From 6f87d7a14699277be6dd17e9e712841c4057c4df Mon Sep 17 00:00:00 2001 From: =?utf8?q?Nicolai=20H=C3=A4hnle?= Date: Wed, 28 Sep 2016 18:20:32 +0200 Subject: [PATCH] gallium/radeon: cleanup and fix branch emits MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Some of the existing code is needlessly complicated. The basic principle should be: control-flow opcodes emit branches to properly terminate the current block, _unless_ the current block already has a terminator (which happens if and only if there was a BRK or CONT). This also fixes a bug where multiple terminators were created in a block. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97887 Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Marek Olšák --- .../drivers/radeon/radeon_setup_tgsi_llvm.c | 51 ++++++---------------- 1 file changed, 14 insertions(+), 37 deletions(-) diff --git a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c index bcb3143..201bed8 100644 --- a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c +++ b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c @@ -796,6 +796,16 @@ void radeon_llvm_emit_store(struct lp_build_tgsi_context *bld_base, } } +/* Emit a branch to the given default target for the current block if + * applicable -- that is, if the current block does not already contain a + * branch from a break or continue. + */ +static void emit_default_branch(LLVMBuilderRef builder, LLVMBasicBlockRef target) +{ + if (!LLVMGetBasicBlockTerminator(LLVMGetInsertBlock(builder))) + LLVMBuildBr(builder, target); +} + static void bgnloop_emit(const struct lp_build_tgsi_action *action, struct lp_build_tgsi_context *bld_base, struct lp_build_emit_data *emit_data) @@ -856,28 +866,8 @@ static void else_emit(const struct lp_build_tgsi_action *action, struct radeon_llvm_context *ctx = radeon_llvm_context(bld_base); struct gallivm_state *gallivm = bld_base->base.gallivm; struct radeon_llvm_branch *current_branch = get_current_branch(ctx); - LLVMBasicBlockRef current_block = LLVMGetInsertBlock(gallivm->builder); - - /* We need to add a terminator to the current block if the previous - * instruction was an ENDIF.Example: - * IF - * [code] - * IF - * [code] - * ELSE - * [code] - * ENDIF <-- - * ELSE<-- - * [code] - * ENDIF - */ - if (current_block != current_branch->if_block) { - LLVMBuildBr(gallivm->builder, current_branch->endif_block); - } - if (!LLVMGetBasicBlockTerminator(current_branch->if_block)) { - LLVMBuildBr(gallivm->builder, current_branch->endif_block); - } + emit_default_branch(gallivm->builder, current_branch->endif_block); current_branch->has_else = 1; LLVMPositionBuilderAtEnd(gallivm->builder, current_branch->else_block); } @@ -889,26 +879,15 @@ static void endif_emit(const struct lp_build_tgsi_action *action, struct radeon_llvm_context *ctx = radeon_llvm_context(bld_base); struct gallivm_state *gallivm = bld_base->base.gallivm; struct radeon_llvm_branch *current_branch = get_current_branch(ctx); - LLVMBasicBlockRef current_block = LLVMGetInsertBlock(gallivm->builder); - /* If we have consecutive ENDIF instructions, then the first ENDIF - * will not have a terminator, so we need to add one. */ - if (current_block != current_branch->if_block - && current_block != current_branch->else_block - && !LLVMGetBasicBlockTerminator(current_block)) { + emit_default_branch(gallivm->builder, current_branch->endif_block); - LLVMBuildBr(gallivm->builder, current_branch->endif_block); - } + /* Need to fixup an empty else block if there was no ELSE opcode. */ if (!LLVMGetBasicBlockTerminator(current_branch->else_block)) { LLVMPositionBuilderAtEnd(gallivm->builder, current_branch->else_block); LLVMBuildBr(gallivm->builder, current_branch->endif_block); } - if (!LLVMGetBasicBlockTerminator(current_branch->if_block)) { - LLVMPositionBuilderAtEnd(gallivm->builder, current_branch->if_block); - LLVMBuildBr(gallivm->builder, current_branch->endif_block); - } - LLVMPositionBuilderAtEnd(gallivm->builder, current_branch->endif_block); ctx->branch_depth--; } @@ -921,9 +900,7 @@ static void endloop_emit(const struct lp_build_tgsi_action *action, struct gallivm_state *gallivm = bld_base->base.gallivm; struct radeon_llvm_loop *current_loop = get_current_loop(ctx); - if (!LLVMGetBasicBlockTerminator(LLVMGetInsertBlock(gallivm->builder))) { - LLVMBuildBr(gallivm->builder, current_loop->loop_block); - } + emit_default_branch(gallivm->builder, current_loop->loop_block); LLVMPositionBuilderAtEnd(gallivm->builder, current_loop->endloop_block); ctx->loop_depth--; -- 2.7.4