From f698d2175aa01ae5be342ac6ea6d09366b8b36a4 Mon Sep 17 00:00:00 2001 From: Steven Bosscher Date: Fri, 4 Jun 2004 12:31:26 +0000 Subject: [PATCH] except.c (for_each_eh_region): New function. * except.c (for_each_eh_region): New function. * except.h (for_each_eh_region): Add a prototype for it. * tree-cfg.c (update_eh_labels): New function, callback for for_each_eh_region. (label_for_bb): Make global static, unfortunately. (cleanup_dead_labels): Also update label references for exception regions. From-SVN: r82622 --- gcc/ChangeLog | 12 +++++++++++- gcc/except.c | 14 ++++++++++++++ gcc/except.h | 3 +++ gcc/tree-cfg.c | 34 +++++++++++++++++++++++++++++++--- 4 files changed, 59 insertions(+), 4 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7771f78fcba..bb08ea4b05e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,13 @@ +2004-06-04 Steven Bosscher + + * except.c (for_each_eh_region): New function. + * except.h (for_each_eh_region): Add a prototype for it. + * tree-cfg.c (update_eh_labels): New function, callback for + for_each_eh_region. + (label_for_bb): Make global static, unfortunately. + (cleanup_dead_labels): Also update label references for + exception regions. + 2004-06-03 Chris Demetriou * config/mips/mips.c (struct irix_section_align_entry): Fix @@ -19,7 +29,7 @@ documentation to reflect the new macro name and to clarify its meaning. -2004-06-04 Steven Bosscher +2004-06-03 Steven Bosscher * rtl.def (VAR_LOCATION): Make RTX_EXTRA. diff --git a/gcc/except.c b/gcc/except.c index f3bc4ef3f2c..65aa8b5c4cc 100644 --- a/gcc/except.c +++ b/gcc/except.c @@ -2742,6 +2742,20 @@ for_each_eh_label_1 (void **pentry, void *data) (*callback) (entry->label); return 1; } + +/* Invoke CALLBACK for every exception region in the current function. */ + +void +for_each_eh_region (void (*callback) (struct eh_region *)) +{ + int i, n = cfun->eh->last_region_number; + for (i = 1; i <= n; ++i) + { + struct eh_region *region = cfun->eh->region_array[i]; + if (region) + (*callback) (region); + } +} /* This section describes CFG exception edges for flow. */ diff --git a/gcc/except.h b/gcc/except.h index 2fed79f30fb..4c596a9df11 100644 --- a/gcc/except.h +++ b/gcc/except.h @@ -90,6 +90,9 @@ extern void note_current_region_may_contain_throw (void); loop hackery; should not be used by new code. */ extern void for_each_eh_label (void (*) (rtx)); +/* Invokes CALLBACK for every exception region in the current function. */ +extern void for_each_eh_region (void (*) (struct eh_region *)); + /* Determine if the given INSN can throw an exception. */ extern bool can_throw_internal_1 (int); extern bool can_throw_internal (rtx); diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c index 21277d86bf2..d6823cb5216 100644 --- a/gcc/tree-cfg.c +++ b/gcc/tree-cfg.c @@ -762,13 +762,38 @@ cleanup_tree_cfg (void) } -/* Cleanup useless labels from the flow graph. */ +/* Cleanup useless labels in basic blocks. This is something we wish + to do early because it allows us to group case labels before creating + the edges for the CFG, and it speeds up block statement iterators in + all passes later on. + We only run this pass once, running it more than once is probably not + profitable. */ + +/* A map from basic block index to the leading label of that block. */ +static tree *label_for_bb; + +/* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */ +static void +update_eh_label (struct eh_region *region) +{ + tree old_label = get_eh_region_tree_label (region); + if (old_label) + { + tree new_label = label_for_bb[label_to_block (old_label)->index]; + set_eh_region_tree_label (region, new_label); + } +} + +/* Cleanup redundant labels. This is a three-steo process: + 1) Find the leading label for each block. + 2) Redirect all references to labels to the leading labels. + 3) Cleanup all useless labels. */ static void cleanup_dead_labels (void) { basic_block bb; - tree *label_for_bb = xcalloc (last_basic_block, sizeof (tree)); + label_for_bb = xcalloc (last_basic_block, sizeof (tree)); /* Find a suitable label for each block. We use the first user-defined label is there is one, or otherwise just the first label we see. */ @@ -805,7 +830,8 @@ cleanup_dead_labels (void) } } - /* Now redirect all jumps/branches to the selected label for each block. */ + /* Now redirect all jumps/branches to the selected label. + First do so for each block ending in a control statement. */ FOR_EACH_BB (bb) { tree stmt = last_stmt (bb); @@ -864,6 +890,8 @@ cleanup_dead_labels (void) } } + for_each_eh_region (update_eh_label); + /* Finally, purge dead labels. All user-defined labels and labels that can be the target of non-local gotos are preserved. */ FOR_EACH_BB (bb) -- 2.30.2