1 files changed, 131 insertions, 0 deletions
diff --git a/arch/x86/math-emu/fpu_etc.c b/arch/x86/math-emu/fpu_etc.c
new file mode 100644
index 000000000..1b118fd93
--- /dev/null
+++ b/arch/x86/math-emu/fpu_etc.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0
+/*---------------------------------------------------------------------------+
+ |  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());
+}