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-rw-r--r--kernel/arch/x86/math-emu/fpu_etc.c130
1 files changed, 130 insertions, 0 deletions
diff --git a/kernel/arch/x86/math-emu/fpu_etc.c b/kernel/arch/x86/math-emu/fpu_etc.c
new file mode 100644
index 000000000..233e5af56
--- /dev/null
+++ b/kernel/arch/x86/math-emu/fpu_etc.c
@@ -0,0 +1,130 @@
+/*---------------------------------------------------------------------------+
+ | fpu_etc.c |
+ | |
+ | Implement a few FPU instructions. |
+ | |
+ | Copyright (C) 1992,1993,1994,1997 |
+ | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
+ | Australia. E-mail billm@suburbia.net |
+ | |
+ | |
+ +---------------------------------------------------------------------------*/
+
+#include "fpu_system.h"
+#include "exception.h"
+#include "fpu_emu.h"
+#include "status_w.h"
+#include "reg_constant.h"
+
+static void fchs(FPU_REG *st0_ptr, u_char st0tag)
+{
+ if (st0tag ^ TAG_Empty) {
+ signbyte(st0_ptr) ^= SIGN_NEG;
+ clear_C1();
+ } else
+ FPU_stack_underflow();
+}
+
+static void fabs(FPU_REG *st0_ptr, u_char st0tag)
+{
+ if (st0tag ^ TAG_Empty) {
+ setpositive(st0_ptr);
+ clear_C1();
+ } else
+ FPU_stack_underflow();
+}
+
+static void ftst_(FPU_REG *st0_ptr, u_char st0tag)
+{
+ switch (st0tag) {
+ case TAG_Zero:
+ setcc(SW_C3);
+ break;
+ case TAG_Valid:
+ if (getsign(st0_ptr) == SIGN_POS)
+ setcc(0);
+ else
+ setcc(SW_C0);
+ break;
+ case TAG_Special:
+ switch (FPU_Special(st0_ptr)) {
+ case TW_Denormal:
+ if (getsign(st0_ptr) == SIGN_POS)
+ setcc(0);
+ else
+ setcc(SW_C0);
+ if (denormal_operand() < 0) {
+#ifdef PECULIAR_486
+ /* This is weird! */
+ if (getsign(st0_ptr) == SIGN_POS)
+ setcc(SW_C3);
+#endif /* PECULIAR_486 */
+ return;
+ }
+ break;
+ case TW_NaN:
+ setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
+ EXCEPTION(EX_Invalid);
+ break;
+ case TW_Infinity:
+ if (getsign(st0_ptr) == SIGN_POS)
+ setcc(0);
+ else
+ setcc(SW_C0);
+ break;
+ default:
+ setcc(SW_C0 | SW_C2 | SW_C3); /* Operand is not comparable */
+ EXCEPTION(EX_INTERNAL | 0x14);
+ break;
+ }
+ break;
+ case TAG_Empty:
+ setcc(SW_C0 | SW_C2 | SW_C3);
+ EXCEPTION(EX_StackUnder);
+ break;
+ }
+}
+
+static void fxam(FPU_REG *st0_ptr, u_char st0tag)
+{
+ int c = 0;
+ switch (st0tag) {
+ case TAG_Empty:
+ c = SW_C3 | SW_C0;
+ break;
+ case TAG_Zero:
+ c = SW_C3;
+ break;
+ case TAG_Valid:
+ c = SW_C2;
+ break;
+ case TAG_Special:
+ switch (FPU_Special(st0_ptr)) {
+ case TW_Denormal:
+ c = SW_C2 | SW_C3; /* Denormal */
+ break;
+ case TW_NaN:
+ /* We also use NaN for unsupported types. */
+ if ((st0_ptr->sigh & 0x80000000)
+ && (exponent(st0_ptr) == EXP_OVER))
+ c = SW_C0;
+ break;
+ case TW_Infinity:
+ c = SW_C2 | SW_C0;
+ break;
+ }
+ }
+ if (getsign(st0_ptr) == SIGN_NEG)
+ c |= SW_C1;
+ setcc(c);
+}
+
+static FUNC_ST0 const fp_etc_table[] = {
+ fchs, fabs, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal,
+ ftst_, fxam, (FUNC_ST0) FPU_illegal, (FUNC_ST0) FPU_illegal
+};
+
+void FPU_etc(void)
+{
+ (fp_etc_table[FPU_rm]) (&st(0), FPU_gettag0());
+}