freedreno/ir3: only tex instructions have wrmask

At the ir3 level, we would assume that we could use wrmask to mask
off other components of an instruction returning a vecN when they are
not used.  Which would let RA use components not written for other live
values.  But this is only true for tex instructions.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/freedreno/ir3/ir3_depth.c

@@ -177,13 +177,10 @@ remove_unused_by_block(struct ir3_block *block)
 		if (instr->flags & IR3_INSTR_UNUSED) {
 			if (instr->opc == OPC_META_SPLIT) {
 				struct ir3_instruction *src = ssa(instr->regs[1]);
-				/* leave inputs alone.. we can't optimize out components of
-				 * an input, since the hw is still going to be writing all
-				 * of the components, and we could end up in a situation
-				 * where multiple inputs overlap.
+				/* tex (cat5) instructions have a writemask, so we can
+				 * mask off unused components.  Other instructions do not.
 				 */
-				if ((src->opc != OPC_META_INPUT) &&
-						(src->regs[0]->wrmask > 1)) {
+				if (is_tex(src) && (src->regs[0]->wrmask > 1)) {
 					src->regs[0]->wrmask &= ~(1 << instr->split.off);
 
 					/* prune no-longer needed right-neighbors.  We could