile/internal/ssa/schedule.go
+++ b/src/cmd/compile/internal/ssa/schedule.go
@@ -132,19 +132,14 @@
}
}
- // TODO: make this logic permanent in types.IsMemory?
- isMem := func(v *Value) bool {
- return v.Type.IsMemory() || v.Type.IsTuple() && v.Type.FieldType(1).IsMemory()
- }
-
for _, b := range f.Blocks {
// Find store chain for block.
// Store chains for different blocks overwrite each other, so
// the calculated store chain is good only for this block.
for _, v := range b.Values {
- if v.Op != OpPhi && isMem(v) {
+ if v.Op != OpPhi && v.Type.IsMemory() {
for _, w := range v.Args {
- if isMem(w) {
+ if w.Type.IsMemory() {
nextMem[w.ID] = v
}
}
@@ -164,7 +159,7 @@
uses[w.ID]++
}
// Any load must come before the following store.
- if !isMem(v) && isMem(w) {
+ if !v.Type.IsMemory() && w.Type.IsMemory() {
// v is a load.
s := nextMem[w.ID]
if s == nil || s.Block != b {
@@ -315,11 +310,7 @@
if v.Op == OpInitMem || v.Op == OpPhi {
continue
}
- a := v
- if v.Op == OpSelect1 {
- a = a.Args[0]
- }
- sset.add(a.MemoryArg().ID) // record that v's memory arg is used
+ sset.add(v.MemoryArg().ID) // record that v's memory arg is used
}
if v.Op == OpNilCheck {
hasNilCheck = true
@@ -335,7 +326,7 @@
for _, v := range stores {
if !sset.contains(v.ID) {
if last != nil {
- f.Fatalf("two stores live simutaneously: %v and %v", v, last)
+ f.Fatalf("two stores live simultaneously: %v and %v", v, last)
}
last = v
}
@@ -362,9 +353,6 @@
}
break
}
- if w.Op == OpSelect1 {
- w = w.Args[0]
- }
w = w.MemoryArg()
}
var stack []*Value
diff --git a/src/cmd/compile/internal/ssa/trim.go b/src/cmd/compile/internal/ssa/trim.go
index 09e80bd..04b4fd4 100644
--- a/src/cmd/compile/internal/ssa/trim.go
+++ b/src/cmd/compile/internal/ssa/trim.go
@@ -46,10 +46,24 @@
v.resetArgs()
continue
}
- // Pad the arguments of the remaining phi-ops, so
+ // Pad the arguments of the remaining phi-ops so
// they match the new predecessor count of `s`.
- for len(v.Args) < len(s.Preds) {
- v.AddArg(v.Args[0])
+ // Since s did not have a Phi op corresponding to
+ // the phi op in b, the other edges coming into s
+ // must be loopback edges from s, so v is the right
+ // argument to v!
+ args := make([]*Value, len(v.Args))
+ copy(args, v.Args)
+ v.resetArgs()
+ for x := 0; x < j; x++ {
+ v.AddArg(v)
+ }
+ v.AddArg(args[0])
+ for x := j + 1; x < ns; x++ {
+ v.AddArg(v)
+ }
+ for _, a := range args[1:] {
+ v.AddArg(a)
}
}
b.Values[k] = v
diff --git a/src/cmd/compile/internal/ssa/value.go b/src/cmd/compile/internal/ssa/value.go
index a0ba112..7edc71b 100644
--- a/src/cmd/compile/internal/ssa/value.go
+++ b/src/cmd/compile/internal/ssa/value.go
@@ -319,10 +319,8 @@
}
// MemoryArg returns the memory argument for the Value.
-// The returned value, if non-nil, will be memory-typed,
-// except in the case where v is Select1, in which case
-// the returned value will be a tuple containing a memory
-// type. Otherwise, nil is returned.
+// The returned value, if non-nil, will be memory-typed (or a tuple with a memory-typed second part).
+// Otherwise, nil is returned.
func (v *Value) MemoryArg() *Value {
if v.Op == OpPhi {
v.Fatalf("MemoryArg on Phi")
@@ -331,8 +329,7 @@
if na == 0 {
return nil
}
- if m := v.Args[na-1]; m.Type.IsMemory() ||
- (v.Op == OpSelect1 && m.Type.FieldType(1).IsMemory()) {
+ if m := v.Args[na-1]; m.Type.IsMemory() {
return m
}
return nil
diff --git a/src/cmd/compile/internal/types/type.go b/src/cmd/compile/internal/types/type.go
index 6f2f574..5c44e62 100644
--- a/src/cmd/compile/internal/types/type.go
+++ b/src/cmd/compile/internal/types/type.go
@@ -1324,10 +1324,12 @@
return t.Extra.(*Chan).Dir
}
-func (t *Type) IsMemory() bool { return t == TypeMem }
-func (t *Type) IsFlags() bool { return t == TypeFlags }
-func (t *Type) IsVoid() bool { return t == TypeVoid }
-func (t *Type) IsTuple() bool { return t.Etype == TTUPLE }
+func (t *Type) IsMemory() bool {
+ return t == TypeMem || t.Etype == TTUPLE && t.Extra.(*Tuple).second == TypeMem
+}
+func (t *Type) IsFlags() bool { return t == TypeFlags }
+func (t *Type) IsVoid() bool { return t == TypeVoid }
+func (t *Type) IsTuple() bool { return t.Etype == TTUPLE }
// IsUntyped reports whether t is an untyped type.
func (t *Type) IsUntyped() bool {
