Mesa (master): freedreno/ir3: fix addr/pred spilling

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Module: Mesa
Branch: master
Commit: 1fd6a91d4a23aec40bd599cec0b6fe5d7bdc0cfb
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1fd6a91d4a23aec40bd599cec0b6fe5d7bdc0cfb

Author: Rob Clark <robdclark at chromium.org>
Date:   Mon Aug 12 11:34:18 2019 -0700

freedreno/ir3: fix addr/pred spilling

The live_values and use_count was not being properly updated.  This
starts triggering problems with the next patch, where we allow copy
propagation for RELATIV access.

Signed-off-by: Rob Clark <robdclark at chromium.org>
Reviewed-by: Eric Anholt <eric at anholt.net>

---

 src/freedreno/ir3/ir3_sched.c | 49 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 42 insertions(+), 7 deletions(-)

diff --git a/src/freedreno/ir3/ir3_sched.c b/src/freedreno/ir3/ir3_sched.c
index a311956e925..9a544a8e651 100644
--- a/src/freedreno/ir3/ir3_sched.c
+++ b/src/freedreno/ir3/ir3_sched.c
@@ -59,6 +59,11 @@ struct ir3_sched_ctx {
 	bool error;
 };
 
+static bool is_scheduled(struct ir3_instruction *instr)
+{
+	return !!(instr->flags & IR3_INSTR_MARK);
+}
+
 static bool is_sfu_or_mem(struct ir3_instruction *instr)
 {
 	return is_sfu(instr) || is_mem(instr);
@@ -87,8 +92,32 @@ unuse_each_src(struct ir3_sched_ctx *ctx, struct ir3_instruction *instr)
 	}
 }
 
+static void clear_cache(struct ir3_sched_ctx *ctx, struct ir3_instruction *instr);
 static void use_instr(struct ir3_instruction *instr);
 
+/* transfers a use-count to new instruction, for cases where we
+ * "spill" address or predicate.  Note this might cause the
+ * previous instruction that loaded a0.x/p0.x to become live
+ * again, when we previously thought it was dead.
+ */
+static void
+transfer_use(struct ir3_sched_ctx *ctx, struct ir3_instruction *orig_instr,
+		struct ir3_instruction *new_instr)
+{
+	struct ir3_instruction *src;
+
+	debug_assert(is_scheduled(orig_instr));
+
+	foreach_ssa_src_n(src, n, new_instr) {
+		if (__is_false_dep(new_instr, n))
+			continue;
+		ctx->live_values += dest_regs(src);
+		use_instr(src);
+	}
+
+	clear_cache(ctx, orig_instr);
+}
+
 static void
 use_each_src(struct ir3_instruction *instr)
 {
@@ -346,11 +375,6 @@ struct ir3_sched_notes {
 	bool addr_conflict, pred_conflict;
 };
 
-static bool is_scheduled(struct ir3_instruction *instr)
-{
-	return !!(instr->flags & IR3_INSTR_MARK);
-}
-
 /* could an instruction be scheduled if specified ssa src was scheduled? */
 static bool
 could_sched(struct ir3_instruction *instr, struct ir3_instruction *src)
@@ -372,6 +396,8 @@ static bool
 check_instr(struct ir3_sched_ctx *ctx, struct ir3_sched_notes *notes,
 		struct ir3_instruction *instr)
 {
+	debug_assert(!is_scheduled(instr));
+
 	/* For instructions that write address register we need to
 	 * make sure there is at least one instruction that uses the
 	 * addr value which is otherwise ready.
@@ -640,6 +666,15 @@ find_eligible_instr(struct ir3_sched_ctx *ctx, struct ir3_sched_notes *notes,
 	return best_instr;
 }
 
+static struct ir3_instruction *
+split_instr(struct ir3_sched_ctx *ctx, struct ir3_instruction *orig_instr)
+{
+	struct ir3_instruction *new_instr = ir3_instr_clone(orig_instr);
+	ir3_insert_by_depth(new_instr, &ctx->depth_list);
+	transfer_use(ctx, orig_instr, new_instr);
+	return new_instr;
+}
+
 /* "spill" the address register by remapping any unscheduled
  * instructions which depend on the current address register
  * to a clone of the instruction which wrote the address reg.
@@ -670,7 +705,7 @@ split_addr(struct ir3_sched_ctx *ctx)
 		 */
 		if (indirect->address == ctx->addr) {
 			if (!new_addr) {
-				new_addr = ir3_instr_clone(ctx->addr);
+				new_addr = split_instr(ctx, ctx->addr);
 				/* original addr is scheduled, but new one isn't: */
 				new_addr->flags &= ~IR3_INSTR_MARK;
 			}
@@ -714,7 +749,7 @@ split_pred(struct ir3_sched_ctx *ctx)
 		 */
 		if (ssa(predicated->regs[1]) == ctx->pred) {
 			if (!new_pred) {
-				new_pred = ir3_instr_clone(ctx->pred);
+				new_pred = split_instr(ctx, ctx->pred);
 				/* original pred is scheduled, but new one isn't: */
 				new_pred->flags &= ~IR3_INSTR_MARK;
 			}