This pass inserts branches on the 0 exec mask over divergent branches branches when it's expected that jumping over the untaken control flow will be cheaper than having every workitem no-op through it. More...

#include "AMDGPU.h"
#include "AMDGPUSubtarget.h"
#include "SIInstrInfo.h"
#include "SIMachineFunctionInfo.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetMachine.h"
#include <cassert>
#include <cstdint>
#include <iterator>

Include dependency graph for SIInsertSkips.cpp:

Go to the source code of this file.

Macros
#define	DEBUG_TYPE "si-insert-skips"

Functions
static INITIALIZE_PASS(SIInsertSkips, DEBUG_TYPE, "SI insert s_cbranch_execz instructions", false, false) char &llvm bool	opcodeEmitsNoInsts (unsigned Opc)

Variables
static cl::opt< unsigned >	SkipThresholdFlag ("amdgpu-skip-threshold", cl::desc("Number of instructions before jumping over divergent control flow"), cl::init(12), cl::Hidden)

Detailed Description

This pass inserts branches on the 0 exec mask over divergent branches branches when it's expected that jumping over the untaken control flow will be cheaper than having every workitem no-op through it.

Definition in file SIInsertSkips.cpp.

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE "si-insert-skips"

Definition at line 42 of file SIInsertSkips.cpp.

Function Documentation

◆ opcodeEmitsNoInsts()

static INITIALIZE_PASS (SIInsertSkips, DEBUG_TYPE, "SI insert s_cbranch_execz instructions", false, false) char &llvm bool opcodeEmitsNoInsts ( unsigned Opc ) &

static

Definition at line 96 of file SIInsertSkips.cpp.

References llvm::ISD::EH_LABEL, From, llvm::MachineBasicBlock::getParent(), llvm::AMDGPUISD::KILL, and llvm::MachineBasicBlock::succ_empty().

Variable Documentation

◆ SkipThresholdFlag

cl::opt<unsigned> SkipThresholdFlag("amdgpu-skip-threshold", cl::desc("Number of instructions before jumping over divergent control flow"), cl::init(12), cl::Hidden)