maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

AMDGPU: Restore using MRI to find highest used regs 

If there are no calls, this is a faster path than
searching the entire program for calls.

This was supposed to be left in r309781.
Fixes unused variable warning.

llvm-svn: 309832
This commit is contained in:
Matt Arsenault 2017-08-02 17:15:01 +00:00
parent 5577363a2c
commit 2738ede6b2
1 changed files with 24 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp
View File

@ -500,13 +500,31 @@ AMDGPUAsmPrinter::SIFunctionResourceInfo AMDGPUAsmPrinter::analyzeResourceUsage(
// If there are no calls, MachineRegisterInfo can tell us the used register
// count easily.
MCPhysReg HighestVGPRReg = AMDGPU::NoRegister;
for (MCPhysReg Reg : reverse(AMDGPU::VGPR_32RegClass.getRegisters())) {
if (MRI.isPhysRegUsed(Reg)) {
HighestVGPRReg = Reg;
break;
if (!FrameInfo.hasCalls()) {
MCPhysReg HighestVGPRReg = AMDGPU::NoRegister;
for (MCPhysReg Reg : reverse(AMDGPU::VGPR_32RegClass.getRegisters())) {
if (MRI.isPhysRegUsed(Reg)) {
HighestVGPRReg = Reg;
break;
}
}
MCPhysReg HighestSGPRReg = AMDGPU::NoRegister;
for (MCPhysReg Reg : reverse(AMDGPU::SGPR_32RegClass.getRegisters())) {
if (MRI.isPhysRegUsed(Reg)) {
HighestSGPRReg = Reg;
break;
}
}
// We found the maximum register index. They start at 0, so add one to get the
// number of registers.
Info.NumVGPR = HighestVGPRReg == AMDGPU::NoRegister ? 0 :
TRI.getHWRegIndex(HighestVGPRReg) + 1;
Info.NumExplicitSGPR = HighestSGPRReg == AMDGPU::NoRegister ? 0 :
TRI.getHWRegIndex(HighestSGPRReg) + 1;
return Info;
}
int32_t MaxVGPR = -1;