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| author | Jeffrey A Law <law@cygnus.com> | 1998-11-19 22:45:14 +0000 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 1998-11-19 15:45:14 -0700 |
| commit | 9f5a2691a147626d10fba7bc366a059678c606e9 (patch) | |
| tree | 34a37695a988b7faf09d172d86491067e36d8ff0 | |
| parent | e9741ffa9765fdd679ff6270fe7dd7d18f6ead41 (diff) | |
| download | gcc-9f5a2691a147626d10fba7bc366a059678c606e9.zip gcc-9f5a2691a147626d10fba7bc366a059678c606e9.tar.gz gcc-9f5a2691a147626d10fba7bc366a059678c606e9.tar.bz2 | |
reorg.c (relax_delay_slots): When optimizing for code size...
* reorg.c (relax_delay_slots): When optimizing for code size, if a
return with a filled delay slot is followed by a return with an
unfilled delay slot, delete the first return and reemit the insn
that was previously in its delay slot.
From-SVN: r23729
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/reorg.c | 34 |
2 files changed, 39 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 78981928..92ae27a 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ Thu Nov 19 22:20:51 1998 Jeffrey A Law (law@cygnus.com) + * reorg.c (relax_delay_slots): When optimizing for code size, if a + return with a filled delay slot is followed by a return with an + unfilled delay slot, delete the first return and reemit the insn + that was previously in its delay slot. + * i860.c (single_insn_src_p): Add missing parens. * ginclude/math-3300.h: Likewise. diff --git a/gcc/reorg.c b/gcc/reorg.c index 65d8ce8..f4b9f1f 100644 --- a/gcc/reorg.c +++ b/gcc/reorg.c @@ -4200,6 +4200,40 @@ relax_delay_slots (first) continue; } + /* See if we have a RETURN insn with a filled delay slot followed + by a RETURN insn with an unfilled a delay slot. If so, we can delete + the first RETURN (but not it's delay insn). This gives the same + effect in fewer instructions. + + Only do so if optimizing for size since this results in slower, but + smaller code. */ + if (optimize_size + && GET_CODE (PATTERN (delay_insn)) == RETURN + && next + && GET_CODE (next) == JUMP_INSN + && GET_CODE (PATTERN (next)) == RETURN) + { + int i; + + /* Delete the RETURN and just execute the delay list insns. + + We do this by deleting the INSN containing the SEQUENCE, then + re-emitting the insns separately, and then deleting the RETURN. + This allows the count of the jump target to be properly + decremented. */ + + /* Clear the from target bit, since these insns are no longer + in delay slots. */ + for (i = 0; i < XVECLEN (pat, 0); i++) + INSN_FROM_TARGET_P (XVECEXP (pat, 0, i)) = 0; + + trial = PREV_INSN (insn); + delete_insn (insn); + emit_insn_after (pat, trial); + delete_scheduled_jump (delay_insn); + continue; + } + /* Now look only at the cases where we have a filled JUMP_INSN. */ if (GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) != JUMP_INSN || ! (condjump_p (XVECEXP (PATTERN (insn), 0, 0)) |