GCNPreRAOptimizations.cpp File Reference

This pass combines split register tuple initialization into a single pseudo: More...

#include "AMDGPU.h"
#include "GCNSubtarget.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/InitializePasses.h"

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "amdgpu-pre-ra-optimizations"

Functions
	INITIALIZE_PASS_BEGIN (GCNPreRAOptimizations, DEBUG_TYPE, "AMDGPU Pre-RA optimizations", false, false) INITIALIZE_PASS_END(GCNPreRAOptimizations

Variables
	DEBUG_TYPE
Pre RA	optimizations
Pre RA	false

Detailed Description

This pass combines split register tuple initialization into a single pseudo:

undef %0.sub1:sreg_64 = S_MOV_B32 1 %0.sub0:sreg_64 = S_MOV_B32 2 => %0:sreg_64 = S_MOV_B64_IMM_PSEUDO 0x200000001

This is to allow rematerialization of a value instead of spilling. It is supposed to be done after register coalescer to allow it to do its job and before actual register allocation to allow rematerialization.

Right now the pass only handles 64 bit SGPRs with immediate initializers, although the same shall be possible with other register classes and instructions if necessary.

Definition in file GCNPreRAOptimizations.cpp.

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "amdgpu-pre-ra-optimizations"

Definition at line 36 of file GCNPreRAOptimizations.cpp.

Function Documentation

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	GCNPreRAOptimizations	,
		DEBUG_TYPE	,
		"AMDGPU Pre-RA optimizations"	,
		false	,
		false
	)

Variable Documentation

DEBUG_TYPE

DEBUG_TYPE

Definition at line 74 of file GCNPreRAOptimizations.cpp.

false

Pre RA false

Definition at line 75 of file GCNPreRAOptimizations.cpp.

optimizations

Pre RA optimizations

Definition at line 74 of file GCNPreRAOptimizations.cpp.