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Print struct return functions and calls as actually returning the hidden

argument struct pointer, enabling ABI compatibility for the CBE with
platforms with strange struct-return ABIs.  This fixes 252.eon and
CoyoteBench/fftbench on Darwin/X86 among other things.

llvm-svn: 28442
This commit is contained in:
Chris Lattner 2006-05-23 23:39:48 +00:00
parent ac9665d682
commit 2ce3eb8210

View File

@ -13,6 +13,7 @@
//===----------------------------------------------------------------------===//
#include "CTargetMachine.h"
#include "llvm/CallingConv.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Module.h"
@ -115,6 +116,9 @@ namespace {
const std::string &VariableName = "",
bool IgnoreName = false);
void printStructReturnPointerFunctionType(std::ostream &Out,
const PointerType *Ty);
void writeOperand(Value *Operand);
void writeOperandInternal(Value *Operand);
@ -298,6 +302,35 @@ bool CBackendNameAllUsedStructsAndMergeFunctions::runOnModule(Module &M) {
return Changed;
}
/// printStructReturnPointerFunctionType - This is like printType for a struct
/// return type, except, instead of printing the type as void (*)(Struct*, ...)
/// print it as "Struct (*)(...)", for struct return functions.
void CWriter::printStructReturnPointerFunctionType(std::ostream &Out,
const PointerType *TheTy) {
const FunctionType *FTy = cast<FunctionType>(TheTy->getElementType());
std::stringstream FunctionInnards;
FunctionInnards << " (*) (";
bool PrintedType = false;
FunctionType::param_iterator I = FTy->param_begin(), E = FTy->param_end();
const Type *RetTy = cast<PointerType>(I->get())->getElementType();
for (++I; I != E; ++I) {
if (PrintedType)
FunctionInnards << ", ";
printType(FunctionInnards, *I, "");
PrintedType = true;
}
if (FTy->isVarArg()) {
if (PrintedType)
FunctionInnards << ", ...";
} else if (!PrintedType) {
FunctionInnards << "void";
}
FunctionInnards << ')';
std::string tstr = FunctionInnards.str();
printType(Out, RetTy, tstr);
}
// Pass the Type* and the variable name and this prints out the variable
// declaration.
@ -332,24 +365,24 @@ std::ostream &CWriter::printType(std::ostream &Out, const Type *Ty,
switch (Ty->getTypeID()) {
case Type::FunctionTyID: {
const FunctionType *MTy = cast<FunctionType>(Ty);
const FunctionType *FTy = cast<FunctionType>(Ty);
std::stringstream FunctionInnards;
FunctionInnards << " (" << NameSoFar << ") (";
for (FunctionType::param_iterator I = MTy->param_begin(),
E = MTy->param_end(); I != E; ++I) {
if (I != MTy->param_begin())
for (FunctionType::param_iterator I = FTy->param_begin(),
E = FTy->param_end(); I != E; ++I) {
if (I != FTy->param_begin())
FunctionInnards << ", ";
printType(FunctionInnards, *I, "");
}
if (MTy->isVarArg()) {
if (MTy->getNumParams())
if (FTy->isVarArg()) {
if (FTy->getNumParams())
FunctionInnards << ", ...";
} else if (!MTy->getNumParams()) {
} else if (!FTy->getNumParams()) {
FunctionInnards << "void";
}
FunctionInnards << ')';
std::string tstr = FunctionInnards.str();
printType(Out, MTy->getReturnType(), tstr);
printType(Out, FTy->getReturnType(), tstr);
return Out;
}
case Type::StructTyID: {
@ -1223,6 +1256,9 @@ void CWriter::printContainedStructs(const Type *Ty,
}
void CWriter::printFunctionSignature(const Function *F, bool Prototype) {
/// isCStructReturn - Should this function actually return a struct by-value?
bool isCStructReturn = F->getCallingConv() == CallingConv::CSRet;
if (F->hasInternalLinkage()) Out << "static ";
// Loop over the arguments, printing them...
@ -1233,55 +1269,97 @@ void CWriter::printFunctionSignature(const Function *F, bool Prototype) {
// Print out the name...
