[cfe-commits] r111282 - /cfe/trunk/lib/Analysis/CFG.cpp

[Ted Kremenek]

Author: kremenek
Date: Tue Aug 17 15:59:56 2010
New Revision: 111282

URL: http://llvm.org/viewvc/llvm-project?rev=111282&view=rev
Log:
CFGBuilder: don't create the empty "loop back" block for DoStmts if the loop edge can never be taken.

Modified:
    cfe/trunk/lib/Analysis/CFG.cpp

Modified: cfe/trunk/lib/Analysis/CFG.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/CFG.cpp?rev=111282&r1=111281&r2=111282&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/CFG.cpp (original)
+++ cfe/trunk/lib/Analysis/CFG.cpp Tue Aug 17 15:59:56 2010
@@ -1476,18 +1476,22 @@
         return 0;
     }
 
-    // Add an intermediate block between the BodyBlock and the
-    // ExitConditionBlock to represent the "loop back" transition.  Create an
-    // empty block to represent the transition block for looping back to the
-    // head of the loop.
-    // FIXME: Can we do this more efficiently without adding another block?
-    Block = NULL;
-    Succ = BodyBlock;
-    CFGBlock *LoopBackBlock = createBlock();
-    LoopBackBlock->setLoopTarget(D);
+    if (!KnownVal.isFalse()) {
+      // Add an intermediate block between the BodyBlock and the
+      // ExitConditionBlock to represent the "loop back" transition.  Create an
+      // empty block to represent the transition block for looping back to the
+      // head of the loop.
+      // FIXME: Can we do this more efficiently without adding another block?
+      Block = NULL;
+      Succ = BodyBlock;
+      CFGBlock *LoopBackBlock = createBlock();
+      LoopBackBlock->setLoopTarget(D);
 
-    // Add the loop body entry as a successor to the condition.
-    AddSuccessor(ExitConditionBlock, KnownVal.isFalse() ? NULL : LoopBackBlock);
+      // Add the loop body entry as a successor to the condition.
+      AddSuccessor(ExitConditionBlock, LoopBackBlock);
+    }
+    else
+      AddSuccessor(ExitConditionBlock, NULL);
   }
 
   // Link up the condition block with the code that follows the loop.