diff options
Diffstat (limited to 'gcc/loop.c')
| -rw-r--r-- | gcc/loop.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/gcc/loop.c b/gcc/loop.c index 17955b49dea..e0af19dd45e 100644 --- a/gcc/loop.c +++ b/gcc/loop.c @@ -8284,6 +8284,7 @@ check_dbra_loop (struct loop *loop, int insn_count) enum rtx_code cmp_code; int comparison_const_width; unsigned HOST_WIDE_INT comparison_sign_mask; + bool keep_first_compare; add_val = INTVAL (bl->biv->add_val); comparison_value = XEXP (comparison, 1); @@ -8476,13 +8477,26 @@ check_dbra_loop (struct loop *loop, int insn_count) not delete the label. */ LABEL_NUSES (XEXP (jump_label, 0))++; + /* If we have a separate comparison insn that does more + than just set cc0, the result of the comparison might + be used outside the loop. */ + keep_first_compare = (compare_and_branch == 2 +#ifdef HAVE_CC0 + && sets_cc0_p (first_compare) <= 0 +#endif + ); + /* Emit an insn after the end of the loop to set the biv's proper exit value if it is used anywhere outside the loop. */ - if ((REGNO_LAST_UID (bl->regno) != INSN_UID (first_compare)) + if (keep_first_compare + || (REGNO_LAST_UID (bl->regno) != INSN_UID (first_compare)) || ! bl->init_insn || REGNO_FIRST_UID (bl->regno) != INSN_UID (bl->init_insn)) loop_insn_sink (loop, gen_load_of_final_value (reg, final_value)); + if (keep_first_compare) + loop_insn_sink (loop, PATTERN (first_compare)); + /* Delete compare/branch at end of loop. */ delete_related_insns (PREV_INSN (loop_end)); if (compare_and_branch == 2) |