[PATCH] D58705: [X86] Don't peek through bitcasts before checking ISD::isBuildVectorOfConstantSDNodes in combineTruncatedArithmetic

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This revision was automatically updated to reflect the committed changes.
Closed by commit rL355116: [X86] Don't peek through bitcasts before checking ISD… (authored by ctopper, committed by ).
Herald added a project: LLVM.

Changed prior to commit:
  https://reviews.llvm.org/D58705?vs=188603&id=188759#toc

Repository:
  rL LLVM

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58705/new/

https://reviews.llvm.org/D58705

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


Index: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
@@ -38717,8 +38717,11 @@
       return true;
 
     // See if this is a single use constant which can be constant folded.
-    SDValue BC = peekThroughOneUseBitcasts(Op);
-    return ISD::isBuildVectorOfConstantSDNodes(BC.getNode());
+    // NOTE: We don't peek throught bitcasts here because there is currently
+    // no support for constant folding truncate+bitcast+vector_of_constants. So
+    // we'll just send up with a truncate on both operands which will
+    // get turned back into (truncate (binop)) causing an infinite loop.
+    return ISD::isBuildVectorOfConstantSDNodes(Op.getNode());
   };
 
   auto TruncateArithmetic = [&](SDValue N0, SDValue N1) {


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