[llvm-commits] [llvm] r65167 - /llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
Dan Gohman
gohman at apple.com
Fri Feb 20 13:27:24 PST 2009
Author: djg
Date: Fri Feb 20 15:27:23 2009
New Revision: 65167
URL: http://llvm.org/viewvc/llvm-project?rev=65167&view=rev
Log:
Simplify code and reduce indentation. No functionality change.
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=65167&r1=65166&r2=65167&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Fri Feb 20 15:27:23 2009
@@ -2074,9 +2074,9 @@
const Type *NewCmpTy = NULL;
unsigned TyBits = CmpTy->getPrimitiveSizeInBits();
unsigned NewTyBits = 0;
- int64_t NewCmpVal = CmpVal;
SCEVHandle *NewStride = NULL;
- Value *NewIncV = NULL;
+ Value *NewCmpLHS = NULL;
+ Value *NewCmpRHS = NULL;
int64_t Scale = 1;
// Check stride constant and the comparision constant signs to detect
@@ -2096,87 +2096,84 @@
continue;
Scale = SSInt / CmpSSInt;
- NewCmpVal = CmpVal * Scale;
+ int64_t NewCmpVal = CmpVal * Scale;
APInt Mul = APInt(BitWidth, NewCmpVal);
// Check for overflow.
- if (Mul.getSExtValue() != NewCmpVal) {
- NewCmpVal = CmpVal;
+ if (Mul.getSExtValue() != NewCmpVal)
continue;
- }
// Watch out for overflow.
if (ICmpInst::isSignedPredicate(Predicate) &&
(CmpVal & SignBit) != (NewCmpVal & SignBit))
- NewCmpVal = CmpVal;
+ continue;
- if (NewCmpVal != CmpVal) {
- // Pick the best iv to use trying to avoid a cast.
- NewIncV = NULL;
- for (std::vector<IVStrideUse>::iterator UI = SI->second.Users.begin(),
- E = SI->second.Users.end(); UI != E; ++UI) {
- NewIncV = UI->OperandValToReplace;
- if (NewIncV->getType() == CmpTy)
- break;
- }
- if (!NewIncV) {
- NewCmpVal = CmpVal;
- continue;
- }
+ if (NewCmpVal == CmpVal)
+ continue;
+ // Pick the best iv to use trying to avoid a cast.
+ NewCmpLHS = NULL;
+ for (std::vector<IVStrideUse>::iterator UI = SI->second.Users.begin(),
+ E = SI->second.Users.end(); UI != E; ++UI) {
+ NewCmpLHS = UI->OperandValToReplace;
+ if (NewCmpLHS->getType() == CmpTy)
+ break;
+ }
+ if (!NewCmpLHS)
+ continue;
- NewCmpTy = NewIncV->getType();
- NewTyBits = isa<PointerType>(NewCmpTy)
- ? UIntPtrTy->getPrimitiveSizeInBits()
- : NewCmpTy->getPrimitiveSizeInBits();
- if (RequiresTypeConversion(NewCmpTy, CmpTy)) {
- // Check if it is possible to rewrite it using
- // an iv / stride of a smaller integer type.
- bool TruncOk = false;
- if (NewCmpTy->isInteger()) {
- unsigned Bits = NewTyBits;
- if (ICmpInst::isSignedPredicate(Predicate))
- --Bits;
- uint64_t Mask = (1ULL << Bits) - 1;
- if (((uint64_t)NewCmpVal & Mask) == (uint64_t)NewCmpVal)
- TruncOk = true;
- }
- if (!TruncOk) {
- NewCmpVal = CmpVal;
- continue;
- }
+ NewCmpTy = NewCmpLHS->getType();
+ NewTyBits = isa<PointerType>(NewCmpTy)
+ ? UIntPtrTy->getPrimitiveSizeInBits()
+ : NewCmpTy->getPrimitiveSizeInBits();
+ if (RequiresTypeConversion(NewCmpTy, CmpTy)) {
+ // Check if it is possible to rewrite it using
+ // an iv / stride of a smaller integer type.
+ bool TruncOk = false;
+ if (NewCmpTy->isInteger()) {
+ unsigned Bits = NewTyBits;
+ if (ICmpInst::isSignedPredicate(Predicate))
+ --Bits;
+ uint64_t Mask = (1ULL << Bits) - 1;
+ if (((uint64_t)NewCmpVal & Mask) == (uint64_t)NewCmpVal)
+ TruncOk = true;
}
-
- // Don't rewrite if use offset is non-constant and the new type is
- // of a different type.
