[llvm-commits] [llvm] r111122 - in /llvm/trunk: lib/Transforms/Utils/SimplifyCFG.cpp test/Transforms/SimplifyCFG/indirectbr.ll

[Dan Gohman]

Author: djg
Date: Mon Aug 16 09:41:14 2010
New Revision: 111122

URL: http://llvm.org/viewvc/llvm-project?rev=111122&view=rev
Log:
Instead, teach SimplifyCFG to trim non-address-taken blocks from
indirectbr destination lists.

Modified:
    llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
    llvm/trunk/test/Transforms/SimplifyCFG/indirectbr.ll

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=111122&r1=111121&r2=111122&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Mon Aug 16 09:41:14 2010
@@ -2057,12 +2057,13 @@
         return true;
       }
     }
-  } else if (IndirectBrInst *IBI = dyn_cast<IndirectBrInst>(BB->getTerminator())) {
+  } else if (IndirectBrInst *IBI =
+               dyn_cast<IndirectBrInst>(BB->getTerminator())) {
     // Eliminate redundant destinations.
     SmallPtrSet<Value *, 8> Succs;
     for (unsigned i = 0, e = IBI->getNumDestinations(); i != e; ++i) {
       BasicBlock *Dest = IBI->getDestination(i);
-      if (!Succs.insert(Dest)) {
+      if (!Dest->hasAddressTaken() || !Succs.insert(Dest)) {
         Dest->removePredecessor(BB);
         IBI->removeDestination(i);
         --i; --e;

Modified: llvm/trunk/test/Transforms/SimplifyCFG/indirectbr.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/indirectbr.ll?rev=111122&r1=111121&r2=111122&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/indirectbr.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/indirectbr.ll Mon Aug 16 09:41:14 2010
@@ -49,3 +49,16 @@
   ret void
 }
 
+; SimplifyCFG should notice that BB0 does not have its address taken and
+; remove it from entry's successor list.
+
+; CHECK: indbrtest2
+; CHECK: entry:
+; CHECK-NEXT: unreachable
+
+define void @indbrtest2(i8* %t) {
+entry:
+  indirectbr i8* %t, [label %BB0, label %BB0]
+BB0:
+  ret void
+}