diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index 69bc38e8c762..2419d4f32885 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -1794,6 +1794,15 @@ Instruction *InstCombiner::foldICmpOrConstant(ICmpInst &Cmp, BinaryOperator *Or, ConstantInt::get(V->getType(), 1)); } + // X | C == C --> X <=u C + // X | C != C --> X >u C + // iff C+1 is a power of 2 (C is a bitmask of the low bits) + if (Cmp.isEquality() && Cmp.getOperand(1) == Or->getOperand(1) && + (*C + 1).isPowerOf2()) { + Pred = (Pred == CmpInst::ICMP_EQ) ? CmpInst::ICMP_ULE : CmpInst::ICMP_UGT; + return new ICmpInst(Pred, Or->getOperand(0), Or->getOperand(1)); + } + if (!Cmp.isEquality() || *C != 0 || !Or->hasOneUse()) return nullptr; diff --git a/llvm/test/Transforms/InstCombine/icmp.ll b/llvm/test/Transforms/InstCombine/icmp.ll index c95257139a7d..b1dc395b3d95 100644 --- a/llvm/test/Transforms/InstCombine/icmp.ll +++ b/llvm/test/Transforms/InstCombine/icmp.ll @@ -1876,12 +1876,12 @@ define <2 x i1> @icmp_and_X_-16_ne-16_vec(<2 x i32> %X) { ret <2 x i1> %cmp } +; PR32524: https://bugs.llvm.org/show_bug.cgi?id=32524 ; X | C == C --> X <=u C (when C+1 is PowerOf2). define i1 @or1_eq1(i32 %x) { ; CHECK-LABEL: @or1_eq1( -; CHECK-NEXT: [[T0:%.*]] = or i32 %x, 1 -; CHECK-NEXT: [[T1:%.*]] = icmp eq i32 [[T0]], 1 +; CHECK-NEXT: [[T1:%.*]] = icmp ult i32 %x, 2 ; CHECK-NEXT: ret i1 [[T1]] ; %t0 = or i32 %x, 1 @@ -1893,8 +1893,7 @@ define i1 @or1_eq1(i32 %x) { define <2 x i1> @or3_eq3_vec(<2 x i8> %x) { ; CHECK-LABEL: @or3_eq3_vec( -; CHECK-NEXT: [[T0:%.*]] = or <2 x i8> %x, -; CHECK-NEXT: [[T1:%.*]] = icmp eq <2 x i8> [[T0]], +; CHECK-NEXT: [[T1:%.*]] = icmp ult <2 x i8> %x, ; CHECK-NEXT: ret <2 x i1> [[T1]] ; %t0 = or <2 x i8> %x, @@ -1906,8 +1905,7 @@ define <2 x i1> @or3_eq3_vec(<2 x i8> %x) { define i1 @or7_ne7(i32 %x) { ; CHECK-LABEL: @or7_ne7( -; CHECK-NEXT: [[T0:%.*]] = or i32 %x, 7 -; CHECK-NEXT: [[T1:%.*]] = icmp ne i32 [[T0]], 7 +; CHECK-NEXT: [[T1:%.*]] = icmp ugt i32 %x, 7 ; CHECK-NEXT: ret i1 [[T1]] ; %t0 = or i32 %x, 7 @@ -1919,8 +1917,7 @@ define i1 @or7_ne7(i32 %x) { define <2 x i1> @or63_ne63_vec(<2 x i8> %x) { ; CHECK-LABEL: @or63_ne63_vec( -; CHECK-NEXT: [[T0:%.*]] = or <2 x i8> %x, -; CHECK-NEXT: [[T1:%.*]] = icmp ne <2 x i8> [[T0]], +; CHECK-NEXT: [[T1:%.*]] = icmp ugt <2 x i8> %x, ; CHECK-NEXT: ret <2 x i1> [[T1]] ; %t0 = or <2 x i8> %x,