intel/compiler: Don't change hstride if not needed

Alignment requirements may have changed the horizontal stride already,
so don't set it if not required to avoid breaking said requirements.

Fixes several tests such as
dEQP-VK.subgroups.vote.graphics.subgroupallequal_int8_t

Signed-off-by: Iván Briano <ivan.briano@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/intel/compiler/brw_eu_emit.c

@@ -95,14 +95,15 @@ brw_set_dest(struct brw_codegen *p, brw_inst *inst, struct brw_reg dest)
    else if (dest.file == BRW_GENERAL_REGISTER_FILE)
       assert(dest.nr < 128);
 
-   /* The hardware has a restriction where if the destination is Byte,
-    * the instruction needs to have a stride of 2 (except for packed byte
-    * MOV). This seems to be required even if the destination is the NULL
-    * register.
+   /* The hardware has a restriction where a destination of size Byte with
+    * a stride of 1 is only allowed for a packed byte MOV. For any other
+    * instruction, the stride must be at least 2, even when the destination
+    * is the NULL register.
     */
    if (dest.file == BRW_ARCHITECTURE_REGISTER_FILE &&
        dest.nr == BRW_ARF_NULL &&
-       type_sz(dest.type) == 1) {
+       type_sz(dest.type) == 1 &&
+       dest.hstride == BRW_HORIZONTAL_STRIDE_1) {
       dest.hstride = BRW_HORIZONTAL_STRIDE_2;
    }