i386: move math-emu

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

1 files changed, 397 insertions, 0 deletions

diff --git a/arch/x86/math-emu/poly_sin.c b/arch/x86/math-emu/poly_sin.c
new file mode 100644
index 00000000000..a36313fb06f
--- /dev/null
+++ b/arch/x86/math-emu/poly_sin.c
@@ -0,0 +1,397 @@
+/*---------------------------------------------------------------------------+
+ |  poly_sin.c                                                               |
+ |                                                                           |
+ |  Computation of an approximation of the sin function and the cosine       |
+ |  function by a polynomial.                                                |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1994,1997,1999                                    |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@melbpc.org.au                             |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+
+#include "exception.h"
+#include "reg_constant.h"
+#include "fpu_emu.h"
+#include "fpu_system.h"
+#include "control_w.h"
+#include "poly.h"
+
+
+#define	N_COEFF_P	4
+#define	N_COEFF_N	4
+
+static const unsigned long long pos_terms_l[N_COEFF_P] =
+{
+  0xaaaaaaaaaaaaaaabLL,
+  0x00d00d00d00cf906LL,
+  0x000006b99159a8bbLL,
+  0x000000000d7392e6LL
+};
+
+static const unsigned long long neg_terms_l[N_COEFF_N] =
+{
+  0x2222222222222167LL,
+  0x0002e3bc74aab624LL,
+  0x0000000b09229062LL,
+  0x00000000000c7973LL
+};
+
+
+
+#define	N_COEFF_PH	4
+#define	N_COEFF_NH	4
+static const unsigned long long pos_terms_h[N_COEFF_PH] =
+{
+  0x0000000000000000LL,
+  0x05b05b05b05b0406LL,
+  0x000049f93edd91a9LL,
+  0x00000000c9c9ed62LL
+};
+
+static const unsigned long long neg_terms_h[N_COEFF_NH] =
+{
+  0xaaaaaaaaaaaaaa98LL,
+  0x001a01a01a019064LL,
+  0x0000008f76c68a77LL,
+  0x0000000000d58f5eLL
+};
+
+
+/*--- poly_sine() -----------------------------------------------------------+
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+void	poly_sine(FPU_REG *st0_ptr)
+{
+  int                 exponent, echange;
+  Xsig                accumulator, argSqrd, argTo4;
+  unsigned long       fix_up, adj;
+  unsigned long long  fixed_arg;
+  FPU_REG	      result;
+
+  exponent = exponent(st0_ptr);
+
+  accumulator.lsw = accumulator.midw = accumulator.msw = 0;
+
+  /* Split into two ranges, for arguments below and above 1.0 */
+  /* The boundary between upper and lower is approx 0.88309101259 */
+  if ( (exponent < -1) || ((exponent == -1) && (st0_ptr->sigh <= 0xe21240aa)) )
+    {
+      /* The argument is <= 0.88309101259 */
+
+      argSqrd.msw = st0_ptr->sigh; argSqrd.midw = st0_ptr->sigl; argSqrd.lsw = 0;
+      mul64_Xsig(&argSqrd, &significand(st0_ptr));
+      shr_Xsig(&argSqrd, 2*(-1-exponent));
+      argTo4.msw = argSqrd.msw; argTo4.midw = argSqrd.midw;
+      argTo4.lsw = argSqrd.lsw;
+      mul_Xsig_Xsig(&argTo4, &argTo4);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), neg_terms_l,
+		      N_COEFF_N-1);
+      mul_Xsig_Xsig(&accumulator, &argSqrd);
+      negate_Xsig(&accumulator);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), pos_terms_l,
+		      N_COEFF_P-1);
+
+      shr_Xsig(&accumulator, 2);    /* Divide by four */
+      accumulator.msw |= 0x80000000;  /* Add 1.0 */
+
+      mul64_Xsig(&accumulator, &significand(st0_ptr));
+      mul64_Xsig(&accumulator, &significand(st0_ptr));
+      mul64_Xsig(&accumulator, &significand(st0_ptr));
+
+      /* Divide by four, FPU_REG compatible, etc */
+      exponent = 3*exponent;
+
+      /* The minimum exponent difference is 3 */
+      shr_Xsig(&accumulator, exponent(st0_ptr) - exponent);
+
+      negate_Xsig(&accumulator);
+      XSIG_LL(accumulator) += significand(st0_ptr);
+
+      echange = round_Xsig(&accumulator);
+
+      setexponentpos(&result, exponent(st0_ptr) + echange);
+    }
+  else
+    {
+      /* The argument is > 0.88309101259 */
