MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagation
authorAleksandar Markovic <aleksandar.markovic@imgtec.com>
Thu, 27 Jul 2017 16:08:48 +0000 (18:08 +0200)
committerRalf Baechle <ralf@linux-mips.org>
Tue, 29 Aug 2017 13:21:55 +0000 (15:21 +0200)
commite78bf0dc4789bdea1453595ae89e8db65918e22e
tree40ef066e80acc6a224b581895735bdc891d650f0
parentb7fc2cc59aa5f49ecd1eae4f90ec229a7e52c47c
MIPS: math-emu: <MAX|MAXA|MIN|MINA>.<D|S>: Fix quiet NaN propagation

Fix the value returned by <MAX|MAXA|MIN|MINA>.<D|S> fd,fs,ft, if both
inputs are quiet NaNs. The <MAX|MAXA|MIN|MINA>.<D|S> specifications
state that the returned value in such cases should be the quiet NaN
contained in register fs.

A relevant example:

MAX.S fd,fs,ft:
  If fs contains qNaN1, and ft contains qNaN2, fd is going to contain
  qNaN1 (without this patch, it used to contain qNaN2).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Jin Qian <jinqian@google.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: <stable@vger.kernel.org> # 4.3+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16880/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch/mips/math-emu/dp_fmax.c
arch/mips/math-emu/dp_fmin.c
arch/mips/math-emu/sp_fmax.c
arch/mips/math-emu/sp_fmin.c