From a5c0b8784aacfc0e7d2ff90a92dd56bb53b97bdd Mon Sep 17 00:00:00 2001 From: =?UTF-8?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=UTF-8 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 (cherry picked from commit 6f87d7a14699277be6dd17e9e712841c4057c4df) [Emil Velikov: resolve trivial conflicts] Signed-off-by: Emil Velikov Conflicts: src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c --- .../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 74b36ece212..9ae27ec20f8 100644 --- a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c +++ b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c @@ -513,6 +513,16 @@ void radeon_llvm_emit_store( } } +/* 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, @@ -577,28 +587,8 @@ static void else_emit( 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); } @@ -611,26 +601,15 @@ static void endif_emit( 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--; } @@ -644,9 +623,7 @@ static void endloop_emit( 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--;