It appears that some critical expression attributes are lost when memory
reference expressions
are converted to rtl BLKmode operands typically used in (set BLK BLK)
operations for example.
This bug prevents volatile and read-only BLKmode memory reference operands from
being
treatedf properly as may be required, while these memory reference properties
seem properly
retained in all other circimstances?
In particular the lost of this information assocaited with BLKmode mov-mem
operands
inhibits the simple optional allocation of read-only data to program-rom, which
may then
be properly identified by it's MEM_READONLY_P property, enabing specilized
instructions to
to used to access it.
--
Summary: MEM_READONLY_P & MEM_VOLATILE_P properties are lost on
BLKmode rtl operands.
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: schlie at comcast dot net
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: ppc-apple-darwin7.8
GCC host triplet: ppc-apple-darwin7.8
GCC target triplet: avr-unknown-none
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20355
