[ARM][LowOverheadLoops] Revert non-header LE target
Revert the hardware loop upon finding a LoopEnd that doesn't target
the loop header, instead of asserting a failure.
Differential Revision: https://reviews.llvm.org/D65268
llvm-svn: 367296
diff --git a/llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp b/llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
index dd36702..303986a 100644
--- a/llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
+++ b/llvm/lib/Target/ARM/ARMLowOverheadLoops.cpp
@@ -207,9 +207,15 @@
return false;
}
- if (!End->getOperand(1).isMBB() ||
- End->getOperand(1).getMBB() != ML->getHeader())
- report_fatal_error("Expected LoopEnd to target Loop Header");
+ if (!End->getOperand(1).isMBB())
+ report_fatal_error("Expected LoopEnd to target basic block");
+
+ // TODO Maybe there's cases where the target doesn't have to be the header,
+ // but for now be safe and revert.
+ if (End->getOperand(1).getMBB() != ML->getHeader()) {
+ LLVM_DEBUG(dbgs() << "ARM Loops: LoopEnd is not targetting header.\n");
+ Revert = true;
+ }
// The WLS and LE instructions have 12-bits for the label offset. WLS
// requires a positive offset, while LE uses negative.