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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>
273 lines
6 KiB
ArmAsm
273 lines
6 KiB
ArmAsm
.file "reg_u_sub.S"
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/*---------------------------------------------------------------------------+
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| reg_u_sub.S |
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| Core floating point subtraction routine. |
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| Copyright (C) 1992,1993,1995,1997 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
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| E-mail billm@suburbia.net |
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| Call from C as: |
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| int FPU_u_sub(FPU_REG *arg1, FPU_REG *arg2, FPU_REG *answ, |
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| int control_w) |
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| Return value is the tag of the answer, or-ed with FPU_Exception if |
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| one was raised, or -1 on internal error. |
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+---------------------------------------------------------------------------*/
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/*
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| Kernel subtraction routine FPU_u_sub(reg *arg1, reg *arg2, reg *answ).
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| Takes two valid reg f.p. numbers (TAG_Valid), which are
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| treated as unsigned numbers,
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| and returns their difference as a TAG_Valid or TAG_Zero f.p.
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| number.
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| The first number (arg1) must be the larger.
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| The returned number is normalized.
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| Basic checks are performed if PARANOID is defined.
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*/
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#include "exception.h"
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#include "fpu_emu.h"
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#include "control_w.h"
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.text
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ENTRY(FPU_u_sub)
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pushl %ebp
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movl %esp,%ebp
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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 /* source 1 */
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movl PARAM2,%edi /* source 2 */
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movl PARAM6,%ecx
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subl PARAM7,%ecx /* exp1 - exp2 */
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#ifdef PARANOID
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/* source 2 is always smaller than source 1 */
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js L_bugged_1
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testl $0x80000000,SIGH(%edi) /* The args are assumed to be be normalized */
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je L_bugged_2
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testl $0x80000000,SIGH(%esi)
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je L_bugged_2
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#endif /* PARANOID */
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/*--------------------------------------+
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| Form a register holding the |
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| smaller number |
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+--------------------------------------*/
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movl SIGH(%edi),%eax /* register ms word */
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movl SIGL(%edi),%ebx /* register ls word */
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movl PARAM3,%edi /* destination */
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movl PARAM6,%edx
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movw %dx,EXP(%edi) /* Copy exponent to destination */
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xorl %edx,%edx /* register extension */
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/*--------------------------------------+
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| Shift the temporary register |
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| right the required number of |
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| places. |
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+--------------------------------------*/
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cmpw $32,%cx /* shrd only works for 0..31 bits */
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jnc L_more_than_31
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/* less than 32 bits */
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shrd %cl,%ebx,%edx
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shrd %cl,%eax,%ebx
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shr %cl,%eax
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jmp L_shift_done
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L_more_than_31:
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cmpw $64,%cx
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jnc L_more_than_63
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subb $32,%cl
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jz L_exactly_32
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shrd %cl,%eax,%edx
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shr %cl,%eax
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orl %ebx,%ebx
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jz L_more_31_no_low /* none of the lowest bits is set */
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orl $1,%edx /* record the fact in the extension */
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L_more_31_no_low:
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movl %eax,%ebx
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xorl %eax,%eax
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jmp L_shift_done
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L_exactly_32:
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movl %ebx,%edx
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movl %eax,%ebx
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xorl %eax,%eax
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jmp L_shift_done
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L_more_than_63:
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cmpw $65,%cx
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jnc L_more_than_64
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/* Shift right by 64 bits */
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movl %eax,%edx
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orl %ebx,%ebx
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jz L_more_63_no_low
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orl $1,%edx
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jmp L_more_63_no_low
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L_more_than_64:
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jne L_more_than_65
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/* Shift right by 65 bits */
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/* Carry is clear if we get here */
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movl %eax,%edx
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rcrl %edx
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jnc L_shift_65_nc
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orl $1,%edx
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jmp L_more_63_no_low
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L_shift_65_nc:
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orl %ebx,%ebx
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jz L_more_63_no_low
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orl $1,%edx
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jmp L_more_63_no_low
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L_more_than_65:
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movl $1,%edx /* The shifted nr always at least one '1' */
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L_more_63_no_low:
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xorl %ebx,%ebx
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xorl %eax,%eax
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L_shift_done:
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L_subtr:
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/*------------------------------+
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| Do the subtraction |
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+------------------------------*/
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xorl %ecx,%ecx
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subl %edx,%ecx
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movl %ecx,%edx
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movl SIGL(%esi),%ecx
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sbbl %ebx,%ecx
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movl %ecx,%ebx
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movl SIGH(%esi),%ecx
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sbbl %eax,%ecx
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movl %ecx,%eax
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#ifdef PARANOID
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/* We can never get a borrow */
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jc L_bugged
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#endif /* PARANOID */
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/*--------------------------------------+
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| Normalize the result |
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+--------------------------------------*/
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testl $0x80000000,%eax
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jnz L_round /* no shifting needed */
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orl %eax,%eax
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jnz L_shift_1 /* shift left 1 - 31 bits */
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orl %ebx,%ebx
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jnz L_shift_32 /* shift left 32 - 63 bits */
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/*
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* A rare case, the only one which is non-zero if we got here
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* is: 1000000 .... 0000
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* -0111111 .... 1111 1
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* --------------------
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* 0000000 .... 0000 1
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*/
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cmpl $0x80000000,%edx
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jnz L_must_be_zero
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/* Shift left 64 bits */
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subw $64,EXP(%edi)
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xchg %edx,%eax
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jmp fpu_reg_round
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L_must_be_zero:
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#ifdef PARANOID
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orl %edx,%edx
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jnz L_bugged_3
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#endif /* PARANOID */
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/* The result is zero */
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movw $0,EXP(%edi) /* exponent */
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movl $0,SIGL(%edi)
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movl $0,SIGH(%edi)
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movl TAG_Zero,%eax
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jmp L_exit
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L_shift_32:
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movl %ebx,%eax
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movl %edx,%ebx
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movl $0,%edx
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subw $32,EXP(%edi) /* Can get underflow here */
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/* We need to shift left by 1 - 31 bits */
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L_shift_1:
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bsrl %eax,%ecx /* get the required shift in %ecx */
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subl $31,%ecx
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negl %ecx
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shld %cl,%ebx,%eax
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shld %cl,%edx,%ebx
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shl %cl,%edx
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subw %cx,EXP(%edi) /* Can get underflow here */
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L_round:
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jmp fpu_reg_round /* Round the result */
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#ifdef PARANOID
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L_bugged_1:
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pushl EX_INTERNAL|0x206
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call EXCEPTION
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pop %ebx
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jmp L_error_exit
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L_bugged_2:
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pushl EX_INTERNAL|0x209
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call EXCEPTION
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pop %ebx
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jmp L_error_exit
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L_bugged_3:
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pushl EX_INTERNAL|0x210
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call EXCEPTION
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pop %ebx
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jmp L_error_exit
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L_bugged_4:
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pushl EX_INTERNAL|0x211
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call EXCEPTION
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pop %ebx
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jmp L_error_exit
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L_bugged:
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pushl EX_INTERNAL|0x212
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call EXCEPTION
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pop %ebx
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jmp L_error_exit
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L_error_exit:
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movl $-1,%eax
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#endif /* PARANOID */
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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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ENDPROC(FPU_u_sub)
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