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Diffstat (limited to 'contrib/llvm/lib/Target/R600/AMDGPUFrameLowering.cpp')
-rw-r--r-- | contrib/llvm/lib/Target/R600/AMDGPUFrameLowering.cpp | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/R600/AMDGPUFrameLowering.cpp b/contrib/llvm/lib/Target/R600/AMDGPUFrameLowering.cpp new file mode 100644 index 0000000..9e8302e --- /dev/null +++ b/contrib/llvm/lib/Target/R600/AMDGPUFrameLowering.cpp @@ -0,0 +1,113 @@ +//===----------------------- AMDGPUFrameLowering.cpp ----------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//==-----------------------------------------------------------------------===// +// +// Interface to describe a layout of a stack frame on a AMDIL target machine +// +//===----------------------------------------------------------------------===// +#include "AMDGPUFrameLowering.h" +#include "AMDGPURegisterInfo.h" +#include "R600MachineFunctionInfo.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/IR/Instructions.h" + +using namespace llvm; +AMDGPUFrameLowering::AMDGPUFrameLowering(StackDirection D, unsigned StackAl, + int LAO, unsigned TransAl) + : TargetFrameLowering(D, StackAl, LAO, TransAl) { } + +AMDGPUFrameLowering::~AMDGPUFrameLowering() { } + +unsigned AMDGPUFrameLowering::getStackWidth(const MachineFunction &MF) const { + + // XXX: Hardcoding to 1 for now. + // + // I think the StackWidth should stored as metadata associated with the + // MachineFunction. This metadata can either be added by a frontend, or + // calculated by a R600 specific LLVM IR pass. + // + // The StackWidth determines how stack objects are laid out in memory. + // For a vector stack variable, like: int4 stack[2], the data will be stored + // in the following ways depending on the StackWidth. + // + // StackWidth = 1: + // + // T0.X = stack[0].x + // T1.X = stack[0].y + // T2.X = stack[0].z + // T3.X = stack[0].w + // T4.X = stack[1].x + // T5.X = stack[1].y + // T6.X = stack[1].z + // T7.X = stack[1].w + // + // StackWidth = 2: + // + // T0.X = stack[0].x + // T0.Y = stack[0].y + // T1.X = stack[0].z + // T1.Y = stack[0].w + // T2.X = stack[1].x + // T2.Y = stack[1].y + // T3.X = stack[1].z + // T3.Y = stack[1].w + // + // StackWidth = 4: + // T0.X = stack[0].x + // T0.Y = stack[0].y + // T0.Z = stack[0].z + // T0.W = stack[0].w + // T1.X = stack[1].x + // T1.Y = stack[1].y + // T1.Z = stack[1].z + // T1.W = stack[1].w + return 1; +} + +/// \returns The number of registers allocated for \p FI. +int AMDGPUFrameLowering::getFrameIndexOffset(const MachineFunction &MF, + int FI) const { + const MachineFrameInfo *MFI = MF.getFrameInfo(); + // Start the offset at 2 so we don't overwrite work group information. + // XXX: We should only do this when the shader actually uses this + // information. + unsigned OffsetBytes = 2 * (getStackWidth(MF) * 4); + int UpperBound = FI == -1 ? MFI->getNumObjects() : FI; + + for (int i = MFI->getObjectIndexBegin(); i < UpperBound; ++i) { + OffsetBytes = RoundUpToAlignment(OffsetBytes, MFI->getObjectAlignment(i)); + OffsetBytes += MFI->getObjectSize(i); + // Each register holds 4 bytes, so we must always align the offset to at + // least 4 bytes, so that 2 frame objects won't share the same register. + OffsetBytes = RoundUpToAlignment(OffsetBytes, 4); + } + + if (FI != -1) + OffsetBytes = RoundUpToAlignment(OffsetBytes, MFI->getObjectAlignment(FI)); + + return OffsetBytes / (getStackWidth(MF) * 4); +} + +const TargetFrameLowering::SpillSlot * +AMDGPUFrameLowering::getCalleeSavedSpillSlots(unsigned &NumEntries) const { + NumEntries = 0; + return nullptr; +} +void +AMDGPUFrameLowering::emitPrologue(MachineFunction &MF) const { +} +void +AMDGPUFrameLowering::emitEpilogue(MachineFunction &MF, + MachineBasicBlock &MBB) const { +} + +bool +AMDGPUFrameLowering::hasFP(const MachineFunction &MF) const { + return false; +} |