diff options
| author | Jan Hubicka <jh@suse.cz> | 2002-02-19 12:39:01 +0100 |
|---|---|---|
| committer | Jan Hubicka <hubicka@gcc.gnu.org> | 2002-02-19 11:39:01 +0000 |
| commit | fd973d5630bb29a2a0a90aa325b26395b8882320 (patch) | |
| tree | 222a2716de93e05a06cbe5eabc0d34f99a518c09 | |
| parent | 419a71d37c276fdc2dbd8e7487ca719861b62e75 (diff) | |
| download | gcc-fd973d5630bb29a2a0a90aa325b26395b8882320.zip gcc-fd973d5630bb29a2a0a90aa325b26395b8882320.tar.gz gcc-fd973d5630bb29a2a0a90aa325b26395b8882320.tar.bz2 | |
* regmove.c (regmove_optimize): Avoid increasing of register pressure.
From-SVN: r49864
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/regmove.c | 26 |
2 files changed, 19 insertions, 11 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index ffb087c..b6f6a1c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +Tue Feb 19 12:37:23 CET 2002 Jan Hubicka <jh@suse.cz> + + * regmove.c (regmove_optimize): Avoid increasing of register pressure. + 2002-02-19 Neil Booth <neil@daikokuya.demon.co.uk> PR other/5718 diff --git a/gcc/regmove.c b/gcc/regmove.c index 9530128..aa1c17b 100644 --- a/gcc/regmove.c +++ b/gcc/regmove.c @@ -1328,19 +1328,22 @@ regmove_optimize (f, nregs, regmove_dump_file) } src_class = reg_preferred_class (REGNO (src)); dst_class = reg_preferred_class (REGNO (dst)); - if (! regclass_compatible_p (src_class, dst_class)) + + if (! (src_note = find_reg_note (insn, REG_DEAD, src))) { - if (!copy_src) - { - copy_src = src; - copy_dst = dst; - } + /* We used to force the copy here like in other cases, but + it produces worse code, as it eliminates no copy + instructions and the copy emitted will be produced by + reload anyway. On patterns with multiple alternatives, + there may be better sollution availble. + + In particular this change produced slower code for numeric + i387 programs. */ + continue; } - /* Can not modify an earlier insn to set dst if this insn - uses an old value in the source. */ - if (reg_overlap_mentioned_p (dst, SET_SRC (set))) + if (! regclass_compatible_p (src_class, dst_class)) { if (!copy_src) { @@ -1350,7 +1353,9 @@ regmove_optimize (f, nregs, regmove_dump_file) continue; } - if (! (src_note = find_reg_note (insn, REG_DEAD, src))) + /* Can not modify an earlier insn to set dst if this insn + uses an old value in the source. */ + if (reg_overlap_mentioned_p (dst, SET_SRC (set))) { if (!copy_src) { @@ -1360,7 +1365,6 @@ regmove_optimize (f, nregs, regmove_dump_file) continue; } - /* If src is set once in a different basic block, and is set equal to a constant, then do not use it for this optimization, as this would make it |