From 09c5c12e560b7804b14f599e858929787193da30 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Thu, 26 Nov 2015 14:35:27 +0000 Subject: [PATCH] Revert "Improve verification of loop->latch in verify_loop_structure" 2015-11-26 Tom de Vries revert: 2015-11-25 Tom de Vries * cfgloop.c (find_single_latch): New function, factored out of ... (flow_loops_find): ... here. (verify_loop_structure): Improve verification of loop->latch. * cfgloop.h (find_single_latch): Declare. * omp-low.c (expand_omp_for_generic): Initialize latch of orig_loop. From-SVN: r230967 --- gcc/ChangeLog | 11 ++++++++ gcc/cfgloop.c | 70 +++++++++++++++------------------------------------ gcc/cfgloop.h | 1 - gcc/omp-low.c | 1 - 4 files changed, 31 insertions(+), 52 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8609f0dcdaf..da80e714099 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,14 @@ +2015-11-26 Tom de Vries + + revert: + 2015-11-25 Tom de Vries + + * cfgloop.c (find_single_latch): New function, factored out of ... + (flow_loops_find): ... here. + (verify_loop_structure): Improve verification of loop->latch. + * cfgloop.h (find_single_latch): Declare. + * omp-low.c (expand_omp_for_generic): Initialize latch of orig_loop. + 2015-11-26 Matthew Wahab * config/aarch64/aarch64-simd-builtins.def: diff --git a/gcc/cfgloop.c b/gcc/cfgloop.c index e7cb78a5351..83a526276db 100644 --- a/gcc/cfgloop.c +++ b/gcc/cfgloop.c @@ -388,33 +388,6 @@ bb_loop_header_p (basic_block header) return false; } -/* Return the latch block for this header block, if it has just a single one. - Otherwise, return NULL. */ - -basic_block -find_single_latch (struct loop* loop) -{ - basic_block header = loop->header; - edge_iterator ei; - edge e; - basic_block latch = NULL; - - FOR_EACH_EDGE (e, ei, header->preds) - { - basic_block cand = e->src; - if (!flow_bb_inside_loop_p (loop, cand)) - continue; - - if (latch != NULL) - /* More than one latch edge. */ - return NULL; - - latch = cand; - } - - return latch; -} - /* Find all the natural loops in the function and save in LOOPS structure and recalculate loop_father information in basic block structures. If LOOPS is non-NULL then the loop structures for already recorded loops @@ -509,10 +482,29 @@ flow_loops_find (struct loops *loops) { struct loop *loop = larray[i]; basic_block header = loop->header; + edge_iterator ei; + edge e; flow_loop_tree_node_add (header->loop_father, loop); loop->num_nodes = flow_loop_nodes_find (loop->header, loop); - loop->latch = find_single_latch (loop); + + /* Look for the latch for this header block, if it has just a + single one. */ + FOR_EACH_EDGE (e, ei, header->preds) + { + basic_block latch = e->src; + + if (flow_bb_inside_loop_p (loop, latch)) + { + if (loop->latch != NULL) + { + /* More than one latch edge. */ + loop->latch = NULL; + break; + } + loop->latch = latch; + } + } } return loops; @@ -1442,28 +1434,6 @@ verify_loop_structure (void) error ("loop %d%'s latch is not dominated by its header", i); err = 1; } - if (find_single_latch (loop) == NULL) - { - error ("loop %d%'s latch is is not the only latch", i); - err = 1; - } - } - else - { - if (loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)) - { - if (find_single_latch (loop) != NULL) - { - error ("loop %d%'s latch is missing", i); - err = 1; - } - } - else - { - error ("loop %d%'s latch is missing, and loops may not have" - " multiple latches", i); - err = 1; - } } if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) { diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h index 7faf591796f..ee73bf994c1 100644 --- a/gcc/cfgloop.h +++ b/gcc/cfgloop.h @@ -270,7 +270,6 @@ bool mark_irreducible_loops (void); void release_recorded_exits (function *); void record_loop_exits (void); void rescan_loop_exit (edge, bool, bool); -basic_block find_single_latch (struct loop*); /* Loop data structure manipulation/querying. */ extern void flow_loop_tree_node_add (struct loop *, struct loop *); diff --git a/gcc/omp-low.c b/gcc/omp-low.c index 0b44588b5a1..f17a828330a 100644 --- a/gcc/omp-low.c +++ b/gcc/omp-low.c @@ -8907,7 +8907,6 @@ expand_omp_for_generic (struct omp_region *region, orig_loop->header = l1_bb; /* The loop may have multiple latches. */ add_loop (orig_loop, new_loop); - orig_loop->latch = find_single_latch (orig_loop); } } } -- 2.30.2