diff options
Diffstat (limited to 'gcc/loop-doloop.c')
| -rw-r--r-- | gcc/loop-doloop.c | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/gcc/loop-doloop.c b/gcc/loop-doloop.c index 1b5ca4dc6d2..965e2e3edd8 100644 --- a/gcc/loop-doloop.c +++ b/gcc/loop-doloop.c @@ -257,20 +257,21 @@ add_test (rtx cond, basic_block bb, basic_block dest) describes the loop, DESC describes the number of iterations of the loop, and DOLOOP_INSN is the low-overhead looping insn to emit at the end of the loop. CONDITION is the condition separated from the - DOLOOP_SEQ. */ + DOLOOP_SEQ. COUNT is the number of iterations of the LOOP. */ static void doloop_modify (struct loop *loop, struct niter_desc *desc, - rtx doloop_seq, rtx condition) + rtx doloop_seq, rtx condition, rtx count) { rtx counter_reg; - rtx count, tmp, noloop = NULL_RTX; + rtx tmp, noloop = NULL_RTX; rtx sequence; rtx jump_insn; rtx jump_label; int nonneg = 0, irr; bool increment_count; basic_block loop_end = desc->out_edge->src; + enum machine_mode mode; jump_insn = BB_END (loop_end); @@ -291,8 +292,8 @@ doloop_modify (struct loop *loop, struct niter_desc *desc, counter_reg = XEXP (condition, 0); if (GET_CODE (counter_reg) == PLUS) counter_reg = XEXP (counter_reg, 0); + mode = GET_MODE (counter_reg); - count = copy_rtx (desc->niter_expr); increment_count = false; switch (GET_CODE (condition)) { @@ -323,7 +324,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc, Note that the maximum value loaded is iterations_max - 1. */ if (desc->niter_max <= ((unsigned HOST_WIDEST_INT) 1 - << (GET_MODE_BITSIZE (GET_MODE (counter_reg)) - 1))) + << (GET_MODE_BITSIZE (mode) - 1))) nonneg = 1; break; @@ -333,7 +334,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc, } if (increment_count) - count = simplify_gen_binary (PLUS, desc->mode, count, const1_rtx); + count = simplify_gen_binary (PLUS, mode, count, const1_rtx); /* Insert initialization of the count register into the loop header. */ start_sequence (); @@ -438,12 +439,14 @@ doloop_optimize (struct loop *loop) { enum machine_mode mode; rtx doloop_seq, doloop_pat, doloop_reg; - rtx iterations; + rtx iterations, count; rtx iterations_max; rtx start_label; rtx condition; unsigned level, est_niter; struct niter_desc *desc; + unsigned word_mode_size; + unsigned HOST_WIDE_INT word_mode_max; if (dump_file) fprintf (dump_file, "Doloop: Processing loop %d.\n", loop->num); @@ -481,6 +484,7 @@ doloop_optimize (struct loop *loop) return false; } + count = copy_rtx (desc->niter_expr); iterations = desc->const_iter ? desc->niter_expr : const0_rtx; iterations_max = GEN_INT (desc->niter_max); level = get_loop_level (loop) + 1; @@ -492,8 +496,33 @@ doloop_optimize (struct loop *loop) doloop_reg = gen_reg_rtx (mode); doloop_seq = gen_doloop_end (doloop_reg, iterations, iterations_max, GEN_INT (level), start_label); - if (! doloop_seq && mode != word_mode) + + word_mode_size = GET_MODE_BITSIZE (word_mode); + word_mode_max + = ((unsigned HOST_WIDE_INT) 1 << (word_mode_size - 1) << 1) - 1; + if (! doloop_seq + && mode != word_mode + /* Before trying mode different from the one in that # of iterations is + computed, we must be sure that the number of iterations fits into + the new mode. */ + && (word_mode_size >= GET_MODE_BITSIZE (mode) + || desc->niter_max <= word_mode_max)) { + if (word_mode_size > GET_MODE_BITSIZE (mode)) + { + count = simplify_gen_unary (ZERO_EXTEND, word_mode, + count, mode); + iterations = simplify_gen_unary (ZERO_EXTEND, word_mode, + iterations, mode); + iterations_max = simplify_gen_unary (ZERO_EXTEND, word_mode, + iterations_max, mode); + } + else + { + count = lowpart_subreg (word_mode, count, mode); + iterations = lowpart_subreg (word_mode, iterations, mode); + iterations_max = lowpart_subreg (word_mode, iterations_max, mode); + } PUT_MODE (doloop_reg, word_mode); doloop_seq = gen_doloop_end (doloop_reg, iterations, iterations_max, GEN_INT (level), start_label); @@ -528,7 +557,7 @@ doloop_optimize (struct loop *loop) return false; } - doloop_modify (loop, desc, doloop_seq, condition); + doloop_modify (loop, desc, doloop_seq, condition, count); return true; } |