Import of Linux/MIPS 1.3.0

1 files changed, 105 insertions, 0 deletions

diff --git a/arch/i386/math-emu/reg_mul.c b/arch/i386/math-emu/reg_mul.c
new file mode 100644
index 000000000..75246187b
--- /dev/null
+++ b/arch/i386/math-emu/reg_mul.c
@@ -0,0 +1,105 @@
+/*---------------------------------------------------------------------------+
+ |  reg_mul.c                                                                |
+ |                                                                           |
+ | Multiply one FPU_REG by another, put the result in a destination FPU_REG. |
+ |                                                                           |
+ | Copyright (C) 1992,1993                                                   |
+ |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
+ |                       Australia.  E-mail   billm@vaxc.cc.monash.edu.au    |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ | The destination may be any FPU_REG, including one of the source FPU_REGs. |
+ +---------------------------------------------------------------------------*/
+
+#include "exception.h"
+#include "reg_constant.h"
+#include "fpu_emu.h"
+#include "fpu_system.h"
+
+
+/* This routine must be called with non-empty source registers */
+int reg_mul(FPU_REG const *a, FPU_REG const *b,
+	    FPU_REG *dest, unsigned int control_w)
+{
+  char saved_sign = dest->sign;
+  char sign = (a->sign ^ b->sign);
+
+  if (!(a->tag | b->tag))
+    {
+      /* Both regs Valid, this should be the most common case. */
+      dest->sign = sign;
+      if ( reg_u_mul(a, b, dest, control_w) )
+	{
+	  dest->sign = saved_sign;
+	  return 1;
+	}
+      return 0;
+    }
+  else if ((a->tag <= TW_Zero) && (b->tag <= TW_Zero))
+    {
+#ifdef DENORM_OPERAND
+      if ( ((b->tag == TW_Valid) && (b->exp <= EXP_UNDER)) ||
+	  ((a->tag == TW_Valid) && (a->exp <= EXP_UNDER)) )
+	{
+	  if ( denormal_operand() ) return 1;
+	}
+#endif DENORM_OPERAND
+      /* Must have either both arguments == zero, or
+	 one valid and the other zero.
+	 The result is therefore zero. */
+      reg_move(&CONST_Z, dest);
+      /* 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. */
+      dest->sign = sign;
+      return 0;
+    }
+  else
+    {
+      /* Must have infinities, NaNs, etc */
+      if ( (a->tag == TW_NaN) || (b->tag == TW_NaN) )
+	{ return real_2op_NaN(a, b, dest); }
+      else if (a->tag == TW_Infinity)
+	{
+	  if (b->tag == TW_Zero)
+	    { return arith_invalid(dest); }  /* Zero*Infinity is invalid */
+	  else
+	    {
+#ifdef DENORM_OPERAND
+	      if ( (b->tag == TW_Valid) && (b->exp <= EXP_UNDER) &&
+		  denormal_operand() )
+		return 1;
+#endif DENORM_OPERAND
+	      reg_move(a, dest);
+	      dest->sign = sign;
+	    }
+	  return 0;
+	}
+      else if (b->tag == TW_Infinity)
+	{
+	  if (a->tag == TW_Zero)
+	    { return arith_invalid(dest); }  /* Zero*Infinity is invalid */
+	  else
+	    {
+#ifdef DENORM_OPERAND
+	      if ( (a->tag == TW_Valid) && (a->exp <= EXP_UNDER) &&
+		  denormal_operand() )
+		return 1;
+#endif DENORM_OPERAND
+	      reg_move(b, dest);
+	      dest->sign = sign;
+	    }
+	  return 0;
+	}
+#ifdef PARANOID
+      else
+	{
+	  EXCEPTION(EX_INTERNAL|0x102);
+	  return 1;
+	}
+#endif PARANOID
+    }
+}