Fix crash in AggressiveAntiDepBreaker with empty CriticalPathSet
If no register classes are added to CriticalPathRCs, then the CriticalPathSet
bitmask will be empty. In that case, ExcludeRegs must remain NULL or else this
line will cause a segfault:
} else if ((ExcludeRegs != NULL) && ExcludeRegs->test(AntiDepReg)) {
I have no in-tree test case.
llvm-svn: 190584
diff --git a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
index e079707..2ee7767 100644
--- a/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
+++ b/llvm/lib/CodeGen/AggressiveAntiDepBreaker.cpp
@@ -782,7 +782,7 @@
if (MI == CriticalPathMI) {
CriticalPathSU = CriticalPathStep(CriticalPathSU);
CriticalPathMI = (CriticalPathSU) ? CriticalPathSU->getInstr() : 0;
- } else {
+ } else if (CriticalPathSet.any()) {
ExcludeRegs = &CriticalPathSet;
}