[Mesa-dev] [RFC PATCH 7/9] ac/shader: scan if shaders use derivatives texture instructions

[Samuel Pitoiset]

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/common/ac_shader_info.c | 30 ++++++++++++++++++++++++++++++
 src/amd/common/ac_shader_info.h |  1 +
 2 files changed, 31 insertions(+)

diff --git a/src/amd/common/ac_shader_info.c b/src/amd/common/ac_shader_info.c
index c495879280..55b87cb96a 100644
--- a/src/amd/common/ac_shader_info.c
+++ b/src/amd/common/ac_shader_info.c
@@ -183,6 +183,33 @@ gather_tex_info(const nir_shader *nir, const nir_tex_instr *instr,
 		mark_sampler_desc(instr->sampler->var, info);
 	if (instr->texture)
 		mark_sampler_desc(instr->texture->var, info);
+
+	switch (instr->op) {
+	case nir_texop_tex:
+	case nir_texop_txb:
+	case nir_texop_lod:
+		info->ps.uses_derivatives = true;
+		break;
+	default:
+		break;
+	}
+}
+
+static void
+gather_alu_info(const nir_alu_instr *instr, struct ac_shader_info *info)
+{
+	switch (instr->op) {
+	case nir_op_fddx:
+	case nir_op_fddy:
+	case nir_op_fddx_fine:
+	case nir_op_fddy_fine:
+	case nir_op_fddx_coarse:
+	case nir_op_fddy_coarse:
+		info->ps.uses_derivatives = true;
+		break;
+	default:
+		break;
+	}
 }
 
 static void
@@ -197,6 +224,9 @@ gather_info_block(const nir_shader *nir, const nir_block *block,
 		case nir_instr_type_tex:
 			gather_tex_info(nir, nir_instr_as_tex(instr), info);
 			break;
+		case nir_instr_type_alu:
+			gather_alu_info(nir_instr_as_alu(instr), info);
+			break;
 		default:
 			break;
 		}
diff --git a/src/amd/common/ac_shader_info.h b/src/amd/common/ac_shader_info.h
index 8e1102c081..ce62865825 100644
--- a/src/amd/common/ac_shader_info.h
+++ b/src/amd/common/ac_shader_info.h
@@ -65,6 +65,7 @@ struct ac_shader_info {
 		bool uses_persp_center;
 		uint32_t flat_shaded_mask;
 		bool uses_kill;
+		bool uses_derivatives;
 	} ps;
 	struct {
 		bool uses_grid_size;
-- 
2.16.2