1 //===----------------------- R600FrameLowering.cpp ------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //==-----------------------------------------------------------------------===// 9 10 #include "R600FrameLowering.h" 11 #include "AMDGPUSubtarget.h" 12 #include "R600RegisterInfo.h" 13 #include "llvm/CodeGen/MachineFrameInfo.h" 14 #include "llvm/CodeGen/MachineFunction.h" 15 #include "llvm/Support/MathExtras.h" 16 17 using namespace llvm; 18 19 R600FrameLowering::~R600FrameLowering() = default; 20 21 /// \returns The number of registers allocated for \p FI. getFrameIndexReference(const MachineFunction & MF,int FI,unsigned & FrameReg) const22int R600FrameLowering::getFrameIndexReference(const MachineFunction &MF, 23 int FI, 24 unsigned &FrameReg) const { 25 const MachineFrameInfo &MFI = MF.getFrameInfo(); 26 const R600RegisterInfo *RI 27 = MF.getSubtarget<R600Subtarget>().getRegisterInfo(); 28 29 // Fill in FrameReg output argument. 30 FrameReg = RI->getFrameRegister(MF); 31 32 // Start the offset at 2 so we don't overwrite work group information. 33 // FIXME: We should only do this when the shader actually uses this 34 // information. 35 unsigned OffsetBytes = 2 * (getStackWidth(MF) * 4); 36 int UpperBound = FI == -1 ? MFI.getNumObjects() : FI; 37 38 for (int i = MFI.getObjectIndexBegin(); i < UpperBound; ++i) { 39 OffsetBytes = alignTo(OffsetBytes, MFI.getObjectAlignment(i)); 40 OffsetBytes += MFI.getObjectSize(i); 41 // Each register holds 4 bytes, so we must always align the offset to at 42 // least 4 bytes, so that 2 frame objects won't share the same register. 43 OffsetBytes = alignTo(OffsetBytes, 4); 44 } 45 46 if (FI != -1) 47 OffsetBytes = alignTo(OffsetBytes, MFI.getObjectAlignment(FI)); 48 49 return OffsetBytes / (getStackWidth(MF) * 4); 50 } 51