diff options
| author | Richard Henderson <rth@cygnus.com> | 1997-11-02 22:24:36 -0800 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 1997-11-02 23:24:36 -0700 |
| commit | be2053f3dda4a62aa0eb793adb19b6348ca8ab93 (patch) | |
| tree | 046b01787ef740c898b1a3ea886c4f3a94d3a101 /gcc/combine.c | |
| parent | 0ae231b2281a84173bb75c5d8649f788511733dc (diff) | |
| download | gcc-be2053f3dda4a62aa0eb793adb19b6348ca8ab93.tar.gz | |
combine.c (try_combine): Don't elim_i1 when it is used in i2src.
* combine.c (try_combine): Don't elim_i1 when it is used in i2src.
* combine.c (try_combine): When setting elim_i2, check whether newi2pat
sets i2dest. When calling distribute_notes for i3dest_killed, pass
elim_i2 and elim_i1.
Co-Authored-By: Jim Wilson <wilson@cygnus.com>
From-SVN: r16296
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 20bcaf9b37e..80fac52e28e 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -1240,6 +1240,7 @@ try_combine (i3, i2, i1) rtx i2pat; /* Indicates if I2DEST or I1DEST is in I2SRC or I1_SRC. */ int i2dest_in_i2src = 0, i1dest_in_i1src = 0, i2dest_in_i1src = 0; + int i1dest_in_i2src = 0; int i1_feeds_i3 = 0; /* Notes that must be added to REG_NOTES in I3 and I2. */ rtx new_i3_notes, new_i2_notes; @@ -1423,6 +1424,7 @@ try_combine (i3, i2, i1) i2dest_in_i2src = reg_overlap_mentioned_p (i2dest, i2src); i1dest_in_i1src = i1 && reg_overlap_mentioned_p (i1dest, i1src); i2dest_in_i1src = i1 && reg_overlap_mentioned_p (i2dest, i1src); + i1dest_in_i2src = i1 && reg_overlap_mentioned_p (i1dest, i2src); /* See if I1 directly feeds into I3. It does if I1DEST is not used in I2SRC. */ @@ -2146,10 +2148,12 @@ try_combine (i3, i2, i1) rtx i3links, i2links, i1links = 0; rtx midnotes = 0; register int regno; - /* Compute which registers we expect to eliminate. */ - rtx elim_i2 = (newi2pat || i2dest_in_i2src || i2dest_in_i1src + /* Compute which registers we expect to eliminate. newi2pat may be setting + either i3dest or i2dest, so we must check it. */ + rtx elim_i2 = ((newi2pat && reg_set_p (i2dest, newi2pat)) + || i2dest_in_i2src || i2dest_in_i1src ? 0 : i2dest); - rtx elim_i1 = i1 == 0 || i1dest_in_i1src ? 0 : i1dest; + rtx elim_i1 = i1 == 0 || i1dest_in_i1src || i1dest_in_i2src ? 0 : i1dest; /* Get the old REG_NOTES and LOG_LINKS from all our insns and clear them. */ @@ -2317,7 +2321,7 @@ try_combine (i3, i2, i1) distribute_notes (gen_rtx (EXPR_LIST, REG_DEAD, i3dest_killed, NULL_RTX), NULL_RTX, i3, newi2pat ? i2 : NULL_RTX, - NULL_RTX, NULL_RTX); + elim_i2, elim_i1); } if (i2dest_in_i2src) |