linux/arch/x86/math-emu/reg_u_add.S
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

170 lines
3.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
.file "reg_u_add.S"
/*---------------------------------------------------------------------------+
| reg_u_add.S |
| |
| Add two valid (TAG_Valid) FPU_REG numbers, of the same sign, and put the |
| result in a destination FPU_REG. |
| |
| Copyright (C) 1992,1993,1995,1997 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
| E-mail billm@suburbia.net |
| |
| Call from C as: |
| int FPU_u_add(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *answ, |
| int control_w) |
| Return value is the tag of the answer, or-ed with FPU_Exception if |
| one was raised, or -1 on internal error. |
| |
+---------------------------------------------------------------------------*/
/*
| Kernel addition routine FPU_u_add(reg *arg1, reg *arg2, reg *answ).
| Takes two valid reg f.p. numbers (TAG_Valid), which are
| treated as unsigned numbers,
| and returns their sum as a TAG_Valid or TAG_Special f.p. number.
| The returned number is normalized.
| Basic checks are performed if PARANOID is defined.
*/
#include "exception.h"
#include "fpu_emu.h"
#include "control_w.h"
.text
ENTRY(FPU_u_add)
pushl %ebp
movl %esp,%ebp
pushl %esi
pushl %edi
pushl %ebx
movl PARAM1,%esi /* source 1 */
movl PARAM2,%edi /* source 2 */
movl PARAM6,%ecx
movl %ecx,%edx
subl PARAM7,%ecx /* exp1 - exp2 */
jge L_arg1_larger
/* num1 is smaller */
movl SIGL(%esi),%ebx
movl SIGH(%esi),%eax
movl %edi,%esi
movl PARAM7,%edx
negw %cx
jmp L_accum_loaded
L_arg1_larger:
/* num1 has larger or equal exponent */
movl SIGL(%edi),%ebx
movl SIGH(%edi),%eax
L_accum_loaded:
movl PARAM3,%edi /* destination */
movw %dx,EXP(%edi) /* Copy exponent to destination */
xorl %edx,%edx /* clear the extension */
#ifdef PARANOID
testl $0x80000000,%eax
je L_bugged
testl $0x80000000,SIGH(%esi)
je L_bugged
#endif /* PARANOID */
/* The number to be shifted is in %eax:%ebx:%edx */
cmpw $32,%cx /* shrd only works for 0..31 bits */
jnc L_more_than_31
/* less than 32 bits */
shrd %cl,%ebx,%edx
shrd %cl,%eax,%ebx
shr %cl,%eax
jmp L_shift_done
L_more_than_31:
cmpw $64,%cx
jnc L_more_than_63
subb $32,%cl
jz L_exactly_32
shrd %cl,%eax,%edx
shr %cl,%eax
orl %ebx,%ebx
jz L_more_31_no_low /* none of the lowest bits is set */
orl $1,%edx /* record the fact in the extension */
L_more_31_no_low:
movl %eax,%ebx
xorl %eax,%eax
jmp L_shift_done
L_exactly_32:
movl %ebx,%edx
movl %eax,%ebx
xorl %eax,%eax
jmp L_shift_done
L_more_than_63:
cmpw $65,%cx
jnc L_more_than_64
movl %eax,%edx
orl %ebx,%ebx
jz L_more_63_no_low
orl $1,%edx
jmp L_more_63_no_low
L_more_than_64:
movl $1,%edx /* The shifted nr always at least one '1' */
L_more_63_no_low:
xorl %ebx,%ebx
xorl %eax,%eax
L_shift_done:
/* Now do the addition */
addl SIGL(%esi),%ebx
adcl SIGH(%esi),%eax
jnc L_round_the_result
/* Overflow, adjust the result */
rcrl $1,%eax
rcrl $1,%ebx
rcrl $1,%edx
jnc L_no_bit_lost
orl $1,%edx
L_no_bit_lost:
incw EXP(%edi)
L_round_the_result:
jmp fpu_reg_round /* Round the result */
#ifdef PARANOID
/* If we ever get here then we have problems! */
L_bugged:
pushl EX_INTERNAL|0x201
call EXCEPTION
pop %ebx
movl $-1,%eax
jmp L_exit
L_exit:
popl %ebx
popl %edi
popl %esi
leave
ret
#endif /* PARANOID */
ENDPROC(FPU_u_add)