[llvm] r299448 - [x86] remove dead select-of-constants transform; NFCI

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Tue Apr  4 11:54:58 2017
New Revision: 299448

URL: http://llvm.org/viewvc/llvm-project?rev=299448&view=rev
Log:
[x86] remove dead select-of-constants transform; NFCI

https://reviews.llvm.org/D30537 / https://reviews.llvm.org/rL296977 added these transforms
and other related transforms to the generic DAGCombiner (with a hook that x86 sets to true),
so these patterns should not exist by the time we reach the target-specific combiner hook.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=299448&r1=299447&r2=299448&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Tue Apr  4 11:54:58 2017
@@ -29767,18 +29767,6 @@ static SDValue combineSelectOfTwoConstan
                        DAG.getConstant(ShAmt, DL, MVT::i8));
   }
 
-  // Optimize Cond ? cst+1 : cst -> zext(setcc(C)+cst.
-  if (FalseC->getAPIntValue() + 1 == TrueC->getAPIntValue()) {
-    if (NeedsCondInvert) // Invert the condition if needed.
-      Cond = DAG.getNode(ISD::XOR, DL, Cond.getValueType(), Cond,
-                         DAG.getConstant(1, DL, Cond.getValueType()));
-
-    // Zero extend the condition if needed.
-    Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, FalseC->getValueType(0), Cond);
-    return DAG.getNode(ISD::ADD, DL, Cond.getValueType(), Cond,
-                       SDValue(FalseC, 0));
-  }
-
   // Optimize cases that will turn into an LEA instruction.  This requires
   // an i32 or i64 and an efficient multiplier (1, 2, 3, 4, 5, 8, 9).
   if (N->getValueType(0) == MVT::i32 || N->getValueType(0) == MVT::i64) {