diff options
Diffstat (limited to 'contrib/gcc/doloop.c')
-rw-r--r-- | contrib/gcc/doloop.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/contrib/gcc/doloop.c b/contrib/gcc/doloop.c index 06d8d57..25deb503 100644 --- a/contrib/gcc/doloop.c +++ b/contrib/gcc/doloop.c @@ -598,9 +598,13 @@ doloop_modify_runtime (loop, iterations_max, If the loop has been unrolled, the full calculation is - t1 = abs_inc * unroll_number; increment per loop - n = abs (final - initial) / t1; full loops - n += (abs (final - initial) % t1) != 0; partial loop + t1 = abs_inc * unroll_number; increment per loop + n = (abs (final - initial) + abs_inc - 1) / t1; full loops + n += ((abs (final - initial) + abs_inc - 1) % t1) >= abs_inc; + partial loop + which works out to be equivalent to + + n = (abs (final - initial) + t1 - 1) / t1; However, in certain cases the unrolled loop will be preconditioned by emitting copies of the loop body with conditional branches, @@ -682,13 +686,15 @@ doloop_modify_runtime (loop, iterations_max, if (shift_count < 0) abort (); - if (!loop_info->preconditioned) + if (loop_info->preconditioned) + diff = expand_simple_binop (GET_MODE (diff), PLUS, + diff, GEN_INT (abs_inc - 1), + diff, 1, OPTAB_LIB_WIDEN); + else diff = expand_simple_binop (GET_MODE (diff), PLUS, diff, GEN_INT (abs_loop_inc - 1), diff, 1, OPTAB_LIB_WIDEN); - /* (abs (final - initial) + abs_inc * unroll_number - 1) - / (abs_inc * unroll_number) */ diff = expand_simple_binop (GET_MODE (diff), LSHIFTRT, diff, GEN_INT (shift_count), diff, 1, OPTAB_LIB_WIDEN); |