[llvm-commits] [llvm] r146597 - in /llvm/trunk: lib/Analysis/ScalarEvolutionExpander.cpp test/Transforms/LoopStrengthReduce/post-inc-icmpzero.ll

[Andrew Trick]

Author: atrick
Date: Wed Dec 14 16:07:19 2011
New Revision: 146597

URL: http://llvm.org/viewvc/llvm-project?rev=146597&view=rev
Log:
LSR: Fold redundant bitcasts on-the-fly.

Modified:
    llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
    llvm/trunk/test/Transforms/LoopStrengthReduce/post-inc-icmpzero.ll

Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=146597&r1=146596&r2=146597&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Wed Dec 14 16:07:19 2011
@@ -73,9 +73,14 @@
          "InsertNoopCastOfTo cannot change sizes!");
 
   // Short-circuit unnecessary bitcasts.
-  if (Op == Instruction::BitCast && V->getType() == Ty)
-    return V;
-
+  if (Op == Instruction::BitCast) {
+    if (V->getType() == Ty)
+      return V;
+    if (CastInst *CI = dyn_cast<CastInst>(V)) {
+      if (CI->getOperand(0)->getType() == Ty)
+        return CI->getOperand(0);
+    }
+  }
   // Short-circuit unnecessary inttoptr<->ptrtoint casts.
   if ((Op == Instruction::PtrToInt || Op == Instruction::IntToPtr) &&
       SE.getTypeSizeInBits(Ty) == SE.getTypeSizeInBits(V->getType())) {

Modified: llvm/trunk/test/Transforms/LoopStrengthReduce/post-inc-icmpzero.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/post-inc-icmpzero.ll?rev=146597&r1=146596&r2=146597&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopStrengthReduce/post-inc-icmpzero.ll (original)
+++ llvm/trunk/test/Transforms/LoopStrengthReduce/post-inc-icmpzero.ll Wed Dec 14 16:07:19 2011
@@ -4,12 +4,12 @@
 ; LSR should property handle the post-inc offset when folding the
 ; non-IV operand of an icmp into the IV.
 
-; CHECK:   %5 = sub i64 %sub.ptr.lhs.cast, %sub.ptr.rhs.cast
-; CHECK:   %6 = lshr i64 %5, 1
-; CHECK:   %7 = mul i64 %6, 2
+; CHECK:   %4 = sub i64 %sub.ptr.lhs.cast, %sub.ptr.rhs.cast
+; CHECK:   %5 = lshr i64 %4, 1
+; CHECK:   %6 = mul i64 %5, 2
 ; CHECK:   br label %for.body
 ; CHECK: for.body:
-; CHECK:   %lsr.iv2 = phi i64 [ %lsr.iv.next, %for.body ], [ %7, %for.body.lr.ph ]
+; CHECK:   %lsr.iv2 = phi i64 [ %lsr.iv.next, %for.body ], [ %6, %for.body.lr.ph ]
 ; CHECK:   %lsr.iv.next = add i64 %lsr.iv2, -2
 ; CHECK:   %lsr.iv.next3 = inttoptr i64 %lsr.iv.next to i16*
 ; CHECK:   %cmp27 = icmp eq i16* %lsr.iv.next3, null