FunctionInnards << Mang->getValueName(F) << '(';
bool PrintedArg = false;
if (!F->isExternal()) {
if (!F->arg_empty()) {
Function::const_arg_iterator I = F->arg_begin(), E = F->arg_end();
// If this is a struct-return function, don't print the hidden
// struct-return argument.
if (isCStructReturn) {
assert(I != E && "Invalid struct return function!");
++I;
}
std::string ArgName;
if (F->arg_begin()->hasName() || !Prototype)
ArgName = Mang->getValueName(F->arg_begin());
printType(FunctionInnards, F->arg_begin()->getType(), ArgName);
for (Function::const_arg_iterator I = ++F->arg_begin(), E = F->arg_end();
I != E; ++I) {
FunctionInnards << ", ";
for (; I != E; ++I) {
if (PrintedArg) FunctionInnards << ", ";
if (I->hasName() || !Prototype)
ArgName = Mang->getValueName(I);
else
ArgName = "";
printType(FunctionInnards, I->getType(), ArgName);
PrintedArg = true;
}
}
} else {
// Loop over the arguments, printing them...
for (FunctionType::param_iterator I = FT->param_begin(),
E = FT->param_end(); I != E; ++I) {
if (I != FT->param_begin()) FunctionInnards << ", ";
// Loop over the arguments, printing them.
FunctionType::param_iterator I = FT->param_begin(), E = FT->param_end();
// If this is a struct-return function, don't print the hidden
// struct-return argument.
if (isCStructReturn) {
assert(I != E && "Invalid struct return function!");
++I;
}
for (; I != E; ++I) {
if (PrintedArg) FunctionInnards << ", ";
printType(FunctionInnards, *I);
PrintedArg = true;
}
}
// Finish printing arguments... if this is a vararg function, print the ...,
// unless there are no known types, in which case, we just emit ().
//
if (FT->isVarArg() && FT->getNumParams()) {
if (FT->getNumParams()) FunctionInnards << ", ";
if (FT->isVarArg() && PrintedArg) {
if (PrintedArg) FunctionInnards << ", ";
FunctionInnards << "..."; // Output varargs portion of signature!
} else if (!FT->isVarArg() && FT->getNumParams() == 0) {
} else if (!FT->isVarArg() && !PrintedArg) {
FunctionInnards << "void"; // ret() -> ret(void) in C.
}
FunctionInnards << ')';
// Print out the return type and the entire signature for that matter
printType(Out, F->getReturnType(), FunctionInnards.str());
// Get the return tpe for the function.
const Type *RetTy;
if (!isCStructReturn)
RetTy = F->getReturnType();
else {
// If this is a struct-return function, print the struct-return type.
RetTy = cast<PointerType>(FT->getParamType(0))->getElementType();
}
// Print out the return type and the signature built above.
printType(Out, RetTy, FunctionInnards.str());
}
void CWriter::printFunction(Function &F) {
printFunctionSignature(&F, false);
Out << " {\n";
// If this is a struct return function, handle the result with magic.
if (F.getCallingConv() == CallingConv::CSRet) {
const Type *StructTy =
cast<PointerType>(F.arg_begin()->getType())->getElementType();
Out << " ";
printType(Out, StructTy, "StructReturn");
Out << "; /* Struct return temporary */\n";
Out << " ";
printType(Out, F.arg_begin()->getType(), Mang->getValueName(F.arg_begin()));
Out << " = &StructReturn;\n";
}
bool PrintedVar = false;
// print local variable information for the function
for (inst_iterator I = inst_begin(&F), E = inst_end(&F); I != E; ++I)
if (const AllocaInst *AI = isDirectAlloca(&*I)) {
Out << " ";
printType(Out, AI->getAllocatedType(), Mang->getValueName(AI));
Out << "; /* Address-exposed local */\n";
PrintedVar = true;
} else if (I->getType() != Type::VoidTy && !isInlinableInst(*I)) {
Out << " ";
printType(Out, I->getType(), Mang->getValueName(&*I));
@ -1293,8 +1371,10 @@ void CWriter::printFunction(Function &F) {
Mang->getValueName(&*I)+"__PHI_TEMPORARY");
Out << ";\n";
}
PrintedVar = true;
}
if (PrintedVar)
Out << '\n';
if (F.hasExternalLinkage() && F.getName() == "main")
@ -1366,6 +1446,12 @@ void CWriter::printBasicBlock(BasicBlock *BB) {
// necessary because we use the instruction classes as opaque types...
