Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 209 insertions, 0 deletions

diff --git a/arch/x86/math-emu/poly_atan.c b/arch/x86/math-emu/poly_atan.c
new file mode 100644
index 0000000000..7e7412c5a1
--- /dev/null
+++ b/arch/x86/math-emu/poly_atan.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0
+/*---------------------------------------------------------------------------+
+ |  poly_atan.c                                                              |
+ |                                                                           |
+ | Compute the arctan of a FPU_REG, using a polynomial approximation.        |
+ |                                                                           |
+ | Copyright (C) 1992,1993,1994,1997                                         |
+ |                  W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
+ |                  E-mail   billm@suburbia.net                              |
+ |                                                                           |
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+
+#include "exception.h"
+#include "reg_constant.h"
+#include "fpu_emu.h"
+#include "fpu_system.h"
+#include "status_w.h"
+#include "control_w.h"
+#include "poly.h"
+
+#define	HIPOWERon	6	/* odd poly, negative terms */
+static const unsigned long long oddnegterms[HIPOWERon] = {
+	0x0000000000000000LL,	/* Dummy (not for - 1.0) */
+	0x015328437f756467LL,
+	0x0005dda27b73dec6LL,
+	0x0000226bf2bfb91aLL,
+	0x000000ccc439c5f7LL,
+	0x0000000355438407LL
+};
+
+#define	HIPOWERop	6	/* odd poly, positive terms */
+static const unsigned long long oddplterms[HIPOWERop] = {
+/*  0xaaaaaaaaaaaaaaabLL,  transferred to fixedpterm[] */
+	0x0db55a71875c9ac2LL,
+	0x0029fce2d67880b0LL,
+	0x0000dfd3908b4596LL,
+	0x00000550fd61dab4LL,
+	0x0000001c9422b3f9LL,
+	0x000000003e3301e1LL
+};
+
+static const unsigned long long denomterm = 0xebd9b842c5c53a0eLL;
+
+static const Xsig fixedpterm = MK_XSIG(0xaaaaaaaa, 0xaaaaaaaa, 0xaaaaaaaa);
+
+static const Xsig pi_signif = MK_XSIG(0xc90fdaa2, 0x2168c234, 0xc4c6628b);
+
+/*--- poly_atan() -----------------------------------------------------------+
+ |                                                                           |
+ +---------------------------------------------------------------------------*/
+void poly_atan(FPU_REG *st0_ptr, u_char st0_tag,
+	       FPU_REG *st1_ptr, u_char st1_tag)
+{
+	u_char transformed, inverted, sign1, sign2;
+	int exponent;
+	long int dummy_exp;
+	Xsig accumulator, Numer, Denom, accumulatore, argSignif, argSq, argSqSq;
+	u_char tag;
+
+	sign1 = getsign(st0_ptr);
+	sign2 = getsign(st1_ptr);
+	if (st0_tag == TAG_Valid) {
+		exponent = exponent(st0_ptr);
+	} else {
+		/* This gives non-compatible stack contents... */
+		FPU_to_exp16(st0_ptr, st0_ptr);
+		exponent = exponent16(st0_ptr);
+	}
+	if (st1_tag == TAG_Valid) {
+		exponent -= exponent(st1_ptr);
+	} else {
+		/* This gives non-compatible stack contents... */
+		FPU_to_exp16(st1_ptr, st1_ptr);
+		exponent -= exponent16(st1_ptr);
+	}
+
+	if ((exponent < 0) || ((exponent == 0) &&
+			       ((st0_ptr->sigh < st1_ptr->sigh) ||
+				((st0_ptr->sigh == st1_ptr->sigh) &&
+				 (st0_ptr->sigl < st1_ptr->sigl))))) {
+		inverted = 1;
+		Numer.lsw = Denom.lsw = 0;
+		XSIG_LL(Numer) = significand(st0_ptr);
+		XSIG_LL(Denom) = significand(st1_ptr);
+	} else {
+		inverted = 0;
