On 11/15/2016 09:21 AM, Richard Sandiford wrote:
If the size passed in to rtx_addr_can_trap_p was zero, the frame
handling would get the size from the mode instead. However, this
too can be zero if the mode is BLKmode, i.e. if we have a BLKmode
memory reference with no MEM_SIZE (which should be rare these days).
This meant that the conditions for a 4-byte access at offset X were
stricter than those for an access of unknown size at offset X.
This patch checks whether the size is still zero, as the
SYMBOL_REF handling does.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Thanks,
Richard
[ This patch is part of the SVE series posted here:
https://gcc.gnu.org/ml/gcc/2016-11/msg00030.html ]
gcc/
2016-11-15 Richard Sandiford <richard.sandif...@arm.com>
Alan Hayward <alan.hayw...@arm.com>
David Sherwood <david.sherw...@arm.com>
* rtlanal.c (rtx_addr_can_trap_p_1): Handle unknown sizes.
I guess it's conservatively correct in that claiming we can trap when we
can't never hurts correctness.
I'm OK with the patch, but am quite curious how we got to this point
without an attached MEM_SIZE.
jeff
