From 11d5d20e8bd6809363291574c817b8659f6b5fb5 Mon Sep 17 00:00:00 2001
From: Ian Romanick <ian.d.romanick@intel.com>
Date: Mon, 3 Nov 2025 11:11:53 -0800
Subject: [PATCH] brw: Force allow_spilling when spill_all is set

This ensures that g0 is reserved for spilling since there is going to be
spilling.

Fixes: 8bca7e520ce ("intel/brw: Only force g0's liveness to be the whole program if spilling")
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
(cherry picked from commit 1fc2f52d36211c753bb94cd5d46ec1c4d3d0dd46)

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38803>
---
 .pick_status.json                           | 2 +-
 src/intel/compiler/brw/brw_reg_allocate.cpp | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/.pick_status.json b/.pick_status.json
index eee7ad04ad9..1c037af387a 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -1424,7 +1424,7 @@
         "description": "brw: Force allow_spilling when spill_all is set",
         "nominated": true,
         "nomination_type": 2,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "8bca7e520ce01a59292c982f3b992bd4a2b3547e",
         "notes": null
diff --git a/src/intel/compiler/brw/brw_reg_allocate.cpp b/src/intel/compiler/brw/brw_reg_allocate.cpp
index 6d3526692e8..aca02d614e0 100644
--- a/src/intel/compiler/brw/brw_reg_allocate.cpp
+++ b/src/intel/compiler/brw/brw_reg_allocate.cpp
@@ -1429,6 +1429,12 @@ brw_reg_alloc::assign_regs(bool allow_spilling, bool spill_all)
 bool
 brw_assign_regs(brw_shader &s, bool allow_spilling, bool spill_all)
 {
+   /* Ensure that g0 is reserved for spilling since there is going to be
+    * spilling.
+    */
+   if (spill_all)
+      allow_spilling = true;
+
    brw_reg_alloc alloc(&s);
    bool success = alloc.assign_regs(allow_spilling, spill_all);
    if (!success && allow_spilling) {