diff options
| author | rsandifo <rsandifo@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-07-06 18:27:35 +0000 |
|---|---|---|
| committer | rsandifo <rsandifo@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-07-06 18:27:35 +0000 |
| commit | e9350468d1b00050bfbb74850a3c97e711b92a16 (patch) | |
| tree | 1284532d79574aa97537f07b98681c409f9ae900 /gcc/loop.c | |
| parent | d92fe3e03f4db0125d343d785d7d323fb1ddade6 (diff) | |
| download | gcc-e9350468d1b00050bfbb74850a3c97e711b92a16.tar.gz | |
PR rtl-optimization/16380
* loop.c (check_dbra_loop): Sink comparison instructions if they
do something other than set cc0.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@84161 138bc75d-0d04-0410-961f-82ee72b054a4
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) |