radeonsi: implement forcing per-sample_interpolation using the shader key only

It was partly a state and partly emulated by shader code, but since we want
to do this in a fragment shader prolog, we need to put it into the shader
key, which will be used to generate the prolog.

This also removes the spi_ps_input states and moves the registers
to the PS state.

Reviewed-by: Nicolai Hähnle <[email protected]>

1 files changed, 12 insertions, 34 deletions

diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index c595f208274..0a92a7b54e6 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -833,14 +833,11 @@ static int lookup_interp_param_index(unsigned interpolate, unsigned location)
 }
 
 /* This shouldn't be used by explicit INTERP opcodes. */
-static LLVMValueRef get_interp_param(struct si_shader_context *si_shader_ctx,
-				     unsigned param)
+static unsigned select_interp_param(struct si_shader_context *si_shader_ctx,
+				    unsigned param)
 {
-	struct gallivm_state *gallivm = &si_shader_ctx->radeon_bld.gallivm;
-	unsigned sample_param = 0;
-	LLVMValueRef default_ij, sample_ij, force_sample;
-
-	default_ij = LLVMGetParam(si_shader_ctx->radeon_bld.main_fn, param);
+	if (!si_shader_ctx->shader->key.ps.force_persample_interp)
+		return param;
 
 	/* If the shader doesn't use center/centroid, just return the parameter.
 	 *
@@ -850,36 +847,15 @@ static LLVMValueRef get_interp_param(struct si_shader_context *si_shader_ctx,
 	switch (param) {
 	case SI_PARAM_PERSP_CENTROID:
 	case SI_PARAM_PERSP_CENTER:
-		if (!si_shader_ctx->shader->selector->forces_persample_interp_for_persp)
-			return default_ij;
-
-		sample_param = SI_PARAM_PERSP_SAMPLE;
-		break;
+		return SI_PARAM_PERSP_SAMPLE;
 
 	case SI_PARAM_LINEAR_CENTROID:
 	case SI_PARAM_LINEAR_CENTER:
-		if (!si_shader_ctx->shader->selector->forces_persample_interp_for_linear)
-			return default_ij;
-
-		sample_param = SI_PARAM_LINEAR_SAMPLE;
-		break;
+		return SI_PARAM_LINEAR_SAMPLE;
 
 	default:
-		return default_ij;
+		return param;
 	}
-
-	/* Otherwise, we have to select (i,j) based on a user data SGPR. */
-	sample_ij = LLVMGetParam(si_shader_ctx->radeon_bld.main_fn, sample_param);
-
-	/* TODO: this can be done more efficiently by switching between
-	 * 2 prologs.
-	 */
-	force_sample = LLVMGetParam(si_shader_ctx->radeon_bld.main_fn,
-				    SI_PARAM_PS_STATE_BITS);
-	force_sample = LLVMBuildTrunc(gallivm->builder, force_sample,
-				      LLVMInt1TypeInContext(gallivm->context), "");
-	return LLVMBuildSelect(gallivm->builder, force_sample,
-			       sample_ij, default_ij, "");
 }
 
 static void declare_input_fs(
@@ -918,8 +894,11 @@ static void declare_input_fs(
 						     decl->Interp.Location);
 	if (interp_param_idx == -1)
 		return;
-	else if (interp_param_idx)
-		interp_param = get_interp_param(si_shader_ctx, interp_param_idx);
+	else if (interp_param_idx) {
+		interp_param_idx = select_interp_param(si_shader_ctx,
+						       interp_param_idx);
+		interp_param = LLVMGetParam(main_fn, interp_param_idx);
+	}
 
 	/* fs.constant returns the param from the middle vertex, so it's not
 	 * really useful for flat shading. It's meant to be used for custom
@@ -3633,7 +3612,6 @@ static void create_function(struct si_shader_context *si_shader_ctx)
 
 	case TGSI_PROCESSOR_FRAGMENT:
 		params[SI_PARAM_ALPHA_REF] = f32;
-		params[SI_PARAM_PS_STATE_BITS] = i32;
 		params[SI_PARAM_PRIM_MASK] = i32;
 		last_sgpr = SI_PARAM_PRIM_MASK;
 		params[SI_PARAM_PERSP_SAMPLE] = v2i32;