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| author | Jakub Jelinek <jakub@redhat.com> | 2002-03-30 19:50:34 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2002-03-30 19:50:34 +0100 |
| commit | 30984c5791c043900dbda277852231a3c4bb452c (patch) | |
| tree | f1d7d7d312ea6cc3e66eac4ca950d27d1a62d1de /gcc/combine.c | |
| parent | 1540f9ebc44746587921098f337cfac4916aa285 (diff) | |
| download | gcc-30984c5791c043900dbda277852231a3c4bb452c.zip gcc-30984c5791c043900dbda277852231a3c4bb452c.tar.gz gcc-30984c5791c043900dbda277852231a3c4bb452c.tar.bz2 | |
re PR rtl-optimization/6086 (Reload misoptimizes DImode PREINC on PPC)
PR optimization/6086
* combine.c (combine_simplify_rtx): If simplify_rtx failed because
of SUBREG of volatile MEM or because the MEM was mode dependent,
return CLOBBER instead of unmodified SUBREG.
From-SVN: r51606
Diffstat (limited to 'gcc/combine.c')
| -rw-r--r-- | gcc/combine.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/combine.c b/gcc/combine.c index 3e97a1a..de3bcef 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -3875,6 +3875,13 @@ combine_simplify_rtx (x, op0_mode, last, in_dest) return temp; } + /* Don't change the mode of the MEM if that would change the meaning + of the address. */ + if (GET_CODE (SUBREG_REG (x)) == MEM + && (MEM_VOLATILE_P (SUBREG_REG (x)) + || mode_dependent_address_p (XEXP (SUBREG_REG (x), 0)))) + return gen_rtx_CLOBBER (mode, const0_rtx); + /* Note that we cannot do any narrowing for non-constants since we might have been counting on using the fact that some bits were zero. We now do this in the SET. */ |