mirror of
https://github.com/gcc-mirror/gcc.git
synced 2026-05-06 23:25:24 +02:00
46d931b3dd
go_through_subreg used:
else if (!can_div_trunc_p (SUBREG_BYTE (x),
REGMODE_NATURAL_SIZE (GET_MODE (x)), offset))
to calculate the register offset for a pseudo subreg x. In the blessed
days before poly-int, this was:
*offset = (SUBREG_BYTE (x) / REGMODE_NATURAL_SIZE (GET_MODE (x)));
But I think this is testing the wrong natural size. If we exclude
paradoxical subregs (which will get an offset of zero regardless),
it's the inner register that is being split, so it should be the
inner register's natural size that we use.
This matters in the testcase because we have an SFmode lowpart
subreg into the last of three variable-sized vectors. The
SUBREG_BYTE is therefore equal to the size of two variable-sized
vectors. Dividing by the vector size gives a register offset of 2,
as expected, but dividing by the size of a scalar FPR would give
a variable offset.
I think something similar could happen for fixed-size targets if
REGMODE_NATURAL_SIZE is different for vectors and integers (say),
although that case would trade an ICE for an incorrect offset.
gcc/
PR rtl-optimization/115281
* ira-conflicts.cc (go_through_subreg): Use the natural size of
the inner mode rather than the outer mode.
gcc/testsuite/
PR rtl-optimization/115281
* gfortran.dg/pr115281.f90: New test.
This directory contains the GNU Compiler Collection (GCC). The GNU Compiler Collection is free software. See the files whose names start with COPYING for copying permission. The manuals, and some of the runtime libraries, are under different terms; see the individual source files for details. The directory INSTALL contains copies of the installation information as HTML and plain text. The source of this information is gcc/doc/install.texi. The installation information includes details of what is included in the GCC sources and what files GCC installs. See the file gcc/doc/gcc.texi (together with other files that it includes) for usage and porting information. An online readable version of the manual is in the files gcc/doc/gcc.info*. See http://gcc.gnu.org/bugs/ for how to report bugs usefully. Copyright years on GCC source files may be listed using range notation, e.g., 1987-2012, indicating that every year in the range, inclusive, is a copyrightable year that could otherwise be listed individually.