Author: baldrick
Date: Wed Dec 19 15:13:37 2007
New Revision: 45218
URL: http://llvm.org/viewvc/llvm-project?rev=45218&view=rev
Log:
When inlining through an 'nounwind' call, mark inlined
calls 'nounwind'. It is important for correct C++
exception handling that nounwind markings do not get
lost, so this transformation is actually needed for
correctness.
Added:
llvm/trunk/test/Transforms/Inline/2007-12-19-InlineNoUnwind.ll
Modified:
llvm/trunk/include/llvm/Instructions.h
llvm/trunk/include/llvm/ParameterAttributes.h
llvm/trunk/include/llvm/Support/CallSite.h
llvm/trunk/lib/Transforms/IPO/PruneEH.cpp
llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
llvm/trunk/lib/VMCore/Function.cpp
llvm/trunk/lib/VMCore/Instructions.cpp
Modified: llvm/trunk/include/llvm/Instructions.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Instructions.h?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Instructions.h (original)
+++ llvm/trunk/include/llvm/Instructions.h Wed Dec 19 15:13:37 2007
@@ -948,6 +948,7 @@
bool doesNotThrow() const {
return paramHasAttr(0, ParamAttr::NoUnwind);
}
+ void setDoesNotThrow(bool doesNotThrow = true);
/// @brief Determine if the call returns a structure.
bool isStructReturn() const {
@@ -1752,6 +1753,7 @@
bool doesNotThrow() const {
return paramHasAttr(0, ParamAttr::NoUnwind);
}
+ void setDoesNotThrow(bool doesNotThrow = true);
/// @brief Determine if the call returns a structure.
bool isStructReturn() const {
Modified: llvm/trunk/include/llvm/ParameterAttributes.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ParameterAttributes.h?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ParameterAttributes.h (original)
+++ llvm/trunk/include/llvm/ParameterAttributes.h Wed Dec 19 15:13:37 2007
@@ -149,6 +149,14 @@
static const ParamAttrsList *getModified(const ParamAttrsList *PAL,
const ParamAttrsVector &modVec);
+ /// @brief Add the specified attributes to those in PAL at index idx.
+ static const ParamAttrsList *includeAttrs(const ParamAttrsList *PAL,
+ uint16_t idx, uint16_t attrs);
+
+ /// @brief Remove the specified attributes from those in PAL at index idx.
+ static const ParamAttrsList *excludeAttrs(const ParamAttrsList *PAL,
+ uint16_t idx, uint16_t attrs);
+
/// 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.
Modified: llvm/trunk/include/llvm/Support/CallSite.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/CallSite.h?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/CallSite.h (original)
+++ llvm/trunk/include/llvm/Support/CallSite.h Wed Dec 19 15:13:37 2007
@@ -75,6 +75,7 @@
/// @brief Determine if the call cannot unwind.
bool doesNotThrow() const;
+ void setDoesNotThrow(bool doesNotThrow = true);
/// getType - Return the type of the instruction that generated this call
site
///
Modified: llvm/trunk/lib/Transforms/IPO/PruneEH.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/PruneEH.cpp?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/PruneEH.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/PruneEH.cpp Wed Dec 19 15:13:37 2007
@@ -122,17 +122,15 @@
// If the SCC doesn't unwind or doesn't throw, note this fact.
if (!SCCMightUnwind || !SCCMightReturn)
for (unsigned i = 0, e = SCC.size(); i != e; ++i) {
- const ParamAttrsList *PAL = SCC[i]->getFunction()->getParamAttrs();
- uint16_t RAttributes = PAL ? PAL->getParamAttrs(0) : 0;
+ uint16_t NewAttributes = ParamAttr::None;
if (!SCCMightUnwind)
- RAttributes |= ParamAttr::NoUnwind;
+ NewAttributes |= ParamAttr::NoUnwind;
if (!SCCMightReturn)
- RAttributes |= ParamAttr::NoReturn;
+ NewAttributes |= ParamAttr::NoReturn;
- ParamAttrsVector modVec;
- modVec.push_back(ParamAttrsWithIndex::get(0, RAttributes));
- PAL = ParamAttrsList::getModified(PAL, modVec);
+ const ParamAttrsList *PAL = SCC[i]->getFunction()->getParamAttrs();
+ PAL = ParamAttrsList::includeAttrs(PAL, 0, NewAttributes);
SCC[i]->getFunction()->setParamAttrs(PAL);
}
Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Wed Dec 19
15:13:37 2007
@@ -8026,16 +8026,9 @@
}
}
- if (isa<InlineAsm>(Callee) && !CS.paramHasAttr(0, ParamAttr::NoUnwind)) {
+ if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) {
// Inline asm calls cannot throw - mark them 'nounwind'.
