R600: Fix calculation of stack offset in AMDGPUFrameLowering

We weren't computing structure size correctly and we were relying on
the original alloca instruction to compute the offset, which isn't
always reliable.

Reviewed-by: Vincent Lejeune <vljn@ovi.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183568 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Tom Stellard 2013-06-07 20:52:05 +00:00
parent fc61b6f111
commit df74b86e1e
2 changed files with 35 additions and 21 deletions

View File

@ -78,27 +78,8 @@ int AMDGPUFrameLowering::getFrameIndexOffset(const MachineFunction &MF,
int UpperBound = FI == -1 ? MFI->getNumObjects() : FI;
for (int i = MFI->getObjectIndexBegin(); i < UpperBound; ++i) {
const AllocaInst *Alloca = MFI->getObjectAllocation(i);
unsigned ArrayElements;
const Type *AllocaType = Alloca->getAllocatedType();
const Type *ElementType;
if (AllocaType->isArrayTy()) {
ArrayElements = AllocaType->getArrayNumElements();
ElementType = AllocaType->getArrayElementType();
} else {
ArrayElements = 1;
ElementType = AllocaType;
}
unsigned VectorElements;
if (ElementType->isVectorTy()) {
VectorElements = ElementType->getVectorNumElements();
} else {
VectorElements = 1;
}
Offset += (VectorElements / getStackWidth(MF)) * ArrayElements;
unsigned Size = MFI->getObjectSize(i);
Offset += (Size / (getStackWidth(MF) * 4));
}
return Offset;
}

View File

@ -30,3 +30,36 @@ entry:
store i32 %3, i32 addrspace(1)* %arrayidx13
ret void
}
; This test checks that the stack offset is calculated correctly for structs.
; All register loads/stores should be optimized away, so there shouldn't be
; any MOVA instructions.
;
; XXX: This generated code has unnecessary MOVs, we should be able to optimize
; this.
; CHECK: @multiple_structs
; CHECK-NOT: MOVA_INT
%struct.point = type { i32, i32 }
define void @multiple_structs(i32 addrspace(1)* %out) {
entry:
%a = alloca %struct.point
%b = alloca %struct.point
%a.x.ptr = getelementptr %struct.point* %a, i32 0, i32 0
%a.y.ptr = getelementptr %struct.point* %a, i32 0, i32 1
%b.x.ptr = getelementptr %struct.point* %b, i32 0, i32 0
%b.y.ptr = getelementptr %struct.point* %b, i32 0, i32 1
store i32 0, i32* %a.x.ptr
store i32 1, i32* %a.y.ptr
store i32 2, i32* %b.x.ptr
store i32 3, i32* %b.y.ptr
%a.indirect.ptr = getelementptr %struct.point* %a, i32 0, i32 0
%b.indirect.ptr = getelementptr %struct.point* %b, i32 0, i32 0
%a.indirect = load i32* %a.indirect.ptr
%b.indirect = load i32* %b.indirect.ptr
%0 = add i32 %a.indirect, %b.indirect
store i32 %0, i32 addrspace(1)* %out
ret void
}