[Mesa-dev] [RFC PATCH 2/9] ac/shader: scan uses_persp_{centroid, center}

[Samuel Pitoiset]

This allows us to remove one nir_foreach_variable loop.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/common/ac_nir_to_llvm.c | 16 ++--------------
 src/amd/common/ac_shader_info.c | 11 ++++++++---
 src/amd/common/ac_shader_info.h |  2 ++
 3 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index 9586cd4d46..358e3f04fd 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -5564,20 +5564,8 @@ prepare_interp_optimize(struct radv_shader_context *ctx,
 	if (!ctx->options->key.fs.multisample)
 		return;
 
-	bool uses_center = false;
-	bool uses_centroid = false;
-	nir_foreach_variable(variable, &nir->inputs) {
-		if (glsl_get_base_type(glsl_without_array(variable->type)) != GLSL_TYPE_FLOAT ||
-		    variable->data.sample)
-			continue;
-
-		if (variable->data.centroid)
-			uses_centroid = true;
-		else
-			uses_center = true;
-	}
-
-	if (uses_center && uses_centroid) {
+	if (ctx->shader_info->info.ps.uses_persp_center &&
+	    ctx->shader_info->info.ps.uses_persp_centroid) {
 		LLVMValueRef sel = LLVMBuildICmp(ctx->ac.builder, LLVMIntSLT, ctx->abi.prim_mask, ctx->ac.i32_0, "");
 		ctx->persp_centroid = LLVMBuildSelect(ctx->ac.builder, sel, ctx->persp_center, ctx->persp_centroid, "");
 		ctx->linear_centroid = LLVMBuildSelect(ctx->ac.builder, sel, ctx->linear_center, ctx->linear_centroid, "");
diff --git a/src/amd/common/ac_shader_info.c b/src/amd/common/ac_shader_info.c
index 8dda241324..60e3d62e79 100644
--- a/src/amd/common/ac_shader_info.c
+++ b/src/amd/common/ac_shader_info.c
@@ -231,9 +231,6 @@ gather_info_input_decl_ps(const nir_shader *nir, const nir_variable *var,
 	}
 
 	if (glsl_get_base_type(type) == GLSL_TYPE_FLOAT) {
-		if (var->data.sample)
-			info->ps.force_persample = true;
-
 		if (var->data.sample) {
 			info->ps.input_interp_loc[idx] = INTERP_SAMPLE;
 		} else if (var->data.centroid) {
@@ -242,6 +239,14 @@ gather_info_input_decl_ps(const nir_shader *nir, const nir_variable *var,
 			info->ps.input_interp_loc[idx] = INTERP_CENTER;
 		}
 
+		if (info->ps.input_interp_loc[idx] == INTERP_SAMPLE) {
+			info->ps.force_persample = true;
+		} else if (info->ps.input_interp_loc[idx] == INTERP_CENTROID) {
+			info->ps.uses_persp_centroid = true;
+		} else {
+			info->ps.uses_persp_center = true;
+		}
+
 		info->ps.input_interp_mode[idx] = var->data.interpolation;
 	} else {
 		info->ps.input_interp_mode[idx] = INTERP_MODE_FLAT;
diff --git a/src/amd/common/ac_shader_info.h b/src/amd/common/ac_shader_info.h
index 4469e8c5c9..d02841adfe 100644
--- a/src/amd/common/ac_shader_info.h
+++ b/src/amd/common/ac_shader_info.h
@@ -58,6 +58,8 @@ struct ac_shader_info {
 		bool layer_input;
 		uint8_t input_interp_loc[VARYING_SLOT_VAR31 + 1];
 		uint8_t input_interp_mode[VARYING_SLOT_VAR31 + 1];
+		bool uses_persp_centroid;
+		bool uses_persp_center;
 	} ps;
 	struct {
 		bool uses_grid_size;
-- 
2.16.2