[PATCH] [x86] eliminate unnecessary shuffling/moves with unary scalar math ops (PR21507)

[Sanjay Patel]

================
Comment at: lib/Target/X86/X86InstrSSE.td:3417-3420
@@ -3417,4 +3416,6 @@
+
    def : Pat<(Intr VR128:$src),
              (vt (COPY_TO_REGCLASS(
              !cast<Instruction>("V"#NAME#Suffix##r) (ScalarVT (IMPLICIT_DEF)),
                     (ScalarVT (COPY_TO_REGCLASS VR128:$src, RC))), VR128))>;
+
----------------
andreadb wrote:
> Hi Sanjay,
> 
> do we still need this pattern? I maybe wrong, but your new pattern (at line 3413) should make this one dead.
Thanks, Andrea. 

Yes, I'm not seeing how this pattern will do anything now, and there's no difference on any regression tests. I'll remove it.

http://reviews.llvm.org/D9504

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