+      /* We use sin(st(0)) = cos(pi/2-st(0)) */
+
+      fixed_arg = significand(st0_ptr);
+
+      if ( exponent == 0 )
+	{
+	  /* The argument is >= 1.0 */
+
+	  /* Put the binary point at the left. */
+	  fixed_arg <<= 1;
+	}
+      /* pi/2 in hex is: 1.921fb54442d18469 898CC51701B839A2 52049C1 */
+      fixed_arg = 0x921fb54442d18469LL - fixed_arg;
+      /* There is a special case which arises due to rounding, to fix here. */
+      if ( fixed_arg == 0xffffffffffffffffLL )
+	fixed_arg = 0;
+
+      XSIG_LL(argSqrd) = fixed_arg; argSqrd.lsw = 0;
+      mul64_Xsig(&argSqrd, &fixed_arg);
+
+      XSIG_LL(argTo4) = XSIG_LL(argSqrd); argTo4.lsw = argSqrd.lsw;
+      mul_Xsig_Xsig(&argTo4, &argTo4);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), neg_terms_h,
+		      N_COEFF_NH-1);
+      mul_Xsig_Xsig(&accumulator, &argSqrd);
+      negate_Xsig(&accumulator);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), pos_terms_h,
+		      N_COEFF_PH-1);
+      negate_Xsig(&accumulator);
+
+      mul64_Xsig(&accumulator, &fixed_arg);
+      mul64_Xsig(&accumulator, &fixed_arg);
+
+      shr_Xsig(&accumulator, 3);
+      negate_Xsig(&accumulator);
+
+      add_Xsig_Xsig(&accumulator, &argSqrd);
+
+      shr_Xsig(&accumulator, 1);
+
+      accumulator.lsw |= 1;  /* A zero accumulator here would cause problems */
+      negate_Xsig(&accumulator);
+
+      /* The basic computation is complete. Now fix the answer to
+	 compensate for the error due to the approximation used for
+	 pi/2
+	 */
+
+      /* This has an exponent of -65 */
+      fix_up = 0x898cc517;
+      /* The fix-up needs to be improved for larger args */
+      if ( argSqrd.msw & 0xffc00000 )
+	{
+	  /* Get about 32 bit precision in these: */
+	  fix_up -= mul_32_32(0x898cc517, argSqrd.msw) / 6;
+	}
+      fix_up = mul_32_32(fix_up, LL_MSW(fixed_arg));
+
+      adj = accumulator.lsw;    /* temp save */
+      accumulator.lsw -= fix_up;
+      if ( accumulator.lsw > adj )
+	XSIG_LL(accumulator) --;
+
+      echange = round_Xsig(&accumulator);
+
+      setexponentpos(&result, echange - 1);
+    }
+
+  significand(&result) = XSIG_LL(accumulator);
+  setsign(&result, getsign(st0_ptr));
+  FPU_copy_to_reg0(&result, TAG_Valid);
+
+#ifdef PARANOID
+  if ( (exponent(&result) >= 0)
+      && (significand(&result) > 0x8000000000000000LL) )
+    {
+      EXCEPTION(EX_INTERNAL|0x150);
+    }
+#endif /* PARANOID */
+
+}
+
+
+
+/*--- poly_cos() ------------------------------------------------------------+
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+void	poly_cos(FPU_REG *st0_ptr)
+{
+  FPU_REG	      result;
+  long int            exponent, exp2, echange;
+  Xsig                accumulator, argSqrd, fix_up, argTo4;
+  unsigned long long  fixed_arg;
+
+#ifdef PARANOID
+  if ( (exponent(st0_ptr) > 0)
+      || ((exponent(st0_ptr) == 0)
+	  && (significand(st0_ptr) > 0xc90fdaa22168c234LL)) )
+    {
+      EXCEPTION(EX_Invalid);
+      FPU_copy_to_reg0(&CONST_QNaN, TAG_Special);
+      return;
+    }
+#endif /* PARANOID */
+
+  exponent = exponent(st0_ptr);
+
+  accumulator.lsw = accumulator.midw = accumulator.msw = 0;
+
+  if ( (exponent < -1) || ((exponent == -1) && (st0_ptr->sigh <= 0xb00d6f54)) )
+    {
+      /* arg is < 0.687705 */
+
+      argSqrd.msw = st0_ptr->sigh; argSqrd.midw = st0_ptr->sigl;
+      argSqrd.lsw = 0;
+      mul64_Xsig(&argSqrd, &significand(st0_ptr));
+
+      if ( exponent < -1 )
+	{
+	  /* shift the argument right by the required places */
+	  shr_Xsig(&argSqrd, 2*(-1-exponent));
+	}
+
+      argTo4.msw = argSqrd.msw; argTo4.midw = argSqrd.midw;
+      argTo4.lsw = argSqrd.lsw;
+      mul_Xsig_Xsig(&argTo4, &argTo4);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), neg_terms_h,
+		      N_COEFF_NH-1);
+      mul_Xsig_Xsig(&accumulator, &argSqrd);
+      negate_Xsig(&accumulator);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), pos_terms_h,
