[cfe-commits] r70983 - in /cfe/branches/Apple/Dib: lib/CodeGen/CodeGenModule.cpp test/CodeGen/function-attributes.c test/CodeGen/functions.c
Mike Stump
mrs at apple.com
Tue May 5 10:25:14 PDT 2009
Author: mrs
Date: Tue May 5 12:25:09 2009
New Revision: 70983
URL: http://llvm.org/viewvc/llvm-project?rev=70983&view=rev
Log:
Merge in 70971:
When defining a function whose type has no prototype, make an effort
to go back and clean up existing uses of the bitcasted function. This
is not just an optimization: it is required for correctness to get
always inline functions to work, see testcases in function-attributes.c.
Modified:
cfe/branches/Apple/Dib/lib/CodeGen/CodeGenModule.cpp
cfe/branches/Apple/Dib/test/CodeGen/function-attributes.c
cfe/branches/Apple/Dib/test/CodeGen/functions.c
Modified: cfe/branches/Apple/Dib/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/Apple/Dib/lib/CodeGen/CodeGenModule.cpp?rev=70983&r1=70982&r2=70983&view=diff
==============================================================================
--- cfe/branches/Apple/Dib/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/branches/Apple/Dib/lib/CodeGen/CodeGenModule.cpp Tue May 5 12:25:09 2009
@@ -834,6 +834,69 @@
}
}
+/// ReplaceUsesOfNonProtoTypeWithRealFunction - This function is called when we
+/// implement a function with no prototype, e.g. "int foo() {}". If there are
+/// existing call uses of the old function in the module, this adjusts them to
+/// call the new function directly.
+///
+/// This is not just a cleanup: the always_inline pass requires direct calls to
+/// functions to be able to inline them. If there is a bitcast in the way, it
+/// won't inline them. Instcombine normally deletes these calls, but it isn't
+/// run at -O0.
+static void ReplaceUsesOfNonProtoTypeWithRealFunction(llvm::GlobalValue *Old,
+ llvm::Function *NewFn) {
+ // If we're redefining a global as a function, don't transform it.
+ llvm::Function *OldFn = dyn_cast<llvm::Function>(Old);
+ if (OldFn == 0) return;
+
+ const llvm::Type *NewRetTy = NewFn->getReturnType();
+ llvm::SmallVector<llvm::Value*, 4> ArgList;
+
+ for (llvm::Value::use_iterator UI = OldFn->use_begin(), E = OldFn->use_end();
+ UI != E; ) {
+ // TODO: Do invokes ever occur in C code? If so, we should handle them too.
+ llvm::CallInst *CI = dyn_cast<llvm::CallInst>(*UI++);
+ if (!CI) continue;
+
+ // If the return types don't match exactly, and if the call isn't dead, then
+ // we can't transform this call.
+ if (CI->getType() != NewRetTy && !CI->use_empty())
+ continue;
+
+ // If the function was passed too few arguments, don't transform. If extra
+ // arguments were passed, we silently drop them. If any of the types
+ // mismatch, we don't transform.
+ unsigned ArgNo = 0;
+ bool DontTransform = false;
+ for (llvm::Function::arg_iterator AI = NewFn->arg_begin(),
+ E = NewFn->arg_end(); AI != E; ++AI, ++ArgNo) {
+ if (CI->getNumOperands()-1 == ArgNo ||
+ CI->getOperand(ArgNo+1)->getType() != AI->getType()) {
+ DontTransform = true;
+ break;
+ }
+ }
+ if (DontTransform)
+ continue;
+
+ // Okay, we can transform this. Create the new call instruction and copy
+ // over the required information.
+ ArgList.append(CI->op_begin()+1, CI->op_begin()+1+ArgNo);
+ llvm::CallInst *NewCall = llvm::CallInst::Create(NewFn, ArgList.begin(),
+ ArgList.end(), "", CI);
+ ArgList.clear();
+ if (NewCall->getType() != llvm::Type::VoidTy)
+ NewCall->takeName(CI);
+ NewCall->setCallingConv(CI->getCallingConv());
+ NewCall->setAttributes(CI->getAttributes());
+
+ // Finally, remove the old call, replacing any uses with the new one.
