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add support for phi translation and incorpation of new expression.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90782 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2009-12-07 19:04:49 +00:00
parent d84ea47b89
commit 6fcca1cc87
1 changed files with 152 additions and 129 deletions
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75
lib/Analysis/PHITransAddr.cpp
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@ -16,6 +16,22 @@
#include "llvm/Analysis/InstructionSimplify.h"
using namespace llvm;
static bool CanPHITrans(Instruction *Inst) {
if (isa<PHINode>(Inst) ||
isa<BitCastInst>(Inst) ||
isa<GetElementPtrInst>(Inst))
return true;
if (Inst->getOpcode() == Instruction::And &&
isa<ConstantInt>(Inst->getOperand(1)))
return true;
// cerr << "MEMDEP: Could not PHI translate: " << *Pointer;
// if (isa<BitCastInst>(PtrInst) || isa<GetElementPtrInst>(PtrInst))
// cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0);
return false;
}
/// IsPotentiallyPHITranslatable - If this needs PHI translation, return true
/// if we have some hope of doing it. This should be used as a filter to
/// avoid calling PHITranslateValue in hopeless situations.
@ -23,18 +39,7 @@ bool PHITransAddr::IsPotentiallyPHITranslatable() const {
// If the input value is not an instruction, or if it is not defined in CurBB,
// then we don't need to phi translate it.
Instruction *Inst = dyn_cast<Instruction>(Addr);
if (isa<PHINode>(Inst) ||
isa<BitCastInst>(Inst) ||
isa<GetElementPtrInst>(Inst) ||
(Inst->getOpcode() == Instruction::And &&
isa<ConstantInt>(Inst->getOperand(1))))
return true;
// cerr << "MEMDEP: Could not PHI translate: " << *Pointer;
// if (isa<BitCastInst>(PtrInst) || isa<GetElementPtrInst>(PtrInst))
// cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0);
return false;
return Inst == 0 || CanPHITrans(Inst);
}
@ -44,18 +49,44 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
Instruction *Inst = dyn_cast<Instruction>(V);
if (Inst == 0) return V;
// If 'Inst' is defined in this block, it must be an input that needs to be
// phi translated or an intermediate expression that needs to be incorporated
// into the expression.
if (Inst->getParent() == CurBB) {
assert(std::count(InstInputs.begin(), InstInputs.end(), Inst) &&
"Not an input?");
// If this is a PHI, go ahead and translate it.
if (PHINode *PN = dyn_cast<PHINode>(Inst))
return PN->getIncomingValueForBlock(PredBB);
// If this is a non-phi value, and it is analyzable, we can incorporate it
// into the expression by making all instruction operands be inputs.
if (!CanPHITrans(Inst))
return 0;
// Okay, we can incorporate it, this instruction is no longer an input.
InstInputs.erase(std::find(InstInputs.begin(), InstInputs.end(), Inst));
// All instruction operands are now inputs (and of course, they may also be
// defined in this block, so they may need to be phi translated themselves.
for (unsigned i = 0, e = Inst->getNumOperands(); i != e; ++i)
if (Instruction *Op = dyn_cast<Instruction>(Inst->getOperand(i)))
InstInputs.push_back(Op);
} else {
// Determine whether 'Inst' is an input to our PHI translatable expression.
bool isInput = std::count(InstInputs.begin(), InstInputs.end(), Inst);
// If 'Inst' is not defined in this block, it is either an input, or an
// intermediate result.
if (Inst->getParent() != CurBB) {
// If it is an input, then it remains an input.
// If it is an input defined in a different block, then it remains an input.
if (isInput)
return Inst;
}
// Otherwise, it must be an intermediate result. See if its operands need
// to be phi translated, and if so, reconstruct it.
// Ok, it must be an intermediate result (either because it started that way
// or because we just incorporated it into the expression). See if its
// operands need to be phi translated, and if so, reconstruct it.
if (BitCastInst *BC = dyn_cast<BitCastInst>(Inst)) {
Value *PHIIn = PHITranslateSubExpr(BC->getOperand(0), CurBB, PredBB);
@ -159,14 +190,6 @@ Value *PHITransAddr::PHITranslateSubExpr(Value *V, BasicBlock *CurBB,
// Otherwise, we failed.
return 0;
}
// Otherwise, it is defined in this block. It must be an input and must be
// phi translated.
assert(isInput && "Instruction defined in block must be an input");
abort(); // unimplemented so far.
}