i386: move math-emu

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 148 insertions, 0 deletions

diff --git a/arch/x86/math-emu/reg_u_mul.S b/arch/x86/math-emu/reg_u_mul.S
new file mode 100644
index 000000000000..973f12af97df
--- /dev/null
+++ b/arch/x86/math-emu/reg_u_mul.S
@@ -0,0 +1,148 @@
+        .file   "reg_u_mul.S"
+/*---------------------------------------------------------------------------+
+ |  reg_u_mul.S                                                              |
+ |                                                                           |
+ | Core multiplication routine                                               |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1995,1997                                         |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@suburbia.net                              |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ |   Basic multiplication routine.                                           |
+ |   Does not check the resulting exponent for overflow/underflow            |
+ |                                                                           |
+ |   FPU_u_mul(FPU_REG *a, FPU_REG *b, FPU_REG *c, unsigned int cw);         |
+ |                                                                           |
+ |   Internal working is at approx 128 bits.                                 |
+ |   Result is rounded to nearest 53 or 64 bits, using "nearest or even".    |
+ +---------------------------------------------------------------------------*/
+
+#include "exception.h"
+#include "fpu_emu.h"
+#include "control_w.h"
+
+
+
+#ifndef NON_REENTRANT_FPU
+/*  Local storage on the stack: */
+#define FPU_accum_0     -4(%ebp)        /* ms word */
+#define FPU_accum_1     -8(%ebp)
+
+#else
+/*  Local storage in a static area: */
+.data
+        .align 4,0
+FPU_accum_0:
+        .long   0
+FPU_accum_1:
+        .long   0
+#endif /* NON_REENTRANT_FPU */
+
+
+.text
+ENTRY(FPU_u_mul)
+        pushl   %ebp
+        movl    %esp,%ebp
+#ifndef NON_REENTRANT_FPU
+        subl    $8,%esp
+#endif /* NON_REENTRANT_FPU */ 
+
+        pushl   %esi
+        pushl   %edi
+        pushl   %ebx
+
+        movl    PARAM1,%esi
+        movl    PARAM2,%edi
+
+#ifdef PARANOID
+        testl   $0x80000000,SIGH(%esi)
+        jz      L_bugged
+        testl   $0x80000000,SIGH(%edi)
+        jz      L_bugged
+#endif /* PARANOID */
+
+        xorl    %ecx,%ecx
+        xorl    %ebx,%ebx
+
+        movl    SIGL(%esi),%eax
+        mull    SIGL(%edi)
+        movl    %eax,FPU_accum_0
+        movl    %edx,FPU_accum_1
+
+        movl    SIGL(%esi),%eax
+        mull    SIGH(%edi)
+        addl    %eax,FPU_accum_1
+        adcl    %edx,%ebx
+/*      adcl    $0,%ecx         // overflow here is not possible */
+
+        movl    SIGH(%esi),%eax
+        mull    SIGL(%edi)
+        addl    %eax,FPU_accum_1
+        adcl    %edx,%ebx
+        adcl    $0,%ecx
+
+        movl    SIGH(%esi),%eax
+        mull    SIGH(%edi)
+        addl    %eax,%ebx
+        adcl    %edx,%ecx
+
+        /* Get the sum of the exponents. */
+        movl    PARAM6,%eax
+        subl    EXP_BIAS-1,%eax
+
+        /* Two denormals can cause an exponent underflow */
+        cmpl    EXP_WAY_UNDER,%eax
+        jg      Exp_not_underflow
+
+        /* Set to a really low value allow correct handling */
+        movl    EXP_WAY_UNDER,%eax
+
+Exp_not_underflow:
+
+/*  Have now finished with the sources */
+        movl    PARAM3,%edi     /* Point to the destination */
+        movw    %ax,EXP(%edi)
+
+/*  Now make sure that the result is normalized */
+        testl   $0x80000000,%ecx
+        jnz     LResult_Normalised
+
+        /* Normalize by shifting left one bit */
+        shll    $1,FPU_accum_0
+        rcll    $1,FPU_accum_1
+        rcll    $1,%ebx
+        rcll    $1,%ecx
+        decw    EXP(%edi)
+
+LResult_Normalised:
+        movl    FPU_accum_0,%eax
+        movl    FPU_accum_1,%edx
+        orl     %eax,%eax
+        jz      L_extent_zero
+
+        orl     $1,%edx
+
+L_extent_zero:
+        movl    %ecx,%eax
+        jmp     fpu_reg_round
+
+
+#ifdef PARANOID
+L_bugged:
+        pushl   EX_INTERNAL|0x205
+        call    EXCEPTION
+        pop     %ebx
+        jmp     L_exit
+
+L_exit:
+        popl    %ebx
+        popl    %edi
+        popl    %esi
+        leave
+        ret
+#endif /* PARANOID */ 
+