r255244 - in /branches/gcc-7-branch/gcc: Change...

[danielh@gcc.gnu.org]

Author: danielh
Date: Wed Nov 29 17:03:32 2017
New Revision: 255244

URL: https://gcc.gnu.org/viewcvs?rev=255244&root=gcc&view=rev
Log:
[SPARC] Prevent -mfix-ut699 from generating b2bst errata sequences

The sequence
  st
  fdivd / fsqrtd
  std
was generated in some cases with -mfix-ut699 when there was
a st before the div/sqrt. This sequence could trigger the b2bst errata.

Now the following safe sequence is generated instead:
  st
  nop
  fdivd / fsqrtd
  std

Backport from mainline
2017-11-29  Martin Aberg  <maberg@gaisler.com>

gcc/
	* config/sparc/sparc.md (divdf3_fix): Add NOP and adjust length
        to prevent b2bst errata sequence.
        (sqrtdf2_fix): Likewise.

Modified:
    branches/gcc-7-branch/gcc/ChangeLog
    branches/gcc-7-branch/gcc/config/sparc/sparc.md