[llvm-commits] [llvm] r40458 - in /llvm/trunk: lib/Analysis/PostDominators.cpp test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll

[Devang Patel]

Author: dpatel
Date: Mon Jul 23 20:02:25 2007
New Revision: 40458

URL: http://llvm.org/viewvc/llvm-project?rev=40458&view=rev
Log:
Unreachable block is not a root node in post dominator tree.

Added:
    llvm/trunk/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll
Modified:
    llvm/trunk/lib/Analysis/PostDominators.cpp

Modified: llvm/trunk/lib/Analysis/PostDominators.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/PostDominators.cpp?rev=40458&r1=40457&r2=40458&view=diff

==============================================================================
--- llvm/trunk/lib/Analysis/PostDominators.cpp (original)
+++ llvm/trunk/lib/Analysis/PostDominators.cpp Mon Jul 23 20:02:25 2007
@@ -112,8 +112,12 @@
   // relationships.  These blocks, which have no successors, end with return and
   // unwind instructions.
   for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
-    if (succ_begin(I) == succ_end(I))
-      Roots.push_back(I);
+    if (succ_begin(I) == succ_end(I)) {
+      Instruction *Insn = I->getTerminator();
+      // Unreachable block is not a root node.
+      if (!isa<UnreachableInst>(Insn))
+        Roots.push_back(I);
+    }
   
   Vertex.push_back(0);
   

Added: llvm/trunk/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll?rev=40458&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll (added)
+++ llvm/trunk/test/Transforms/ADCE/2007-07-23-InfiniteLoop.ll Mon Jul 23 20:02:25 2007
@@ -0,0 +1,13 @@
+; RUN: llvm-as < %s |   opt -adce | llvm-dis | grep switch
+; PR 1564
+  
+define fastcc void @out() {
+    start:
+            br label %loop
+    unreachable:
+            unreachable
+    loop:
+            switch i32 0, label %unreachable [
+                     i32 0, label %loop
+            ]
+}