freedreno/ir3: use instr flag to mark unused instructions

Rather than magic depth value, which won't be available in later stages.

Signed-off-by: Rob Clark <robclark@freedesktop.org>

src/gallium/drivers/freedreno/ir3/ir3.h

@@ -177,6 +177,7 @@ struct ir3_instruction {
 		 * before register assignment is done:
 		 */
 		IR3_INSTR_MARK  = 0x1000,
+		IR3_INSTR_UNUSED= 0x2000,
 	} flags;
 	int repeat;
 #ifdef DEBUG
@@ -243,11 +244,7 @@ struct ir3_instruction {
 		 * result of moving a const to a reg would have a low cost,  so to
 		 * it could make sense to duplicate the instruction at various
 		 * points where the result is needed to reduce register footprint.
-		 *
-		 * DEPTH_UNUSED used to mark unused instructions after depth
-		 * calculation pass.
 		 */
-#define DEPTH_UNUSED  ~0
 		unsigned depth;
 		/* When we get to the RA stage, we no longer need depth, but
 		 * we do need instruction's position/name:

src/gallium/drivers/freedreno/ir3/ir3_depth.c

@@ -139,7 +139,7 @@ remove_unused_by_block(struct ir3_block *block)
 			/* mark it, in case it is input, so we can
 			 * remove unused inputs:
 			 */
-			instr->depth = DEPTH_UNUSED;
+			instr->flags |= IR3_INSTR_UNUSED;
 			/* and remove from instruction list: */
 			list_delinit(&instr->node);
 		}
@@ -175,14 +175,14 @@ ir3_depth(struct ir3 *ir)
 	 */
 	for (i = 0; i < ir->indirects_count; i++) {
 		struct ir3_instruction *instr = ir->indirects[i];
-		if (instr->depth == DEPTH_UNUSED)
+		if (instr->flags & IR3_INSTR_UNUSED)
 			ir->indirects[i] = NULL;
 	}
 
 	/* cleanup unused inputs: */
 	for (i = 0; i < ir->ninputs; i++) {
 		struct ir3_instruction *in = ir->inputs[i];
-		if (in && (in->depth == DEPTH_UNUSED))
+		if (in && (in->flags & IR3_INSTR_UNUSED))
 			ir->inputs[i] = NULL;
 	}
 }

src/gallium/drivers/freedreno/ir3/ir3_ra.c

@@ -314,6 +314,14 @@ writes_gpr(struct ir3_instruction *instr)
 	return is_temp(instr->regs[0]);
 }
 
+static bool
+instr_before(struct ir3_instruction *a, struct ir3_instruction *b)
+{
+	if (a->flags & IR3_INSTR_UNUSED)
+		return false;
+	return (a->ip < b->ip);
+}
+
 static struct ir3_instruction *
 get_definer(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr,
 		int *sz, int *off)
@@ -348,7 +356,7 @@ get_definer(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr,
 
 			dd = get_definer(ctx, src->instr, &dsz, &doff);
 
-			if ((!d) || (dd->ip < d->ip)) {
+			if ((!d) || instr_before(dd, d)) {
 				d = dd;
 				*sz = dsz;
 				*off = doff - n;
@@ -369,9 +377,14 @@ get_definer(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr,
 		 */
 		int cnt = 0;
 
-		d = f;
+		/* need to skip over unused in the group: */
+		while (f && (f->flags & IR3_INSTR_UNUSED)) {
+			f = f->cp.right;
+			cnt++;
+		}
+
 		while (f) {
-			if (f->ip < d->ip)
+			if ((!d) || instr_before(f, d))
 				d = f;
 			if (f == instr)
 				*off = cnt;
@@ -414,7 +427,7 @@ get_definer(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr,
 		*sz = MAX2(*sz, dsz);
 		*off = doff;
 
-		if (dd->ip < d->ip) {
+		if (instr_before(dd, d)) {
 			d = dd;
 		}
 	}
@@ -432,7 +445,7 @@ get_definer(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr,
 		foreach_src(src, d) {
 			if (!src->instr)
 				continue;
-			if (src->instr->ip < dd->ip)
+			if (instr_before(src->instr, dd))
 				dd = src->instr;
 		}
 
@@ -446,7 +459,7 @@ get_definer(struct ir3_ra_ctx *ctx, struct ir3_instruction *instr,
 		dd = get_definer(ctx, d->regs[1]->instr, &dsz, &doff);
 
 		/* by definition, should come before: */
-		debug_assert(dd->ip < d->ip);
+		debug_assert(instr_before(dd, d));
 
 		*sz = MAX2(*sz, dsz);
 

src/gallium/drivers/freedreno/ir3/ir3_sched.c

@@ -246,7 +246,7 @@ instr_eligibility(struct ir3_sched_ctx *ctx, struct ir3_sched_notes *notes,
 
 		for (unsigned i = 0; i < ir->baryfs_count; i++) {
 			struct ir3_instruction *baryf = ir->baryfs[i];
-			if (baryf->depth == DEPTH_UNUSED)
+			if (baryf->flags & IR3_INSTR_UNUSED)
 				continue;
 			if (!is_scheduled(baryf)) {
 				notes->blocked_kill = true;