Initial import

1 files changed, 350 insertions, 0 deletions

diff --git a/arch/x86/math-emu/reg_compare.c b/arch/x86/math-emu/reg_compare.c
new file mode 100644
index 000000000..ecce55fc2
--- /dev/null
+++ b/arch/x86/math-emu/reg_compare.c
@@ -0,0 +1,350 @@
+/*---------------------------------------------------------------------------+
+ |  reg_compare.c                                                            |
+ |                                                                           |
+ | Compare two floating point registers                                      |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1994,1997                                         |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@suburbia.net                              |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ | compare() is the core FPU_REG comparison function                         |
+ +---------------------------------------------------------------------------*/
+
+#include "fpu_system.h"
+#include "exception.h"
+#include "fpu_emu.h"
+#include "control_w.h"
+#include "status_w.h"
+
+static int compare(FPU_REG const *b, int tagb)
+{
+	int diff, exp0, expb;
+	u_char st0_tag;
+	FPU_REG *st0_ptr;
+	FPU_REG x, y;
+	u_char st0_sign, signb = getsign(b);
+
+	st0_ptr = &st(0);
+	st0_tag = FPU_gettag0();
+	st0_sign = getsign(st0_ptr);
+
+	if (tagb == TAG_Special)
+		tagb = FPU_Special(b);
+	if (st0_tag == TAG_Special)
+		st0_tag = FPU_Special(st0_ptr);
+
+	if (((st0_tag != TAG_Valid) && (st0_tag != TW_Denormal))
+	    || ((tagb != TAG_Valid) && (tagb != TW_Denormal))) {
+		if (st0_tag == TAG_Zero) {
+			if (tagb == TAG_Zero)
+				return COMP_A_eq_B;
+			if (tagb == TAG_Valid)
+				return ((signb ==
+					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B);
+			if (tagb == TW_Denormal)
+				return ((signb ==
+					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
+				    | COMP_Denormal;
+		} else if (tagb == TAG_Zero) {
+			if (st0_tag == TAG_Valid)
+				return ((st0_sign ==
+					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
+			if (st0_tag == TW_Denormal)
+				return ((st0_sign ==
+					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
+				    | COMP_Denormal;
+		}
+
+		if (st0_tag == TW_Infinity) {
+			if ((tagb == TAG_Valid) || (tagb == TAG_Zero))
+				return ((st0_sign ==
+					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
+			else if (tagb == TW_Denormal)
+				return ((st0_sign ==
+					 SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
+				    | COMP_Denormal;
+			else if (tagb == TW_Infinity) {
+				/* The 80486 book says that infinities can be equal! */
+				return (st0_sign == signb) ? COMP_A_eq_B :
+				    ((st0_sign ==
+				      SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B);
+			}
+			/* Fall through to the NaN code */
+		} else if (tagb == TW_Infinity) {
+			if ((st0_tag == TAG_Valid) || (st0_tag == TAG_Zero))
+				return ((signb ==
+					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B);
+			if (st0_tag == TW_Denormal)
+				return ((signb ==
+					 SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
+				    | COMP_Denormal;
+			/* Fall through to the NaN code */
+		}
+
+		/* The only possibility now should be that one of the arguments
+		   is a NaN */
+		if ((st0_tag == TW_NaN) || (tagb == TW_NaN)) {
+			int signalling = 0, unsupported = 0;
+			if (st0_tag == TW_NaN) {
+				signalling =
+				    (st0_ptr->sigh & 0xc0000000) == 0x80000000;
+				unsupported = !((exponent(st0_ptr) == EXP_OVER)
+						&& (st0_ptr->
+						    sigh & 0x80000000));
+			}
+			if (tagb == TW_NaN) {
+				signalling |=
+				    (b->sigh & 0xc0000000) == 0x80000000;
+				unsupported |= !((exponent(b) == EXP_OVER)
+						 && (b->sigh & 0x80000000));
+			}
+			if (signalling || unsupported)
+				return COMP_No_Comp | COMP_SNaN | COMP_NaN;
+			else
+				/* Neither is a signaling NaN */
+				return COMP_No_Comp | COMP_NaN;
+		}
+
+		EXCEPTION(EX_Invalid);
+	}
+
+	if (st0_sign != signb) {
+		return ((st0_sign == SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
+		    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
+		       COMP_Denormal : 0);
+	}
+
+	if ((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) {
+		FPU_to_exp16(st0_ptr, &x);
+		FPU_to_exp16(b, &y);
+		st0_ptr = &x;
+		b = &y;
+		exp0 = exponent16(st0_ptr);
+		expb = exponent16(b);
+	} else {
+		exp0 = exponent(st0_ptr);
+		expb = exponent(b);
+	}
+
+#ifdef PARANOID
+	if (!(st0_ptr->sigh & 0x80000000))
+		EXCEPTION(EX_Invalid);
+	if (!(b->sigh & 0x80000000))
+		EXCEPTION(EX_Invalid);
+#endif /* PARANOID */
+
+	diff = exp0 - expb;
+	if (diff == 0) {
+		diff = st0_ptr->sigh - b->sigh;	/* Works only if ms bits are
+						   identical */
+		if (diff == 0) {
+			diff = st0_ptr->sigl > b->sigl;
+			if (diff == 0)
+				diff = -(st0_ptr->sigl < b->sigl);
+		}
+	}
+
+	if (diff > 0) {
+		return ((st0_sign == SIGN_POS) ? COMP_A_gt_B : COMP_A_lt_B)
+		    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
+		       COMP_Denormal : 0);
+	}
+	if (diff < 0) {
+		return ((st0_sign == SIGN_POS) ? COMP_A_lt_B : COMP_A_gt_B)
+		    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
+		       COMP_Denormal : 0);
+	}
+
+	return COMP_A_eq_B
+	    | (((st0_tag == TW_Denormal) || (tagb == TW_Denormal)) ?
