OpenCloudOS-Kernel/arch/x86/math-emu/div_Xsig.S

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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>
2017-11-01 22:07:57 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
.file "div_Xsig.S"
/*---------------------------------------------------------------------------+
| div_Xsig.S |
| |
| Division subroutine for 96 bit quantities |
| |
| Copyright (C) 1994,1995 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@jacobi.maths.monash.edu.au |
| |
| |
+---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------+
| Divide the 96 bit quantity pointed to by a, by that pointed to by b, and |
| put the 96 bit result at the location d. |
| |
| The result may not be accurate to 96 bits. It is intended for use where |
| a result better than 64 bits is required. The result should usually be |
| good to at least 94 bits. |
| The returned result is actually divided by one half. This is done to |
| prevent overflow. |
| |
| .aaaaaaaaaaaaaa / .bbbbbbbbbbbbb -> .dddddddddddd |
| |
| void div_Xsig(Xsig *a, Xsig *b, Xsig *dest) |
| |
+---------------------------------------------------------------------------*/
#include "exception.h"
#include "fpu_emu.h"
#define XsigLL(x) (x)
#define XsigL(x) 4(x)
#define XsigH(x) 8(x)
#ifndef NON_REENTRANT_FPU
/*
Local storage on the stack:
Accumulator: FPU_accum_3:FPU_accum_2:FPU_accum_1:FPU_accum_0
*/
#define FPU_accum_3 -4(%ebp)
#define FPU_accum_2 -8(%ebp)
#define FPU_accum_1 -12(%ebp)
#define FPU_accum_0 -16(%ebp)
#define FPU_result_3 -20(%ebp)
#define FPU_result_2 -24(%ebp)
#define FPU_result_1 -28(%ebp)
#else
.data
/*
Local storage in a static area:
Accumulator: FPU_accum_3:FPU_accum_2:FPU_accum_1:FPU_accum_0
*/
.align 4,0
FPU_accum_3:
.long 0
FPU_accum_2:
.long 0
FPU_accum_1:
.long 0
FPU_accum_0:
.long 0
FPU_result_3:
.long 0
FPU_result_2:
.long 0
FPU_result_1:
.long 0
#endif /* NON_REENTRANT_FPU */
.text
SYM_FUNC_START(div_Xsig)
pushl %ebp
movl %esp,%ebp
#ifndef NON_REENTRANT_FPU
subl $28,%esp
#endif /* NON_REENTRANT_FPU */
pushl %esi
pushl %edi
pushl %ebx
movl PARAM1,%esi /* pointer to num */
movl PARAM2,%ebx /* pointer to denom */
#ifdef PARANOID
testl $0x80000000, XsigH(%ebx) /* Divisor */
je L_bugged
#endif /* PARANOID */
/*---------------------------------------------------------------------------+
| Divide: Return arg1/arg2 to arg3. |
| |
| The maximum returned value is (ignoring exponents) |
| .ffffffff ffffffff |
| ------------------ = 1.ffffffff fffffffe |
| .80000000 00000000 |
| and the minimum is |
| .80000000 00000000 |
| ------------------ = .80000000 00000001 (rounded) |
| .ffffffff ffffffff |
| |
+---------------------------------------------------------------------------*/
/* Save extended dividend in local register */
/* Divide by 2 to prevent overflow */
clc
movl XsigH(%esi),%eax
rcrl %eax
movl %eax,FPU_accum_3
movl XsigL(%esi),%eax
rcrl %eax
movl %eax,FPU_accum_2
movl XsigLL(%esi),%eax
rcrl %eax
movl %eax,FPU_accum_1
movl $0,%eax
rcrl %eax
movl %eax,FPU_accum_0
movl FPU_accum_2,%eax /* Get the current num */
movl FPU_accum_3,%edx
/*----------------------------------------------------------------------*/
/* Initialization done.
Do the first 32 bits. */
/* We will divide by a number which is too large */
movl XsigH(%ebx),%ecx
addl $1,%ecx
jnc LFirst_div_not_1
/* here we need to divide by 100000000h,
i.e., no division at all.. */
mov %edx,%eax
jmp LFirst_div_done
LFirst_div_not_1:
divl %ecx /* Divide the numerator by the augmented
denom ms dw */
LFirst_div_done:
movl %eax,FPU_result_3 /* Put the result in the answer */
mull XsigH(%ebx) /* mul by the ms dw of the denom */
subl %eax,FPU_accum_2 /* Subtract from the num local reg */
sbbl %edx,FPU_accum_3
movl FPU_result_3,%eax /* Get the result back */
mull XsigL(%ebx) /* now mul the ls dw of the denom */
subl %eax,FPU_accum_1 /* Subtract from the num local reg */
sbbl %edx,FPU_accum_2
sbbl $0,FPU_accum_3
je LDo_2nd_32_bits /* Must check for non-zero result here */
#ifdef PARANOID
jb L_bugged_1
#endif /* PARANOID */
/* need to subtract another once of the denom */
incl FPU_result_3 /* Correct the answer */
movl XsigL(%ebx),%eax
movl XsigH(%ebx),%edx
subl %eax,FPU_accum_1 /* Subtract from the num local reg */
sbbl %edx,FPU_accum_2
#ifdef PARANOID
sbbl $0,FPU_accum_3
jne L_bugged_1 /* Must check for non-zero result here */
#endif /* PARANOID */
/*----------------------------------------------------------------------*/
/* Half of the main problem is done, there is just a reduced numerator
to handle now.
