[Bug target/63408] [4.9/5/6 regression] GCC emits incorrect fixed->fp conversion instruction on Cortex-M4 target

["ramana at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63408

--- Comment #13 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
Author: ramana
Date: Wed Jun 24 08:28:08 2015
New Revision: 224879

URL: https://gcc.gnu.org/viewcvs?rev=224879&root=gcc&view=rev
Log:
Fix PR target/63408

The attached patch fixes PR target/63408 and adds a regression test
for the same. The problem is essentially that
vfp3_const_double_for_fract_bits() needs to be aware that negative
values cannot be used in this context.

Tested with a bootstrap and regression test run on armhf. Applied.




2015-06-24  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

        PR target/63408
        * config/arm/arm.c (vfp3_const_double_for_fract_bits): Disable
        for negative numbers.

2015-06-24  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>

        PR target/63408
        * gcc.target/arm/pr63408.c: New test.


Added:
    trunk/gcc/testsuite/gcc.target/arm/pr63408.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/arm/arm.c
    trunk/gcc/testsuite/ChangeLog