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-rw-r--r--include/llvm/ParameterAttributes.h33
-rw-r--r--lib/Transforms/Scalar/InstructionCombining.cpp9
-rw-r--r--lib/VMCore/Function.cpp45
-rw-r--r--lib/VMCore/Verifier.cpp37
-rw-r--r--test/Transforms/InstCombine/2007-11-25-CompatibleAttributes.ll12
5 files changed, 101 insertions, 35 deletions
diff --git a/include/llvm/ParameterAttributes.h b/include/llvm/ParameterAttributes.h
index 4c48d8707f..1dd98eaa90 100644
--- a/include/llvm/ParameterAttributes.h
+++ b/include/llvm/ParameterAttributes.h
@@ -43,6 +43,34 @@ enum Attributes {
ReadOnly = 1 << 10 ///< Function only reads from memory
};
+/// These attributes can safely be dropped from a function or a function call:
+/// doing so may reduce the number of optimizations performed, but it will not
+/// change a correct program into an incorrect one.
+/// @brief Attributes that do not change the calling convention.
+const uint16_t Informative = NoReturn | NoUnwind | NoAlias |
+ ReadNone | ReadOnly;
+
+/// The following attribute sets are used by the verifier:
+
+/// @brief Attributes that only apply to function parameters.
+const uint16_t ParameterOnly = ByVal | InReg | Nest | StructRet;
+
+/// @brief Attributes that only apply to function return values.
+const uint16_t ReturnOnly = NoReturn | NoUnwind | ReadNone | ReadOnly;
+
+/// @brief Attributes that only apply to integers.
+const uint16_t IntegerTypeOnly = SExt | ZExt;
+
+/// @brief Attributes that only apply to pointers.
+const uint16_t PointerTypeOnly = ByVal | Nest | NoAlias | StructRet;
+
+/// @brief Attributes that are mutually incompatible.
+const uint16_t MutuallyIncompatible[3] = {
+ ByVal | InReg | Nest | StructRet,
+ ZExt | SExt,
+ ReadNone | ReadOnly
+};
+
}
/// This is just a pair of values to associate a set of parameter attributes
@@ -110,6 +138,11 @@ class ParamAttrsList : public FoldingSetNode {
/// @brief Get a ParamAttrsList instance.
static ParamAttrsList *get(const ParamAttrsVector &attrVec);
+ /// Returns whether each of the specified lists of attributes can be safely
+ /// replaced with the other in a function or a function call.
+ /// @brief Whether one attribute list can safely replace the other.
+ static bool areCompatible(const ParamAttrsList *A, const ParamAttrsList *B);
+
/// @}
/// @name Accessors
/// @{
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 5537631eef..85fd2c3bdb 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -7990,11 +7990,12 @@ bool InstCombiner::transformConstExprCastCall(CallSite CS) {
const FunctionType *ActualFT =
cast<FunctionType>(cast<PointerType>(CE->getType())->getElementType());
- // If the parameter attributes don't match up, don't do the xform. We don't
- // want to lose an sret attribute or something.
- if (FT->getParamAttrs() != ActualFT->getParamAttrs())
+ // If the parameter attributes are not compatible, don't do the xform. We
+ // don't want to lose an sret attribute or something.
+ if (!ParamAttrsList::areCompatible(FT->getParamAttrs(),
+ ActualFT->getParamAttrs()))
return false;
-
+
// Check to see if we are changing the return type...
if (OldRetTy != FT->getReturnType()) {
if (Callee->isDeclaration() && !Caller->use_empty() &&
diff --git a/lib/VMCore/Function.cpp b/lib/VMCore/Function.cpp
index 6c29371862..2b83e6b917 100644
--- a/lib/VMCore/Function.cpp
+++ b/lib/VMCore/Function.cpp
@@ -86,7 +86,6 @@ ParamAttrsList::getParamAttrs(uint16_t Index) const {
return ParamAttr::None;
}
-
std::string
ParamAttrsList::getParamAttrsText(uint16_t Attrs) {
std::string Result;
@@ -115,6 +114,50 @@ ParamAttrsList::getParamAttrsText(uint16_t Attrs) {
return Result;
}
+/// onlyInformative - Returns whether only informative attributes are set.
