[llvm-commits] [llvm] r67811 - /llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp

[Dale Johannesen]

Author: johannes
Date: Thu Mar 26 20:13:37 2009
New Revision: 67811

URL: http://llvm.org/viewvc/llvm-project?rev=67811&view=rev
Log:
One more place to skip debug info.


Modified:
    llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp?rev=67811&r1=67810&r2=67811&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/CodeGenPrepare.cpp Thu Mar 26 20:13:37 2009
@@ -145,10 +145,11 @@
   return EverMadeChange;
 }
 
-/// EliminateMostlyEmptyBlocks - eliminate blocks that contain only PHI nodes
-/// and an unconditional branch.  Passes before isel (e.g. LSR/loopsimplify)
-/// often split edges in ways that are non-optimal for isel.  Start by
-/// eliminating these blocks so we can split them the way we want them.
+/// EliminateMostlyEmptyBlocks - eliminate blocks that contain only PHI nodes,
+/// debug info directives, and an unconditional branch.  Passes before isel
+/// (e.g. LSR/loopsimplify) often split edges in ways that are non-optimal for
+/// isel.  Start by eliminating these blocks so we can split them the way we
+/// want them.
 bool CodeGenPrepare::EliminateMostlyEmptyBlocks(Function &F) {
   bool MadeChange = false;
   // Note that this intentionally skips the entry block.
@@ -160,12 +161,18 @@
     if (!BI || !BI->isUnconditional())
       continue;
 
-    // If the instruction before the branch isn't a phi node, then other stuff
-    // is happening here.
+    // If the instruction before the branch (skipping debug info) isn't a phi
+    // node, then other stuff is happening here.
     BasicBlock::iterator BBI = BI;
     if (BBI != BB->begin()) {
       --BBI;
-      if (!isa<PHINode>(BBI)) continue;
+      while (isa<DbgInfoIntrinsic>(BBI)) {
+        if (BBI == BB->begin())
+          break;
+        --BBI;
+      }
+      if (!isa<DbgInfoIntrinsic>(BBI) && !isa<PHINode>(BBI))
+        continue;
     }
 
     // Do not break infinite loops.