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

[NVPTX] Mark special registers as reserved 

A reserved register:
 - is not allocatable
 - is considered always live
 - is ignored by liveness tracking

NVPTX special registers match the criteria, and marking them as
reserved helps to avoid machine verifier error:

    *** Bad machine code: Using an undefined physical register ***
    - function:    foo
    - basic block: %bb.0  (0x557bb178b708)
    - instruction: %0:int32regs = MOV_SPECIAL $envreg0
    - operand 1:   $envreg0

Differential Revision: https://reviews.llvm.org/D113008
This commit is contained in:
Andrew Savonichev 2021-11-03 15:48:04 +03:00
parent 1427742750
commit 123ad720f1
2 changed files with 9 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
llvm/lib/Target/NVPTX/NVPTXRegisterInfo.cpp
View File

@ -107,6 +107,14 @@ NVPTXRegisterInfo::getCalleeSavedRegs(const MachineFunction *) const {
BitVector NVPTXRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
for (unsigned Reg = NVPTX::ENVREG0; Reg <= NVPTX::ENVREG31; ++Reg) {
markSuperRegs(Reserved, Reg);
}
markSuperRegs(Reserved, NVPTX::VRFrame32);
markSuperRegs(Reserved, NVPTX::VRFrameLocal32);
markSuperRegs(Reserved, NVPTX::VRFrame64);
markSuperRegs(Reserved, NVPTX::VRFrameLocal64);
markSuperRegs(Reserved, NVPTX::VRDepot);
return Reserved;
}

2
llvm/test/CodeGen/NVPTX/envreg.ll
View File

@ -1,4 +1,4 @@
; RUN: llc < %s -march=nvptx -mcpu=sm_20 | FileCheck %s
; RUN: llc < %s -march=nvptx -mcpu=sm_20 -verify-machineinstrs | FileCheck %s
declare i32 @llvm.nvvm.read.ptx.sreg.envreg0()