- const ParamAttrsList *PAL = CS.getParamAttrs();
- uint16_t RAttributes = PAL ? PAL->getParamAttrs(0) : 0;
- RAttributes |= ParamAttr::NoUnwind;
-
- ParamAttrsVector modVec;
- modVec.push_back(ParamAttrsWithIndex::get(0, RAttributes));
- PAL = ParamAttrsList::getModified(PAL, modVec);
- CS.setParamAttrs(PAL);
+ CS.setDoesNotThrow();
Changed = true;
}
Modified: llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/InlineFunction.cpp Wed Dec 19 15:13:37 2007
@@ -194,6 +194,10 @@
bool MustClearTailCallFlags =
isa<CallInst>(TheCall) && !cast<CallInst>(TheCall)->isTailCall();
+ // If the call to the callee cannot throw, set the 'nounwind' flag on any
+ // calls that we inline.
+ bool MarkNoUnwind = CS.doesNotThrow();
+
BasicBlock *OrigBB = TheCall->getParent();
Function *Caller = OrigBB->getParent();
@@ -207,7 +211,7 @@
std::vector<ReturnInst*> Returns;
ClonedCodeInfo InlinedFunctionInfo;
Function::iterator FirstNewBlock;
-
+
{ // Scope to destroy ValueMap after cloning.
DenseMap<const Value*, Value*> ValueMap;
@@ -323,15 +327,33 @@
// If we are inlining tail call instruction through a call site that isn't
// marked 'tail', we must remove the tail marker for any calls in the inlined
- // code.
- if (MustClearTailCallFlags && InlinedFunctionInfo.ContainsCalls) {
+ // code. Also, calls inlined through a 'nounwind' call site should be marked
+ // 'nounwind'.
+ if (InlinedFunctionInfo.ContainsCalls &&
+ (MustClearTailCallFlags || MarkNoUnwind)) {
for (Function::iterator BB = FirstNewBlock, E = Caller->end();
BB != E; ++BB)
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- if (CallInst *CI = dyn_cast<CallInst>(I))
- CI->setTailCall(false);
+ if (CallInst *CI = dyn_cast<CallInst>(I)) {
+ if (MustClearTailCallFlags)
+ CI->setTailCall(false);
+ if (MarkNoUnwind)
+ CI->setDoesNotThrow();
+ }
}
+ // If we are inlining through a 'nounwind' call site then any inlined
'unwind'
+ // instructions are unreachable.
+ if (InlinedFunctionInfo.ContainsUnwinds && MarkNoUnwind)
+ for (Function::iterator BB = FirstNewBlock, E = Caller->end();
+ BB != E; ++BB) {
+ TerminatorInst *Term = BB->getTerminator();
+ if (isa<UnwindInst>(Term)) {
+ new UnreachableInst(Term);
+ BB->getInstList().erase(Term);
+ }
+ }
+
// If we are inlining for an invoke instruction, we must make sure to rewrite
// any inlined 'unwind' instructions into branches to the invoke exception
// destination, and call instructions into invoke instructions.
