diff --git a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp index 1eb7e481d43cd..37f720ec40f4e 100644 --- a/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp +++ b/llvm/lib/Transforms/Scalar/ConstraintElimination.cpp @@ -451,6 +451,19 @@ static Decomposition decompose(Value *V, return ResA; }; + Type *Ty = V->getType()->getScalarType(); + if (Ty->isPointerTy() && !IsSigned) { + if (auto *GEP = dyn_cast(V)) + return decomposeGEP(*GEP, Preconditions, IsSigned, DL); + return V; + } + + // Don't handle integers > 64 bit. Our coefficients are 64-bit large, so + // coefficient add/mul may wrap, while the operation in the full bit width + // would not. + if (!Ty->isIntegerTy() || Ty->getIntegerBitWidth() > 64) + return V; + // Decompose \p V used with a signed predicate. if (IsSigned) { if (auto *CI = dyn_cast(V)) { @@ -478,9 +491,6 @@ static Decomposition decompose(Value *V, return int64_t(CI->getZExtValue()); } - if (auto *GEP = dyn_cast(V)) - return decomposeGEP(*GEP, Preconditions, IsSigned, DL); - Value *Op0; bool IsKnownNonNegative = false; if (match(V, m_ZExt(m_Value(Op0)))) { diff --git a/llvm/test/Transforms/ConstraintElimination/large-constant-ints.ll b/llvm/test/Transforms/ConstraintElimination/large-constant-ints.ll index 6b616aa700330..9568b155af13a 100644 --- a/llvm/test/Transforms/ConstraintElimination/large-constant-ints.ll +++ b/llvm/test/Transforms/ConstraintElimination/large-constant-ints.ll @@ -96,6 +96,7 @@ else: ret i1 false } +; TODO: This could be folded. define i1 @sub_decomp_i80(i80 %a) { ; CHECK-LABEL: @sub_decomp_i80( ; CHECK-NEXT: entry: @@ -104,7 +105,8 @@ define i1 @sub_decomp_i80(i80 %a) { ; CHECK-NEXT: br i1 [[C]], label [[THEN:%.*]], label [[ELSE:%.*]] ; CHECK: then: ; CHECK-NEXT: [[SUB_1:%.*]] = sub nuw i80 [[A]], 1973801615886922022913 -; CHECK-NEXT: ret i1 true +; CHECK-NEXT: [[C_1:%.*]] = icmp ult i80 [[SUB_1]], 1346612317380797267967 +; CHECK-NEXT: ret i1 [[C_1]] ; CHECK: else: ; CHECK-NEXT: ret i1 false ; @@ -418,12 +420,12 @@ entry: ret i1 %res } -; FIXME: This is a miscompile. define i1 @pr68751(i128 %arg) { ; CHECK-LABEL: @pr68751( ; CHECK-NEXT: [[SHL1:%.*]] = shl nuw nsw i128 [[ARG:%.*]], 32 ; CHECK-NEXT: [[SHL2:%.*]] = shl nuw nsw i128 [[SHL1]], 32 -; CHECK-NEXT: ret i1 true +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i128 [[SHL2]], 0 +; CHECK-NEXT: ret i1 [[CMP]] ; %shl1 = shl nuw nsw i128 %arg, 32 %shl2 = shl nuw nsw i128 %shl1, 32 diff --git a/llvm/test/Transforms/ConstraintElimination/shl.ll b/llvm/test/Transforms/ConstraintElimination/shl.ll index 982e0e7458333..9f98a9d3a57ca 100644 --- a/llvm/test/Transforms/ConstraintElimination/shl.ll +++ b/llvm/test/Transforms/ConstraintElimination/shl.ll @@ -1277,7 +1277,8 @@ define i1 @shl_55() { ; CHECK-LABEL: @shl_55( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[SHL_UB:%.*]] = shl nuw nsw i256 1, 55 -; CHECK-NEXT: ret i1 true +; CHECK-NEXT: [[SHL_CMP:%.*]] = icmp uge i256 [[SHL_UB]], 1 +; CHECK-NEXT: ret i1 [[SHL_CMP]] ; entry: %shl.ub = shl nuw nsw i256 1, 55