i386: move math-emu

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

1 files changed, 132 insertions, 0 deletions

diff --git a/arch/x86/math-emu/reg_mul.c b/arch/x86/math-emu/reg_mul.c
new file mode 100644
index 0000000..40f50b6
--- /dev/null
+++ b/arch/x86/math-emu/reg_mul.c
@@ -0,0 +1,132 @@
+/*---------------------------------------------------------------------------+
+ |  reg_mul.c                                                                |
+ |                                                                           |
+ | Multiply one FPU_REG by another, put the result in a destination FPU_REG. |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1997                                              |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@suburbia.net                              |
+ |                                                                           |
+ | Returns the tag of the result if no exceptions or errors occurred.        |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ | The destination may be any FPU_REG, including one of the source FPU_REGs. |
+ +---------------------------------------------------------------------------*/
+
+#include "fpu_emu.h"
+#include "exception.h"
+#include "reg_constant.h"
+#include "fpu_system.h"
+
+
+/*
+  Multiply two registers to give a register result.
+  The sources are st(deststnr) and (b,tagb,signb).
+  The destination is st(deststnr).
+  */
+/* This routine must be called with non-empty source registers */
+int FPU_mul(FPU_REG const *b, u_char tagb, int deststnr, int control_w)
+{
+  FPU_REG *a = &st(deststnr);
+  FPU_REG *dest = a;
+  u_char taga = FPU_gettagi(deststnr);
+  u_char saved_sign = getsign(dest);
+  u_char sign = (getsign(a) ^ getsign(b));
+  int tag;
+
+
+  if ( !(taga | tagb) )
+    {
+      /* Both regs Valid, this should be the most common case. */
+
+      tag = FPU_u_mul(a, b, dest, control_w, sign, exponent(a) + exponent(b));
+      if ( tag < 0 )
+	{
+	  setsign(dest, saved_sign);
+	  return tag;
+	}
+      FPU_settagi(deststnr, tag);
+      return tag;
+    }
+
+  if ( taga == TAG_Special )
+    taga = FPU_Special(a);
+  if ( tagb == TAG_Special )
+    tagb = FPU_Special(b);
+
+  if ( ((taga == TAG_Valid) && (tagb == TW_Denormal))
+	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
+	    || ((taga == TW_Denormal) && (tagb == TW_Denormal)) )
+    {
+      FPU_REG x, y;
+      if ( denormal_operand() < 0 )
+	return FPU_Exception;
+
+      FPU_to_exp16(a, &x);
+      FPU_to_exp16(b, &y);
+      tag = FPU_u_mul(&x, &y, dest, control_w, sign,
+		      exponent16(&x) + exponent16(&y));
+      if ( tag < 0 )
+	{
+	  setsign(dest, saved_sign);
+	  return tag;
+	}
+      FPU_settagi(deststnr, tag);
+      return tag;
+    }
+  else if ( (taga <= TW_Denormal) && (tagb <= TW_Denormal) )
+    {
+      if ( ((tagb == TW_Denormal) || (taga == TW_Denormal))
+	   && (denormal_operand() < 0) )
+	return FPU_Exception;
+
+      /* Must have either both arguments == zero, or
+	 one valid and the other zero.
+	 The result is therefore zero. */
+      FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
+      /* The 80486 book says that the answer is +0, but a real
+	 80486 behaves this way.
+	 IEEE-754 apparently says it should be this way. */
+      setsign(dest, sign);
+      return TAG_Zero;
+    }
+      /* Must have infinities, NaNs, etc */
+  else if ( (taga == TW_NaN) || (tagb == TW_NaN) )
+    {
+      return real_2op_NaN(b, tagb, deststnr, &st(0));
+    }
+  else if ( ((taga == TW_Infinity) && (tagb == TAG_Zero))
+	    || ((tagb == TW_Infinity) && (taga == TAG_Zero)) )
+    {
+      return arith_invalid(deststnr);  /* Zero*Infinity is invalid */
+    }
+  else if ( ((taga == TW_Denormal) || (tagb == TW_Denormal))
+	    && (denormal_operand() < 0) )
+    {
+      return FPU_Exception;
+    }
+  else if (taga == TW_Infinity)
+    {
+      FPU_copy_to_regi(a, TAG_Special, deststnr);
+      setsign(dest, sign);
+      return TAG_Special;
+    }
+  else if (tagb == TW_Infinity)
+    {
+      FPU_copy_to_regi(b, TAG_Special, deststnr);
+      setsign(dest, sign);
+      return TAG_Special;
+    }
+
+#ifdef PARANOID
+  else
+    {
+      EXCEPTION(EX_INTERNAL|0x102);
+      return FPU_Exception;
+    }
+#endif /* PARANOID */ 
+
+	return 0;
+}