diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/icmp.ll | 19 |
2 files changed, 22 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 0c434a54cbe..ea175cd10ff 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -1646,7 +1646,7 @@ Instruction *InstCombiner::foldICmpAndConstConst(ICmpInst &Cmp, if (!match(And->getOperand(1), m_APInt(C2))) return nullptr; - if (!And->hasOneUse() || !And->getOperand(0)->hasOneUse()) + if (!And->hasOneUse()) return nullptr; // If the LHS is an 'and' of a truncate and we can widen the and/compare to @@ -1658,7 +1658,7 @@ Instruction *InstCombiner::foldICmpAndConstConst(ICmpInst &Cmp, // set or if it is an equality comparison. Extending a relational comparison // when we're checking the sign bit would not work. Value *W; - if (match(And->getOperand(0), m_Trunc(m_Value(W))) && + if (match(And->getOperand(0), m_OneUse(m_Trunc(m_Value(W)))) && (Cmp.isEquality() || (!C1->isNegative() && !C2->isNegative()))) { // TODO: Is this a good transform for vectors? Wider types may reduce // throughput. Should this transform be limited (even for scalars) by using @@ -1680,7 +1680,7 @@ Instruction *InstCombiner::foldICmpAndConstConst(ICmpInst &Cmp, // (icmp pred (and A, (or (shl 1, B), 1), 0)) // // iff pred isn't signed - if (!Cmp.isSigned() && C1->isNullValue() && + if (!Cmp.isSigned() && C1->isNullValue() && And->getOperand(0)->hasOneUse() && match(And->getOperand(1), m_One())) { Constant *One = cast<Constant>(And->getOperand(1)); Value *Or = And->getOperand(0); diff --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll index 68d98de0b4e..18d449228bd 100644 --- a/llvm/test/Transforms/InstCombine/icmp.ll +++ b/llvm/test/Transforms/InstCombine/icmp.ll @@ -1615,6 +1615,25 @@ define <2 x i1> @icmp_add_and_shr_ne_0_vec(<2 x i32> %X) { ret <2 x i1> %tobool } +; Variation of the above with an extra use of the shift +define i1 @icmp_and_shr_multiuse(i32 %X) { +; CHECK-LABEL: @icmp_and_shr_multiuse( +; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 240 +; CHECK-NEXT: [[AND2:%.*]] = and i32 [[X]], 496 +; CHECK-NEXT: [[TOBOOL:%.*]] = icmp ne i32 [[AND]], 224 +; CHECK-NEXT: [[TOBOOL2:%.*]] = icmp ne i32 [[AND2]], 432 +; CHECK-NEXT: [[AND3:%.*]] = and i1 [[TOBOOL]], [[TOBOOL2]] +; CHECK-NEXT: ret i1 [[AND3]] +; + %shr = lshr i32 %X, 4 + %and = and i32 %shr, 15 + %and2 = and i32 %shr, 31 ; second use of the shift + %tobool = icmp ne i32 %and, 14 + %tobool2 = icmp ne i32 %and2, 27 + %and3 = and i1 %tobool, %tobool2 + ret i1 %and3 +} + ; PR16244 define i1 @test71(i8* %x) { ; CHECK-LABEL: @test71( |
