diff options
Diffstat (limited to 'gcc/tree-ssa-loop-ivcanon.c')
| -rw-r--r-- | gcc/tree-ssa-loop-ivcanon.c | 44 |
1 files changed, 31 insertions, 13 deletions
diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c index 4cfdb27..319a410 100644 --- a/gcc/tree-ssa-loop-ivcanon.c +++ b/gcc/tree-ssa-loop-ivcanon.c @@ -594,6 +594,8 @@ remove_redundant_iv_tests (struct loop *loop) /* Stores loops that will be unlooped after we process whole loop tree. */ static vec<loop_p> loops_to_unloop; static vec<int> loops_to_unloop_nunroll; +/* Stores loops that has been peeled. */ +static bitmap peeled_loops; /* Cancel all fully unrolled loops by putting __builtin_unreachable on the latch edge. @@ -962,14 +964,17 @@ try_peel_loop (struct loop *loop, vec<edge> to_remove = vNULL; edge e; - /* If the iteration bound is known and large, then we can safely eliminate - the check in peeled copies. */ - if (TREE_CODE (niter) != INTEGER_CST) - exit = NULL; - - if (!flag_peel_loops || PARAM_VALUE (PARAM_MAX_PEEL_TIMES) <= 0) + if (!flag_peel_loops || PARAM_VALUE (PARAM_MAX_PEEL_TIMES) <= 0 + || !peeled_loops) return false; + if (bitmap_bit_p (peeled_loops, loop->num)) + { + if (dump_file) + fprintf (dump_file, "Not peeling: loop is already peeled\n"); + return false; + } + /* Peel only innermost loops. While the code is perfectly capable of peeling non-innermost loops, the heuristics would probably need some improvements. */ @@ -990,6 +995,8 @@ try_peel_loop (struct loop *loop, /* Check if there is an estimate on the number of iterations. */ npeel = estimated_loop_iterations_int (loop); if (npeel < 0) + npeel = likely_max_loop_iterations_int (loop); + if (npeel < 0) { if (dump_file) fprintf (dump_file, "Not peeling: number of iterations is not " @@ -1036,8 +1043,7 @@ try_peel_loop (struct loop *loop, && wi::leu_p (npeel, wi::to_widest (niter))) { bitmap_ones (wont_exit); - if (wi::eq_p (wi::to_widest (niter), npeel)) - bitmap_clear_bit (wont_exit, 0); + bitmap_clear_bit (wont_exit, 0); } else { @@ -1074,14 +1080,14 @@ try_peel_loop (struct loop *loop, } if (loop->any_upper_bound) { - if (wi::ltu_p (npeel, loop->nb_iterations_estimate)) + if (wi::ltu_p (npeel, loop->nb_iterations_upper_bound)) loop->nb_iterations_upper_bound -= npeel; else loop->nb_iterations_upper_bound = 0; } if (loop->any_likely_upper_bound) { - if (wi::ltu_p (npeel, loop->nb_iterations_estimate)) + if (wi::ltu_p (npeel, loop->nb_iterations_likely_upper_bound)) loop->nb_iterations_likely_upper_bound -= npeel; else { @@ -1107,6 +1113,7 @@ try_peel_loop (struct loop *loop, else if (loop->header->frequency) scale = RDIV (entry_freq * REG_BR_PROB_BASE, loop->header->frequency); scale_loop_profile (loop, scale, 0); + bitmap_set_bit (peeled_loops, loop->num); return true; } /* Adds a canonical induction variable to LOOP if suitable. @@ -1519,9 +1526,20 @@ pass_complete_unroll::execute (function *fun) if (number_of_loops (fun) <= 1) return 0; - return tree_unroll_loops_completely (flag_unroll_loops - || flag_peel_loops - || optimize >= 3, true); + /* If we ever decide to run loop peeling more than once, we will need to + track loops already peeled in loop structures themselves to avoid + re-peeling the same loop multiple times. */ + if (flag_peel_loops) + peeled_loops = BITMAP_ALLOC (NULL); + int val = tree_unroll_loops_completely (flag_unroll_loops + || flag_peel_loops + || optimize >= 3, true); + if (peeled_loops) + { + BITMAP_FREE (peeled_loops); + peeled_loops = NULL; + } + return val; } } // anon namespace |