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CBackend: Implement unaligned load/store. 

llvm-svn: 46646
This commit is contained in:
Lauro Ramos Venancio 2008-02-01 21:25:59 +00:00
parent 9aa789fda3
commit 192c07b727
2 changed files with 50 additions and 14 deletions
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49
llvm/lib/Target/CBackend/CBackend.cpp
View File

@ -147,6 +147,9 @@ namespace {
void writeOperandWithCast(Value* Operand, const ICmpInst &I);
bool writeInstructionCast(const Instruction &I);
void writeMemoryAccess(Value *Operand, const Type *OperandType,
bool IsVolatile, unsigned Alignment);
private :
std::string InterpretASMConstraint(InlineAsm::ConstraintInfo& c);
@ -2935,29 +2938,47 @@ void CWriter::printIndexingExpression(Value *Ptr, gep_type_iterator I,
}
}
void CWriter::visitLoadInst(LoadInst &I) {
Out << '*';
if (I.isVolatile()) {
void CWriter::writeMemoryAccess(Value *Operand, const Type *OperandType,
bool IsVolatile, unsigned Alignment) {
bool IsUnaligned = Alignment &&
Alignment < TD->getABITypeAlignment(OperandType);
if (!IsUnaligned)
Out << '*';
if (IsVolatile || IsUnaligned) {
Out << "((";
printType(Out, I.getType(), false, "volatile*");
if (IsUnaligned)
Out << "struct __attribute__ ((packed, aligned(" << Alignment << "))) {";
printType(Out, OperandType, false, IsUnaligned ? "data" : "volatile*");
if (IsUnaligned) {
Out << "; } ";
if (IsVolatile) Out << "volatile ";
Out << "*";
}
Out << ")";
}
writeOperand(I.getOperand(0));
writeOperand(Operand);
if (I.isVolatile())
if (IsVolatile || IsUnaligned) {
Out << ')';
if (IsUnaligned)
Out << "->data";
}
}
void CWriter::visitLoadInst(LoadInst &I) {
writeMemoryAccess(I.getOperand(0), I.getType(), I.isVolatile(),
I.getAlignment());
}
void CWriter::visitStoreInst(StoreInst &I) {
Out << '*';
if (I.isVolatile()) {
Out << "((";
printType(Out, I.getOperand(0)->getType(), false, " volatile*");
Out << ")";
}
writeOperand(I.getPointerOperand());
if (I.isVolatile()) Out << ')';
writeMemoryAccess(I.getPointerOperand(), I.getOperand(0)->getType(),
I.isVolatile(), I.getAlignment());
Out << " = ";
Value *Operand = I.getOperand(0);
Constant *BitMask = 0;

15
llvm/test/CodeGen/CBackend/2008-02-01-UnalignedLoadStore.ll Normal file
View File

@ -0,0 +1,15 @@
; RUN: llvm-as < %s | llc -march=c | \
; RUN: grep {struct __attribute__ ((packed, aligned(} | count 4
define void @test(i32* %P) {
%X = load i32* %P, align 1
store i32 %X, i32* %P, align 1
ret void
}
define void @test2(i32* %P) {
%X = volatile load i32* %P, align 2
volatile store i32 %X, i32* %P, align 2
ret void
}