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Douglas Leung 2cfa58259f MIPS: math-emu: <MADDF|MSUBF>.D: Fix accuracy (64-bit case)
Implement fused multiply-add with correct accuracy.

Fused multiply-add operation has better accuracy than respective
sequential execution of multiply and add operations applied on the
same inputs. This is because accuracy errors accumulate in latter
case.

This patch implements fused multiply-add with the same accuracy
as it is implemented in hardware, using 128-bit intermediate
calculations.

One test case example (raw bits) that this patch fixes:

MADDF.D fd,fs,ft:
  fd = 0x00000ca000000000
  fs = ft = 0x3f40624dd2f1a9fc

Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Fixes: 83d43305a1 ("MIPS: math-emu: Add support for the MIPS R6 MSUBF FPU instruction")

Signed-off-by: Douglas Leung <douglas.leung@imgtec.com>
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>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: Bo Hu <bohu@google.com>
Cc: James Hogan <james.hogan@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> # 4.7+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16891/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-29 15:21:56 +02:00
Documentation dt-bindings: vendors: Add VoCore as a vendor 2017-08-29 15:21:53 +02:00
arch MIPS: math-emu: <MADDF|MSUBF>.D: Fix accuracy (64-bit case) 2017-08-29 15:21:56 +02:00
block blk-mq-debugfs: Add names for recently added flags 2017-08-25 08:07:44 -06:00
certs modsign: add markers to endif-statements in certs/Makefile 2017-07-14 11:01:37 +10:00
crypto crypto: authencesn - Fix digest_null crash 2017-07-18 17:01:11 +08:00
drivers MIPS: Alchemy: Threaded carddetect irqs for devboards 2017-08-29 15:21:53 +02:00
firmware firmware/Makefile: force recompilation if makefile changes 2017-05-08 17:15:10 -07:00
fs Merge branch 'akpm' (patches from Andrew) 2017-08-25 18:02:27 -07:00
include IOMMU Fixes for Linux v4.13-rc6 2017-08-27 17:10:34 -07:00
init random: do not ignore early device randomness 2017-07-12 16:26:00 -07:00
ipc ipc: add missing container_of()s for randstruct 2017-08-02 17:16:12 -07:00
kernel Minor page waitqueue cleanups 2017-08-27 13:55:12 -07:00
lib kernel/watchdog: Prevent false positives with turbo modes 2017-08-18 12:35:02 +02:00
mm Avoid page waitqueue race leaving possible page locker waiting 2017-08-27 16:25:09 -07:00
net Two nfsd bugfixes, neither 4.13 regressions, but both potentially 2017-08-25 17:27:26 -07:00
samples samples/bpf: fix bpf tunnel cleanup 2017-07-31 22:02:47 -07:00
scripts Kbuild fixes for v4.13 2017-08-24 14:22:27 -07:00
security Now that IPC and other changes have landed, enable manual markings for 2017-07-19 08:55:18 -07:00
sound ASoC: rt5677: Reintroduce I2C device IDs 2017-08-24 18:04:29 +02:00
tools NTB bug fixes to address an incorrect ntb_mw_count reference in the NTB 2017-08-27 17:01:54 -07:00
usr ramfs: clarify help text that compression applies to ramfs as well as legacy ramdisk. 2017-07-06 16:24:30 -07:00
virt KVM/ARM Fixes for v4.13-rc4 2017-08-03 17:59:58 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap power supply and reset changes for the v4.12 series (part 2) 2017-05-12 12:02:21 -07:00
COPYING
CREDITS avr32: remove support for AVR32 architecture 2017-05-01 09:27:15 +02:00
Kbuild kbuild: Consolidate header generation from ASM offset information 2017-04-13 05:43:37 +09:00
Kconfig
MAINTAINERS MIPS: Add Onion Omega2+ board 2017-08-29 15:21:54 +02:00
Makefile Linux 4.13-rc7 2017-08-27 17:20:40 -07:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.