From 96b5d381d4a670fd3f2fed4ca73ded601ec779e9 Mon Sep 17 00:00:00 2001 From: xiezhiheng Date: Fri, 24 Nov 2023 15:47:33 +0800 Subject: [PATCH 3/4] [Backport] Rework cold and hot label attributes in predict.c. Reference: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=93c18375823fdd0e384f673f75e39136719135dd --- gcc/gimplify.c | 10 +++++++- gcc/predict.c | 23 ------------------- .../gcc.dg/tree-ssa/attr-hotcold-2.c | 4 ++-- 3 files changed, 11 insertions(+), 26 deletions(-) diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 5264a4f3d..c6a06d014 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -2340,10 +2340,18 @@ gimplify_label_expr (tree *expr_p, gimple_seq *pre_p) gcc_assert (decl_function_context (LABEL_EXPR_LABEL (*expr_p)) == current_function_decl); - glabel *label_stmt = gimple_build_label (LABEL_EXPR_LABEL (*expr_p)); + tree label = LABEL_EXPR_LABEL (*expr_p); + glabel *label_stmt = gimple_build_label (label); gimple_set_location (label_stmt, EXPR_LOCATION (*expr_p)); gimplify_seq_add_stmt (pre_p, label_stmt); + if (lookup_attribute ("cold", DECL_ATTRIBUTES (label))) + gimple_seq_add_stmt (pre_p, gimple_build_predict (PRED_COLD_LABEL, + NOT_TAKEN)); + else if (lookup_attribute ("hot", DECL_ATTRIBUTES (label))) + gimple_seq_add_stmt (pre_p, gimple_build_predict (PRED_HOT_LABEL, + TAKEN)); + return GS_ALL_DONE; } diff --git a/gcc/predict.c b/gcc/predict.c index fa4e626fa..d68fb17ba 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -2701,29 +2701,6 @@ tree_estimate_probability_bb (basic_block bb) FOR_EACH_EDGE (e, ei, bb->succs) { - /* Predict edges to user labels with attributes. */ - if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) - { - gimple_stmt_iterator gi; - for (gi = gsi_start_bb (e->dest); !gsi_end_p (gi); gsi_next (&gi)) - { - glabel *label_stmt = dyn_cast (gsi_stmt (gi)); - tree decl; - - if (!label_stmt) - break; - decl = gimple_label_label (label_stmt); - if (DECL_ARTIFICIAL (decl)) - continue; - - /* Finally, we have a user-defined label. */ - if (lookup_attribute ("cold", DECL_ATTRIBUTES (decl))) - predict_edge_def (e, PRED_COLD_LABEL, NOT_TAKEN); - else if (lookup_attribute ("hot", DECL_ATTRIBUTES (decl))) - predict_edge_def (e, PRED_HOT_LABEL, TAKEN); - } - } - /* Predict early returns to be probable, as we've already taken care for error returns and other cases are often used for fast paths through function. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c b/gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c index 13d2916c4..184dd10dd 100644 --- a/gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c +++ b/gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c @@ -20,9 +20,9 @@ void f(int x, int y) /* { dg-final { scan-tree-dump-times "hot label heuristics" 1 "profile_estimate" } } */ /* { dg-final { scan-tree-dump-times "cold label heuristics" 1 "profile_estimate" } } */ -/* { dg-final { scan-tree-dump-times "block 4, loop depth 0, count 0, freq \[1-4\]\[^0-9\]" 3 "profile_estimate" } } */ +/* { dg-final { scan-tree-dump "A \\\[0\\\..*\\\]" "profile_estimate" } } */ /* Note: we're attempting to match some number > 6000, i.e. > 60%. The exact number ought to be tweekable without having to juggle the testcase around too much. */ -/* { dg-final { scan-tree-dump-times "block 5, loop depth 0, count 0, freq \[6-9\]\[0-9\]\[0-9\]\[0-9\]" 3 "profile_estimate" } } */ +/* { dg-final { scan-tree-dump "B \\\[\[6-9\]\[0-9\]\\\..*\\\]" "profile_estimate" } } */ -- 2.19.1