[llvm-commits] [llvm] r69215 - /llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
Dale Johannesen
dalej at apple.com
Wed Apr 15 14:03:12 PDT 2009
On Apr 15, 2009, at 2:01 PMPDT, Chris Lattner wrote:
>
> On Apr 15, 2009, at 1:41 PM, Dale Johannesen wrote:
>
>> Author: johannes
>> Date: Wed Apr 15 15:41:02 2009
>> New Revision: 69215
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=69215&view=rev
>> Log:
>> Eliminate zext over (iv & const) or ((iv+const)&const)
>> if a longer iv is available. These subscript forms are
>> not common; they're a bottleneck in OpenSSL.
>
> Testcase? :)
Coming. Apparently I'm in a hurry, although I didn't find that out
until lunch.
>
> -Chris
>
>>
>>
>>
>> Modified:
>> llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
>>
>> Modified: llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp?rev=69215&r1=69214&r2=69215&view=diff
>>
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =
>> =====================================================================
>> --- llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp (original)
>> +++ llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp Wed Apr 15
>> 15:41:02 2009
>> @@ -798,48 +798,106 @@
>> if (PN == OrigControllingPHI && PN->getType() != LargestType)
>> for (Value::use_iterator UI = PN->use_begin(), UE = PN-
>>> use_end();
>> UI != UE; ++UI) {
>> - if (isa<SExtInst>(UI) && NoSignedWrap) {
>> + Instruction *UInst = dyn_cast<Instruction>(*UI);
>> + if (UInst && isa<SExtInst>(UInst) && NoSignedWrap) {
>> Value *TruncIndVar = getSignExtendedTruncVar(AR, SE,
>> LargestType, L,
>> - UI->getType(),
>> Rewriter, InsertPt);
>> - UI->replaceAllUsesWith(TruncIndVar);
>> - if (Instruction *DeadUse = dyn_cast<Instruction>(*UI))
>> - DeadInsts.insert(DeadUse);
>> + UInst->getType(),
>> Rewriter, InsertPt);
>> + UInst->replaceAllUsesWith(TruncIndVar);
>> + DeadInsts.insert(UInst);
>> }
>> // See if we can figure out sext(i+constant) doesn't wrap,
>> so we can
>> // use a larger add. This is common in subscripting.
>> - Instruction *UInst = dyn_cast<Instruction>(*UI);
>> if (UInst && UInst->getOpcode()==Instruction::Add &&
>> UInst->hasOneUse() &&
>> isa<ConstantInt>(UInst->getOperand(1)) &&
>> - isa<SExtInst>(UInst->use_begin()) && NoSignedWrap &&
>> LimitVal) {
>> - uint64_t numBits = LimitVal->getValue().getBitWidth();
>> - ConstantInt* RHS = dyn_cast<ConstantInt>(UInst-
>>> getOperand(1));
>> - if (((APInt::getSignedMaxValue(numBits) - IncrVal-
>>> getValue()) -
>> - RHS->getValue()).sgt(LimitVal->getValue())) {
>> - SExtInst* oldSext = dyn_cast<SExtInst>(UInst-
>>> use_begin());
>> - Value *TruncIndVar = getSignExtendedTruncVar(AR, SE,
>> LargestType, L,
>> - oldSext->getType(),
>> Rewriter,
>> - InsertPt);
>> - APInt APcopy = APInt(RHS->getValue());
>> - ConstantInt* newRHS =
>> - ConstantInt::get(APcopy.sext(oldSext->getType()->
>> -
>> getPrimitiveSizeInBits()));
>> - Value *NewAdd = BinaryOperator::CreateAdd(TruncIndVar,
>> newRHS,
>> - UInst-
>>> getName()+".nosex",
>> - UInst);
>> - oldSext->replaceAllUsesWith(NewAdd);
>> - if (Instruction *DeadUse =
>> dyn_cast<Instruction>(oldSext))
>> - DeadInsts.insert(DeadUse);
>> - if (Instruction *DeadUse = dyn_cast<Instruction>(UInst))
>> - DeadInsts.insert(DeadUse);
>> + NoSignedWrap && LimitVal) {
>> + uint64_t oldBitSize = LimitVal->getValue().getBitWidth();
>> + uint64_t newBitSize = LargestType-
>>> getPrimitiveSizeInBits();
>> + ConstantInt* AddRHS = dyn_cast<ConstantInt>(UInst-
>>> getOperand(1));
>> + if (((APInt::getSignedMaxValue(oldBitSize) - IncrVal-
>>> getValue()) -
>> + AddRHS->getValue()).sgt(LimitVal->getValue())) {
>> + // We've determined this is (i+constant) and it won't
>> overflow.
