diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineAndOrXor.cpp | 25 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/onehot_merge.ll | 4 |
2 files changed, 6 insertions, 23 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp index 88bb69beef..c520db597c 100644 --- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -1543,23 +1543,6 @@ static Instruction *MatchSelectFromAndOr(Value *A, Value *B, return 0; } -/// IsOneHotValue - Returns true for "one-hot" values (values where at most -/// one bit can be set). -static bool IsOneHotValue(Value *V) { - // Match 1<<K. - if (BinaryOperator *BO = dyn_cast<BinaryOperator>(V)) - if (BO->getOpcode() == Instruction::Shl) { - ConstantInt *One = dyn_cast<ConstantInt>(BO->getOperand(0)); - return One && One->isOne(); - } - - // Check for power of two integer constants. - if (ConstantInt *K = dyn_cast<ConstantInt>(V)) - return K->getValue().isPowerOf2(); - - return false; -} - /// FoldOrOfICmps - Fold (icmp)|(icmp) if possible. Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { ICmpInst::Predicate LHSCC = LHS->getPredicate(), RHSCC = RHS->getPredicate(); @@ -1581,13 +1564,13 @@ Value *InstCombiner::FoldOrOfICmps(ICmpInst *LHS, ICmpInst *RHS) { Value *Mask = 0; Value *Masked = 0; if (LAnd->getOperand(0) == RAnd->getOperand(0) && - IsOneHotValue(LAnd->getOperand(1)) && - IsOneHotValue(RAnd->getOperand(1))) { + isKnownToBeAPowerOfTwo(LAnd->getOperand(1)) && + isKnownToBeAPowerOfTwo(RAnd->getOperand(1))) { Mask = Builder->CreateOr(LAnd->getOperand(1), RAnd->getOperand(1)); Masked = Builder->CreateAnd(LAnd->getOperand(0), Mask); } else if (LAnd->getOperand(1) == RAnd->getOperand(1) && - IsOneHotValue(LAnd->getOperand(0)) && - IsOneHotValue(RAnd->getOperand(0))) { + isKnownToBeAPowerOfTwo(LAnd->getOperand(0)) && + isKnownToBeAPowerOfTwo(RAnd->getOperand(0))) { Mask = Builder->CreateOr(LAnd->getOperand(0), RAnd->getOperand(0)); Masked = Builder->CreateAnd(LAnd->getOperand(1), Mask); } diff --git a/test/Transforms/InstCombine/onehot_merge.ll b/test/Transforms/InstCombine/onehot_merge.ll index 51f955c2c2..496d847b53 100644 --- a/test/Transforms/InstCombine/onehot_merge.ll +++ b/test/Transforms/InstCombine/onehot_merge.ll @@ -16,7 +16,7 @@ bb: ;CHECK: @foo1_and ;CHECK: shl i32 1, %c1 -;CHECK-NEXT: shl i32 1, %c2 +;CHECK-NEXT: lshr i32 -2147483648, %c2 ;CHECK-NEXT: or i32 ;CHECK-NEXT: and i32 ;CHECK-NEXT: icmp ne i32 %1, %0 @@ -24,7 +24,7 @@ bb: define i1 @foo1_and(i32 %k, i32 %c1, i32 %c2) { bb: %tmp = shl i32 1, %c1 - %tmp4 = shl i32 1, %c2 + %tmp4 = lshr i32 -2147483648, %c2 %tmp1 = and i32 %tmp, %k %tmp2 = icmp eq i32 %tmp1, 0 %tmp5 = and i32 %tmp4, %k |