+ if (!CI->use_empty())
+ CI->replaceAllUsesWith(NewCall);
+ CI->eraseFromParent();
+ }
+}
+
void CodeGenModule::EmitGlobalFunctionDefinition(const FunctionDecl *D) {
const llvm::FunctionType *Ty;
@@ -869,8 +932,10 @@
if (cast<llvm::GlobalValue>(Entry)->getType()->getElementType() != Ty) {
+ llvm::GlobalValue *OldFn = cast<llvm::GlobalValue>(Entry);
+
// If the types mismatch then we have to rewrite the definition.
- assert(cast<llvm::GlobalValue>(Entry)->isDeclaration() &&
+ assert(OldFn->isDeclaration() &&
"Shouldn't replace non-declaration");
// F is the Function* for the one with the wrong type, we must make a new
@@ -883,15 +948,23 @@
// correct type, RAUW, then steal the name.
GlobalDeclMap.erase(getMangledName(D));
llvm::Function *NewFn = cast<llvm::Function>(GetAddrOfFunction(D, Ty));
- NewFn->takeName(cast<llvm::GlobalValue>(Entry));
+ NewFn->takeName(OldFn);
+
+ // If this is an implementation of a function without a prototype, try to
+ // replace any existing uses of the function (which may be calls) with uses
+ // of the new function
+ if (D->getType()->isFunctionNoProtoType())
+ ReplaceUsesOfNonProtoTypeWithRealFunction(OldFn, NewFn);
// Replace uses of F with the Function we will endow with a body.
- llvm::Constant *NewPtrForOldDecl =
- llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
- Entry->replaceAllUsesWith(NewPtrForOldDecl);
+ if (!Entry->use_empty()) {
+ llvm::Constant *NewPtrForOldDecl =
+ llvm::ConstantExpr::getBitCast(NewFn, Entry->getType());
+ Entry->replaceAllUsesWith(NewPtrForOldDecl);
+ }
// Ok, delete the old function now, which is dead.
- cast<llvm::GlobalValue>(Entry)->eraseFromParent();
+ OldFn->eraseFromParent();
Entry = NewFn;
}
Modified: cfe/branches/Apple/Dib/test/CodeGen/function-attributes.c
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/Apple/Dib/test/CodeGen/function-attributes.c?rev=70983&r1=70982&r2=70983&view=diff
==============================================================================
--- cfe/branches/Apple/Dib/test/CodeGen/function-attributes.c (original)
+++ cfe/branches/Apple/Dib/test/CodeGen/function-attributes.c Tue May 5 12:25:09 2009
@@ -47,4 +47,23 @@
void f13(void) __attribute__((pure)) __attribute__((const));
void f13(void){}
+
+// Ensure that these get inlined: rdar://6853279
+// RUN: not grep '@ai_' %t &&
+static __inline__ __attribute__((always_inline))
+int ai_1() { return 4; }
+
+static __inline__ __attribute__((always_inline))
+struct {
+ int a, b, c, d, e;
+} ai_2() { }
+
+
+int foo() {
+ ai_2();
+ return ai_1();
+}
+
+
+
// RUN: true
Modified: cfe/branches/Apple/Dib/test/CodeGen/functions.c
URL: http://llvm.org/viewvc/llvm-project/cfe/branches/Apple/Dib/test/CodeGen/functions.c?rev=70983&r1=70982&r2=70983&view=diff
==============================================================================
--- cfe/branches/Apple/Dib/test/CodeGen/functions.c (original)
+++ cfe/branches/Apple/Dib/test/CodeGen/functions.c Tue May 5 12:25:09 2009
@@ -23,7 +23,7 @@
void f0() {}
void f1();
-// RUN: grep 'call void (...)\* bitcast (void ()\* @f1' %t &&
+// RUN: grep 'call void @f1()' %t &&
void f2(void) {
f1(1, 2, 3);
}
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