From bdf1bf1cb5422a944205ea30b2eb203a73bdd736 Mon Sep 17 00:00:00 2001 From: Nicolai Hähnle Date: Tue, 29 Nov 2016 16:25:21 +0100 Subject: radeonsi: generate an explicit switch instruction over vertex streams MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit SimplifyCFG generates a switch instruction anyway when all four streams are present, but is simultaneously not smart enough to eliminate some redundant jumps that it generates. The generated assembly is still a bit silly, probably because the control flow annotation doesn't know how to handle a switch with uniform condition. Reviewed-by: Marek Olšák --- src/gallium/drivers/radeonsi/si_shader.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c index 31a0b3047c1..469e0c1cc3d 100644 --- a/src/gallium/drivers/radeonsi/si_shader.c +++ b/src/gallium/drivers/radeonsi/si_shader.c @@ -6407,8 +6407,14 @@ si_generate_gs_copy_shader(struct si_screen *sscreen, } } + LLVMBasicBlockRef end_bb; + LLVMValueRef switch_inst; + + end_bb = LLVMAppendBasicBlockInContext(gallivm->context, ctx.main_fn, "end"); + switch_inst = LLVMBuildSwitch(builder, stream_id, end_bb, 4); + for (int stream = 0; stream < 4; stream++) { - struct lp_build_if_state if_ctx_stream; + LLVMBasicBlockRef bb; if (!gsinfo->num_stream_output_components[stream]) continue; @@ -6416,12 +6422,9 @@ si_generate_gs_copy_shader(struct si_screen *sscreen, if (stream > 0 && !gs_selector->so.num_outputs) continue; - LLVMValueRef is_stream = - LLVMBuildICmp(builder, LLVMIntEQ, - stream_id, - lp_build_const_int32(gallivm, stream), ""); - - lp_build_if(&if_ctx_stream, gallivm, is_stream); + bb = LLVMInsertBasicBlockInContext(gallivm->context, end_bb, "out"); + LLVMAddCase(switch_inst, lp_build_const_int32(gallivm, stream), bb); + LLVMPositionBuilderAtEnd(builder, bb); /* Fetch vertex data from GSVS ring */ for (i = 0; i < gsinfo->num_outputs; ++i) { @@ -6455,9 +6458,11 @@ si_generate_gs_copy_shader(struct si_screen *sscreen, if (stream == 0) si_llvm_export_vs(bld_base, outputs, gsinfo->num_outputs); - lp_build_endif(&if_ctx_stream); + LLVMBuildBr(builder, end_bb); } + LLVMPositionBuilderAtEnd(builder, end_bb); + LLVMBuildRetVoid(gallivm->builder); /* Dump LLVM IR before any optimization passes */ -- cgit v1.2.3