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Add more i1 optimizations. add, sub, mul, s/udiv on i1 are now simplified away. 

llvm-svn: 51817
This commit is contained in:
Nick Lewycky 2008-05-31 17:59:52 +00:00
parent df9242a833
commit 26b8cd84b3
2 changed files with 39 additions and 5 deletions
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20
llvm/lib/Transforms/Scalar/InstructionCombining.cpp
View File

@ -2551,9 +2551,6 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
bool Changed = SimplifyCommutative(I);
Value *LHS = I.getOperand(0), *RHS = I.getOperand(1);
if (I.getType() == Type::Int1Ty)
return BinaryOperator::CreateXor(LHS, RHS);
if (Constant *RHSC = dyn_cast<Constant>(RHS)) {
// X + undef -> undef
if (isa<UndefValue>(RHS))
@ -2637,8 +2634,11 @@ Instruction *InstCombiner::visitAdd(BinaryOperator &I) {
}
}
if (I.getType() == Type::Int1Ty)
return BinaryOperator::CreateXor(LHS, RHS);
// X + X --> X << 1
if (I.getType()->isInteger() && I.getType() != Type::Int1Ty) {
if (I.getType()->isInteger()) {
if (Instruction *Result = AssociativeOpt(I, AddRHS(RHS))) return Result;
if (Instruction *RHSI = dyn_cast<Instruction>(RHS)) {
@ -2976,6 +2976,9 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) {
return NV;
}
if (I.getType() == Type::Int1Ty)
return BinaryOperator::CreateXor(Op0, Op1);
if (BinaryOperator *Op1I = dyn_cast<BinaryOperator>(Op1)) {
if (Op1I->getOpcode() == Instruction::Add &&
!Op0->getType()->isFPOrFPVector()) {
@ -3170,12 +3173,15 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) {
if (Value *Op1v = dyn_castNegVal(I.getOperand(1)))
return BinaryOperator::CreateMul(Op0v, Op1v);
if (I.getType() == Type::Int1Ty)
return BinaryOperator::CreateAnd(Op0, I.getOperand(1));
// If one of the operands of the multiply is a cast from a boolean value, then
// we know the bool is either zero or one, so this is a 'masking' multiply.
// See if we can simplify things based on how the boolean was originally
// formed.
CastInst *BoolCast = 0;
if (ZExtInst *CI = dyn_cast<ZExtInst>(I.getOperand(0)))
if (ZExtInst *CI = dyn_cast<ZExtInst>(Op0))
if (CI->getOperand(0)->getType() == Type::Int1Ty)
BoolCast = CI;
if (!BoolCast)
@ -3331,6 +3337,10 @@ Instruction *InstCombiner::commonIDivTransforms(BinaryOperator &I) {
if (LHS->equalsInt(0))
return ReplaceInstUsesWith(I, Constant::getNullValue(I.getType()));
// It can't be division by zero, hence it must be division by one.
if (I.getType() == Type::Int1Ty)
return ReplaceInstUsesWith(I, Op0);
return 0;
}

24
llvm/test/Transforms/InstCombine/2008-05-31-Bools.ll Normal file
View File

@ -0,0 +1,24 @@
; RUN: llvm-as < %s | opt -instcombine | llvm-dis > %t
; RUN: grep {xor} %t
; RUN: grep {and} %t
; RUN: not grep {div} %t
define i1 @foo1(i1 %a, i1 %b) {
%A = sub i1 %a, %b
ret i1 %A
}
define i1 @foo2(i1 %a, i1 %b) {
%A = mul i1 %a, %b
ret i1 %A
}
define i1 @foo3(i1 %a, i1 %b) {
%A = udiv i1 %a, %b
ret i1 %A
}
define i1 @foo4(i1 %a, i1 %b) {
%A = sdiv i1 %a, %b
ret i1 %A
}