Bug 951527 - SpiderMonkey: Fix codegen for mixed-type MoveGroup cycles. r=jandem

This commit is contained in:
Dan Gohman 2013-12-18 08:19:25 -08:00
parent 35f470e6f8
commit 6b3f1be05f
4 changed files with 61 additions and 28 deletions

View File

@ -113,8 +113,8 @@ MoveResolver::resolve()
// assert that we do not find two cycles in one move chain
// traversal (which would indicate two moves to the same
// destination).
pm->setInCycle();
blocking->setInCycle();
pm->setCycleEnd();
blocking->setCycleBegin(pm->type());
hasCycles_ = true;
pending_.remove(blocking);
stack.pushBack(blocking);

View File

@ -110,7 +110,8 @@ class MoveOp
protected:
MoveOperand from_;
MoveOperand to_;
bool cycle_;
bool cycleBegin_;
bool cycleEnd_;
public:
enum Type {
@ -123,18 +124,30 @@ class MoveOp
protected:
Type type_;
// If cycleBegin_ is true, endCycleType_ is the type of the move at the end
// of the cycle. For example, given these moves:
// INT32 move a -> b
// GENERAL move b -> a
// the move resolver starts by copying b into a temporary location, so that
// the last move can read it. This copy needs to use use type GENERAL.
Type endCycleType_;
public:
MoveOp()
{ }
MoveOp(const MoveOperand &from, const MoveOperand &to, Type type)
: from_(from),
to_(to),
cycle_(false),
cycleBegin_(false),
cycleEnd_(false),
type_(type)
{ }
bool inCycle() const {
return cycle_;
bool isCycleBegin() const {
return cycleBegin_;
}
bool isCycleEnd() const {
return cycleEnd_;
}
const MoveOperand &from() const {
return from_;
@ -145,6 +158,10 @@ class MoveOp
Type type() const {
return type_;
}
Type endCycleType() const {
JS_ASSERT(isCycleBegin());
return endCycleType_;
}
};
class MoveResolver
@ -161,9 +178,14 @@ class MoveResolver
: MoveOp(from, to, type)
{ }
void setInCycle() {
JS_ASSERT(!inCycle());
cycle_ = true;
void setCycleBegin(Type endCycleType) {
JS_ASSERT(!isCycleBegin() && !isCycleEnd());
cycleBegin_ = true;
endCycleType_ = endCycleType;
}
void setCycleEnd() {
JS_ASSERT(!isCycleBegin() && !isCycleEnd());
cycleEnd_ = true;
}
};

View File

@ -274,14 +274,16 @@ MoveEmitterARM::emit(const MoveOp &move)
const MoveOperand &from = move.from();
const MoveOperand &to = move.to();
if (move.inCycle()) {
if (inCycle_) {
completeCycle(from, to, move.type());
inCycle_ = false;
return;
}
if (move.isCycleEnd()) {
JS_ASSERT(inCycle_);
completeCycle(from, to, move.type());
inCycle_ = false;
return;
}
breakCycle(from, to, move.type());
if (move.isCycleBegin()) {
JS_ASSERT(!inCycle_);
breakCycle(from, to, move.endCycleType());
inCycle_ = true;
}

View File

@ -38,9 +38,8 @@ MoveEmitterX86::characterizeCycle(const MoveResolver &moves, size_t i,
if (!*allGeneralRegs && !*allFloatRegs)
return -1;
// The first and last move of the cycle are marked with inCycle(). Stop
// iterating when we see the last one.
if (j != i && move.inCycle())
// Stop iterating when we see the last one.
if (j != i && move.isCycleEnd())
break;
// Check that this move is actually part of the cycle. This is
@ -103,14 +102,15 @@ MoveEmitterX86::emit(const MoveResolver &moves)
const MoveOperand &from = move.from();
const MoveOperand &to = move.to();
if (move.inCycle()) {
// If this is the end of a cycle for which we're using the stack,
// handle the end.
if (inCycle_) {
completeCycle(to, move.type());
inCycle_ = false;
continue;
}
if (move.isCycleEnd()) {
JS_ASSERT(inCycle_);
completeCycle(to, move.type());
inCycle_ = false;
continue;
}
if (move.isCycleBegin()) {
JS_ASSERT(!inCycle_);
// Characterize the cycle.
bool allGeneralRegs = true, allFloatRegs = true;
@ -123,7 +123,7 @@ MoveEmitterX86::emit(const MoveResolver &moves)
}
// Otherwise use the stack.
breakCycle(to, move.type());
breakCycle(to, move.endCycleType());
inCycle_ = true;
}
@ -256,7 +256,9 @@ MoveEmitterX86::breakCycle(const MoveOperand &to, MoveOp::Type type)
case MoveOp::INT32:
#endif
case MoveOp::GENERAL:
JS_ASSERT(pushedAtCycle_ == -1);
masm.Push(toOperand(to));
pushedAtCycle_ = masm.framePushed();
break;
default:
MOZ_ASSUME_UNREACHABLE("Unexpected move type");
@ -266,6 +268,8 @@ MoveEmitterX86::breakCycle(const MoveOperand &to, MoveOp::Type type)
void
MoveEmitterX86::completeCycle(const MoveOperand &to, MoveOp::Type type)
{
JS_ASSERT(pushedAtCycle_ != -1);
// There is some pattern:
// (A -> B)
// (B -> A)
@ -274,6 +278,7 @@ MoveEmitterX86::completeCycle(const MoveOperand &to, MoveOp::Type type)
// saved value of B, to A.
switch (type) {
case MoveOp::FLOAT32:
JS_ASSERT(pushedAtCycle_ - pushedAtStart_ >= sizeof(float));
if (to.isMemory()) {
masm.loadFloat32(cycleSlot(), ScratchFloatReg);
masm.storeFloat32(ScratchFloatReg, toAddress(to));
@ -282,6 +287,7 @@ MoveEmitterX86::completeCycle(const MoveOperand &to, MoveOp::Type type)
}
break;
case MoveOp::DOUBLE:
JS_ASSERT(pushedAtCycle_ - pushedAtStart_ >= sizeof(double));
if (to.isMemory()) {
masm.loadDouble(cycleSlot(), ScratchFloatReg);
masm.storeDouble(ScratchFloatReg, toAddress(to));
@ -291,6 +297,7 @@ MoveEmitterX86::completeCycle(const MoveOperand &to, MoveOp::Type type)
break;
#ifdef JS_CPU_X64
case MoveOp::INT32:
JS_ASSERT(pushedAtCycle_ - pushedAtStart_ >= sizeof(int32_t));
// x64 can't pop to a 32-bit destination.
if (to.isMemory()) {
masm.load32(cycleSlot(), ScratchReg);
@ -304,11 +311,13 @@ MoveEmitterX86::completeCycle(const MoveOperand &to, MoveOp::Type type)
case MoveOp::INT32:
#endif
case MoveOp::GENERAL:
JS_ASSERT(pushedAtCycle_ - pushedAtStart_ >= sizeof(intptr_t));
if (to.isMemory()) {
masm.Pop(toPopOperand(to));
} else {
masm.Pop(to.reg());
}
pushedAtCycle_ = -1;
break;
default:
MOZ_ASSUME_UNREACHABLE("Unexpected move type");