Fix use after free in Thumb2SizeReduction (PR4707). A MachineInstr was used after erasure.

llvm-svn: 79189
2009-08-16 11:56:42 +00:00 · 2009-08-16 11:56:42 +00:00 · 2c64130c43
parent 195fd9d970
commit 2c64130c43
1 changed files with 4 additions and 1 deletions
--- a/llvm/lib/Target/ARM/Thumb2SizeReduction.cpp
+++ b/llvm/lib/Target/ARM/Thumb2SizeReduction.cpp
@ -654,8 +654,11 @@ bool Thumb2SizeReduce::ReduceMBB(MachineBasicBlock &MBB) {
      }

      // Try to transform ro a 16-bit non-two-address instruction.
-      if (Entry.NarrowOpc1 && ReduceToNarrow(MBB, MI, Entry, LiveCPSR))
+      if (Entry.NarrowOpc1 && ReduceToNarrow(MBB, MI, Entry, LiveCPSR)) {
        Modified = true;
+        MachineBasicBlock::iterator I = prior(NextMII);
+        MI = &*I;
+      }
    }

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