1 files changed, 167 insertions, 0 deletions

diff --git a/arch/i386/math-emu/reg_u_add.S b/arch/i386/math-emu/reg_u_add.S
new file mode 100644
index 000000000000..47c4c2434d85
--- /dev/null
+++ b/arch/i386/math-emu/reg_u_add.S
@@ -0,0 +1,167 @@
+        .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 */