Index: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp =================================================================== --- llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -5167,6 +5167,7 @@ return WillIncrement ? !C->isMaxValue(IsSigned) : !C->isMinValue(IsSigned); }; + Constant *FirstDefinedEltOfVectorConstant; if (auto *CI = dyn_cast(C)) { // Bail out if the constant can't be safely incremented/decremented. if (!ConstantIsOk(CI)) @@ -5186,12 +5187,26 @@ auto *CI = dyn_cast(Elt); if (!CI || !ConstantIsOk(CI)) return llvm::None; + FirstDefinedEltOfVectorConstant = CI; } } else { // ConstantExpr? return llvm::None; } + // It may not be safe to change a compare predicate in the presence of + // undefined elements, so replace those elements with the first valid constant + // that we found. + if (Type->isVectorTy() && C->containsUndefElement()) { + unsigned NumElts = Type->getVectorNumElements(); + SmallVector Out(NumElts); + for (unsigned i = 0; i != NumElts; ++i) { + Constant *EltC = C->getAggregateElement(i); + Out[i] = isa(EltC) ? FirstDefinedEltOfVectorConstant : EltC; + } + C = ConstantVector::get(Out); + } + CmpInst::Predicate NewPred = CmpInst::getFlippedStrictnessPredicate(Pred); // Increment or decrement the constant. Index: llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-eq-to-icmp-ule.ll =================================================================== --- llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-eq-to-icmp-ule.ll +++ llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-eq-to-icmp-ule.ll @@ -82,7 +82,7 @@ define <3 x i1> @p3_vec_splat_undef(<3 x i8> %x) { ; CHECK-LABEL: @p3_vec_splat_undef( -; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <3 x i8> [[X:%.*]], +; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <3 x i8> [[X:%.*]], ; CHECK-NEXT: ret <3 x i1> [[TMP1]] ; %tmp0 = and <3 x i8> %x, Index: llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sge-to-icmp-sle.ll =================================================================== --- llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sge-to-icmp-sle.ll +++ llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sge-to-icmp-sle.ll @@ -61,7 +61,7 @@ define <3 x i1> @p3_vec_splat_undef(<3 x i8> %x) { ; CHECK-LABEL: @p3_vec_splat_undef( -; CHECK-NEXT: [[TMP1:%.*]] = icmp slt <3 x i8> [[X:%.*]], +; CHECK-NEXT: [[TMP1:%.*]] = icmp slt <3 x i8> [[X:%.*]], ; CHECK-NEXT: ret <3 x i1> [[TMP1]] ; %tmp0 = and <3 x i8> %x, Index: llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sle-to-icmp-sle.ll =================================================================== --- llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sle-to-icmp-sle.ll +++ llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sle-to-icmp-sle.ll @@ -76,7 +76,7 @@ define <3 x i1> @p3_vec_splat_undef() { ; CHECK-LABEL: @p3_vec_splat_undef( ; CHECK-NEXT: [[X:%.*]] = call <3 x i8> @gen3x8() -; CHECK-NEXT: [[TMP1:%.*]] = icmp slt <3 x i8> [[X]], +; CHECK-NEXT: [[TMP1:%.*]] = icmp slt <3 x i8> [[X]], ; CHECK-NEXT: ret <3 x i1> [[TMP1]] ; %x = call <3 x i8> @gen3x8() Index: llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-uge-to-icmp-ule.ll =================================================================== --- llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-uge-to-icmp-ule.ll +++ llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-uge-to-icmp-ule.ll @@ -82,7 +82,7 @@ define <3 x i1> @p3_vec_splat_undef(<3 x i8> %x) { ; CHECK-LABEL: @p3_vec_splat_undef( -; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <3 x i8> [[X:%.*]], +; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <3 x i8> [[X:%.*]], ; CHECK-NEXT: ret <3 x i1> [[TMP1]] ; %tmp0 = and <3 x i8> %x, Index: llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ule-to-icmp-ule.ll =================================================================== --- llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ule-to-icmp-ule.ll +++ llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ule-to-icmp-ule.ll @@ -99,7 +99,7 @@ define <3 x i1> @p3_vec_splat_undef() { ; CHECK-LABEL: @p3_vec_splat_undef( ; CHECK-NEXT: [[X:%.*]] = call <3 x i8> @gen3x8() -; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <3 x i8> [[X]], +; CHECK-NEXT: [[TMP1:%.*]] = icmp ult <3 x i8> [[X]], ; CHECK-NEXT: ret <3 x i1> [[TMP1]] ; %x = call <3 x i8> @gen3x8() Index: llvm/test/Transforms/InstCombine/icmp-vec.ll =================================================================== --- llvm/test/Transforms/InstCombine/icmp-vec.ll +++ llvm/test/Transforms/InstCombine/icmp-vec.ll @@ -181,7 +181,7 @@ define <2 x i1> @PR27756_2(<2 x i8> %a) { ; CHECK-LABEL: @PR27756_2( -; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i8> [[A:%.*]], +; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i8> [[A:%.*]], ; CHECK-NEXT: ret <2 x i1> [[CMP]] ; %cmp = icmp sle <2 x i8> %a, Index: llvm/test/Transforms/InstCombine/reuse-constant-from-select-in-icmp.ll =================================================================== --- llvm/test/Transforms/InstCombine/reuse-constant-from-select-in-icmp.ll +++ llvm/test/Transforms/InstCombine/reuse-constant-from-select-in-icmp.ll @@ -106,7 +106,7 @@ define <2 x i32> @p8_vec_nonsplat_undef0(<2 x i32> %x, <2 x i32> %y) { ; CHECK-LABEL: @p8_vec_nonsplat_undef0( -; CHECK-NEXT: [[T_INV:%.*]] = icmp ugt <2 x i32> [[X:%.*]], +; CHECK-NEXT: [[T_INV:%.*]] = icmp ugt <2 x i32> [[X:%.*]], ; CHECK-NEXT: [[R:%.*]] = select <2 x i1> [[T_INV]], <2 x i32> , <2 x i32> [[Y:%.*]] ; CHECK-NEXT: ret <2 x i32> [[R]] ; @@ -126,7 +126,7 @@ } define <2 x i32> @p10_vec_nonsplat_undef2(<2 x i32> %x, <2 x i32> %y) { ; CHECK-LABEL: @p10_vec_nonsplat_undef2( -; CHECK-NEXT: [[T_INV:%.*]] = icmp ugt <2 x i32> [[X:%.*]], +; CHECK-NEXT: [[T_INV:%.*]] = icmp ugt <2 x i32> [[X:%.*]], ; CHECK-NEXT: [[R:%.*]] = select <2 x i1> [[T_INV]], <2 x i32> , <2 x i32> [[Y:%.*]] ; CHECK-NEXT: ret <2 x i32> [[R]] ;