From facfab28fe47467d3adb3eae179075e4424c3b82 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marek=20Ol=C5=A1=C3=A1k?= Date: Wed, 5 Jul 2017 23:33:13 +0200 Subject: [PATCH] radeonsi/gfx9: add workarounds to avoid VGPR indexing completely MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit For inputs and outputs, indirect indexing is lowered by the GLSL compiler. For temporaries, use alloca and disable the "promote-alloca" pass. In the future, we could switch all codepaths to alloca permanently and just rely on the "promote-alloca" pass. Reviewed-by: Nicolai Hähnle --- src/gallium/drivers/radeonsi/si_pipe.c | 25 ++++++++++++++++------ src/gallium/drivers/radeonsi/si_pipe.h | 1 + .../drivers/radeonsi/si_shader_tgsi_setup.c | 3 +-- 3 files changed, 21 insertions(+), 8 deletions(-) diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c index afb2bcb..8a4bc41 100644 --- a/src/gallium/drivers/radeonsi/si_pipe.c +++ b/src/gallium/drivers/radeonsi/si_pipe.c @@ -141,8 +141,9 @@ si_create_llvm_target_machine(struct si_screen *sscreen) char features[256]; snprintf(features, sizeof(features), - "+DumpCode,+vgpr-spilling,-fp32-denormals,+fp64-denormals%s%s", + "+DumpCode,+vgpr-spilling,-fp32-denormals,+fp64-denormals%s%s%s", sscreen->b.chip_class >= GFX9 ? ",+xnack" : ",-xnack", + sscreen->llvm_has_working_vgpr_indexing ? "" : ",-promote-alloca", sscreen->b.debug_flags & DBG_SI_SCHED ? ",+si-scheduler" : ""); return LLVMCreateTargetMachine(ac_get_llvm_target(triple), triple, @@ -757,7 +758,6 @@ static int si_get_shader_param(struct pipe_screen* pscreen, /* Supported boolean features. */ case PIPE_SHADER_CAP_TGSI_CONT_SUPPORTED: case PIPE_SHADER_CAP_TGSI_SQRT_SUPPORTED: - case PIPE_SHADER_CAP_INDIRECT_OUTPUT_ADDR: case PIPE_SHADER_CAP_INDIRECT_TEMP_ADDR: case PIPE_SHADER_CAP_INDIRECT_CONST_ADDR: case PIPE_SHADER_CAP_INTEGERS: @@ -767,10 +767,18 @@ static int si_get_shader_param(struct pipe_screen* pscreen, return 1; case PIPE_SHADER_CAP_INDIRECT_INPUT_ADDR: - /* TODO: Indirection of geometry shader input dimension is not - * handled yet - */ - return shader != PIPE_SHADER_GEOMETRY; + /* TODO: Indirect indexing of GS inputs is unimplemented. */ + return shader != PIPE_SHADER_GEOMETRY && + (sscreen->llvm_has_working_vgpr_indexing || + /* TCS and TES load inputs directly from LDS or + * offchip memory, so indirect indexing is trivial. */ + shader == PIPE_SHADER_TESS_CTRL || + shader == PIPE_SHADER_TESS_EVAL); + + case PIPE_SHADER_CAP_INDIRECT_OUTPUT_ADDR: + return sscreen->llvm_has_working_vgpr_indexing || + /* TCS stores outputs directly to memory. */ + shader == PIPE_SHADER_TESS_CTRL; /* Unsupported boolean features. */ case PIPE_SHADER_CAP_SUBROUTINES: @@ -1006,6 +1014,11 @@ struct pipe_screen *radeonsi_screen_create(struct radeon_winsys *ws, sscreen->b.family <= CHIP_POLARIS12) || sscreen->b.family == CHIP_VEGA10 || sscreen->b.family == CHIP_RAVEN; + /* While it would be nice not to have this flag, we are constrained + * by the reality that LLVM 5.0 doesn't have working VGPR indexing + * on GFX9. + */ + sscreen->llvm_has_working_vgpr_indexing = sscreen->b.chip_class <= VI; sscreen->b.has_cp_dma = true; sscreen->b.has_streamout = true; diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h index bd724e8..c028aba 100644 --- a/src/gallium/drivers/radeonsi/si_pipe.h +++ b/src/gallium/drivers/radeonsi/si_pipe.h @@ -83,6 +83,7 @@ struct si_screen { bool has_draw_indirect_multi; bool has_ds_bpermute; bool has_msaa_sample_loc_bug; + bool llvm_has_working_vgpr_indexing; /* Whether shaders are monolithic (1-part) or separate (3-part). */ bool use_monolithic_shaders; diff --git a/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c b/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c index b37d4b2..9c4a234 100644 --- a/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c +++ b/src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c @@ -755,8 +755,7 @@ static void emit_declaration(struct lp_build_tgsi_context *bld_base, * promote allocas into registers when profitable. */ if (array_size > 16 || - /* TODO: VGPR indexing is buggy on GFX9. */ - ctx->screen->b.chip_class == GFX9) { + !ctx->screen->llvm_has_working_vgpr_indexing) { array_alloca = LLVMBuildAlloca(builder, LLVMArrayType(ctx->f32, array_size), "array"); -- 2.7.4