+		exponent = -exponent;
+		Numer.lsw = Denom.lsw = 0;
+		XSIG_LL(Numer) = significand(st1_ptr);
+		XSIG_LL(Denom) = significand(st0_ptr);
+	}
+	div_Xsig(&Numer, &Denom, &argSignif);
+	exponent += norm_Xsig(&argSignif);
+
+	if ((exponent >= -1)
+	    || ((exponent == -2) && (argSignif.msw > 0xd413ccd0))) {
+		/* The argument is greater than sqrt(2)-1 (=0.414213562...) */
+		/* Convert the argument by an identity for atan */
+		transformed = 1;
+
+		if (exponent >= 0) {
+#ifdef PARANOID
+			if (!((exponent == 0) &&
+			      (argSignif.lsw == 0) && (argSignif.midw == 0) &&
+			      (argSignif.msw == 0x80000000))) {
+				EXCEPTION(EX_INTERNAL | 0x104);	/* There must be a logic error */
+				return;
+			}
+#endif /* PARANOID */
+			argSignif.msw = 0;	/* Make the transformed arg -> 0.0 */
+		} else {
+			Numer.lsw = Denom.lsw = argSignif.lsw;
+			XSIG_LL(Numer) = XSIG_LL(Denom) = XSIG_LL(argSignif);
+
+			if (exponent < -1)
+				shr_Xsig(&Numer, -1 - exponent);
+			negate_Xsig(&Numer);
+
+			shr_Xsig(&Denom, -exponent);
+			Denom.msw |= 0x80000000;
+
+			div_Xsig(&Numer, &Denom, &argSignif);
+
+			exponent = -1 + norm_Xsig(&argSignif);
+		}
+	} else {
+		transformed = 0;
+	}
+
+	argSq.lsw = argSignif.lsw;
+	argSq.midw = argSignif.midw;
+	argSq.msw = argSignif.msw;
+	mul_Xsig_Xsig(&argSq, &argSq);
+
+	argSqSq.lsw = argSq.lsw;
+	argSqSq.midw = argSq.midw;
+	argSqSq.msw = argSq.msw;
+	mul_Xsig_Xsig(&argSqSq, &argSqSq);
+
+	accumulatore.lsw = argSq.lsw;
+	XSIG_LL(accumulatore) = XSIG_LL(argSq);
+
+	shr_Xsig(&argSq, 2 * (-1 - exponent - 1));
+	shr_Xsig(&argSqSq, 4 * (-1 - exponent - 1));
+
+	/* Now have argSq etc with binary point at the left
+	   .1xxxxxxxx */
+
+	/* Do the basic fixed point polynomial evaluation */
+	accumulator.msw = accumulator.midw = accumulator.lsw = 0;
+	polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq),
+			oddplterms, HIPOWERop - 1);
+	mul64_Xsig(&accumulator, &XSIG_LL(argSq));
+	negate_Xsig(&accumulator);
+	polynomial_Xsig(&accumulator, &XSIG_LL(argSqSq), oddnegterms,
+			HIPOWERon - 1);
+	negate_Xsig(&accumulator);
+	add_two_Xsig(&accumulator, &fixedpterm, &dummy_exp);
+
+	mul64_Xsig(&accumulatore, &denomterm);
+	shr_Xsig(&accumulatore, 1 + 2 * (-1 - exponent));
+	accumulatore.msw |= 0x80000000;
+
+	div_Xsig(&accumulator, &accumulatore, &accumulator);
+
+	mul_Xsig_Xsig(&accumulator, &argSignif);
+	mul_Xsig_Xsig(&accumulator, &argSq);
+
+	shr_Xsig(&accumulator, 3);
+	negate_Xsig(&accumulator);
+	add_Xsig_Xsig(&accumulator, &argSignif);
+
+	if (transformed) {
+		/* compute pi/4 - accumulator */
+		shr_Xsig(&accumulator, -1 - exponent);
+		negate_Xsig(&accumulator);
+		add_Xsig_Xsig(&accumulator, &pi_signif);
+		exponent = -1;
+	}
+
+	if (inverted) {
+		/* compute pi/2 - accumulator */
+		shr_Xsig(&accumulator, -exponent);
+		negate_Xsig(&accumulator);
+		add_Xsig_Xsig(&accumulator, &pi_signif);
+		exponent = 0;
+	}
+
+	if (sign1) {
+		/* compute pi - accumulator */
+		shr_Xsig(&accumulator, 1 - exponent);
+		negate_Xsig(&accumulator);
+		add_Xsig_Xsig(&accumulator, &pi_signif);
+		exponent = 1;
+	}
+
+	exponent += round_Xsig(&accumulator);
+
+	significand(st1_ptr) = XSIG_LL(accumulator);
+	setexponent16(st1_ptr, exponent);
+
+	tag = FPU_round(st1_ptr, 1, 0, FULL_PRECISION, sign2);
+	FPU_settagi(1, tag);
+
+	set_precision_flag_up();	/* We do not really know if up or down,
+					   use this as the default. */
+
+}