Modified: llvm/trunk/lib/VMCore/Function.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Function.cpp?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/Function.cpp (original)
+++ llvm/trunk/lib/VMCore/Function.cpp Wed Dec 19 15:13:37 2007
@@ -261,6 +261,32 @@
return get(newVec);
}
+const ParamAttrsList *
+ParamAttrsList::includeAttrs(const ParamAttrsList *PAL,
+ uint16_t idx, uint16_t attrs) {
+ uint16_t OldAttrs = PAL ? PAL->getParamAttrs(idx) : 0;
+ uint16_t NewAttrs = OldAttrs | attrs;
+ if (NewAttrs == OldAttrs)
+ return PAL;
+
+ ParamAttrsVector modVec;
+ modVec.push_back(ParamAttrsWithIndex::get(idx, NewAttrs));
+ return getModified(PAL, modVec);
+}
+
+const ParamAttrsList *
+ParamAttrsList::excludeAttrs(const ParamAttrsList *PAL,
+ uint16_t idx, uint16_t attrs) {
+ uint16_t OldAttrs = PAL ? PAL->getParamAttrs(idx) : 0;
+ uint16_t NewAttrs = OldAttrs & ~attrs;
+ if (NewAttrs == OldAttrs)
+ return PAL;
+
+ ParamAttrsVector modVec;
+ modVec.push_back(ParamAttrsWithIndex::get(idx, NewAttrs));
+ return getModified(PAL, modVec);
+}
+
ParamAttrsList::~ParamAttrsList() {
ParamAttrsLists->RemoveNode(this);
}
Modified: llvm/trunk/lib/VMCore/Instructions.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/Instructions.cpp?rev=45218&r1=45217&r2=45218&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/Instructions.cpp (original)
+++ llvm/trunk/lib/VMCore/Instructions.cpp Wed Dec 19 15:13:37 2007
@@ -71,6 +71,12 @@
else
return cast<InvokeInst>(I)->doesNotThrow();
}
+void CallSite::setDoesNotThrow(bool doesNotThrow) {
+ if (CallInst *CI = dyn_cast<CallInst>(I))
+ CI->setDoesNotThrow(doesNotThrow);
+ else
+ cast<InvokeInst>(I)->setDoesNotThrow(doesNotThrow);
+}
//===----------------------------------------------------------------------===//
// TerminatorInst Class
@@ -405,6 +411,15 @@
return false;
}
+void CallInst::setDoesNotThrow(bool doesNotThrow) {
+ const ParamAttrsList *PAL = getParamAttrs();
+ if (doesNotThrow)
+ PAL = ParamAttrsList::includeAttrs(PAL, 0, ParamAttr::NoUnwind);
+ else
+ PAL = ParamAttrsList::excludeAttrs(PAL, 0, ParamAttr::NoUnwind);
+ setParamAttrs(PAL);
+}
+
//===----------------------------------------------------------------------===//
// InvokeInst Implementation
@@ -483,6 +498,15 @@
return false;
}
+void InvokeInst::setDoesNotThrow(bool doesNotThrow) {
+ const ParamAttrsList *PAL = getParamAttrs();
+ if (doesNotThrow)
+ PAL = ParamAttrsList::includeAttrs(PAL, 0, ParamAttr::NoUnwind);
+ else
+ PAL = ParamAttrsList::excludeAttrs(PAL, 0, ParamAttr::NoUnwind);
+ setParamAttrs(PAL);
+}
+
//===----------------------------------------------------------------------===//
// ReturnInst Implementation
Added: llvm/trunk/test/Transforms/Inline/2007-12-19-InlineNoUnwind.ll
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/2007-12-19-InlineNoUnwind.ll?rev=45218&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Inline/2007-12-19-InlineNoUnwind.ll (added)
+++ llvm/trunk/test/Transforms/Inline/2007-12-19-InlineNoUnwind.ll Wed Dec 19
15:13:37 2007
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s -o - | opt -inline | llvm-dis | grep nounwind
+; RUN: llvm-as < %s -o - | opt -inline | llvm-dis | grep unreachable
+
+declare i1 @extern()
+
+define internal i32 @test() {
+entry:
+ %n = call i1 @extern( )
+ br i1 %n, label %r, label %u
+r:
+ ret i32 0;
+u:
+ unwind
+}
+
+define i32 @caller() {
+ %X = call i32 @test( ) nounwind
+ ret i32 %X
+}
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