[PATCH] D15132: [X86][SSE] Update the cost table for integer-integer conversions on SSE2.

[Cong Hou via llvm-commits]

congh added inline comments.

================
Comment at: lib/Target/X86/X86TargetTransformInfo.cpp:703
@@ +702,3 @@
+    { ISD::ZERO_EXTEND, MVT::v4i16,  MVT::v4i8,   1 },
+    { ISD::SIGN_EXTEND, MVT::v4i16,  MVT::v4i8,   6 },
+
----------------
RKSimon wrote:
> These values don't appear to be correct for SSE41 which has PMOVSX/PMOVZX ops - maybe split off the 128-bit extension ops from AVXConversionTbl into SSE41ConversionTbl ?
SSSE3 also provides pshufb from which several operations here can benefit. So you suggestion adding more tables for SSSE3/SSE4.1?


http://reviews.llvm.org/D15132