[X86] AVX512: Specify compressed displacement for vmovntdqa

Use the max 64-bit element size with EVEX_CD8.  This should work since element
size is ignored for a full-vector access (FVM).

llvm-svn: 211175

llvm/lib/Target/X86/X86InstrAVX512.td

@@ -1798,7 +1798,7 @@ def VMOVNTDQAZrm : AVX5128I<0x2A, MRMSrcMem, (outs VR512:$dst),
                             "vmovntdqa\t{$src, $dst|$dst, $src}",
                             [(set VR512:$dst,
                               (int_x86_avx512_movntdqa addr:$src))]>,
-                   EVEX, EVEX_V512;
+                   EVEX, EVEX_V512, EVEX_CD8<64, CD8VF>;
 
 //===----------------------------------------------------------------------===//
 // AVX-512 - Integer arithmetic

llvm/test/MC/X86/avx512-encodings.s

@@ -3159,3 +3159,7 @@ vmovntdqa 0x12345678(%rbx), %zmm13
 // CHECK: vmovntdqa
 // CHECK: encoding: [0x62,0xc2,0x7d,0x48,0x2a,0x14,0x56]
 vmovntdqa (%r14,%rdx,2), %zmm18
+
+// CHECK: vmovntdqa
+// CHECK: encoding: [0x62,0xc2,0x7d,0x48,0x2a,0x7c,0x14,0x02]
+vmovntdqa 128(%r12,%rdx), %zmm23