In some cases, the "fail BB dominator" may be null after the BB was split (and

becomes reachable when before it wasn't). Check to make sure that it's not null
before trying to use it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128434 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/StackProtector.cpp b/lib/CodeGen/StackProtector.cpp
index 02d8fd6dea9611509ca136084618f9321989c33b..1a588e25d6e3fa2bc9dff99c89edc348e25d2875 100644 (file)
--- a/lib/CodeGen/StackProtector.cpp
+++ b/lib/CodeGen/StackProtector.cpp
@@ -221,7 +221,8 @@ bool StackProtector::InsertStackProtectors() {
     BasicBlock *NewBB = BB->splitBasicBlock(RI, "SP_return");
     if (DT && DT->isReachableFromEntry(BB)) {
       DT->addNewBlock(NewBB, BB);
-      FailBBDom = DT->findNearestCommonDominator(FailBBDom, BB);
+      if (FailBBDom)
+        FailBBDom = DT->findNearestCommonDominator(FailBBDom, BB);
     }
 
     // Remove default branch instruction to the new BB.

diff --git a/test/CodeGen/X86/crash.ll b/test/CodeGen/X86/crash.ll
index 2d8e63e313421ec4f525d52ef2dda3928e26007e..7c4e64cdf6f29b2135c73c0479ab95d427f10c87 100644 (file)
--- a/test/CodeGen/X86/crash.ll
+++ b/test/CodeGen/X86/crash.ll
@@ -189,7 +189,7 @@ for.inc44:                                        ; preds = %for.body
 }
 
 ; PR9028
-define void @f(i64 %A) nounwind {
+define void @func_60(i64 %A) nounwind {
 entry:
   %0 = zext i64 %A to i160
   %1 = shl i160 %0, 64
@@ -199,3 +199,19 @@ entry:
   store i576 %4, i576* undef, align 8
   ret void
 }
+
+; <rdar://problem/9187792>
+define fastcc void @func_61() nounwind sspreq {
+entry:
+  %t1 = tail call i64 @llvm.objectsize.i64(i8* undef, i1 false)
+  %t2 = icmp eq i64 %t1, -1
+  br i1 %t2, label %bb2, label %bb1
+
+bb1:
+  ret void
+
+bb2:
+  ret void
+}
+
+declare i64 @llvm.objectsize.i64(i8*, i1) nounwind readnone