//===----------------------------------------------------------------------===//
#include "AMDGPU.h"
+#include "AMDGPUSubtarget.h"
#include "SIInstrInfo.h"
#include "SIMachineFunctionInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
static const unsigned SkipThreshold = 12;
static char ID;
- const TargetRegisterInfo *TRI;
+ const SIRegisterInfo *TRI;
const SIInstrInfo *TII;
bool shouldSkip(MachineBasicBlock *From, MachineBasicBlock *To);
public:
SILowerControlFlowPass(TargetMachine &tm) :
- MachineFunctionPass(ID), TRI(0), TII(0) { }
+ MachineFunctionPass(ID), TRI(nullptr), TII(nullptr) { }
- virtual bool runOnMachineFunction(MachineFunction &MF);
+ bool runOnMachineFunction(MachineFunction &MF) override;
- const char *getPassName() const {
+ const char *getPassName() const override {
return "SI Lower control flow instructions";
}
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc DL = MI.getDebugLoc();
- if (MBB.getParent()->getInfo<SIMachineFunctionInfo>()->ShaderType !=
+ if (MBB.getParent()->getInfo<SIMachineFunctionInfo>()->getShaderType() !=
ShaderType::PIXEL ||
!shouldSkip(&MBB, &MBB.getParent()->back()))
return;
DebugLoc DL = MI.getDebugLoc();
const MachineOperand &Op = MI.getOperand(0);
- // Kill is only allowed in pixel / geometry shaders
- assert(MBB.getParent()->getInfo<SIMachineFunctionInfo>()->ShaderType ==
- ShaderType::PIXEL ||
- MBB.getParent()->getInfo<SIMachineFunctionInfo>()->ShaderType ==
- ShaderType::GEOMETRY);
+#ifndef NDEBUG
+ const SIMachineFunctionInfo *MFI
+ = MBB.getParent()->getInfo<SIMachineFunctionInfo>();
+ // Kill is only allowed in pixel / geometry shaders.
+ assert(MFI->getShaderType() == ShaderType::PIXEL ||
+ MFI->getShaderType() == ShaderType::GEOMETRY);
+#endif
// Clear this thread from the exec mask if the operand is negative
if ((Op.isImm() || Op.isFPImm())) {
BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_MOV_B32), AMDGPU::M0)
.addReg(Idx);
MBB.insert(I, MovRel);
- MI.eraseFromParent();
- return;
- }
+ } else {
- assert(AMDGPU::SReg_64RegClass.contains(Save));
- assert(AMDGPU::VReg_32RegClass.contains(Idx));
+ assert(AMDGPU::SReg_64RegClass.contains(Save));
+ assert(AMDGPU::VReg_32RegClass.contains(Idx));
- // Save the EXEC mask
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_MOV_B64), Save)
- .addReg(AMDGPU::EXEC);
+ // Save the EXEC mask
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_MOV_B64), Save)
+ .addReg(AMDGPU::EXEC);
- // Read the next variant into VCC (lower 32 bits) <- also loop target
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_READFIRSTLANE_B32),
- AMDGPU::VCC_LO)
- .addReg(Idx);
+ // Read the next variant into VCC (lower 32 bits) <- also loop target
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_READFIRSTLANE_B32),
+ AMDGPU::VCC_LO)
+ .addReg(Idx);
- // Move index from VCC into M0
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_MOV_B32), AMDGPU::M0)
- .addReg(AMDGPU::VCC_LO);
+ // Move index from VCC into M0
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_MOV_B32), AMDGPU::M0)
+ .addReg(AMDGPU::VCC_LO);
- // Compare the just read M0 value to all possible Idx values
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CMP_EQ_U32_e32), AMDGPU::VCC)
- .addReg(AMDGPU::M0)
- .addReg(Idx);
+ // Compare the just read M0 value to all possible Idx values
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CMP_EQ_U32_e32), AMDGPU::VCC)
+ .addReg(AMDGPU::M0)
+ .addReg(Idx);
- // Update EXEC, save the original EXEC value to VCC
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_AND_SAVEEXEC_B64), AMDGPU::VCC)
- .addReg(AMDGPU::VCC);
+ // Update EXEC, save the original EXEC value to VCC
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_AND_SAVEEXEC_B64), AMDGPU::VCC)
+ .addReg(AMDGPU::VCC);
- // Do the actual move
- MBB.insert(I, MovRel);
+ // Do the actual move
+ MBB.insert(I, MovRel);
- // Update EXEC, switch all done bits to 0 and all todo bits to 1
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_XOR_B64), AMDGPU::EXEC)
- .addReg(AMDGPU::EXEC)
- .addReg(AMDGPU::VCC);
