From 728bd3ad79ef0d4a2380c69b10e2d39e013d30e0 Mon Sep 17 00:00:00 2001
From: Simon Perretta <simon.perretta@imgtec.com>
Date: Sun, 6 Apr 2025 13:45:58 +0100
Subject: [PATCH] pco: ensure srcs/dests interfere for instructions with repeat
 > 1

Signed-off-by: Simon Perretta <simon.perretta@imgtec.com>
Acked-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36412>
---
 src/imagination/pco/pco_ra.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/imagination/pco/pco_ra.c b/src/imagination/pco/pco_ra.c
index df51aec3389..31819904a7a 100644
--- a/src/imagination/pco/pco_ra.c
+++ b/src/imagination/pco/pco_ra.c
@@ -627,6 +627,21 @@ static bool pco_ra_func(pco_func *func,
       }
    }
 
+   /* Make srcs and dests interfere for instructions with repeat > 1. */
+   pco_foreach_instr_in_func_rev (instr, func) {
+      if (!pco_instr_has_rpt(instr))
+         continue;
+
+      if (pco_instr_get_rpt(instr) < 2)
+         continue;
+
+      pco_foreach_instr_dest_ssa (pdest, instr) {
+         pco_foreach_instr_src_ssa (psrc, instr) {
+            ra_add_node_interference(ra_graph, pdest->val, psrc->val);
+         }
+      }
+   }
+
    bool allocated = ra_allocate(ra_graph);
    assert(allocated);
    /* TODO: spilling. */