From 310d17fcf17bdeb897f12b4577f8faf3abba9e77 Mon Sep 17 00:00:00 2001 From: Samuel Pitoiset Date: Wed, 10 Jan 2018 20:12:11 +0100 Subject: [PATCH] ac: only load used channels when sampling buffer views MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This allows to reduce the number of dwords that are loaded with buffer_load_format_xyzw. For example, when the only used channel is 1, the driver will emit buffer_load_format_x instead. Shader stats for DOW3 (with some local hacky scripts for SPIRV): 143 shaders in 143 tests Totals: SGPRS: 5344 -> 5352 (0.15 %) VGPRS: 3476 -> 3452 (-0.69 %) Spilled SGPRs: 30 -> 29 (-3.33 %) Spilled VGPRs: 0 -> 0 (0.00 %) Private memory VGPRs: 0 -> 0 (0.00 %) Scratch size: 0 -> 0 (0.00 %) dwords per thread Code Size: 269860 -> 269808 (-0.02 %) bytes LDS: 0 -> 0 (0.00 %) blocks Max Waves: 1267 -> 1272 (0.39 %) Wait states: 0 -> 0 (0.00 %) Signed-off-by: Samuel Pitoiset Reviewed-by: Bas Nieuwenhuizen Reviewed-by: Nicolai Hähnle --- src/amd/common/ac_nir_to_llvm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c index b40769f..5b8c346 100644 --- a/src/amd/common/ac_nir_to_llvm.c +++ b/src/amd/common/ac_nir_to_llvm.c @@ -2315,11 +2315,14 @@ static LLVMValueRef build_tex_intrinsic(struct ac_nir_context *ctx, struct ac_image_args *args) { if (instr->sampler_dim == GLSL_SAMPLER_DIM_BUF) { + unsigned mask = nir_ssa_def_components_read(&instr->dest.ssa); + return ac_build_buffer_load_format(&ctx->ac, args->resource, args->addr, ctx->ac.i32_0, - 4, true); + util_last_bit(mask), + true); } args->opcode = ac_image_sample; -- 2.7.4