Mesa (master): ir3: disallow moving memory writes over discard

[GitLab Mirror]

Module: Mesa
Branch: master
Commit: 7e25e5b56f9e746f7ce006ce47510ad2bd24174a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=7e25e5b56f9e746f7ce006ce47510ad2bd24174a

Author: Danylo Piliaiev <dpiliaiev at igalia.com>
Date:   Tue Mar  2 14:30:01 2021 +0200

ir3: disallow moving memory writes over discard

Writes to global memory should not be moved over discard,
otherwise we could have unintended side-effects or lack of
side-effects where they should be observed.

Fixes tests:
 dEQP-VK.rasterization.frag_side_effects.color_at_beginning.kill
 dEQP-VK.rasterization.frag_side_effects.color_at_end.kill

Signed-off-by: Danylo Piliaiev <dpiliaiev at igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9365>

---

 src/freedreno/ir3/ir3_compiler_nir.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/freedreno/ir3/ir3_compiler_nir.c b/src/freedreno/ir3/ir3_compiler_nir.c
index 7c06bf34553..9718f148c64 100644
--- a/src/freedreno/ir3/ir3_compiler_nir.c
+++ b/src/freedreno/ir3/ir3_compiler_nir.c
@@ -1956,6 +1956,9 @@ emit_intrinsic(struct ir3_context *ctx, nir_intrinsic_instr *intr)
 		cond->regs[0]->flags &= ~IR3_REG_SSA;
 
 		kill = ir3_KILL(b, cond, 0);
+		/* Side-effects should not be moved on a different side of the kill */
+		kill->barrier_class = IR3_BARRIER_IMAGE_W | IR3_BARRIER_BUFFER_W;
+		kill->barrier_conflict = IR3_BARRIER_IMAGE_W | IR3_BARRIER_BUFFER_W;
 		kill->regs[1]->num = regid(REG_P0, 0);
 		array_insert(ctx->ir, ctx->ir->predicates, kill);