>> + if (isa<SExtInst>(UInst->use_begin())) {
>> + SExtInst* oldSext = dyn_cast<SExtInst>(UInst-
>>> use_begin());
>> + Value *TruncIndVar = getSignExtendedTruncVar(AR, SE,
>> LargestType,
>> + L, oldSext-
>>> getType(), Rewriter,
>> + InsertPt);
>> + APInt APcopy = APInt(AddRHS->getValue());
>> + ConstantInt* newAddRHS
>> =ConstantInt::get(APcopy.sext(newBitSize));
>> + Value *NewAdd =
>> + BinaryOperator::CreateAdd(TruncIndVar,
>> newAddRHS,
>> + UInst->getName()
>> +".nosex", UInst);
>> + oldSext->replaceAllUsesWith(NewAdd);
>> + if (Instruction *DeadUse =
>> dyn_cast<Instruction>(oldSext))
>> + DeadInsts.insert(DeadUse);
>> + DeadInsts.insert(UInst);
>> + }
>> }
>> }
>> - if (isa<ZExtInst>(UI) && NoUnsignedWrap) {
>> + if (UInst && isa<ZExtInst>(UInst) && NoUnsignedWrap) {
>> Value *TruncIndVar = getZeroExtendedTruncVar(AR, SE,
>> LargestType, L,
>> - UI->getType(),
>> Rewriter, InsertPt);
>> - UI->replaceAllUsesWith(TruncIndVar);
>> - if (Instruction *DeadUse = dyn_cast<Instruction>(*UI))
>> + UInst->getType(),
>> Rewriter, InsertPt);
>> + UInst->replaceAllUsesWith(TruncIndVar);
>> + DeadInsts.insert(UInst);
>> + }
>> + // If we have zext(i&constant), we can use the larger
>> variable. This
>> + // is not common but is a bottleneck in Openssl.
>> + // (RHS doesn't have to be constant. There should be a
>> better approach
>> + // than bottom-up pattern matching for this...)
>> + if (UInst && UInst->getOpcode()==Instruction::And &&
>> + UInst->hasOneUse() &&
>> + isa<ConstantInt>(UInst->getOperand(1)) &&
>> + isa<ZExtInst>(UInst->use_begin())) {
>> + uint64_t newBitSize = LargestType-
>>> getPrimitiveSizeInBits();
>> + ConstantInt* AndRHS = dyn_cast<ConstantInt>(UInst-
>>> getOperand(1));
>> + ZExtInst* oldZext = dyn_cast<ZExtInst>(UInst-
>> >use_begin());
>> + Value *TruncIndVar = getSignExtendedTruncVar(AR, SE,
>> LargestType,
>> + L, oldZext->getType(), Rewriter,
>> InsertPt);
>> + APInt APcopy = APInt(AndRHS->getValue());
>> + ConstantInt* newAndRHS =
>> ConstantInt::get(APcopy.zext(newBitSize));
>> + Value *NewAnd =
>> + BinaryOperator::CreateAnd(TruncIndVar, newAndRHS,
>> + UInst->getName()
>> +".nozex", UInst);
>> + oldZext->replaceAllUsesWith(NewAnd);
>> + if (Instruction *DeadUse = dyn_cast<Instruction>(oldZext))
>> DeadInsts.insert(DeadUse);
>> + DeadInsts.insert(UInst);
>> + }
>> + // If we have zext((i+constant)&constant), we can use the
>> larger
>> + // variable even if the add does overflow. This works
>> whenever the
>> + // constant being ANDed is the same size as i, which it
>> presumably is.
>> + // We don't need to restrict the expression being and'ed to
>> i+const,
>> + // but we have to promote everything in it, so it's
>> convenient.
>> + if (UInst && UInst->getOpcode()==Instruction::Add &&
>> + UInst->hasOneUse() &&
>> + isa<ConstantInt>(UInst->getOperand(1))) {
>> + uint64_t newBitSize = LargestType-
>>> getPrimitiveSizeInBits();
>> + ConstantInt* AddRHS = dyn_cast<ConstantInt>(UInst-
>>> getOperand(1));
>> + Instruction *UInst2 = dyn_cast<Instruction>(UInst-
>>> use_begin());
>> + if (UInst2 && UInst2->getOpcode() == Instruction::And &&
>> + UInst2->hasOneUse() &&
>> + isa<ConstantInt>(UInst2->getOperand(1)) &&
>> + isa<ZExtInst>(UInst2->use_begin())) {
>> + ZExtInst* oldZext = dyn_cast<ZExtInst>(UInst2-
>>> use_begin());
>> + Value *TruncIndVar = getSignExtendedTruncVar(AR, SE,
>> LargestType,
>> + L, oldZext->getType(),
>> Rewriter, InsertPt);
>> + ConstantInt* AndRHS = dyn_cast<ConstantInt>(UInst2-
>>> getOperand(1));
>> + APInt APcopy = APInt(AddRHS->getValue());
>> + ConstantInt* newAddRHS =
>> ConstantInt::get(APcopy.zext(newBitSize));
>> + Value *NewAdd =
>> + BinaryOperator::CreateAdd(TruncIndVar, newAddRHS,
>> + UInst->getName()
>> +".nozex", UInst2);
>> + APInt APcopy2 = APInt(AndRHS->getValue());
>> + ConstantInt* newAndRHS =
>> ConstantInt::get(APcopy2.zext(newBitSize));
>> + Value *NewAnd =
>> + BinaryOperator::CreateAnd(NewAdd, newAndRHS,
>> + UInst->getName()
>> +".nozex", UInst2);
>> + oldZext->replaceAllUsesWith(NewAnd);
>> + if (Instruction *DeadUse =
>> dyn_cast<Instruction>(oldZext))
>> + DeadInsts.insert(DeadUse);
>> + DeadInsts.insert(UInst);
>> + DeadInsts.insert(UInst2);
>> + }
>> }
>> }
>>
>>
>>
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