i386: move math-emu

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

1 files changed, 121 insertions, 0 deletions

diff --git a/arch/x86/math-emu/poly.h b/arch/x86/math-emu/poly.h
new file mode 100644
index 000000000000..4db798114923
--- /dev/null
+++ b/arch/x86/math-emu/poly.h
@@ -0,0 +1,121 @@
+/*---------------------------------------------------------------------------+
+ |  poly.h                                                                   |
+ |                                                                           |
+ |  Header file for the FPU-emu poly*.c source files.                        |
+ |                                                                           |
+ | Copyright (C) 1994,1999                                                   |
+ |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
+ |                       Australia.  E-mail   billm@melbpc.org.au            |
+ |                                                                           |
+ | Declarations and definitions for functions operating on Xsig (12-byte     |
+ | extended-significand) quantities.                                         |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+#ifndef _POLY_H
+#define _POLY_H
+
+/* This 12-byte structure is used to improve the accuracy of computation
+   of transcendental functions.
+   Intended to be used to get results better than 8-byte computation
+   allows. 9-byte would probably be sufficient.
+   */
+typedef struct {
+  unsigned long lsw;
+  unsigned long midw;
+  unsigned long msw;
+} Xsig;
+
+asmlinkage void mul64(unsigned long long const *a, unsigned long long const *b,
+                      unsigned long long *result);
+asmlinkage void polynomial_Xsig(Xsig *, const unsigned long long *x,
+                                const unsigned long long terms[], const int n);
+
+asmlinkage void mul32_Xsig(Xsig *, const unsigned long mult);
+asmlinkage void mul64_Xsig(Xsig *, const unsigned long long *mult);
+asmlinkage void mul_Xsig_Xsig(Xsig *dest, const Xsig *mult);
+
+asmlinkage void shr_Xsig(Xsig *, const int n);
+asmlinkage int round_Xsig(Xsig *);
+asmlinkage int norm_Xsig(Xsig *);
+asmlinkage void div_Xsig(Xsig *x1, const Xsig *x2, const Xsig *dest);
+
+/* Macro to extract the most significant 32 bits from a long long */
+#define LL_MSW(x)     (((unsigned long *)&x)[1])
+
+/* Macro to initialize an Xsig struct */
+#define MK_XSIG(a,b,c)     { c, b, a }
+
+/* Macro to access the 8 ms bytes of an Xsig as a long long */
+#define XSIG_LL(x)         (*(unsigned long long *)&x.midw)
+
+
+/*
+   Need to run gcc with optimizations on to get these to
+   actually be in-line.
+   */
+
+/* Multiply two fixed-point 32 bit numbers, producing a 32 bit result.
+   The answer is the ms word of the product. */
+/* Some versions of gcc make it difficult to stop eax from being clobbered.
+   Merely specifying that it is used doesn't work...
+ */
+static inline unsigned long mul_32_32(const unsigned long arg1,
+                                      const unsigned long arg2)
+{
+  int retval;
+  asm volatile ("mull %2; movl %%edx,%%eax" \
+                :"=a" (retval) \
+                :"0" (arg1), "g" (arg2) \
+                :"dx");
+  return retval;
+}
+
+
+/* Add the 12 byte Xsig x2 to Xsig dest, with no checks for overflow. */
+static inline void add_Xsig_Xsig(Xsig *dest, const Xsig *x2)
+{
+  asm volatile ("movl %1,%%edi; movl %2,%%esi;\n"
+                "movl (%%esi),%%eax; addl %%eax,(%%edi);\n"
+                "movl 4(%%esi),%%eax; adcl %%eax,4(%%edi);\n"
+                "movl 8(%%esi),%%eax; adcl %%eax,8(%%edi);\n"
+                 :"=g" (*dest):"g" (dest), "g" (x2)
+                 :"ax","si","di");
+}
+
+
+/* Add the 12 byte Xsig x2 to Xsig dest, adjust exp if overflow occurs. */
+/* Note: the constraints in the asm statement didn't always work properly
+   with gcc 2.5.8.  Changing from using edi to using ecx got around the
+   problem, but keep fingers crossed! */
+static inline void add_two_Xsig(Xsig *dest, const Xsig *x2, long int *exp)
+{
+  asm volatile ("movl %2,%%ecx; movl %3,%%esi;\n"
+                "movl (%%esi),%%eax; addl %%eax,(%%ecx);\n"
+                "movl 4(%%esi),%%eax; adcl %%eax,4(%%ecx);\n"
+                "movl 8(%%esi),%%eax; adcl %%eax,8(%%ecx);\n"
+                "jnc 0f;\n"
+                "rcrl 8(%%ecx); rcrl 4(%%ecx); rcrl (%%ecx)\n"
+                "movl %4,%%ecx; incl (%%ecx)\n"
+                "movl $1,%%eax; jmp 1f;\n"
+                "0: xorl %%eax,%%eax;\n"
+                "1:\n"
+                :"=g" (*exp), "=g" (*dest)
+                :"g" (dest), "g" (x2), "g" (exp)
+                :"cx","si","ax");
+}
+
+
+/* Negate (subtract from 1.0) the 12 byte Xsig */
+/* This is faster in a loop on my 386 than using the "neg" instruction. */
+static inline void negate_Xsig(Xsig *x)
+{
+  asm volatile("movl %1,%%esi;\n"
+               "xorl %%ecx,%%ecx;\n"
+               "movl %%ecx,%%eax; subl (%%esi),%%eax; movl %%eax,(%%esi);\n"
+               "movl %%ecx,%%eax; sbbl 4(%%esi),%%eax; movl %%eax,4(%%esi);\n"
+               "movl %%ecx,%%eax; sbbl 8(%%esi),%%eax; movl %%eax,8(%%esi);\n"
+               :"=g" (*x):"g" (x):"si","ax","cx");
+}
+
+#endif /* _POLY_H */