[AMDGPU] Fix isSGPRReg for special registers

perlfu · perlfu · commit 930315f6aa58 · 2022-09-19T08:49:43.000+09:00
Special registers, e.g. MODE, do not have register classes so will cause null pointer exception if passed to isSGPRReg. Reviewed By: arsenm Differential Revision: https://reviews.llvm.org/D134025
diff --git a/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp b/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
@@ -2696,7 +2696,7 @@ bool SIRegisterInfo::isSGPRReg(const MachineRegisterInfo &MRI,
     RC = MRI.getRegClass(Reg);
   else
     RC = getPhysRegClass(Reg);
-  return isSGPRClass(RC);
+  return RC ? isSGPRClass(RC) : false;
 }
 
 const TargetRegisterClass *

Original file line number	Diff line number	Diff line change
`@@ -2696,7 +2696,7 @@ bool SIRegisterInfo::isSGPRReg(const MachineRegisterInfo &MRI,`
`2696`	`2696`	`RC = MRI.getRegClass(Reg);`
`2697`	`2697`	`else`
`2698`	`2698`	`RC = getPhysRegClass(Reg);`
`2699`		`- return isSGPRClass(RC);`
	`2699`	`+ return RC ? isSGPRClass(RC) : false;`
`2700`	`2700`	`}`
`2701`	`2701`
`2702`	`2702`	`const TargetRegisterClass *`