[llvm-commits] [llvm] r94323 - in /llvm/trunk: lib/Transforms/Scalar/JumpThreading.cpp test/Transforms/JumpThreading/crash.ll

[Chris Lattner]

Author: lattner
Date: Sat Jan 23 13:21:31 2010
New Revision: 94323

URL: http://llvm.org/viewvc/llvm-project?rev=94323&view=rev
Log:
third bug from PR6119: the xor dupe extension allows
for arbitrary terminators in predecessors, don't assume
it is a conditional or uncond branch.  The testcase shows
an example where they can happen with switches.

Modified:
    llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
    llvm/trunk/test/Transforms/JumpThreading/crash.ll

Modified: llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp?rev=94323&r1=94322&r2=94323&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/JumpThreading.cpp Sat Jan 23 13:21:31 2010
@@ -1424,9 +1424,9 @@
   
   // Unless PredBB ends with an unconditional branch, split the edge so that we
   // can just clone the bits from BB into the end of the new PredBB.
-  BranchInst *OldPredBranch = cast<BranchInst>(PredBB->getTerminator());
+  BranchInst *OldPredBranch = dyn_cast<BranchInst>(PredBB->getTerminator());
   
-  if (!OldPredBranch->isUnconditional()) {
+  if (OldPredBranch == 0 || !OldPredBranch->isUnconditional()) {
     PredBB = SplitEdge(PredBB, BB, this);
     OldPredBranch = cast<BranchInst>(PredBB->getTerminator());
   }

Modified: llvm/trunk/test/Transforms/JumpThreading/crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/JumpThreading/crash.ll?rev=94323&r1=94322&r2=94323&view=diff

==============================================================================
--- llvm/trunk/test/Transforms/JumpThreading/crash.ll (original)
+++ llvm/trunk/test/Transforms/JumpThreading/crash.ll Sat Jan 23 13:21:31 2010
@@ -286,3 +286,30 @@
   br label %for.cond
 }
 
+; PR6119
+define i32 @test10(i32 %action, i32 %type) nounwind {
+entry:
+  %cmp2 = icmp eq i32 %type, 0                    ; <i1> [#uses=1]
+  switch i32 %action, label %lor.rhs [
+    i32 1, label %if.then
+    i32 0, label %lor.end
+  ]
+
+if.then:                                          ; preds = %for.cond, %lor.end, %entry
+  ret i32 undef
+
+lor.rhs:                                          ; preds = %entry
+  %cmp101 = icmp eq i32 %action, 2                ; <i1> [#uses=1]
+  br label %lor.end
+
+lor.end:                                          ; preds = %lor.rhs, %entry
+  %0 = phi i1 [ %cmp101, %lor.rhs ], [ true, %entry ] ; <i1> [#uses=1]
+  %cmp103 = xor i1 %cmp2, %0                      ; <i1> [#uses=1]
+  br i1 %cmp103, label %for.cond, label %if.then
+
+for.cond:                                         ; preds = %for.body, %lor.end
+  br i1 undef, label %if.then, label %for.body
+
+for.body:                                         ; preds = %for.cond
+  br label %for.cond
+}