+		      N_COEFF_PH-1);
+      negate_Xsig(&accumulator);
+
+      mul64_Xsig(&accumulator, &significand(st0_ptr));
+      mul64_Xsig(&accumulator, &significand(st0_ptr));
+      shr_Xsig(&accumulator, -2*(1+exponent));
+
+      shr_Xsig(&accumulator, 3);
+      negate_Xsig(&accumulator);
+
+      add_Xsig_Xsig(&accumulator, &argSqrd);
+
+      shr_Xsig(&accumulator, 1);
+
+      /* It doesn't matter if accumulator is all zero here, the
+	 following code will work ok */
+      negate_Xsig(&accumulator);
+
+      if ( accumulator.lsw & 0x80000000 )
+	XSIG_LL(accumulator) ++;
+      if ( accumulator.msw == 0 )
+	{
+	  /* The result is 1.0 */
+	  FPU_copy_to_reg0(&CONST_1, TAG_Valid);
+	  return;
+	}
+      else
+	{
+	  significand(&result) = XSIG_LL(accumulator);
+      
+	  /* will be a valid positive nr with expon = -1 */
+	  setexponentpos(&result, -1);
+	}
+    }
+  else
+    {
+      fixed_arg = significand(st0_ptr);
+
+      if ( exponent == 0 )
+	{
+	  /* The argument is >= 1.0 */
+
+	  /* Put the binary point at the left. */
+	  fixed_arg <<= 1;
+	}
+      /* pi/2 in hex is: 1.921fb54442d18469 898CC51701B839A2 52049C1 */
+      fixed_arg = 0x921fb54442d18469LL - fixed_arg;
+      /* There is a special case which arises due to rounding, to fix here. */
+      if ( fixed_arg == 0xffffffffffffffffLL )
+	fixed_arg = 0;
+
+      exponent = -1;
+      exp2 = -1;
+
+      /* A shift is needed here only for a narrow range of arguments,
+	 i.e. for fixed_arg approx 2^-32, but we pick up more... */
+      if ( !(LL_MSW(fixed_arg) & 0xffff0000) )
+	{
+	  fixed_arg <<= 16;
+	  exponent -= 16;
+	  exp2 -= 16;
+	}
+
+      XSIG_LL(argSqrd) = fixed_arg; argSqrd.lsw = 0;
+      mul64_Xsig(&argSqrd, &fixed_arg);
+
+      if ( exponent < -1 )
+	{
+	  /* shift the argument right by the required places */
+	  shr_Xsig(&argSqrd, 2*(-1-exponent));
+	}
+
+      argTo4.msw = argSqrd.msw; argTo4.midw = argSqrd.midw;
+      argTo4.lsw = argSqrd.lsw;
+      mul_Xsig_Xsig(&argTo4, &argTo4);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), neg_terms_l,
+		      N_COEFF_N-1);
+      mul_Xsig_Xsig(&accumulator, &argSqrd);
+      negate_Xsig(&accumulator);
+
+      polynomial_Xsig(&accumulator, &XSIG_LL(argTo4), pos_terms_l,
+		      N_COEFF_P-1);
+
+      shr_Xsig(&accumulator, 2);    /* Divide by four */
+      accumulator.msw |= 0x80000000;  /* Add 1.0 */
+
+      mul64_Xsig(&accumulator, &fixed_arg);
+      mul64_Xsig(&accumulator, &fixed_arg);
+      mul64_Xsig(&accumulator, &fixed_arg);
+
+      /* Divide by four, FPU_REG compatible, etc */
+      exponent = 3*exponent;
+
+      /* The minimum exponent difference is 3 */
+      shr_Xsig(&accumulator, exp2 - exponent);
+
+      negate_Xsig(&accumulator);
+      XSIG_LL(accumulator) += fixed_arg;
+
+      /* The basic computation is complete. Now fix the answer to
+	 compensate for the error due to the approximation used for
+	 pi/2
+	 */
+
+      /* This has an exponent of -65 */
+      XSIG_LL(fix_up) = 0x898cc51701b839a2ll;
+      fix_up.lsw = 0;
+
+      /* The fix-up needs to be improved for larger args */
+      if ( argSqrd.msw & 0xffc00000 )
+	{
+	  /* Get about 32 bit precision in these: */
+	  fix_up.msw -= mul_32_32(0x898cc517, argSqrd.msw) / 2;
+	  fix_up.msw += mul_32_32(0x898cc517, argTo4.msw) / 24;
+	}
+
+      exp2 += norm_Xsig(&accumulator);
+      shr_Xsig(&accumulator, 1); /* Prevent overflow */
+      exp2++;
+      shr_Xsig(&fix_up, 65 + exp2);
+
+      add_Xsig_Xsig(&accumulator, &fix_up);
+
+      echange = round_Xsig(&accumulator);
+
+      setexponentpos(&result, exp2 + echange);
+      significand(&result) = XSIG_LL(accumulator);
+    }
+
+  FPU_copy_to_reg0(&result, TAG_Valid);
+
+#ifdef PARANOID
+  if ( (exponent(&result) >= 0)
+      && (significand(&result) > 0x8000000000000000LL) )
+    {
+      EXCEPTION(EX_INTERNAL|0x151);
+    }
+#endif /* PARANOID */
+
+}