+/* 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 __fsmul (float a, float b) __reentrant
+static void dummy(void) __naked
+{
+ __asm
+ .globl ___fsmul
+___fsmul:
+ // extract the two inputs, placing them into:
+ // sign exponent mantissa
+ // ---- -------- --------
+ // a: sign_a exp_a r4/r3/r2
+ // b: sign_b exp_b r7/r6/r5
+
+ lcall fsgetargs
+
+ // first check if either input is zero
+ cjne r4, #0, 00002$
+00001$:
+ ljmp fs_return_zero
+
+00002$:
+ mov a, r7
+ jz 00001$
+
+ // compute final sign bit
+ jnb sign_b, 00003$
+ cpl sign_a
+00003$:
+
+ // check if either input is infinity
+ mov a, exp_b
+ cjne a, #0xFF, 00004$
+ ljmp fs_return_inf
+00004$:
+ mov a, exp_a
+ cjne a, #0xFF, 00005$
+ ljmp fs_return_inf
+00005$:
+
+ // add the exponents
+ add a, exp_b
+ // if carry then no underflow
+ jc 00006$
+ add a, #130
+ jc 00007$
+ ljmp fs_return_zero
+
+00006$:
+ add a, #131
+ dec a
+ jnc 00007$
+ ljmp fs_return_inf
+
+00007$:
+ mov exp_a, a
+
+ // now we need to multipy r4/r3/r2 * r7/r6/r5
+ // ------------------------------------------
+ // r2 * r5 << 0
+ // r3 * r5 + r2 * r6 << 8
+ // r4 * r5 + r3 * r6 + r2 * r7 << 16
+ // r4 * r6 + r3 * r7 << 24
+ // r4 * r7 << 32
+ //
+ // This adds quite a bit of code, but it is a LOT faster
+ // than three calls to __mululong...
+
+ // output goes into r4/r3/r2/r1/r0/xx
+
+ mov a, r2
+ mov b, r5
+ mul ab // r2 * r5
+ // discard lowest 8 bits
+ mov r0, b
+ // range 0-FE
+
+ mov a, r2
+ mov b, r6
+ mul ab // r2 * r6
+ add a, r0
+ mov r0, a
+ clr a
+ addc a, b
+ mov r1, a
+ // range 0-FEFF
+
+ mov a, r3
+ mov b, r5
+ mul ab // r3 * r5
+ add a, r0
+ // discard lowest 8 bits
+ mov a, r1
+ addc a, b
+ mov r1, a
+ clr a
+ rlc a
+ xch a, r2
+ // range 0-1FD
+
+ mov b, r7
+ mul ab // r2 * r7
+ add a, r1
+ mov r1, a
+ mov a, r2
+ addc a, b
+ mov r2, a
+ // range 0-FFFE
+
+ mov a, r3
+ mov r0, a
+ mov b, r6
+ mul ab // r3 * r6
+ add a, r1
+ mov r1, a
+ mov a, r2
+ addc a, b
+ mov r2, a
+ clr a
+ rlc a
+ mov r3, a
+ // range 0-1FDFF
+
+ mov a, r4
+ mov b, r5
+ mul ab // r4 * r5
+ add a, r1
+ mov r1, a
+ mov a, r2
+ addc a, b
+ mov r2, a
+ clr a
+ addc a, r3
+ mov r3, a
+ // range 0-2FC00
+
+ mov a, r0 // r3
+ mov b, r7
+ mul ab // r3 * r7
+ add a, r2
+ mov r2, a
+ mov a, r3
+ addc a, b
+ mov r3, a
+ clr a
+ rlc a
+ xch a, r4
+ // range 0-100FD00
+
+ mov r5, a
+ mov b, r6
+ mul ab // r4 * r6
+ add a, r2
+ mov r2, a
+ mov a, r3
+ addc a, b
+ mov r3, a
+ clr a
+ addc a, r4
+ mov r4, a
+ // range 0-1FEFE00
+
+ mov a, r5 // r4
+ mov b, r7
+ mul ab // r4 * r7
+ add a, r3
+ mov r3, a
+ mov a, r4
+ addc a, b
+ mov r4, a
+ // range 40000000-FFFFFE00
+
+ jb acc.7, 00010$
+ lcall fs_normalize_a
+
+00010$:
+ ljmp fs_round_and_return
+ __endasm;
+}
+
+#else
+
/*
** libgcc support for software floating point.
** Copyright (C) 1991 by Pipeline Associates, Inc. All rights reserved.
/* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
-#include <float.h>
-
union float_long
{
float f;
volatile unsigned long result;
volatile int exp;
char sign;
-
+
fl1.f = a1;
fl2.f = a2;
result &= ~HIDDEN;
/* pack up and go home */
- fl1.l = PACK (sign ? SIGNBIT : 0 , (unsigned long)exp, result);
+ if (exp >= 0x100)
+ fl1.l = (sign ? SIGNBIT : 0) | __INFINITY;
+ else if (exp < 0)
+ fl1.l = 0;
+ else
+ fl1.l = PACK (sign ? SIGNBIT : 0 , exp, result);
return (fl1.f);
}
-
-
-
+#endif
projects / fw / sdcc / blobdiff