X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=device%2Flib%2F_fsadd.c;h=567582e81e158845d820ca6599513932cc98c3e6;hb=08290dfa329a51ede3412b12df48dec205de4c8c;hp=fa0970ae45c2abafef3c4a371622c61e8574cb45;hpb=61da3cca8ba3e73617d60a8a50b31e541af74103;p=fw%2Fsdcc

diff --git a/device/lib/_fsadd.c b/device/lib/_fsadd.c
index fa0970ae..567582e8 100644
--- a/device/lib/_fsadd.c
+++ b/device/lib/_fsadd.c
@@ -1,3 +1,139 @@
+/* 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 __fsadd (float a, float b) __reentrant
+static void dummy(void) __naked
+{
+	__asm
+
+	// 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
+	//
+	// r1: used to extend precision of a's mantissa
+	// r0: general purpose loop counter
+
+	.globl	___fsadd
+___fsadd:
+	lcall	fsgetargs
+
+	.globl	fsadd_direct_entry
+fsadd_direct_entry:
+	// we're going to extend mantissa to 32 bits temporarily
+	mov	r1, #0
+
+	// which exponent is greater?
+	mov	a, exp_b
+	cjne	a, exp_a, 00005$
+	sjmp	00011$
+00005$:	jnc	00010$
+
+	// a's exponent was greater, so shift b's mantissa
+	lcall	fs_swap_a_b
+
+00010$:
+	// b's exponent was greater, so shift a's mantissa
+	mov	a, exp_b
+	clr	c
+	subb	a, exp_a
+	lcall	fs_rshift_a	// acc has # of shifts to do
+
+00011$:
+	// decide if we need to add or subtract
+	// sign_a and sign_b are stored in the flag bits of psw,
+	// so this little trick checks if the arguements ave the
+	// same sign.
+	mov	a, psw
+	swap	a
+	xrl	a, psw
+	jb	acc.1, 00022$
+
+00020$:
+	// add the mantissas (both positive or both negative)
+	mov	a, r2
+	add	a, r5
+	mov	r2, a
+	mov	a, r3
+	addc	a, r6
+	mov	r3, a
+	mov	a, r4
+	addc	a, r7
+	mov	r4, a
+	// check for overflow past 24 bits
+	jnc	00021$
+	mov	a, #1
+	lcall	fs_rshift_a
+	mov	a, r4
+	orl	a, #0x80
+	mov	r4, a
+00021$:
+	ljmp	fs_round_and_return
+
+
+
+00022$:
+	// subtract the mantissas (one of them is negative)
+	clr	c
+	mov	a, r2
+	subb	a, r5
+	mov	r2, a
+	mov	a, r3
+	subb	a, r6
+	mov	r3, a
+	mov	a, r4
+	subb	a, r7
+	mov	r4, a
+	jnc	00025$
+	// if we get a negative result, turn it positive and
+	// flip the sign bit
+	clr	c
+	clr	a
+	subb	a, r1
+	mov	r1, a
+	clr	a
+	subb	a, r2
+	mov	r2, a
+	clr	a
+	subb	a, r3
+	mov	r3, a
+	clr	a
+	subb	a, r4
+	mov	r4, a
+	cpl	sign_a
+00025$:
+	lcall	fs_normalize_a
+	ljmp	fs_round_and_return
+
+	__endasm;
+}
+
+#else
+
+
 /*
 ** libgcc support for software floating point.
 ** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
@@ -14,10 +150,6 @@
 ** uunet!motown!pipeline!phw
 */
 
-/* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
-
-#include <float.h>
-
 union float_long
   {
     float f;
@@ -77,15 +209,13 @@ float __fsadd (float a1, float a2)
     return (0);
 
   /* normalize */
-  /* jwk: TODO: changing the next two whiles in nested ifs 
-     seriously breaks it. Why?????????????????? */ 
   while (mant1<HIDDEN) {
     mant1 <<= 1;
     exp1--;
   }
 
+  /* round off */
   while (mant1 & 0xff000000) {
-    // round off
     if (mant1&1)
       mant1 += 2;
     mant1 >>= 1 ;
@@ -100,3 +230,5 @@ float __fsadd (float a1, float a2)
 
   return (fl1.f);
 }
+
+#endif