- // FIXME: too conservative?
- if (NewTyBits != TyBits && !isa<SCEVConstant>(CondUse->Offset)) {
- NewCmpVal = CmpVal;
+ if (!TruncOk)
continue;
- }
+ }
- bool AllUsesAreAddresses = true;
- bool AllUsesAreOutsideLoop = true;
- std::vector<BasedUser> UsersToProcess;
- SCEVHandle CommonExprs = CollectIVUsers(SI->first, SI->second, L,
- AllUsesAreAddresses,
- AllUsesAreOutsideLoop,
- UsersToProcess);
- // Avoid rewriting the compare instruction with an iv of new stride
- // if it's likely the new stride uses will be rewritten using the
- // stride of the compare instruction.
- if (AllUsesAreAddresses &&
- ValidStride(!CommonExprs->isZero(), Scale, UsersToProcess)) {
- NewCmpVal = CmpVal;
- continue;
- }
+ // Don't rewrite if use offset is non-constant and the new type is
+ // of a different type.
+ // FIXME: too conservative?
+ if (NewTyBits != TyBits && !isa<SCEVConstant>(CondUse->Offset))
+ continue;
- // If scale is negative, use swapped predicate unless it's testing
- // for equality.
- if (Scale < 0 && !Cond->isEquality())
- Predicate = ICmpInst::getSwappedPredicate(Predicate);
+ bool AllUsesAreAddresses = true;
+ bool AllUsesAreOutsideLoop = true;
+ std::vector<BasedUser> UsersToProcess;
+ SCEVHandle CommonExprs = CollectIVUsers(SI->first, SI->second, L,
+ AllUsesAreAddresses,
+ AllUsesAreOutsideLoop,
+ UsersToProcess);
+ // Avoid rewriting the compare instruction with an iv of new stride
+ // if it's likely the new stride uses will be rewritten using the
+ // stride of the compare instruction.
+ if (AllUsesAreAddresses &&
+ ValidStride(!CommonExprs->isZero(), Scale, UsersToProcess))
+ continue;
- NewStride = &StrideOrder[i];
- break;
+ // If scale is negative, use swapped predicate unless it's testing
+ // for equality.
+ if (Scale < 0 && !Cond->isEquality())
+ Predicate = ICmpInst::getSwappedPredicate(Predicate);
+
+ NewStride = &StrideOrder[i];
+ if (!isa<PointerType>(NewCmpTy))
+ NewCmpRHS = ConstantInt::get(NewCmpTy, NewCmpVal);
+ else {
+ NewCmpRHS = ConstantInt::get(UIntPtrTy, NewCmpVal);
+ NewCmpRHS = SCEVExpander::InsertCastOfTo(Instruction::IntToPtr,
+ NewCmpRHS, NewCmpTy);
}
+ break;
}
// Forgo this transformation if it the increment happens to be
@@ -2188,22 +2185,15 @@
if (!Cond->hasOneUse()) {
for (BasicBlock::iterator I = Cond, E = Cond->getParent()->end();
I != E; ++I)
- if (I == NewIncV)
+ if (I == NewCmpLHS)
return Cond;
}
- if (NewCmpVal != CmpVal) {
+ if (NewCmpRHS) {
// Create a new compare instruction using new stride / iv.
ICmpInst *OldCond = Cond;
- Value *RHS;
- if (!isa<PointerType>(NewCmpTy))
- RHS = ConstantInt::get(NewCmpTy, NewCmpVal);
- else {
- RHS = ConstantInt::get(UIntPtrTy, NewCmpVal);
- RHS = SCEVExpander::InsertCastOfTo(Instruction::IntToPtr, RHS, NewCmpTy);
- }
// Insert new compare instruction.
- Cond = new ICmpInst(Predicate, NewIncV, RHS,
+ Cond = new ICmpInst(Predicate, NewCmpLHS, NewCmpRHS,
L->getHeader()->getName() + ".termcond",
OldCond);
@@ -2219,7 +2209,7 @@
SE->getConstant(ConstantInt::get(CmpTy, Scale)))
: SE->getConstant(ConstantInt::get(NewCmpTy,
cast<SCEVConstant>(CondUse->Offset)->getValue()->getSExtValue()*Scale));
- IVUsesByStride[*NewStride].addUser(NewOffset, Cond, NewIncV);
+ IVUsesByStride[*NewStride].addUser(NewOffset, Cond, NewCmpLHS);
CondUse = &IVUsesByStride[*NewStride].Users.back();
CondStride = NewStride;
++NumEliminated;
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