+	       COMP_Denormal : 0);
+
+}
+
+/* This function requires that st(0) is not empty */
+int FPU_compare_st_data(FPU_REG const *loaded_data, u_char loaded_tag)
+{
+	int f = 0, c;
+
+	c = compare(loaded_data, loaded_tag);
+
+	if (c & COMP_NaN) {
+		EXCEPTION(EX_Invalid);
+		f = SW_C3 | SW_C2 | SW_C0;
+	} else
+		switch (c & 7) {
+		case COMP_A_lt_B:
+			f = SW_C0;
+			break;
+		case COMP_A_eq_B:
+			f = SW_C3;
+			break;
+		case COMP_A_gt_B:
+			f = 0;
+			break;
+		case COMP_No_Comp:
+			f = SW_C3 | SW_C2 | SW_C0;
+			break;
+#ifdef PARANOID
+		default:
+			EXCEPTION(EX_INTERNAL | 0x121);
+			f = SW_C3 | SW_C2 | SW_C0;
+			break;
+#endif /* PARANOID */
+		}
+	setcc(f);
+	if (c & COMP_Denormal) {
+		return denormal_operand() < 0;
+	}
+	return 0;
+}
+
+static int compare_st_st(int nr)
+{
+	int f = 0, c;
+	FPU_REG *st_ptr;
+
+	if (!NOT_EMPTY(0) || !NOT_EMPTY(nr)) {
+		setcc(SW_C3 | SW_C2 | SW_C0);
+		/* Stack fault */
+		EXCEPTION(EX_StackUnder);
+		return !(control_word & CW_Invalid);
+	}
+
+	st_ptr = &st(nr);
+	c = compare(st_ptr, FPU_gettagi(nr));
+	if (c & COMP_NaN) {
+		setcc(SW_C3 | SW_C2 | SW_C0);
+		EXCEPTION(EX_Invalid);
+		return !(control_word & CW_Invalid);
+	} else
+		switch (c & 7) {
+		case COMP_A_lt_B:
+			f = SW_C0;
+			break;
+		case COMP_A_eq_B:
+			f = SW_C3;
+			break;
+		case COMP_A_gt_B:
+			f = 0;
+			break;
+		case COMP_No_Comp:
+			f = SW_C3 | SW_C2 | SW_C0;
+			break;
+#ifdef PARANOID
+		default:
+			EXCEPTION(EX_INTERNAL | 0x122);
+			f = SW_C3 | SW_C2 | SW_C0;
+			break;
+#endif /* PARANOID */
+		}
+	setcc(f);
+	if (c & COMP_Denormal) {
+		return denormal_operand() < 0;
+	}
+	return 0;
+}
+
+static int compare_u_st_st(int nr)
+{
+	int f = 0, c;
+	FPU_REG *st_ptr;
+
+	if (!NOT_EMPTY(0) || !NOT_EMPTY(nr)) {
+		setcc(SW_C3 | SW_C2 | SW_C0);
+		/* Stack fault */
+		EXCEPTION(EX_StackUnder);
+		return !(control_word & CW_Invalid);
+	}
+
+	st_ptr = &st(nr);
+	c = compare(st_ptr, FPU_gettagi(nr));
+	if (c & COMP_NaN) {
+		setcc(SW_C3 | SW_C2 | SW_C0);
+		if (c & COMP_SNaN) {	/* This is the only difference between
+					   un-ordered and ordinary comparisons */
+			EXCEPTION(EX_Invalid);
+			return !(control_word & CW_Invalid);
+		}
+		return 0;
+	} else
+		switch (c & 7) {
+		case COMP_A_lt_B:
+			f = SW_C0;
+			break;
+		case COMP_A_eq_B:
+			f = SW_C3;
+			break;
+		case COMP_A_gt_B:
+			f = 0;
+			break;
+		case COMP_No_Comp:
+			f = SW_C3 | SW_C2 | SW_C0;
+			break;
+#ifdef PARANOID
+		default:
+			EXCEPTION(EX_INTERNAL | 0x123);
+			f = SW_C3 | SW_C2 | SW_C0;
+			break;
+#endif /* PARANOID */
+		}
+	setcc(f);
+	if (c & COMP_Denormal) {
+		return denormal_operand() < 0;
+	}
+	return 0;
+}
+
+/*---------------------------------------------------------------------------*/
+
+void fcom_st(void)
+{
+	/* fcom st(i) */
+	compare_st_st(FPU_rm);
+}
+
+void fcompst(void)
+{
+	/* fcomp st(i) */
+	if (!compare_st_st(FPU_rm))
+		FPU_pop();
+}
+
+void fcompp(void)
+{
+	/* fcompp */
+	if (FPU_rm != 1) {
+		FPU_illegal();
+		return;
+	}
+	if (!compare_st_st(1))
+		poppop();
+}
+
+void fucom_(void)
+{
+	/* fucom st(i) */
+	compare_u_st_st(FPU_rm);
+
+}
+
+void fucomp(void)
+{
+	/* fucomp st(i) */
+	if (!compare_u_st_st(FPU_rm))
+		FPU_pop();
+}
+
+void fucompp(void)
+{
+	/* fucompp */
+	if (FPU_rm == 1) {
+		if (!compare_u_st_st(1))
+			poppop();
+	} else
+		FPU_illegal();
+}