diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -5167,6 +5167,7 @@ return WillIncrement ? !C->isMaxValue(IsSigned) : !C->isMinValue(IsSigned); }; + Constant *SafeReplacementConstant = nullptr; if (auto *CI = dyn_cast(C)) { // Bail out if the constant can't be safely incremented/decremented. if (!ConstantIsOk(CI)) @@ -5186,12 +5187,23 @@ auto *CI = dyn_cast(Elt); if (!CI || !ConstantIsOk(CI)) return llvm::None; + + if (!SafeReplacementConstant) + SafeReplacementConstant = 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 safe constant + // that we found. + if (C->containsUndefElement()) { + assert(SafeReplacementConstant && "Replacement constant not set"); + C = Constant::replaceUndefsWith(C, SafeReplacementConstant); + } + CmpInst::Predicate NewPred = CmpInst::getFlippedStrictnessPredicate(Pred); // Increment or decrement the constant. diff --git a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-eq-to-icmp-ule.ll b/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-eq-to-icmp-ule.ll --- a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-eq-to-icmp-ule.ll +++ b/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, diff --git a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sge-to-icmp-sle.ll b/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sge-to-icmp-sle.ll --- a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sge-to-icmp-sle.ll +++ b/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, diff --git a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sle-to-icmp-sle.ll b/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sle-to-icmp-sle.ll --- a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-sle-to-icmp-sle.ll +++ b/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() diff --git a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-uge-to-icmp-ule.ll b/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-uge-to-icmp-ule.ll --- a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-uge-to-icmp-ule.ll +++ b/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, diff --git a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ule-to-icmp-ule.ll b/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ule-to-icmp-ule.ll --- a/llvm/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ule-to-icmp-ule.ll +++ b/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() diff --git a/llvm/test/Transforms/InstCombine/icmp-vec.ll b/llvm/test/Transforms/InstCombine/icmp-vec.ll --- a/llvm/test/Transforms/InstCombine/icmp-vec.ll +++ b/llvm/test/Transforms/InstCombine/icmp-vec.ll @@ -181,7 +181,7 @@ define <3 x i1> @PR27756_2(<3 x i8> %a) { ; CHECK-LABEL: @PR27756_2( -; CHECK-NEXT: [[CMP:%.*]] = icmp slt <3 x i8> [[A:%.*]], +; CHECK-NEXT: [[CMP:%.*]] = icmp slt <3 x i8> [[A:%.*]], ; CHECK-NEXT: ret <3 x i1> [[CMP]] ; %cmp = icmp sle <3 x i8> %a, @@ -190,7 +190,7 @@ define <3 x i1> @PR27756_3(<3 x i8> %a) { ; CHECK-LABEL: @PR27756_3( -; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <3 x i8> [[A:%.*]], +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <3 x i8> [[A:%.*]], ; CHECK-NEXT: ret <3 x i1> [[CMP]] ; %cmp = icmp sge <3 x i8> %a, diff --git a/llvm/test/Transforms/InstCombine/reuse-constant-from-select-in-icmp.ll b/llvm/test/Transforms/InstCombine/reuse-constant-from-select-in-icmp.ll --- a/llvm/test/Transforms/InstCombine/reuse-constant-from-select-in-icmp.ll +++ b/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]] ;