[X86][SSE] Change memop fragment to inherit from vec128load with local alignment controls

[RKSimon]

Summary

First possible step towards merging SSE/AVX memory folding pattern fragments.

Also allows us to remove the duplicate non-temporal load logic.

[RKSimon]

ping?

[craig.topper]

LGTM

lib/Target/X86/X86InstrFragmentsSIMD.td

 // 512-bit aligned load pattern fragments
 def alignedloadv16f32 : PatFrag<(ops node:$ptr),
                                 (v16f32 (alignedload512 node:$ptr))>;
 def alignedloadv8f64  : PatFrag<(ops node:$ptr),
                                 (v8f64  (alignedload512 node:$ptr))>;
 def alignedloadv8i64  : PatFrag<(ops node:$ptr),
                                 (v8i64  (alignedload512 node:$ptr))>;
 
-// Like 'load', but uses special alignment checks suitable for use in
+// Like 'vec128load', but uses special alignment checks suitable for use in
 // memory operands in most SSE instructions, which are required to
 // be naturally aligned on some targets but not on others.  If the subtarget
 // allows unaligned accesses, match any load, though this may require
 // setting a feature bit in the processor (on startup, for example).
 // Opteron 10h and later implement such a feature.
 // Avoid non-temporal aligned loads on supported targets.
-def memop : PatFrag<(ops node:$ptr), (load node:$ptr), [{
-  return (Subtarget->hasSSEUnalignedMem() ||
-          cast<LoadSDNode>(N)->getAlignment() >= 16) &&
-         (!Subtarget->hasSSE41() ||
-          !(cast<LoadSDNode>(N)->getAlignment() >= 16 &&
-            cast<LoadSDNode>(N)->isNonTemporal()));
+def memop : PatFrag<(ops node:$ptr), (vec128load node:$ptr), [{
+  return Subtarget->hasSSEUnalignedMem() ||
+         cast<LoadSDNode>(N)->getAlignment() >= 16;
 }]>;
 
 // 128-bit memop pattern fragments
 // NOTE: all 128-bit integer vector loads are promoted to v2i64
 def memopv4f32 : PatFrag<(ops node:$ptr), (v4f32 (memop node:$ptr))>;
 def memopv2f64 : PatFrag<(ops node:$ptr), (v2f64 (memop node:$ptr))>;
 def memopv2i64 : PatFrag<(ops node:$ptr), (v2i64 (memop node:$ptr))>;