LLVM  16.0.0git
Macros | Functions | Variables
GCNPreRAOptimizations.cpp File Reference
#include "AMDGPU.h"
#include "GCNSubtarget.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/InitializePasses.h"
Include dependency graph for GCNPreRAOptimizations.cpp:

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


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


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


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

Definition at line 36 of file GCNPreRAOptimizations.cpp.

Function Documentation


"AMDGPU Pre-RA optimizations ,
false  ,

Variable Documentation



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.