freedreno/a6xx: also consider alpha-test for ztest-mode

Looks like we don't have CI coverage for this (since deqp==GLES) but
alpha test is conceptually the same as frag shaders with discard, and
should be handled as such.

Signed-off-by: Rob Clark <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5298>

3 files changed, 4 insertions, 1 deletions

diff --git a/src/gallium/drivers/freedreno/a6xx/fd6_emit.c b/src/gallium/drivers/freedreno/a6xx/fd6_emit.c
index 82bf24759a4..256860bdfcc 100644
--- a/src/gallium/drivers/freedreno/a6xx/fd6_emit.c
+++ b/src/gallium/drivers/freedreno/a6xx/fd6_emit.c
@@ -588,11 +588,12 @@ build_vbo_state(struct fd6_emit *emit, const struct ir3_shader_variant *vp)
 static enum a6xx_ztest_mode
 compute_ztest_mode(struct fd6_emit *emit, bool lrz_valid)
 {
+	struct fd6_zsa_stateobj *zsa = fd6_zsa_stateobj(emit->ctx->zsa);
 	const struct ir3_shader_variant *fs = emit->fs;
 
 	if (fs->no_earlyz || fs->writes_pos) {
 		return A6XX_LATE_Z;
-	} else if (fs->has_kill) {
+	} else if (fs->has_kill || zsa->alpha_test) {
 		return lrz_valid ? A6XX_EARLY_LRZ_LATE_Z : A6XX_LATE_Z;
 	} else {
 		return A6XX_EARLY_Z;
diff --git a/src/gallium/drivers/freedreno/a6xx/fd6_zsa.c b/src/gallium/drivers/freedreno/a6xx/fd6_zsa.c
index d7c2000b424..dc7c1fbf087 100644
--- a/src/gallium/drivers/freedreno/a6xx/fd6_zsa.c
+++ b/src/gallium/drivers/freedreno/a6xx/fd6_zsa.c
@@ -190,6 +190,7 @@ fd6_zsa_state_create(struct pipe_context *pctx,
 		 */
 		if (cso->alpha.func != PIPE_FUNC_ALWAYS) {
 			so->lrz.write = false;
+			so->alpha_test = true;
 		}
 
 		uint32_t ref = cso->alpha.ref_value * 255.0;
diff --git a/src/gallium/drivers/freedreno/a6xx/fd6_zsa.h b/src/gallium/drivers/freedreno/a6xx/fd6_zsa.h
index 73bfa4fba06..2d39797116b 100644
--- a/src/gallium/drivers/freedreno/a6xx/fd6_zsa.h
+++ b/src/gallium/drivers/freedreno/a6xx/fd6_zsa.h
@@ -47,6 +47,7 @@ struct fd6_zsa_stateobj {
 
 	struct fd6_lrz_state lrz;
 	bool invalidate_lrz;
+	bool alpha_test;
 
 	struct fd_ringbuffer *stateobj;
 	struct fd_ringbuffer *stateobj_no_alpha;