+ // Update EXEC, switch all done bits to 0 and all todo bits to 1
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_XOR_B64), AMDGPU::EXEC)
+ .addReg(AMDGPU::EXEC)
+ .addReg(AMDGPU::VCC);
- // Loop back to V_READFIRSTLANE_B32 if there are still variants to cover
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_CBRANCH_EXECNZ))
- .addImm(-7)
- .addReg(AMDGPU::EXEC);
+ // Loop back to V_READFIRSTLANE_B32 if there are still variants to cover
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_CBRANCH_EXECNZ))
+ .addImm(-7)
+ .addReg(AMDGPU::EXEC);
- // Restore EXEC
- BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_MOV_B64), AMDGPU::EXEC)
- .addReg(Save);
+ // Restore EXEC
+ BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_MOV_B64), AMDGPU::EXEC)
+ .addReg(Save);
+ }
MI.eraseFromParent();
}
}
bool SILowerControlFlowPass::runOnMachineFunction(MachineFunction &MF) {
- TII = static_cast<const SIInstrInfo*>(MF.getTarget().getInstrInfo());
- TRI = MF.getTarget().getRegisterInfo();
+ TII = static_cast<const SIInstrInfo *>(MF.getSubtarget().getInstrInfo());
+ TRI =
+ static_cast<const SIRegisterInfo *>(MF.getSubtarget().getRegisterInfo());
SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
bool HaveKill = false;
- bool NeedM0 = false;
bool NeedWQM = false;
+ bool NeedFlat = false;
unsigned Depth = 0;
for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
BI != BE; ++BI) {
MachineBasicBlock &MBB = *BI;
- for (MachineBasicBlock::iterator I = MBB.begin(), Next = std::next(I);
- I != MBB.end(); I = Next) {
-
+ MachineBasicBlock::iterator I, Next;
+ for (I = MBB.begin(); I != MBB.end(); I = Next) {
Next = std::next(I);
+
MachineInstr &MI = *I;
- if (TII->isDS(MI.getOpcode())) {
- NeedM0 = true;
+ if (TII->isDS(MI.getOpcode()))
NeedWQM = true;
- }
+
+ // Flat uses m0 in case it needs to access LDS.
+ if (TII->isFLAT(MI.getOpcode()))
+ NeedFlat = true;
switch (MI.getOpcode()) {
default: break;
case AMDGPU::V_INTERP_MOV_F32:
NeedWQM = true;
break;
-
}
}
}
- if (NeedM0) {
+ if (NeedWQM && MFI->getShaderType() == ShaderType::PIXEL) {
MachineBasicBlock &MBB = MF.front();
- // Initialize M0 to a value that won't cause LDS access to be discarded
- // due to offset clamping
- BuildMI(MBB, MBB.getFirstNonPHI(), DebugLoc(), TII->get(AMDGPU::S_MOV_B32),
- AMDGPU::M0).addImm(0xffffffff);
+ BuildMI(MBB, MBB.getFirstNonPHI(), DebugLoc(), TII->get(AMDGPU::S_WQM_B64),
+ AMDGPU::EXEC).addReg(AMDGPU::EXEC);
}
- if (NeedWQM && MFI->ShaderType == ShaderType::PIXEL) {
+ // FIXME: This seems inappropriate to do here.
+ if (NeedFlat && MFI->IsKernel) {
+ // Insert the prologue initializing the SGPRs pointing to the scratch space
+ // for flat accesses.
+ const MachineFrameInfo *FrameInfo = MF.getFrameInfo();
+
+ // TODO: What to use with function calls?
+
+ // FIXME: This is reporting stack size that is used in a scratch buffer
+ // rather than registers as well.
+ uint64_t StackSizeBytes = FrameInfo->getStackSize();
+
+ int IndirectBegin
+ = static_cast<const AMDGPUInstrInfo*>(TII)->getIndirectIndexBegin(MF);
+ // Convert register index to 256-byte unit.
+ uint64_t StackOffset = IndirectBegin < 0 ? 0 : (4 * IndirectBegin / 256);
+
+ assert((StackSizeBytes < 0xffff) && StackOffset < 0xffff &&
+ "Stack limits should be smaller than 16-bits");
+
+ // Initialize the flat scratch register pair.
+ // TODO: Can we use one s_mov_b64 here?
+
+ // Offset is in units of 256-bytes.
MachineBasicBlock &MBB = MF.front();
- BuildMI(MBB, MBB.getFirstNonPHI(), DebugLoc(), TII->get(AMDGPU::S_WQM_B64),
- AMDGPU::EXEC).addReg(AMDGPU::EXEC);
+ DebugLoc NoDL;
+ MachineBasicBlock::iterator Start = MBB.getFirstNonPHI();
+ const MCInstrDesc &SMovK = TII->get(AMDGPU::S_MOVK_I32);
+
+ assert(isInt<16>(StackOffset) && isInt<16>(StackSizeBytes));
+
+ BuildMI(MBB, Start, NoDL, SMovK, AMDGPU::FLAT_SCR_LO)
+ .addImm(StackOffset);
+
+ // Documentation says size is "per-thread scratch size in bytes"
+ BuildMI(MBB, Start, NoDL, SMovK, AMDGPU::FLAT_SCR_HI)
+ .addImm(StackSizeBytes);
}
return true;
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