Don't leave behind unreachable blocks with illegal instructions.

2 files changed, 19 insertions, 0 deletions

diff --git a/lib/Transforms/NaCl/ExpandI64.cpp b/lib/Transforms/NaCl/ExpandI64.cpp
index 8f0efb2478..d6c75c0577 100644
--- a/lib/Transforms/NaCl/ExpandI64.cpp
+++ b/lib/Transforms/NaCl/ExpandI64.cpp
@@ -38,6 +38,7 @@
 #include "llvm/Pass.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Transforms/NaCl.h"
+#include "llvm/Transforms/Utils/Local.h"
 #include <map>
 
 #include "llvm/Support/raw_ostream.h"
@@ -1031,6 +1032,11 @@ bool ExpandI64::runOnModule(Module &M) {
       Instruction *D = Dead.pop_back_val();
       D->eraseFromParent();
     }
+
+    // We only visited blocks found by a DFS walk from the entry, so we haven't
+    // visited any unreachable blocks, and they may still contain illegal
+    // instructions at this point. Being unreachable, they can simply be deleted.
+    removeUnreachableBlocks(*Func);
   }
 
   // post pass - clean up illegal functions that were legalized. We do this
diff --git a/test/Transforms/NaCl/expand-i64.ll b/test/Transforms/NaCl/expand-i64.ll
index 2997264058..df4804d19b 100644
--- a/test/Transforms/NaCl/expand-i64.ll
+++ b/test/Transforms/NaCl/expand-i64.ll
@@ -270,3 +270,16 @@ define i64 @sext(i32 %x) {
   %y = sext i32 %x to i64
   ret i64 %y
 }
+
+; CHECK:      define void @unreachable_blocks(i64* %p) {
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+define void @unreachable_blocks(i64* %p) {
+  ret void
+
+dead:
+  %t = load i64* %p
+  %s = add i64 %t, 1
+  store i64 %s, i64* %p
+  ret void
+}