6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-23 16:30:00 +00:00
Code Issues Projects Releases Wiki Activity

Change Value::getUnderlyingObject to have the MaxLookup value specified as a

Browse Source 
parameter with a default value, instead of just hardcoding it in the
implementation.  The limit of MaxLookup = 6 was introduced in r69151 to fix
a performance problem with O(n^2) behavior in instcombine, but the scalarrepl
pass is relying on getUnderlyingObject to go all the way back to an AllocaInst.
Making the limit part of the method signature makes it clear that by default
the result is limited and should help avoid similar problems in the future.
This fixes pr6126.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94433 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bob Wilson 2010-01-25 18:26:54 +00:00
parent aee6a656e8
commit 032742972f
3 changed files with 11 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
include/llvm/Value.h
View File

@ -285,10 +285,11 @@ public:
/// getUnderlyingObject - This method strips off any GEP address adjustments
/// and pointer casts from the specified value, returning the original object
/// being addressed. Note that the returned value has pointer type if the
/// specified value does.
Value *getUnderlyingObject();
const Value *getUnderlyingObject() const {
return const_cast<Value*>(this)->getUnderlyingObject();
/// specified value does. If the MaxLookup value is non-zero, it limits the
/// number of instructions to be stripped off.
Value *getUnderlyingObject(unsigned MaxLookup = 6);
const Value *getUnderlyingObject(unsigned MaxLookup = 6) const {
return const_cast<Value*>(this)->getUnderlyingObject(MaxLookup);
}
/// DoPHITranslation - If this value is a PHI node with CurBB as its parent,

6
lib/Transforms/Scalar/ScalarReplAggregates.cpp
View File

@ -1384,9 +1384,9 @@ void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, uint64_t Offset) {
// If the source and destination are both to the same alloca, then this is
// a noop copy-to-self, just delete it. Otherwise, emit a load and store
// as appropriate.
AllocaInst *OrigAI = cast<AllocaInst>(Ptr->getUnderlyingObject());
AllocaInst *OrigAI = cast<AllocaInst>(Ptr->getUnderlyingObject(0));
if (MTI->getSource()->getUnderlyingObject() != OrigAI) {
if (MTI->getSource()->getUnderlyingObject(0) != OrigAI) {
// Dest must be OrigAI, change this to be a load from the original
// pointer (bitcasted), then a store to our new alloca.
assert(MTI->getRawDest() == Ptr && "Neither use is of pointer?");
@ -1396,7 +1396,7 @@ void SROA::ConvertUsesToScalar(Value *Ptr, AllocaInst *NewAI, uint64_t Offset) {
LoadInst *SrcVal = Builder.CreateLoad(SrcPtr, "srcval");
SrcVal->setAlignment(MTI->getAlignment());
Builder.CreateStore(SrcVal, NewAI);
} else if (MTI->getDest()->getUnderlyingObject() != OrigAI) {
} else if (MTI->getDest()->getUnderlyingObject(0) != OrigAI) {
// Src must be OrigAI, change this to be a load from NewAI then a store
// through the original dest pointer (bitcasted).
assert(MTI->getRawSource() == Ptr && "Neither use is of pointer?");

7
lib/VMCore/Value.cpp
View File

@ -341,12 +341,11 @@ Value *Value::stripPointerCasts() {
} while (1);
}
Value *Value::getUnderlyingObject() {
Value *Value::getUnderlyingObject(unsigned MaxLookup) {
if (!isa<PointerType>(getType()))
return this;
Value *V = this;
unsigned MaxLookup = 6;
do {
for (unsigned Count = 0; MaxLookup == 0 || Count < MaxLookup; ++Count) {
if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
V = GEP->getPointerOperand();
} else if (Operator::getOpcode(V) == Instruction::BitCast) {
@ -359,7 +358,7 @@ Value *Value::getUnderlyingObject() {
return V;
}
assert(isa<PointerType>(V->getType()) && "Unexpected operand type!");
} while (--MaxLookup);
}
return V;
}