X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=device%2Flib%2F_fsdiv.c;h=1768ec46a9b21c9ee3d2e5c0b29d6f833e2f3e2a;hb=62b66640e43568550cf42435f62f91cead38927b;hp=a89d698b5f0d4efe93297d9ea775c69ee1a1c34d;hpb=5a964d04cfff5accede4e488135633bd1a780576;p=fw%2Fsdcc

diff --git a/device/lib/_fsdiv.c b/device/lib/_fsdiv.c
index a89d698b..1768ec46 100644
--- a/device/lib/_fsdiv.c
+++ b/device/lib/_fsdiv.c
@@ -1,3 +1,211 @@
+/* Floating point library in optimized assembly for 8051
+ * Copyright (c) 2004, Paul Stoffregen, paul@pjrc.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+
+#define SDCC_FLOAT_LIB
+#include <float.h>
+
+
+#ifdef FLOAT_ASM_MCS51
+
+// float __fsdiv (float a, float b) reentrant
+static void dummy(void) _naked
+{
+	_asm
+	.globl	___fsdiv
+___fsdiv:
+	// extract the two inputs, placing them into:
+	//      sign     exponent   mantiassa
+	//      ----     --------   ---------
+	//  a:  sign_a   exp_a      r4/r3/r2
+	//  b:  sign_b   exp_b      r7/r6/r5
+
+	lcall	fsgetargs
+
+	// compute final sign bit
+	jnb	sign_b, 00001$
+	cpl	sign_a
+00001$:
+
+	// if divisor is zero, return infinity
+	cjne	r7, #0, 00002$
+	ljmp	fs_return_inf
+00002$:
+	// if dividend is zero, return zero
+	cjne	r4, #0, 00003$
+	ljmp	fs_return_zero
+00003$:
+
+	// subtract exponents
+	clr	c
+	mov	a, exp_a
+	subb	a, exp_b
+	add	a, #127
+	mov	exp_a, a
+
+	// need extra bits on a's mantissa
+#ifdef FLOAT_FULL_ACCURACY
+	clr	c
+	mov	a, r5
+	subb	a, r2
+	mov	a, r6
+	subb	a, r3
+	mov	a, r7
+	subb	a, r4
+	jc	00005$
+	dec	exp_a
+	clr	c
+	mov	a, r2
+	rlc	a
+	mov	r1, a
+	mov	a, r3
+	rlc	a
+	mov	r2, a
+	mov	a, r4
+	rlc	a
+	mov	r3, a
+	clr	a
+	rlc	a
+	mov	r4, a
+	sjmp	00006$
+00005$:
+#endif
+	clr	a
+	xch	a, r4
+	xch	a, r3
+	xch	a, r2
+	mov	r1, a
+00006$:
+
+	// begin long division
+	push	exp_a
+#ifdef FLOAT_FULL_ACCURACY
+	mov	b, #25
+#else
+	mov	b, #24
+#endif
+00010$:
+	// compare
+	clr	c
+	mov	a, r1
+	subb	a, r5
+	mov	a, r2
+	subb	a, r6
+	mov	a, r3
+	subb	a, r7
+	mov	a, r4
+	subb	a, #0		// carry==0 if mant1 >= mant2
+
+#ifdef FLOAT_FULL_ACCURACY
+	djnz	b, 00011$
+	sjmp	00015$
+00011$:
+#endif
+	jc	00012$
+	// subtract
+	mov	a, r1
+	subb	a, r5
+	mov	r1, a
+	mov	a, r2
+	subb	a, r6
+	mov	r2, a
+	mov	a, r3
+	subb	a, r7
+	mov	r3, a
+	mov	a, r4
+	subb	a, #0
+	mov	r4, a
+	clr	c
+
+00012$:
+	// shift result
+	cpl	c
+	mov	a, r0
+	rlc	a
+	mov	r0, a
+	mov	a, dpl
+	rlc	a
+	mov	dpl, a
+	mov	a, dph
+	rlc	a
+	mov	dph, a
+
+	// shift partial remainder
+	clr	c
+	mov	a, r1
+	rlc	a
+	mov	r1, a
+	mov	a, r2
+	rlc	a
+	mov	r2, a
+	mov	a, r3
+	rlc	a
+	mov	r3, a
+	mov	a, r4
+	rlc	a
+	mov	r4, a
+
+#ifdef FLOAT_FULL_ACCURACY
+	sjmp	00010$
+00015$:
+#else
+	djnz	b, 00010$
+#endif
+
+	// now we've got a division result, so all we need to do
+	// is round off properly, normalize and output a float
+
+#ifdef FLOAT_FULL_ACCURACY
+	cpl	c
+	clr	a
+	mov	r1, a
+	addc	a, r0
+	mov	r2, a
+	clr	a
+	addc	a, dpl
+	mov	r3, a
+	clr	a
+	addc	a, dph
+	mov	r4, a
+	pop	exp_a
+	jnc	00016$
+	inc	exp_a
+	mov	r4, #0x80
+00016$:
+#else
+	mov	r1, #0
+	mov	a, r0
+	mov	r2, a
+	mov	r3, dpl
+	mov	r4, dph
+	pop	exp_a
+#endif
+
+	lcall	fs_normalize_a
+	ljmp	fs_zerocheck_return
+	_endasm;
+}
+
+#else
+
+
+
+
 /*
 ** libgcc support for software floating point.
 ** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
@@ -16,7 +224,6 @@
 
 /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
 
-#include <float.h>
 
 union float_long
   {
@@ -93,3 +300,5 @@ float __fsdiv (float a1, float a2)
   return (fl1.f);
 }
 
+#endif
+