Work with the second 32 bits, FPU_accum_0 not used from now on */
LDo_2nd_32_bits:
movl FPU_accum_2,%edx /* get the reduced num */
movl FPU_accum_1,%eax
/* need to check for possible subsequent overflow */
cmpl XsigH(%ebx),%edx
jb LDo_2nd_div
ja LPrevent_2nd_overflow
cmpl XsigL(%ebx),%eax
jb LDo_2nd_div
LPrevent_2nd_overflow:
/* The numerator is greater or equal, would cause overflow */
/* prevent overflow */
subl XsigL(%ebx),%eax
sbbl XsigH(%ebx),%edx
movl %edx,FPU_accum_2
movl %eax,FPU_accum_1
incl FPU_result_3 /* Reflect the subtraction in the answer */
#ifdef PARANOID
je L_bugged_2 /* Can't bump the result to 1.0 */
#endif /* PARANOID */
LDo_2nd_div:
cmpl $0,%ecx /* augmented denom msw */
jnz LSecond_div_not_1
/* %ecx == 0, we are dividing by 1.0 */
mov %edx,%eax
jmp LSecond_div_done
LSecond_div_not_1:
divl %ecx /* Divide the numerator by the denom ms dw */
LSecond_div_done:
movl %eax,FPU_result_2 /* Put the result in the answer */
mull XsigH(%ebx) /* mul by the ms dw of the denom */
subl %eax,FPU_accum_1 /* Subtract from the num local reg */
sbbl %edx,FPU_accum_2
#ifdef PARANOID
jc L_bugged_2
#endif /* PARANOID */
movl FPU_result_2,%eax /* Get the result back */
mull XsigL(%ebx) /* now mul the ls dw of the denom */
subl %eax,FPU_accum_0 /* Subtract from the num local reg */
sbbl %edx,FPU_accum_1 /* Subtract from the num local reg */
sbbl $0,FPU_accum_2
#ifdef PARANOID
jc L_bugged_2
#endif /* PARANOID */
jz LDo_3rd_32_bits
#ifdef PARANOID
cmpl $1,FPU_accum_2
jne L_bugged_2
#endif /* PARANOID */
/* need to subtract another once of the denom */
movl XsigL(%ebx),%eax
movl XsigH(%ebx),%edx
subl %eax,FPU_accum_0 /* Subtract from the num local reg */
sbbl %edx,FPU_accum_1
sbbl $0,FPU_accum_2
#ifdef PARANOID
jc L_bugged_2
jne L_bugged_2
#endif /* PARANOID */
addl $1,FPU_result_2 /* Correct the answer */
adcl $0,FPU_result_3
#ifdef PARANOID
jc L_bugged_2 /* Must check for non-zero result here */
#endif /* PARANOID */
/*----------------------------------------------------------------------*/
/* The division is essentially finished here, we just need to perform
tidying operations.
Deal with the 3rd 32 bits */
LDo_3rd_32_bits:
/* We use an approximation for the third 32 bits.
To take account of the 3rd 32 bits of the divisor
(call them del), we subtract del * (a/b) */
movl FPU_result_3,%eax /* a/b */
mull XsigLL(%ebx) /* del */
subl %edx,FPU_accum_1
/* A borrow indicates that the result is negative */
jnb LTest_over
movl XsigH(%ebx),%edx
addl %edx,FPU_accum_1
subl $1,FPU_result_2 /* Adjust the answer */
sbbl $0,FPU_result_3
/* The above addition might not have been enough, check again. */
movl FPU_accum_1,%edx /* get the reduced num */
cmpl XsigH(%ebx),%edx /* denom */
jb LDo_3rd_div
movl XsigH(%ebx),%edx
addl %edx,FPU_accum_1
subl $1,FPU_result_2 /* Adjust the answer */
sbbl $0,FPU_result_3
jmp LDo_3rd_div
LTest_over:
movl FPU_accum_1,%edx /* get the reduced num */
/* need to check for possible subsequent overflow */
cmpl XsigH(%ebx),%edx /* denom */
jb LDo_3rd_div
/* prevent overflow */
subl XsigH(%ebx),%edx
movl %edx,FPU_accum_1
addl $1,FPU_result_2 /* Reflect the subtraction in the answer */
adcl $0,FPU_result_3
LDo_3rd_div:
movl FPU_accum_0,%eax
movl FPU_accum_1,%edx
divl XsigH(%ebx)
movl %eax,FPU_result_1 /* Rough estimate of third word */
movl PARAM3,%esi /* pointer to answer */
movl FPU_result_1,%eax
movl %eax,XsigLL(%esi)
movl FPU_result_2,%eax
movl %eax,XsigL(%esi)
movl FPU_result_3,%eax
movl %eax,XsigH(%esi)
L_exit:
popl %ebx
popl %edi
popl %esi
leave
RET
#ifdef PARANOID
/* The logic is wrong if we got here */
L_bugged:
pushl EX_INTERNAL|0x240
call EXCEPTION
pop %ebx
jmp L_exit
L_bugged_1:
pushl EX_INTERNAL|0x241
call EXCEPTION
pop %ebx
jmp L_exit
L_bugged_2:
pushl EX_INTERNAL|0x242
call EXCEPTION
pop %ebx
jmp L_exit
#endif /* PARANOID */
SYM_FUNC_END(div_Xsig)