[x86] Fix EFLAGS copy lowering to correctly handle walking past uses in

multiple successors where some of the uses end up killing the EFLAGS
register.

There was a bug where rather than skipping to the next basic block
queued up with uses once we saw a kill, we stopped processing the blocks
entirely. =/

Test case produces completely nonsensical code w/o this tiny fix.

This was found testing Speculative Load Hardening and split out of that
work.

Differential Revision: https://reviews.llvm.org/D49211

llvm-svn: 336874

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp b/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
index bc504824446..e8a8d88b67d 100644
--- a/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
+++ b/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
@@ -555,7 +555,7 @@ bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
 
       // If the flags were killed, we're done with this block.
       if (FlagsKilled)
-        break;
+        continue;
 
       // Otherwise we need to scan successors for ones where the flags live-in
       // and queue those up for processing.