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Expose constant propogation of an instruction in a clean way

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1376 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2001-11-26 18:57:12 +00:00
parent 4ed17bad69
commit faffb053fe
1 changed files with 24 additions and 37 deletions
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61
lib/Transforms/Scalar/ConstantProp.cpp
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@ -31,7 +31,7 @@
#include "llvm/ConstPoolVals.h"
inline static bool
ConstantFoldUnaryInst(Method *M, Method::inst_iterator &DI,
ConstantFoldUnaryInst(BasicBlock *BB, BasicBlock::iterator &II,
UnaryOperator *Op, ConstPoolVal *D) {
ConstPoolVal *ReplaceWith =
opt::ConstantFoldUnaryInstruction(Op->getOpcode(), D);
@ -42,11 +42,11 @@ ConstantFoldUnaryInst(Method *M, Method::inst_iterator &DI,
Op->replaceAllUsesWith(ReplaceWith);
// Remove the operator from the list of definitions...
Op->getParent()->getInstList().remove(DI.getInstructionIterator());
Op->getParent()->getInstList().remove(II);
// The new constant inherits the old name of the operator...
if (Op->hasName())
ReplaceWith->setName(Op->getName(), M->getSymbolTableSure());
ReplaceWith->setName(Op->getName(), BB->getParent()->getSymbolTableSure());
// Delete the operator now...
delete Op;
@ -54,7 +54,7 @@ ConstantFoldUnaryInst(Method *M, Method::inst_iterator &DI,
}
inline static bool
ConstantFoldCast(Method *M, Method::inst_iterator &DI,
ConstantFoldCast(BasicBlock *BB, BasicBlock::iterator &II,
CastInst *CI, ConstPoolVal *D) {
ConstPoolVal *ReplaceWith =
opt::ConstantFoldCastInstruction(D, CI->getType());
@ -65,11 +65,11 @@ ConstantFoldCast(Method *M, Method::inst_iterator &DI,
CI->replaceAllUsesWith(ReplaceWith);
// Remove the cast from the list of definitions...
CI->getParent()->getInstList().remove(DI.getInstructionIterator());
CI->getParent()->getInstList().remove(II);
// The new constant inherits the old name of the cast...
if (CI->hasName())
ReplaceWith->setName(CI->getName(), M->getSymbolTableSure());
ReplaceWith->setName(CI->getName(), BB->getParent()->getSymbolTableSure());
// Delete the cast now...
delete CI;
@ -77,7 +77,7 @@ ConstantFoldCast(Method *M, Method::inst_iterator &DI,
}
inline static bool
ConstantFoldBinaryInst(Method *M, Method::inst_iterator &DI,
ConstantFoldBinaryInst(BasicBlock *BB, BasicBlock::iterator &II,
BinaryOperator *Op,
ConstPoolVal *D1, ConstPoolVal *D2) {
ConstPoolVal *ReplaceWith =
@ -88,11 +88,11 @@ ConstantFoldBinaryInst(Method *M, Method::inst_iterator &DI,
Op->replaceAllUsesWith(ReplaceWith);
// Remove the operator from the list of definitions...
Op->getParent()->getInstList().remove(DI.getInstructionIterator());
Op->getParent()->getInstList().remove(II);
// The new constant inherits the old name of the operator...
if (Op->hasName())
ReplaceWith->setName(Op->getName(), M->getSymbolTableSure());
ReplaceWith->setName(Op->getName(), BB->getParent()->getSymbolTableSure());
// Delete the operator now...
delete Op;
@ -155,23 +155,23 @@ bool opt::ConstantFoldTerminator(TerminatorInst *T) {
// ConstantFoldInstruction - If an instruction references constants, try to fold
// them together...
//
inline static bool
ConstantFoldInstruction(Method *M, Method::inst_iterator &II) {
bool opt::ConstantPropogation::doConstantPropogation(BasicBlock *BB,
BasicBlock::iterator &II) {
Instruction *Inst = *II;
if (BinaryOperator *BInst = dyn_cast<BinaryOperator>(Inst)) {
ConstPoolVal *D1 = dyn_cast<ConstPoolVal>(Inst->getOperand(0));
ConstPoolVal *D2 = dyn_cast<ConstPoolVal>(Inst->getOperand(1));
if (D1 && D2)
return ConstantFoldBinaryInst(M, II, cast<BinaryOperator>(Inst), D1, D2);
return ConstantFoldBinaryInst(BB, II, cast<BinaryOperator>(Inst), D1, D2);
} else if (CastInst *CI = dyn_cast<CastInst>(Inst)) {
ConstPoolVal *D = dyn_cast<ConstPoolVal>(CI->getOperand(0));
if (D) return ConstantFoldCast(M, II, CI, D);
if (D) return ConstantFoldCast(BB, II, CI, D);
} else if (UnaryOperator *UInst = dyn_cast<UnaryOperator>(Inst)) {
ConstPoolVal *D = dyn_cast<ConstPoolVal>(UInst->getOperand(0));
if (D) return ConstantFoldUnaryInst(M, II, UInst, D);
if (D) return ConstantFoldUnaryInst(BB, II, UInst, D);
} else if (TerminatorInst *TInst = dyn_cast<TerminatorInst>(Inst)) {
return opt::ConstantFoldTerminator(TInst);
@ -183,9 +183,9 @@ ConstantFoldInstruction(Method *M, Method::inst_iterator &II) {
Value *V = PN->getOperand(0);
PN->replaceAllUsesWith(V); // Replace all uses of this PHI
// Unlink from basic block
PN->getParent()->getInstList().remove(II.getInstructionIterator());
PN->getParent()->getInstList().remove(II);
if (PN->hasName()) // Inherit PHINode name
V->setName(PN->getName(), M->getSymbolTableSure());
V->setName(PN->getName(), BB->getParent()->getSymbolTableSure());
delete PN; // Finally, delete the node...
return true;
}
@ -199,32 +199,19 @@ ConstantFoldInstruction(Method *M, Method::inst_iterator &II) {
static bool DoConstPropPass(Method *M) {
bool SomethingChanged = false;
#if 1
Method::inst_iterator It = M->inst_begin();
while (It != M->inst_end())
if (ConstantFoldInstruction(M, It)) {
SomethingChanged = true; // If returned true, iter is already incremented
// Incrementing the iterator in an unchecked manner could mess up the
// internals of 'It'. To make sure everything is happy, tell it we might
// have broken it.
It.resyncInstructionIterator();
} else {
++It;
}
#else
for (Method::iterator BBIt = M->begin(); BBIt != M->end(); ++BBIt) {
BasicBlock *BB = *BBIt;
reduce_apply_bool(BB->begin(), BB->end(),
bind1st(ConstantFoldInstruction, M));
for (Method::iterator BBI = M->begin(); BBI != M->end(); ++BBI) {
BasicBlock *BB = *BBI;
for (BasicBlock::iterator I = BB->begin(); I != BB->end(); )
if (opt::ConstantPropogation::doConstantPropogation(BB, I))
SomethingChanged = true;
else
++I;
}
#endif
return SomethingChanged;
}
// returns true on failure, false on success...
// returns whether or not the underlying method was modified
//
bool opt::ConstantPropogation::doConstantPropogation(Method *M) {
bool Modified = false;