Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 116 insertions, 0 deletions

diff --git a/arch/x86/math-emu/reg_mul.c b/arch/x86/math-emu/reg_mul.c
new file mode 100644
index 000000000..d69618572
--- /dev/null
+++ b/arch/x86/math-emu/reg_mul.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*---------------------------------------------------------------------------+
+ |  reg_mul.c                                                                |
+ |                                                                           |
+ | Multiply one FPU_REG by another, put the result in a destination FPU_REG. |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1997                                              |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@suburbia.net                              |
+ |                                                                           |
+ | Returns the tag of the result if no exceptions or errors occurred.        |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+/*---------------------------------------------------------------------------+
+ | The destination may be any FPU_REG, including one of the source FPU_REGs. |
+ +---------------------------------------------------------------------------*/
+
+#include "fpu_emu.h"
+#include "exception.h"
+#include "reg_constant.h"
+#include "fpu_system.h"
+
+/*
+  Multiply two registers to give a register result.
+  The sources are st(deststnr) and (b,tagb,signb).
+  The destination is st(deststnr).
+  */
+/* This routine must be called with non-empty source registers */
+int FPU_mul(FPU_REG const *b, u_char tagb, int deststnr, int control_w)
+{
+	FPU_REG *a = &st(deststnr);
+	FPU_REG *dest = a;
+	u_char taga = FPU_gettagi(deststnr);
+	u_char saved_sign = getsign(dest);
+	u_char sign = (getsign(a) ^ getsign(b));
+	int tag;
+
+	if (!(taga | tagb)) {
+		/* Both regs Valid, this should be the most common case. */
+
+		tag =
+		    FPU_u_mul(a, b, dest, control_w, sign,
+			      exponent(a) + exponent(b));
+		if (tag < 0) {
+			setsign(dest, saved_sign);
+			return tag;
+		}
+		FPU_settagi(deststnr, tag);
+		return tag;
+	}
+
+	if (taga == TAG_Special)
+		taga = FPU_Special(a);
+	if (tagb == TAG_Special)
+		tagb = FPU_Special(b);
+
+	if (((taga == TAG_Valid) && (tagb == TW_Denormal))
+	    || ((taga == TW_Denormal) && (tagb == TAG_Valid))
+	    || ((taga == TW_Denormal) && (tagb == TW_Denormal))) {
+		FPU_REG x, y;
+		if (denormal_operand() < 0)
+			return FPU_Exception;
+
+		FPU_to_exp16(a, &x);
+		FPU_to_exp16(b, &y);
+		tag = FPU_u_mul(&x, &y, dest, control_w, sign,
+				exponent16(&x) + exponent16(&y));
+		if (tag < 0) {
+			setsign(dest, saved_sign);
+			return tag;
+		}
+		FPU_settagi(deststnr, tag);
+		return tag;
+	} else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) {
+		if (((tagb == TW_Denormal) || (taga == TW_Denormal))
+		    && (denormal_operand() < 0))
+			return FPU_Exception;
+
+		/* Must have either both arguments == zero, or
+		   one valid and the other zero.
+		   The result is therefore zero. */
+		FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr);
+		/* The 80486 book says that the answer is +0, but a real
+		   80486 behaves this way.
+		   IEEE-754 apparently says it should be this way. */
+		setsign(dest, sign);
+		return TAG_Zero;
+	}
+	/* Must have infinities, NaNs, etc */
+	else if ((taga == TW_NaN) || (tagb == TW_NaN)) {
+		return real_2op_NaN(b, tagb, deststnr, &st(0));
+	} else if (((taga == TW_Infinity) && (tagb == TAG_Zero))
+		   || ((tagb == TW_Infinity) && (taga == TAG_Zero))) {
+		return arith_invalid(deststnr);	/* Zero*Infinity is invalid */
+	} else if (((taga == TW_Denormal) || (tagb == TW_Denormal))
+		   && (denormal_operand() < 0)) {
+		return FPU_Exception;
+	} else if (taga == TW_Infinity) {
+		FPU_copy_to_regi(a, TAG_Special, deststnr);
+		setsign(dest, sign);
+		return TAG_Special;
+	} else if (tagb == TW_Infinity) {
+		FPU_copy_to_regi(b, TAG_Special, deststnr);
+		setsign(dest, sign);
+		return TAG_Special;
+	}
+#ifdef PARANOID
+	else {
+		EXCEPTION(EX_INTERNAL | 0x102);
+		return FPU_Exception;
+	}
+#endif /* PARANOID */
+
+	return 0;
+}