diff options
| -rw-r--r-- | gcc/ChangeLog | 4 | ||||
| -rw-r--r-- | gcc/combine.c | 8 |
2 files changed, 10 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 81d0b99..86b5868 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,6 +1,10 @@ 2004-12-31 Hans-Peter Nilsson <hp@bitrange.com> PR target/18701 + * combine.c (combine_simplify_rtx): Do not allow paradoxical + subregs of MEM. + + PR target/18701 * combine.c (gen_lowpart_for_combine): When stripping SUBREG of MEM, adjust imode and isize. diff --git a/gcc/combine.c b/gcc/combine.c index 61b93dd..90934e1 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -3983,10 +3983,14 @@ combine_simplify_rtx (rtx x, enum machine_mode op0_mode, int in_dest) } /* Don't change the mode of the MEM if that would change the meaning - of the address. */ + of the address. Similarly, don't allow widening, as that may + access memory outside the defined object or using an address + that is invalid for a wider mode. */ if (MEM_P (SUBREG_REG (x)) && (MEM_VOLATILE_P (SUBREG_REG (x)) - || mode_dependent_address_p (XEXP (SUBREG_REG (x), 0)))) + || mode_dependent_address_p (XEXP (SUBREG_REG (x), 0)) + || (GET_MODE_SIZE (mode) + > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))))) return gen_rtx_CLOBBER (mode, const0_rtx); /* Note that we cannot do any narrowing for non-constants since |