[llvm-commits] [llvm] r121749 - in /llvm/trunk: lib/Transforms/Utils/SimplifyCFG.cpp test/Transforms/SimplifyCFG/switch_create.ll

[Chris Lattner]

Author: lattner
Date: Mon Dec 13 23:57:30 2010
New Revision: 121749

URL: http://llvm.org/viewvc/llvm-project?rev=121749&view=rev
Log:
reapply my recent change that disables a piece of the switch formation
work, but fixes 400.perlbmk.

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

Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=121749&r1=121748&r2=121749&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Mon Dec 13 23:57:30 2010
@@ -1515,7 +1515,7 @@
       AddPredecessorToBlock(FalseDest, PredBlock, BB);
       PBI->setSuccessor(1, FalseDest);
     }
-    return SimplifyCFG(PBI->getParent()) | true;
+    return true;
   }
   return false;
 }
@@ -1905,17 +1905,25 @@
   
   BasicBlock *BB = BI->getParent();
   
+  DEBUG(dbgs() << "CONVERTING 'icmp' CHAIN with " << Values.size()
+               << " cases into SWITCH.  BB is:\n" << *BB);
+  
   // If there are any extra values that couldn't be folded into the switch
   // then we evaluate them with an explicit branch first.  Split the block
   // right before the condbr to handle it.
   if (ExtraCase) {
-    return false;
+    DEBUG(dbgs() << "  ** 'icmp' chain unhandled condition: " << *ExtraCase
+                 << '\n');
     
     BasicBlock *NewBB = BB->splitBasicBlock(BI, "switch.early.test");
     // Remove the uncond branch added to the old block.
     TerminatorInst *OldTI = BB->getTerminator();
     
-    BranchInst::Create(EdgeBB, NewBB, ExtraCase, OldTI);
+    if (TrueWhenEqual)
+      BranchInst::Create(EdgeBB, NewBB, ExtraCase, OldTI);
+    else
+      BranchInst::Create(NewBB, EdgeBB, ExtraCase, OldTI);
+      
     OldTI->eraseFromParent();
     
     // If there are PHI nodes in EdgeBB, then we need to add a new entry to them
@@ -1955,6 +1963,7 @@
   
   // Erase the old branch instruction.
   EraseTerminatorInstAndDCECond(BI);
+  
   return true;
 }
 
@@ -2410,8 +2419,7 @@
     if (BI->isUnconditional()) {
       if (SimplifyUncondBranch(BI)) return true;
     } else {
-      if (SimplifyCondBranch(BI))
-        return true;
+      if (SimplifyCondBranch(BI)) return true;
     }
   } else if (ReturnInst *RI = dyn_cast<ReturnInst>(BB->getTerminator())) {
     if (SimplifyReturn(RI)) return true;

Modified: llvm/trunk/test/Transforms/SimplifyCFG/switch_create.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/switch_create.ll?rev=121749&r1=121748&r2=121749&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/switch_create.ll (original)
+++ llvm/trunk/test/Transforms/SimplifyCFG/switch_create.ll Mon Dec 13 23:57:30 2010
@@ -1,5 +1,4 @@
 ; RUN: opt < %s -simplifycfg -S | FileCheck %s
-; XFAIL: *
 
 declare void @foo1()
 
@@ -257,7 +256,7 @@
 ; HECK:   %cmp = icmp ult i8 %c, 33
 ; HECK:   br i1 %cmp, label %lor.end, label %switch.early.test
 
-; HECK: switch.early.test:
+; CHECK: switch.early.test:
 ; HECK:   switch i8 %c, label %lor.rhs [
 ; HECK:     i8 46, label %lor.end
 ; HECK:     i8 44, label %lor.end