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| author | Jeff Law <law@redhat.com> | 2002-03-28 16:33:52 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2002-03-28 16:33:52 -0700 |
| commit | 8bc528064fedba642b6246c38b8c48e029321766 (patch) | |
| tree | 77e64e6603c75e448adfa247ed58effe997b148b | |
| parent | 279dccc5db570d56e327fa74361ecf593038433a (diff) | |
| download | gcc-8bc528064fedba642b6246c38b8c48e029321766.zip gcc-8bc528064fedba642b6246c38b8c48e029321766.tar.gz gcc-8bc528064fedba642b6246c38b8c48e029321766.tar.bz2 | |
re PR rtl-optimization/3311 (GCC-SH: gcc loses result of AND operation due to force_to_mode bug)
* combine.c (simplify_and_const_int): Make sure to apply mask
when force_to_mode returns a constant integer. PR3311.
From-SVN: r51532
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/combine.c | 17 |
2 files changed, 18 insertions, 4 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 5a8d6fc..a804219 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +Thu Mar 28 16:35:31 2002 Jeffrey A Law (law@redhat.com) + + * combine.c (simplify_and_const_int): Make sure to apply mask + when force_to_mode returns a constant integer. PR3311. + 2002-03-28 John David Anglin <dave@hiauly1.hia.nrc.ca> * pa-linux.h (LOCAL_LABEL_PREFIX): Define. diff --git a/gcc/combine.c b/gcc/combine.c index 0a611870..adb034d 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -7838,14 +7838,23 @@ simplify_and_const_int (x, mode, varop, constop) int i; /* Simplify VAROP knowing that we will be only looking at some of the - bits in it. */ + bits in it. + + Note by passing in CONSTOP, we guarantee that the bits not set in + CONSTOP are not significant and will never be examined. We must + ensure that is the case by explicitly masking out those bits + before returning. */ varop = force_to_mode (varop, mode, constop, NULL_RTX, 0); - /* If VAROP is a CLOBBER, we will fail so return it; if it is a - CONST_INT, we are done. */ - if (GET_CODE (varop) == CLOBBER || GET_CODE (varop) == CONST_INT) + /* If VAROP is a CLOBBER, we will fail so return it. */ + if (GET_CODE (varop) == CLOBBER) return varop; + /* If VAROP is a CONST_INT, then we need to apply the mask in CONSTOP + to VAROP and return the new constant. */ + if (GET_CODE (varop) == CONST_INT) + return GEN_INT (trunc_int_for_mode (INTVAL (varop) & constop, mode)); + /* See what bits may be nonzero in VAROP. Unlike the general case of a call to nonzero_bits, here we don't care about bits outside MODE. */ |