[llvm] r305788 - [X86][SSE] Dropped old INSERT_VECTOR_ELT lowering TODO

Simon Pilgrim via llvm-commits llvm-commits at lists.llvm.org
Tue Jun 20 03:33:35 PDT 2017


Author: rksimon
Date: Tue Jun 20 05:33:34 2017
New Revision: 305788

URL: http://llvm.org/viewvc/llvm-project?rev=305788&view=rev
Log:
[X86][SSE] Dropped old INSERT_VECTOR_ELT lowering TODO

Target shuffle combining now supports the matching of INSERT_VECTOR_ELT/PINSRW/PINSRB for merging multiple insertions into shuffles/bitmasks.

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=305788&r1=305787&r2=305788&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Tue Jun 20 05:33:34 2017
@@ -14272,8 +14272,6 @@ SDValue X86TargetLowering::LowerINSERT_V
   // If we are inserting a element, see if we can do this more efficiently with
   // a blend shuffle with a rematerializable vector than a costly integer
   // insertion.
-  // TODO: pre-SSE41 targets will tend to use bit masking - this could still
-  // be beneficial if we are inserting several zeros and can combine the masks.
   if ((IsZeroElt || IsAllOnesElt) && Subtarget.hasSSE41() && NumElts <= 8) {
     SmallVector<int, 8> BlendMask;
     for (unsigned i = 0; i != NumElts; ++i)




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