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-rw-r--r--arch/i386/math-emu/reg_convert.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/i386/math-emu/reg_convert.c b/arch/i386/math-emu/reg_convert.c
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index 000000000000..45a258752703
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+++ b/arch/i386/math-emu/reg_convert.c
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+/*---------------------------------------------------------------------------+
+ | reg_convert.c |
+ | |
+ | Convert register representation. |
+ | |
+ | Copyright (C) 1992,1993,1994,1996,1997 |
+ | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ | E-mail billm@suburbia.net |
+ | |
+ | |
+ +---------------------------------------------------------------------------*/
+
+#include "exception.h"
+#include "fpu_emu.h"
+
+
+int FPU_to_exp16(FPU_REG const *a, FPU_REG *x)
+{
+ int sign = getsign(a);
+
+ *(long long *)&(x->sigl) = *(const long long *)&(a->sigl);
+
+ /* Set up the exponent as a 16 bit quantity. */
+ setexponent16(x, exponent(a));
+
+ if ( exponent16(x) == EXP_UNDER )
+ {
+ /* The number is a de-normal or pseudodenormal. */
+ /* We only deal with the significand and exponent. */
+
+ if (x->sigh & 0x80000000)
+ {
+ /* Is a pseudodenormal. */
+ /* This is non-80486 behaviour because the number
+ loses its 'denormal' identity. */
+ addexponent(x, 1);
+ }
+ else
+ {
+ /* Is a denormal. */
+ addexponent(x, 1);
+ FPU_normalize_nuo(x);
+ }
+ }
+
+ if ( !(x->sigh & 0x80000000) )
+ {
+ EXCEPTION(EX_INTERNAL | 0x180);
+ }
+
+ return sign;
+}
+