[llvm-commits] CVS: llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp

[Nick Lewycky]

Changes in directory llvm/lib/Transforms/Scalar:

PredicateSimplifier.cpp updated: 1.45 -> 1.46
---
Log message:

If we know that it's a constant being casted, propagate through the cast
instruction. Doesn't work the other way though (can't recover bits that
have been truncated).


---
Diffs of the changes:  (+10 -1)

 PredicateSimplifier.cpp |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletion(-)


Index: llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp
diff -u llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.45 llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.46
--- llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.45	Thu Jan 11 18:02:12 2007
+++ llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp	Thu Jan 11 19:23:53 2007
@@ -1285,8 +1285,17 @@
                    IG.canonicalize(SI->getFalseValue(), Top)) {
           add(SI, SI->getTrueValue(), ICmpInst::ICMP_EQ, NewContext);
         }
+      } else if (CastInst *CI = dyn_cast<CastInst>(I)) {
+        if (CI->getDestTy()->isFPOrFPVector()) return;
+
+        if (Constant *C = dyn_cast<Constant>(
+                IG.canonicalize(CI->getOperand(0), Top))) {
+          add(CI, ConstantExpr::getCast(CI->getOpcode(), C, CI->getDestTy()),
+              ICmpInst::ICMP_EQ, NewContext);
+        }
+
+        // TODO: "%a = cast ... %b" where %b is NE/LT/GT a constant.
       }
-      // TODO: CastInst "%a = cast ... %b" where %b is EQ or NE a constant.
     }
 
     /// solve - process the work queue