Fix use-after-frees on memory allocated in a Recycler.

This will become asan errors once the patch lands that poisons the
memory after free. The x86 change is a hack, but I don't see how to
solve this properly at the moment.

llvm-svn: 300867

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp b/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
index 2160a8255bc..74ed58e8d04 100644
--- a/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Legalizer.cpp
@@ -223,7 +223,11 @@ bool Legalizer::runOnMachineFunction(MachineFunction &MF) {
       // good chance MI will be deleted.
       NextMI = std::next(MI);
 
-      Changed |= combineExtracts(*MI, MRI, TII);
+      // combineExtracts erases MI.
+      if (combineExtracts(*MI, MRI, TII)) {
+        Changed = true;
+        continue;
+      }
       Changed |= combineMerges(*MI, MRI, TII);
     }
   }