Initial import

1 files changed, 196 insertions, 0 deletions

diff --git a/arch/x86/math-emu/fpu_aux.c b/arch/x86/math-emu/fpu_aux.c
new file mode 100644
index 000000000..dc8adad10
--- /dev/null
+++ b/arch/x86/math-emu/fpu_aux.c
@@ -0,0 +1,196 @@
+/*---------------------------------------------------------------------------+
+ |  fpu_aux.c                                                                |
+ |                                                                           |
+ | Code to implement some of the FPU auxiliary 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 "control_w.h"
+
+static void fnop(void)
+{
+}
+
+static void fclex(void)
+{
+	partial_status &=
+	    ~(SW_Backward | SW_Summary | SW_Stack_Fault | SW_Precision |
+	      SW_Underflow | SW_Overflow | SW_Zero_Div | SW_Denorm_Op |
+	      SW_Invalid);
+	no_ip_update = 1;
+}
+
+/* Needs to be externally visible */
+void finit_soft_fpu(struct i387_soft_struct *soft)
+{
+	struct address *oaddr, *iaddr;
+	memset(soft, 0, sizeof(*soft));
+	soft->cwd = 0x037f;
+	soft->swd = 0;
+	soft->ftop = 0;	/* We don't keep top in the status word internally. */
+	soft->twd = 0xffff;
+	/* The behaviour is different from that detailed in
+	   Section 15.1.6 of the Intel manual */
+	oaddr = (struct address *)&soft->foo;
+	oaddr->offset = 0;
+	oaddr->selector = 0;
+	iaddr = (struct address *)&soft->fip;
+	iaddr->offset = 0;
+	iaddr->selector = 0;
+	iaddr->opcode = 0;
+	soft->no_update = 1;
+}
+
+void finit(void)
+{
+	finit_soft_fpu(&current->thread.fpu.state->soft);
+}
+
+/*
+ * These are nops on the i387..
+ */
+#define feni fnop
+#define fdisi fnop
+#define fsetpm fnop
+
+static FUNC const finit_table[] = {
+	feni, fdisi, fclex, finit,
+	fsetpm, FPU_illegal, FPU_illegal, FPU_illegal
+};
+
+void finit_(void)
+{
+	(finit_table[FPU_rm]) ();
+}
+
+static void fstsw_ax(void)
+{
+	*(short *)&FPU_EAX = status_word();
+	no_ip_update = 1;
+}
+
+static FUNC const fstsw_table[] = {
+	fstsw_ax, FPU_illegal, FPU_illegal, FPU_illegal,
+	FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal
+};
+
+void fstsw_(void)
+{
+	(fstsw_table[FPU_rm]) ();
+}
+
+static FUNC const fp_nop_table[] = {
+	fnop, FPU_illegal, FPU_illegal, FPU_illegal,
+	FPU_illegal, FPU_illegal, FPU_illegal, FPU_illegal
+};
+
+void fp_nop(void)
+{
+	(fp_nop_table[FPU_rm]) ();
+}
+
+void fld_i_(void)
+{
+	FPU_REG *st_new_ptr;
+	int i;
+	u_char tag;
+
+	if (STACK_OVERFLOW) {
+		FPU_stack_overflow();
+		return;
+	}
+
+	/* fld st(i) */
+	i = FPU_rm;
+	if (NOT_EMPTY(i)) {
+		reg_copy(&st(i), st_new_ptr);
+		tag = FPU_gettagi(i);
+		push();
+		FPU_settag0(tag);
+	} else {
+		if (control_word & CW_Invalid) {
+			/* The masked response */
+			FPU_stack_underflow();
+		} else
+			EXCEPTION(EX_StackUnder);
+	}
+
+}
+
+void fxch_i(void)
+{
+	/* fxch st(i) */
+	FPU_REG t;
+	int i = FPU_rm;
+	FPU_REG *st0_ptr = &st(0), *sti_ptr = &st(i);
+	long tag_word = fpu_tag_word;
+	int regnr = top & 7, regnri = ((regnr + i) & 7);
+	u_char st0_tag = (tag_word >> (regnr * 2)) & 3;
+	u_char sti_tag = (tag_word >> (regnri * 2)) & 3;
+
+	if (st0_tag == TAG_Empty) {
+		if (sti_tag == TAG_Empty) {
+			FPU_stack_underflow();
+			FPU_stack_underflow_i(i);
+			return;
+		}
+		if (control_word & CW_Invalid) {
+			/* Masked response */
+			FPU_copy_to_reg0(sti_ptr, sti_tag);
+		}
+		FPU_stack_underflow_i(i);
+		return;
+	}
+	if (sti_tag == TAG_Empty) {
+		if (control_word & CW_Invalid) {
+			/* Masked response */
+			FPU_copy_to_regi(st0_ptr, st0_tag, i);
+		}
+		FPU_stack_underflow();
+		return;
+	}
+	clear_C1();
+
+	reg_copy(st0_ptr, &t);
+	reg_copy(sti_ptr, st0_ptr);
+	reg_copy(&t, sti_ptr);
+
+	tag_word &= ~(3 << (regnr * 2)) & ~(3 << (regnri * 2));
+	tag_word |= (sti_tag << (regnr * 2)) | (st0_tag << (regnri * 2));
+	fpu_tag_word = tag_word;
+}
+
+void ffree_(void)
+{
+	/* ffree st(i) */
+	FPU_settagi(FPU_rm, TAG_Empty);
+}
+
+void ffreep(void)
+{
+	/* ffree st(i) + pop - unofficial code */
+	FPU_settagi(FPU_rm, TAG_Empty);
+	FPU_pop();
+}
+
+void fst_i_(void)
+{
+	/* fst st(i) */
+	FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm);
+}
+
+void fstp_i(void)
+{
+	/* fstp st(i) */
+	FPU_copy_to_regi(&st(0), FPU_gettag0(), FPU_rm);
+	FPU_pop();
+}