From d282a292eca05bd9f701d8509d674e4697f510ec Mon Sep 17 00:00:00 2001 From: Rhys Perry Date: Tue, 7 Jan 2020 19:13:08 +0000 Subject: [PATCH] aco: don't always add logical edges from continue_break blocks to headers MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Otherwise, code like this will be broken: loop { if (...) { break; } else { break; } } The continue_or_break block doesn't have any logical predecessors but it's a logical predecessor of the header block. This liveness error breaks the spiller in init_live_in_vars() (under "keep variables spilled on all incoming paths") and eventually creates garbage reloads. Fixes: 93c8ebfa ('aco: Initial commit of independent AMD compiler') Signed-off-by: Rhys Perry Reviewed-by: Daniel Schürmann Part-of: --- src/amd/compiler/aco_instruction_selection.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp index 64f5270acd0..7fd9c77a61d 100644 --- a/src/amd/compiler/aco_instruction_selection.cpp +++ b/src/amd/compiler/aco_instruction_selection.cpp @@ -7998,7 +7998,8 @@ static void visit_loop(isel_context *ctx, nir_loop *loop) add_linear_edge(block_idx, continue_block); add_linear_edge(continue_block->index, &ctx->program->blocks[loop_header_idx]); - add_logical_edge(block_idx, &ctx->program->blocks[loop_header_idx]); + if (!ctx->cf_info.parent_loop.has_divergent_branch) + add_logical_edge(block_idx, &ctx->program->blocks[loop_header_idx]); ctx->block = &ctx->program->blocks[block_idx]; } else { ctx->block->kind |= (block_kind_continue | block_kind_uniform); -- 2.30.2