diff options
Diffstat (limited to 'gcc/tree-ssa-loop-niter.c')
-rw-r--r-- | gcc/tree-ssa-loop-niter.c | 106 |
1 files changed, 83 insertions, 23 deletions
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index 4acfc67b41f..2529b367300 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -3052,25 +3052,28 @@ estimate_numbers_of_iterations_loop (struct loop *loop, bool use_undefined_p) the function returns false, otherwise returns true. */ bool -estimated_loop_iterations (struct loop *loop, bool conservative, - double_int *nit) +estimated_loop_iterations (struct loop *loop, double_int *nit) { estimate_numbers_of_iterations_loop (loop, true); - if (conservative) - { - if (!loop->any_upper_bound) - return false; + if (!loop->any_estimate) + return false; - *nit = loop->nb_iterations_upper_bound; - } - else - { - if (!loop->any_estimate) - return false; + *nit = loop->nb_iterations_estimate; + return true; +} - *nit = loop->nb_iterations_estimate; - } +/* Sets NIT to an upper bound for the maximum number of executions of the + latch of the LOOP. If we have no reliable estimate, the function returns + false, otherwise returns true. */ + +bool +max_loop_iterations (struct loop *loop, double_int *nit) +{ + estimate_numbers_of_iterations_loop (loop, true); + if (!loop->any_upper_bound) + return false; + *nit = loop->nb_iterations_upper_bound; return true; } @@ -3079,12 +3082,32 @@ estimated_loop_iterations (struct loop *loop, bool conservative, on the number of iterations of LOOP could not be derived, returns -1. */ HOST_WIDE_INT -estimated_loop_iterations_int (struct loop *loop, bool conservative) +estimated_loop_iterations_int (struct loop *loop) +{ + double_int nit; + HOST_WIDE_INT hwi_nit; + + if (!estimated_loop_iterations (loop, &nit)) + return -1; + + if (!double_int_fits_in_shwi_p (nit)) + return -1; + hwi_nit = double_int_to_shwi (nit); + + return hwi_nit < 0 ? -1 : hwi_nit; +} + +/* Similar to max_loop_iterations, but returns the estimate only + if it fits to HOST_WIDE_INT. If this is not the case, or the estimate + on the number of iterations of LOOP could not be derived, returns -1. */ + +HOST_WIDE_INT +max_loop_iterations_int (struct loop *loop) { double_int nit; HOST_WIDE_INT hwi_nit; - if (!estimated_loop_iterations (loop, conservative, &nit)) + if (!max_loop_iterations (loop, &nit)) return -1; if (!double_int_fits_in_shwi_p (nit)) @@ -3099,9 +3122,9 @@ estimated_loop_iterations_int (struct loop *loop, bool conservative) the number of execution of the latch by one. */ HOST_WIDE_INT -max_stmt_executions_int (struct loop *loop, bool conservative) +max_stmt_executions_int (struct loop *loop) { - HOST_WIDE_INT nit = estimated_loop_iterations_int (loop, conservative); + HOST_WIDE_INT nit = max_loop_iterations_int (loop); HOST_WIDE_INT snit; if (nit == -1) @@ -3113,17 +3136,54 @@ max_stmt_executions_int (struct loop *loop, bool conservative) return snit < 0 ? -1 : snit; } +/* Returns an estimate for the number of executions of statements + in the LOOP. For statements before the loop exit, this exceeds + the number of execution of the latch by one. */ + +HOST_WIDE_INT +estimated_stmt_executions_int (struct loop *loop) +{ + HOST_WIDE_INT nit = estimated_loop_iterations_int (loop); + HOST_WIDE_INT snit; + + if (nit == -1) + return -1; + + snit = (HOST_WIDE_INT) ((unsigned HOST_WIDE_INT) nit + 1); + + /* If the computation overflows, return -1. */ + return snit < 0 ? -1 : snit; +} + +/* Sets NIT to the estimated maximum number of executions of the latch of the + LOOP, plus one. If we have no reliable estimate, the function returns + false, otherwise returns true. */ + +bool +max_stmt_executions (struct loop *loop, double_int *nit) +{ + double_int nit_minus_one; + + if (!max_loop_iterations (loop, nit)) + return false; + + nit_minus_one = *nit; + + *nit = double_int_add (*nit, double_int_one); + + return double_int_ucmp (*nit, nit_minus_one) > 0; +} + /* Sets NIT to the estimated number of executions of the latch of the - LOOP, plus one. If CONSERVATIVE is true, we must be sure that NIT is at - least as large as the number of iterations. If we have no reliable - estimate, the function returns false, otherwise returns true. */ + LOOP, plus one. If we have no reliable estimate, the function returns + false, otherwise returns true. */ bool -max_stmt_executions (struct loop *loop, bool conservative, double_int *nit) +estimated_stmt_executions (struct loop *loop, double_int *nit) { double_int nit_minus_one; - if (!estimated_loop_iterations (loop, conservative, nit)) + if (!estimated_loop_iterations (loop, nit)) return false; nit_minus_one = *nit; |