PING #2! On Wed, May 2, 2012 at 10:22 PM, Janne Blomqvist <blomqvist.ja...@gmail.com> wrote: > PING > > On Thu, Apr 26, 2012 at 12:08 AM, Janne Blomqvist > <blomqvist.ja...@gmail.com> wrote: >> Hi, >> >> currently when -frange-check is enabled, we check for overflow when >> doing a formatted read of an integer value. This check, however, is >> against the Fortran numerical model (see 13.4 in F2008), which defines >> a symmetric interval [-huge(), huge()], whereas all targets gfortran >> supports use a two's complement representation with a range of >> [-huge()-1, huge()]. >> >> However, there is no checking against the numerical model when doing >> arithmetic, and thus we can generate and write the value -huge()-1, >> but we cannot read it back in! With the -fno-range-check option, this >> overflow checking can be disabled, but at the cost of disabling all >> overflow checking, which leads to reading nonsense values if the >> hardware supported range overflows. >> >> The attached patch changes this logic such that overflow checking >> against the hardware supported range [-huge()-1, huge()] is always >> done when reading, regardless of the -frange-check flag setting. This >> also seems to be what ifort 12.0 does, I haven't checked other >> compilers. >> >> For some more arguments back and forth, see the PR. >> >> Regtested on x86_64-unknown-linux-gnu, Ok for trunk? >> >> gcc/fortran ChangeLog: >> >> 2012-04-25 Janne Blomqvist <j...@gcc.gnu.org> >> >> PR fortran/52428 >> * gfortran.texi: Update _gfortran_set_options documentation. >> * invoke.texi: Remove runtime behavior description of >> -fno-range-check. >> * trans-decl.c (create_main_function): Don't pass the range-check >> setting to the library. >> >> >> libgfortran ChangeLog: >> >> 2012-04-25 Janne Blomqvist <j...@gcc.gnu.org> >> >> PR fortran/52428 >> * io/io.h (max_value): Rename to si_max, remove second argument. >> * io/list_read.c (convert_integer): Use unsigned types when >> parsing the digits, set max value depending on the sign. >> * io/read.c (max_value): Rename to si_max, remove second argument, >> simplify. >> (read_decimal): Set max value depending on sign, always check >> overflow. >> (read_radix): Calculate max unsigned value directly. >> * libgfortran.h (struct compile_options_t): Remove range_check >> field. >> * runtime/compile_options.c (set_options): Skip handling >> options[7]. >> (init_compile_options): Don't set removed field. >> >> >> gcc/testsuite ChangeLog: >> >> 2012-04-25 Janne Blomqvist <j...@gcc.gnu.org> >> >> PR fortran/52428 >> * gfortran.dg/int_range_io_1.f90: New test. >> >> >> -- >> Janne Blomqvist > > > > -- > Janne Blomqvist
-- Janne Blomqvist
