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| author | J"orn Rennecke <amylaar@cygnus.co.uk> | 1998-02-13 02:26:25 +0000 |
|---|---|---|
| committer | Joern Rennecke <amylaar@gcc.gnu.org> | 1998-02-13 02:26:25 +0000 |
| commit | e3258cef3011a2f6c8a465b7fb8027dfb24867aa (patch) | |
| tree | 23dc9186cf59d6ee728733933384672b2b8c31b5 /gcc | |
| parent | 2dbfb4181cac4d7da8fa16a00139c432cce6de62 (diff) | |
| download | gcc-e3258cef3011a2f6c8a465b7fb8027dfb24867aa.zip gcc-e3258cef3011a2f6c8a465b7fb8027dfb24867aa.tar.gz gcc-e3258cef3011a2f6c8a465b7fb8027dfb24867aa.tar.bz2 | |
* combine.c (can_combine_p): Handle USEs in PARALLELs.
From-SVN: r17899
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/combine.c | 37 |
2 files changed, 41 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9c2828f..60da151 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +Fri Feb 13 10:21:41 1998 J"orn Rennecke <amylaar@cygnus.co.uk> + + * combine.c (can_combine_p): Handle USEs in PARALLELs. + Fri Feb 13 01:34:14 1998 H.J. Lu (hjl@gnu.org) * config/linux.h (LIB_SPEC): Add -lc for -shared if diff --git a/gcc/combine.c b/gcc/combine.c index 0bf6712..615a28b 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -860,6 +860,43 @@ can_combine_p (insn, i3, pred, succ, pdest, psrc) switch (GET_CODE (elt)) { + /* This is important to combine floating point insns + for the SH4 port. */ + case USE: + /* Combining an isolated USE doesn't make sense. + We depend here on combinable_i3_pat to reject them. */ + /* The code below this loop only verifies that the inputs of + the SET in INSN do not change. We call reg_set_between_p + to verify that the REG in the USE does not change betweeen + I3 and INSN. + If the USE in INSN was for a pseudo register, the matching + insn pattern will likely match any register; combining this + with any other USE would only be safe if we knew that the + used registers have identical values, or if there was + something to tell them apart, e.g. different modes. For + now, we forgo such compilcated tests and simply disallow + combining of USES of pseudo registers with any other USE. */ + if (GET_CODE (XEXP (elt, 0)) == REG + && GET_CODE (PATTERN (i3)) == PARALLEL) + { + rtx i3pat = PATTERN (i3); + int i = XVECLEN (i3pat, 0) - 1; + int regno = REGNO (XEXP (elt, 0)); + do + { + rtx i3elt = XVECEXP (i3pat, 0, i); + if (GET_CODE (i3elt) == USE + && GET_CODE (XEXP (i3elt, 0)) == REG + && (REGNO (XEXP (i3elt, 0)) == regno + ? reg_set_between_p (XEXP (elt, 0), + PREV_INSN (insn), i3) + : regno >= FIRST_PSEUDO_REGISTER)) + return 0; + } + while (--i >= 0); + } + break; + /* We can ignore CLOBBERs. */ case CLOBBER: break; |