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bd6be579a7
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>
367 lines
9.9 KiB
ArmAsm
367 lines
9.9 KiB
ArmAsm
.file "div_Xsig.S"
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/*---------------------------------------------------------------------------+
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| div_Xsig.S |
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| Division subroutine for 96 bit quantities |
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| Copyright (C) 1994,1995 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
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| Australia. E-mail billm@jacobi.maths.monash.edu.au |
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+---------------------------------------------------------------------------*/
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/*---------------------------------------------------------------------------+
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| Divide the 96 bit quantity pointed to by a, by that pointed to by b, and |
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| put the 96 bit result at the location d. |
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| The result may not be accurate to 96 bits. It is intended for use where |
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| a result better than 64 bits is required. The result should usually be |
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| good to at least 94 bits. |
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| The returned result is actually divided by one half. This is done to |
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| prevent overflow. |
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| .aaaaaaaaaaaaaa / .bbbbbbbbbbbbb -> .dddddddddddd |
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| void div_Xsig(Xsig *a, Xsig *b, Xsig *dest) |
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+---------------------------------------------------------------------------*/
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#include "exception.h"
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#include "fpu_emu.h"
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#define XsigLL(x) (x)
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#define XsigL(x) 4(x)
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#define XsigH(x) 8(x)
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#ifndef NON_REENTRANT_FPU
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/*
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Local storage on the stack:
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Accumulator: FPU_accum_3:FPU_accum_2:FPU_accum_1:FPU_accum_0
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*/
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#define FPU_accum_3 -4(%ebp)
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#define FPU_accum_2 -8(%ebp)
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#define FPU_accum_1 -12(%ebp)
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#define FPU_accum_0 -16(%ebp)
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#define FPU_result_3 -20(%ebp)
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#define FPU_result_2 -24(%ebp)
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#define FPU_result_1 -28(%ebp)
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#else
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.data
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/*
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Local storage in a static area:
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Accumulator: FPU_accum_3:FPU_accum_2:FPU_accum_1:FPU_accum_0
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*/
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.align 4,0
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FPU_accum_3:
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.long 0
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FPU_accum_2:
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.long 0
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FPU_accum_1:
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.long 0
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FPU_accum_0:
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.long 0
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FPU_result_3:
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.long 0
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FPU_result_2:
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.long 0
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FPU_result_1:
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.long 0
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#endif /* NON_REENTRANT_FPU */
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.text
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ENTRY(div_Xsig)
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pushl %ebp
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movl %esp,%ebp
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#ifndef NON_REENTRANT_FPU
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subl $28,%esp
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#endif /* NON_REENTRANT_FPU */
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pushl %esi
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pushl %edi
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pushl %ebx
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movl PARAM1,%esi /* pointer to num */
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movl PARAM2,%ebx /* pointer to denom */
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#ifdef PARANOID
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testl $0x80000000, XsigH(%ebx) /* Divisor */
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je L_bugged
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#endif /* PARANOID */
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/*---------------------------------------------------------------------------+
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| Divide: Return arg1/arg2 to arg3. |
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| The maximum returned value is (ignoring exponents) |
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| .ffffffff ffffffff |
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| ------------------ = 1.ffffffff fffffffe |
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| .80000000 00000000 |
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| and the minimum is |
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| .80000000 00000000 |
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| ------------------ = .80000000 00000001 (rounded) |
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| .ffffffff ffffffff |
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+---------------------------------------------------------------------------*/
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/* Save extended dividend in local register */
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/* Divide by 2 to prevent overflow */
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clc
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movl XsigH(%esi),%eax
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rcrl %eax
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movl %eax,FPU_accum_3
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movl XsigL(%esi),%eax
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rcrl %eax
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movl %eax,FPU_accum_2
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movl XsigLL(%esi),%eax
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rcrl %eax
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movl %eax,FPU_accum_1
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movl $0,%eax
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rcrl %eax
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movl %eax,FPU_accum_0
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movl FPU_accum_2,%eax /* Get the current num */
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movl FPU_accum_3,%edx
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/*----------------------------------------------------------------------*/
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/* Initialization done.
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Do the first 32 bits. */
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/* We will divide by a number which is too large */
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movl XsigH(%ebx),%ecx
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addl $1,%ecx
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jnc LFirst_div_not_1
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/* here we need to divide by 100000000h,
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i.e., no division at all.. */
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mov %edx,%eax
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jmp LFirst_div_done
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LFirst_div_not_1:
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divl %ecx /* Divide the numerator by the augmented
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denom ms dw */
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LFirst_div_done:
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movl %eax,FPU_result_3 /* Put the result in the answer */
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mull XsigH(%ebx) /* mul by the ms dw of the denom */
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subl %eax,FPU_accum_2 /* Subtract from the num local reg */
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sbbl %edx,FPU_accum_3
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movl FPU_result_3,%eax /* Get the result back */
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mull XsigL(%ebx) /* now mul the ls dw of the denom */
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subl %eax,FPU_accum_1 /* Subtract from the num local reg */
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sbbl %edx,FPU_accum_2
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sbbl $0,FPU_accum_3
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je LDo_2nd_32_bits /* Must check for non-zero result here */
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#ifdef PARANOID
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jb L_bugged_1
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#endif /* PARANOID */
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/* need to subtract another once of the denom */
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incl FPU_result_3 /* Correct the answer */
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movl XsigL(%ebx),%eax
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movl XsigH(%ebx),%edx
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subl %eax,FPU_accum_1 /* Subtract from the num local reg */
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sbbl %edx,FPU_accum_2
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#ifdef PARANOID
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sbbl $0,FPU_accum_3
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jne L_bugged_1 /* Must check for non-zero result here */
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#endif /* PARANOID */
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/*----------------------------------------------------------------------*/
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/* Half of the main problem is done, there is just a reduced numerator
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to handle now.
