linux-stable/arch/x86/math-emu/polynom_Xsig.S
Jiri Slaby bd6be579a7 x86/fpu/math-emu: Add ENDPROC to functions
Functions in math-emu are annotated as ENTRY() symbols, but their
ends are not annotated at all. But these are standard functions
called from C, with proper stack register update etc.

Omitting the ends means:

  * the annotations are not paired and we cannot deal with such functions
    e.g. in objtool

  * the symbols are not marked as functions in the object file

  * there are no sizes of the functions in the object file

So fix this by adding ENDPROC() to each such case in math-emu.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170824080624.7768-1-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-08-29 13:23:30 +02:00

136 lines
3.9 KiB
ArmAsm

/*---------------------------------------------------------------------------+
| polynomial_Xsig.S |
| |
| Fixed point arithmetic polynomial evaluation. |
| |
| Copyright (C) 1992,1993,1994,1995 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@jacobi.maths.monash.edu.au |
| |
| Call from C as: |
| void polynomial_Xsig(Xsig *accum, unsigned long long x, |
| unsigned long long terms[], int n) |
| |
| Computes: |
| terms[0] + (terms[1] + (terms[2] + ... + (terms[n-1]*x)*x)*x)*x) ... )*x |
| and adds the result to the 12 byte Xsig. |
| The terms[] are each 8 bytes, but all computation is performed to 12 byte |
| precision. |
| |
| This function must be used carefully: most overflow of intermediate |
| results is controlled, but overflow of the result is not. |
| |
+---------------------------------------------------------------------------*/
.file "polynomial_Xsig.S"
#include "fpu_emu.h"
#define TERM_SIZE $8
#define SUM_MS -20(%ebp) /* sum ms long */
#define SUM_MIDDLE -24(%ebp) /* sum middle long */
#define SUM_LS -28(%ebp) /* sum ls long */
#define ACCUM_MS -4(%ebp) /* accum ms long */
#define ACCUM_MIDDLE -8(%ebp) /* accum middle long */
#define ACCUM_LS -12(%ebp) /* accum ls long */
#define OVERFLOWED -16(%ebp) /* addition overflow flag */
.text
ENTRY(polynomial_Xsig)
pushl %ebp
movl %esp,%ebp
subl $32,%esp
pushl %esi
pushl %edi
pushl %ebx
movl PARAM2,%esi /* x */
movl PARAM3,%edi /* terms */
movl TERM_SIZE,%eax
mull PARAM4 /* n */
addl %eax,%edi
movl 4(%edi),%edx /* terms[n] */
movl %edx,SUM_MS
movl (%edi),%edx /* terms[n] */
movl %edx,SUM_MIDDLE
xor %eax,%eax
movl %eax,SUM_LS
movb %al,OVERFLOWED
subl TERM_SIZE,%edi
decl PARAM4
js L_accum_done
L_accum_loop:
xor %eax,%eax
movl %eax,ACCUM_MS
movl %eax,ACCUM_MIDDLE
movl SUM_MIDDLE,%eax
mull (%esi) /* x ls long */
movl %edx,ACCUM_LS
movl SUM_MIDDLE,%eax
mull 4(%esi) /* x ms long */
addl %eax,ACCUM_LS
adcl %edx,ACCUM_MIDDLE
adcl $0,ACCUM_MS
movl SUM_MS,%eax
mull (%esi) /* x ls long */
addl %eax,ACCUM_LS
adcl %edx,ACCUM_MIDDLE
adcl $0,ACCUM_MS
movl SUM_MS,%eax
mull 4(%esi) /* x ms long */
addl %eax,ACCUM_MIDDLE
adcl %edx,ACCUM_MS
testb $0xff,OVERFLOWED
jz L_no_overflow
movl (%esi),%eax
addl %eax,ACCUM_MIDDLE
movl 4(%esi),%eax
adcl %eax,ACCUM_MS /* This could overflow too */
L_no_overflow:
/*
* Now put the sum of next term and the accumulator
* into the sum register
*/
movl ACCUM_LS,%eax
addl (%edi),%eax /* term ls long */
movl %eax,SUM_LS
movl ACCUM_MIDDLE,%eax
adcl (%edi),%eax /* term ls long */
movl %eax,SUM_MIDDLE
movl ACCUM_MS,%eax
adcl 4(%edi),%eax /* term ms long */
movl %eax,SUM_MS
sbbb %al,%al
movb %al,OVERFLOWED /* Used in the next iteration */
subl TERM_SIZE,%edi
decl PARAM4
jns L_accum_loop
L_accum_done:
movl PARAM1,%edi /* accum */
movl SUM_LS,%eax
addl %eax,(%edi)
movl SUM_MIDDLE,%eax
adcl %eax,4(%edi)
movl SUM_MS,%eax
adcl %eax,8(%edi)
popl %ebx
popl %edi
popl %esi
leave
ret
ENDPROC(polynomial_Xsig)