Displaying 1 result from an estimated 1 matches for "pmovzxbw".
2014 Dec 02
2
[LLVMdev] Should more vector [zs]extloads be legal for X86 SSE4.1?
...duced by SSE4.1/AVX2 declared
legal? Is it a simple oversight, or did I miss a deeper reason?
While cleaning up PMOV*X patterns, I stumbled upon this braindead testcase:
%0 = load <8 x i8>* %src, align 1
%1 = zext <8 x i8> %0 to <8 x i16>
turning into:
pmovzxbw (%rsi), %xmm0
pand <0xff,0xff,...>, %xmm0, %xmm0
v8i8 isn't legal, so the load became an anyext load from v8i8 to
v8i16, with the pand masking out the unwanted/zero bits.
In that example, if you declare zextloads from v8i8 legal, and add the
simple corresponding pattern,...