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Work with the second 32 bits, FPU_accum_0 not used from now on */
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LDo_2nd_32_bits:
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movl FPU_accum_2,%edx /* get the reduced num */
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movl FPU_accum_1,%eax
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/* need to check for possible subsequent overflow */
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cmpl XsigH(%ebx),%edx
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jb LDo_2nd_div
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ja LPrevent_2nd_overflow
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cmpl XsigL(%ebx),%eax
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jb LDo_2nd_div
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LPrevent_2nd_overflow:
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/* The numerator is greater or equal, would cause overflow */
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/* prevent overflow */
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subl XsigL(%ebx),%eax
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sbbl XsigH(%ebx),%edx
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movl %edx,FPU_accum_2
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movl %eax,FPU_accum_1
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incl FPU_result_3 /* Reflect the subtraction in the answer */
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#ifdef PARANOID
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je L_bugged_2 /* Can't bump the result to 1.0 */
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#endif /* PARANOID */
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LDo_2nd_div:
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cmpl $0,%ecx /* augmented denom msw */
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jnz LSecond_div_not_1
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/* %ecx == 0, we are dividing by 1.0 */
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mov %edx,%eax
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jmp LSecond_div_done
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LSecond_div_not_1:
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divl %ecx /* Divide the numerator by the denom ms dw */
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LSecond_div_done:
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movl %eax,FPU_result_2 /* Put the result in the answer */
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mull XsigH(%ebx) /* mul by the ms dw of the denom */
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subl %eax,FPU_accum_1 /* Subtract from the num local reg */
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sbbl %edx,FPU_accum_2
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#ifdef PARANOID
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jc L_bugged_2
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#endif /* PARANOID */
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movl FPU_result_2,%eax /* Get the result back */
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mull XsigL(%ebx) /* now mul the ls dw of the denom */
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subl %eax,FPU_accum_0 /* Subtract from the num local reg */
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sbbl %edx,FPU_accum_1 /* Subtract from the num local reg */
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sbbl $0,FPU_accum_2
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#ifdef PARANOID
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jc L_bugged_2
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#endif /* PARANOID */
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jz LDo_3rd_32_bits
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#ifdef PARANOID
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cmpl $1,FPU_accum_2
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jne L_bugged_2
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#endif /* PARANOID */
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/* need to subtract another once of the denom */
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movl XsigL(%ebx),%eax
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movl XsigH(%ebx),%edx
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subl %eax,FPU_accum_0 /* Subtract from the num local reg */
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sbbl %edx,FPU_accum_1
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sbbl $0,FPU_accum_2
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#ifdef PARANOID
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jc L_bugged_2
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jne L_bugged_2
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#endif /* PARANOID */
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addl $1,FPU_result_2 /* Correct the answer */
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adcl $0,FPU_result_3
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#ifdef PARANOID
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jc L_bugged_2 /* Must check for non-zero result here */
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#endif /* PARANOID */
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/*----------------------------------------------------------------------*/
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/* The division is essentially finished here, we just need to perform
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tidying operations.
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Deal with the 3rd 32 bits */
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LDo_3rd_32_bits:
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/* We use an approximation for the third 32 bits.
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To take account of the 3rd 32 bits of the divisor
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(call them del), we subtract del * (a/b) */
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movl FPU_result_3,%eax /* a/b */
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mull XsigLL(%ebx) /* del */
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subl %edx,FPU_accum_1
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/* A borrow indicates that the result is negative */
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jnb LTest_over
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movl XsigH(%ebx),%edx
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addl %edx,FPU_accum_1
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subl $1,FPU_result_2 /* Adjust the answer */
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sbbl $0,FPU_result_3
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/* The above addition might not have been enough, check again. */
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movl FPU_accum_1,%edx /* get the reduced num */
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cmpl XsigH(%ebx),%edx /* denom */
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jb LDo_3rd_div
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movl XsigH(%ebx),%edx
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addl %edx,FPU_accum_1
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subl $1,FPU_result_2 /* Adjust the answer */
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sbbl $0,FPU_result_3
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jmp LDo_3rd_div
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LTest_over:
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movl FPU_accum_1,%edx /* get the reduced num */
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/* need to check for possible subsequent overflow */
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cmpl XsigH(%ebx),%edx /* denom */
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jb LDo_3rd_div
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/* prevent overflow */
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subl XsigH(%ebx),%edx
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movl %edx,FPU_accum_1
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addl $1,FPU_result_2 /* Reflect the subtraction in the answer */
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adcl $0,FPU_result_3
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LDo_3rd_div:
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movl FPU_accum_0,%eax
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movl FPU_accum_1,%edx
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divl XsigH(%ebx)
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movl %eax,FPU_result_1 /* Rough estimate of third word */
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movl PARAM3,%esi /* pointer to answer */
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movl FPU_result_1,%eax
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movl %eax,XsigLL(%esi)
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movl FPU_result_2,%eax
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movl %eax,XsigL(%esi)
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movl FPU_result_3,%eax
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movl %eax,XsigH(%esi)
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L_exit:
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popl %ebx
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popl %edi
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popl %esi
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leave
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ret
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#ifdef PARANOID
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/* The logic is wrong if we got here */
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L_bugged:
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pushl EX_INTERNAL|0x240
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call EXCEPTION
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pop %ebx
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jmp L_exit
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L_bugged_1:
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pushl EX_INTERNAL|0x241
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call EXCEPTION
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pop %ebx
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jmp L_exit
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L_bugged_2:
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pushl EX_INTERNAL|0x242
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call EXCEPTION
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pop %ebx
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jmp L_exit
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#endif /* PARANOID */
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ENDPROC(div_Xsig)
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