+static inline bool onlyInformative(uint16_t attrs) {
+ return !(attrs & ~ParamAttr::Informative);
+}
+
+bool
+ParamAttrsList::areCompatible(const ParamAttrsList *A, const ParamAttrsList *B){
+ if (A == B)
+ return true;
+ unsigned ASize = A ? A->size() : 0;
+ unsigned BSize = B ? B->size() : 0;
+ unsigned AIndex = 0;
+ unsigned BIndex = 0;
+
+ while (AIndex < ASize && BIndex < BSize) {
+ uint16_t AIdx = A->getParamIndex(AIndex);
+ uint16_t BIdx = B->getParamIndex(BIndex);
+ uint16_t AAttrs = A->getParamAttrsAtIndex(AIndex);
+ uint16_t BAttrs = B->getParamAttrsAtIndex(AIndex);
+
+ if (AIdx < BIdx) {
+ if (!onlyInformative(AAttrs))
+ return false;
+ ++AIndex;
+ } else if (BIdx < AIdx) {
+ if (!onlyInformative(BAttrs))
+ return false;
+ ++BIndex;
+ } else {
+ if (!onlyInformative(AAttrs ^ BAttrs))
+ return false;
+ ++AIndex;
+ ++BIndex;
+ }
+ }
+ for (; AIndex < ASize; ++AIndex)
+ if (!onlyInformative(A->getParamAttrsAtIndex(AIndex)))
+ return false;
+ for (; BIndex < BSize; ++BIndex)
+ if (!onlyInformative(B->getParamAttrsAtIndex(AIndex)))
+ return false;
+ return true;
+}
+
void
ParamAttrsList::Profile(FoldingSetNodeID &ID) const {
for (unsigned i = 0; i < attrs.size(); ++i) {
diff --git a/lib/VMCore/Verifier.cpp b/lib/VMCore/Verifier.cpp
index 1f726afa5d..a547721d68 100644
--- a/lib/VMCore/Verifier.cpp
+++ b/lib/VMCore/Verifier.cpp
@@ -393,30 +393,6 @@ void Verifier::visitFunction(Function &F) {
Assert1(!FT->isStructReturn() || FT->getReturnType() == Type::VoidTy,
"Invalid struct-return function!", &F);
- const uint16_t ReturnIncompatible =
- ParamAttr::ByVal | ParamAttr::InReg |
- ParamAttr::Nest | ParamAttr::StructRet;
-
- const uint16_t ParameterIncompatible =
- ParamAttr::NoReturn | ParamAttr::NoUnwind |
- ParamAttr::ReadNone | ParamAttr::ReadOnly;
-
- const uint16_t MutuallyIncompatible[3] = {
- ParamAttr::ByVal | ParamAttr::InReg |
- ParamAttr::Nest | ParamAttr::StructRet,
-
- ParamAttr::ZExt | ParamAttr::SExt,
-
- ParamAttr::ReadNone | ParamAttr::ReadOnly
- };
-
- const uint16_t IntegerTypeOnly =
- ParamAttr::SExt | ParamAttr::ZExt;
-
- const uint16_t PointerTypeOnly =
- ParamAttr::ByVal | ParamAttr::Nest |
- ParamAttr::NoAlias | ParamAttr::StructRet;
-
bool SawSRet = false;
if (const ParamAttrsList *Attrs = FT->getParamAttrs()) {
@@ -426,28 +402,29 @@ void Verifier::visitFunction(Function &F) {
uint16_t Attr = Attrs->getParamAttrs(Idx);
if (!Idx) {
- uint16_t RetI = Attr & ReturnIncompatible;
+ uint16_t RetI = Attr & ParamAttr::ParameterOnly;
Assert1(!RetI, "Attribute " + Attrs->getParamAttrsText(RetI) +
"should not apply to functions!", &F);
} else {
- uint16_t ParmI = Attr & ParameterIncompatible;
+ uint16_t ParmI = Attr & ParamAttr::ReturnOnly;
Assert1(!ParmI, "Attribute " + Attrs->getParamAttrsText(ParmI) +
"should only be applied to function!", &F);
}
- for (unsigned i = 0; i < array_lengthof(MutuallyIncompatible); ++i) {
- uint16_t MutI = Attr & MutuallyIncompatible[i];
+ for (unsigned i = 0;
+ i < array_lengthof(ParamAttr::MutuallyIncompatible); ++i) {
+ uint16_t MutI = Attr & ParamAttr::MutuallyIncompatible[i];
Assert1(!(MutI & (MutI - 1)), "Attributes " +
Attrs->getParamAttrsText(MutI) + "are incompatible!", &F);
}
- uint16_t IType = Attr & IntegerTypeOnly;
+ uint16_t IType = Attr & ParamAttr::IntegerTypeOnly;
Assert1(!IType || FT->getParamType(Idx-1)->isInteger(),
"Attribute " + Attrs->getParamAttrsText(IType) +
"should only apply to Integer type!", &F);
- uint16_t PType = Attr & PointerTypeOnly;
+ uint16_t PType = Attr & ParamAttr::PointerTypeOnly;
Assert1(!PType || isa<PointerType>(FT->getParamType(Idx-1)),
"Attribute " + Attrs->getParamAttrsText(PType) +
"should only apply to Pointer type!", &F);
diff --git a/test/Transforms/InstCombine/2007-11-25-CompatibleAttributes.ll b/test/Transforms/InstCombine/2007-11-25-CompatibleAttributes.ll
new file mode 100644
index 0000000000..60a4b3b4ab
--- /dev/null
+++ b/test/Transforms/InstCombine/2007-11-25-CompatibleAttributes.ll
@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep bitcast
+; PR1716
+
+@.str = internal constant [4 x i8] c"%d\0A\00" ; <[4 x i8]*> [#uses=1]
+
+define i32 @main(i32 %argc, i8** %argv) {
+entry:
+ %tmp32 = tail call i32 (i8* noalias , ...) nounwind * bitcast (i32 (i8*, ...) nounwind * @printf to i32 (i8* noalias , ...) nounwind *)( i8* getelementptr ([4 x i8]* @.str, i32 0, i32 0) noalias , i32 0 ) nounwind ; <i32> [#uses=0]
+ ret i32 undef
+}
+
+declare i32 @printf(i8*, ...) nounwind
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-13 01:05:49 +0000