From: Reid Spencer <rspencer@reidspencer.com>
Date: Tue, 12 Dec 2006 05:38:50 +0000 (+0000)
Subject: Don't create usless casts for same-bith-width floating point casts.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f25212a223b649bf602d3a0489254139cd2c07e4;p=oota-llvm.git

Don't create usless casts for same-bith-width floating point casts.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32475 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 2aa0524dfd0..710b738cd24 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -1531,9 +1531,10 @@ Constant *ConstantExpr::getFPCast(Constant *C, const Type *Ty) {
          "Invalid cast");
   unsigned SrcBits = C->getType()->getPrimitiveSizeInBits();
   unsigned DstBits = Ty->getPrimitiveSizeInBits();
+  if (SrcBits == DstBits)
+    return C; // Avoid a useless cast
   Instruction::CastOps opcode =
-    (SrcBits == DstBits ? Instruction::BitCast :
-     (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt));
+     (SrcBits > DstBits ? Instruction::FPTrunc : Instruction::FPExt);
   return getCast(opcode, C, Ty);
 }