[AMDGPU] make ubsan happy with unsigned left shift

Fixes UBSAN error after rG9ee272f13d88f090817235ef4f91e56bb2a153d6
A trivial signed/unsigned shift.

diff --git a/llvm/lib/Target/AMDGPU/SMInstructions.td b/llvm/lib/Target/AMDGPU/SMInstructions.td
index 252f191..df21c86 100644 (file)
--- a/llvm/lib/Target/AMDGPU/SMInstructions.td
+++ b/llvm/lib/Target/AMDGPU/SMInstructions.td
@@ -860,7 +860,7 @@ let OtherPredicates = [HasNoSMemTimeInst] in {
 def : GCNPat <
   (i64 (readcyclecounter)),
   (REG_SEQUENCE SReg_64,
-    (S_GETREG_B32 getHwRegImm<HWREG.SHADER_CYCLES, 0, -12>.ret), sub0,
+    (S_GETREG_B32 -26595), sub0,
     (S_MOV_B32 (i32 0)), sub1)
 >;
 } // let OtherPredicates = [HasNoSMemTimeInst]