//
void CWriter::visitReturnInst(ReturnInst &I) {
// If this is a struct return function, return the temporary struct.
if (I.getParent()->getParent()->getCallingConv() == CallingConv::CSRet) {
Out << " return StructReturn;\n";
return;
}
// Don't output a void return if this is the last basic block in the function
if (I.getNumOperands() == 0 &&
&*--I.getParent()->getParent()->end() == I.getParent() &&
@ -1729,62 +1815,72 @@ void CWriter::visitCallInst(CallInst &I) {
Value *Callee = I.getCalledValue();
// GCC is really a PITA. It does not permit codegening casts of functions to
// If this is a call to a struct-return function, assign to the first
// parameter instead of passing it to the call.
bool isStructRet = I.getCallingConv() == CallingConv::CSRet;
if (isStructRet) {
Out << "*(";
writeOperand(I.getOperand(1));
Out << ") = ";
}
if (I.isTailCall()) Out << " /*tail*/ ";
const PointerType *PTy = cast<PointerType>(Callee->getType());
const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
if (!WroteCallee) {
// If this is an indirect call to a struct return function, we need to cast
// the pointer.
bool NeedsCast = isStructRet && !isa<Function>(Callee);
// GCC is a real PITA. It does not permit codegening casts of functions to
// function pointers if they are in a call (it generates a trap instruction
// instead!). We work around this by inserting a cast to void* in between the
// function and the function pointer cast. Unfortunately, we can't just form
// the constant expression here, because the folder will immediately nuke it.
// instead!). We work around this by inserting a cast to void* in between
// the function and the function pointer cast. Unfortunately, we can't just
// form the constant expression here, because the folder will immediately
// nuke it.
//
// Note finally, that this is completely unsafe. ANSI C does not guarantee
// that void* and function pointers have the same size. :( To deal with this
// in the common case, we handle casts where the number of arguments passed
// match exactly.
//
if (I.isTailCall()) Out << " /*tail*/ ";
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Callee))
if (CE->getOpcode() == Instruction::Cast)
if (Function *RF = dyn_cast<Function>(CE->getOperand(0))) {
const FunctionType *RFTy = RF->getFunctionType();
if (RFTy->getNumParams() == I.getNumOperands()-1) {
// If the call site expects a value, and the actual callee doesn't
// provide one, return 0.
if (I.getType() != Type::VoidTy &&
RFTy->getReturnType() == Type::VoidTy)
Out << "0 /*actual callee doesn't return value*/; ";
NeedsCast = true;
Callee = RF;
} else {
}
if (NeedsCast) {
// Ok, just cast the pointer type.
Out << "((";
printType(Out, CE->getType());
if (!isStructRet)
printType(Out, I.getCalledValue()->getType());
else
printStructReturnPointerFunctionType(Out,
cast<PointerType>(I.getCalledValue()->getType()));
Out << ")(void*)";
printConstant(RF);
Out << ')';
WroteCallee = true;
}
writeOperand(Callee);
if (NeedsCast) Out << ')';
}
const PointerType *PTy = cast<PointerType>(Callee->getType());
const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
const Type *RetTy = FTy->getReturnType();
if (!WroteCallee) writeOperand(Callee);
Out << '(';
unsigned NumDeclaredParams = FTy->getNumParams();
if (I.getNumOperands() != 1) {
CallSite::arg_iterator AI = I.op_begin()+1, AE = I.op_end();
if (NumDeclaredParams && (*AI)->getType() != FTy->getParamType(0)) {
Out << '(';
printType(Out, FTy->getParamType(0));
Out << ')';
unsigned ArgNo = 0;
if (isStructRet) { // Skip struct return argument.
++AI;
++ArgNo;
}
writeOperand(*AI);
unsigned ArgNo;
for (ArgNo = 1, ++AI; AI != AE; ++AI, ++ArgNo) {
Out << ", ";
bool PrintedArg = false;
for (; AI != AE; ++AI, ++ArgNo) {
if (PrintedArg) Out << ", ";
if (ArgNo < NumDeclaredParams &&
(*AI)->getType() != FTy->getParamType(ArgNo)) {
Out << '(';
@ -1792,7 +1888,7 @@ void CWriter::visitCallInst(CallInst &I) {
Out << ')';
}
writeOperand(*AI);
}
PrintedArg = true;
}
Out << ')';
}