sdcc-3.9.0 fork implementing GNU assembler syntax

This fork aims to provide better support for stm8-binutils

1 files changed, 366 insertions, 0 deletions

diff --git a/device/lib/_fsdiv.c b/device/lib/_fsdiv.c
new file mode 100644
index 0000000..72893bc
--- /dev/null
+++ b/device/lib/_fsdiv.c
@@ -0,0 +1,366 @@
+/*-------------------------------------------------------------------------
+   _fsdiv.c - Floating point library in optimized assembly for 8051
+
+   Copyright (c) 2004, Paul Stoffregen, paul@pjrc.com
+
+   This library is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by the
+   Free Software Foundation; either version 2, 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 library; see the file COPYING. If not, write to the
+   Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA.
+
+   As a special exception, if you link this library with other files,
+   some of which are compiled with SDCC, to produce an executable,
+   this library does not by itself cause the resulting executable to
+   be covered by the GNU General Public License. This exception does
+   not however invalidate any other reasons why the executable file
+   might be covered by the GNU General Public License.
+-------------------------------------------------------------------------*/
+
+
+#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$:
+
+	// if divisor is zero, ...
+	cjne	r7, #0, 00003$
+	// if dividend is also zero, return NaN
+	cjne	r4, #0, 00002$
+	ljmp	fs_return_nan
+00002$:
+	// but dividend is non-zero, return infinity
+	ljmp	fs_return_inf
+00003$:
+	// if dividend is zero, return zero
+	cjne	r4, #0, 00004$
+	ljmp	fs_return_zero
+00004$:
+	// if divisor is infinity, ...
+	mov	a, exp_b
+	cjne	a, #0xFF, 00006$
+	// and dividend is also infinity, return NaN
+	mov	a, exp_a
+	cjne	a, #0xFF, 00005$
+	ljmp	fs_return_nan
+00005$:
+	// but dividend is not infinity, return zero
+	ljmp	fs_return_zero
+00006$:
+	// if dividend is infinity, return infinity
+	mov	a, exp_a
+	cjne	a, #0xFF, 00007$
+	ljmp	fs_return_inf
+00007$:
+
+	// subtract exponents
+	clr	c
+	subb	a, exp_b
+	// if no carry then no underflow
+	jnc	00008$
+	add	a, #127
+	jc	00009$
+	ljmp	fs_return_zero
+
+00008$:
+	add	a, #128
+	dec	a
+	jnc	00009$
+	ljmp	fs_return_inf
+
+00009$:
+	mov	exp_a, a
+
+	// need extra bits on a's mantissa
+#ifdef FLOAT_FULL_ACCURACY
+	clr	c
+	mov	a, r5
+	subb	a, r2
+	mov	a, r6
+	subb	a, r3
+	mov	a, r7
+	subb	a, r4
+	jc	00010$
+	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	00011$
+00010$:
+#endif
+	clr	a
+	xch	a, r4
+	xch	a, r3
+	xch	a, r2
+	mov	r1, a
+00011$:
+
+	// begin long division
+	push	exp_a
+#ifdef FLOAT_FULL_ACCURACY
+	mov	b, #25
+#else
+	mov	b, #24
+#endif
+00012$:
+	// compare
+	clr	c
+	mov	a, r1
+	subb	a, r5
+	mov	a, r2
+	subb	a, r6
+	mov	a, r3
+	subb	a, r7
+	mov	a, r4
+	subb	a, #0		// carry==0 if mant1 >= mant2
+
+#ifdef FLOAT_FULL_ACCURACY
+	djnz	b, 00013$
+	sjmp	00015$
+00013$:
+#endif
+	jc	00014$
+	// 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
+
+00014$:
+	// shift result
+	cpl	c
+	mov	a, r0
+	rlc	a
+	mov	r0, a
+	mov	a, dpl
+	rlc	a
+	mov	dpl, a
+	mov	a, dph
+	rlc	a
+	mov	dph, a
+
+	// shift partial remainder
+	clr	c
+	mov	a, r1
+	rlc	a
+	mov	r1, a
+	mov	a, r2
+	rlc	a
+	mov	r2, a
+	mov	a, r3
+	rlc	a
+	mov	r3, a
+	mov	a, r4
+	rlc	a
+	mov	r4, a
+
+#ifdef FLOAT_FULL_ACCURACY
+	sjmp	00012$
+00015$:
+#else
+	djnz	b, 00012$
+#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
+	// incrementing exp_a without checking carry is dangerous
+	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.
+** Permission is granted to do *anything* you want with this file,
+** commercial or otherwise, provided this message remains intact.  So there!
+** I would appreciate receiving any updates/patches/changes that anyone
+** makes, and am willing to be the repository for said changes (am I
+** making a big mistake?).
+**
+** Pat Wood
+** Pipeline Associates, Inc.
+** pipeline!phw@motown.com or
+** sun!pipeline!phw or
+** uunet!motown!pipeline!phw
+*/
+
+/* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
+
+union float_long
+  {
+    float f;
+    long l;
+  };
+
+/* divide two floats */
+static float __fsdiv_org (float a1, float a2)
+{
+  volatile union float_long fl1, fl2;
+  volatile long result;
+  volatile unsigned long mask;
+  volatile long mant1, mant2;
+  volatile int exp;
+  char sign;
+ 
+  fl1.f = a1;
+  fl2.f = a2;
+
+  /* subtract exponents */
+  exp = EXP (fl1.l) ;
+  exp -= EXP (fl2.l);
+  exp += EXCESS;
+
+  /* compute sign */
+  sign = SIGN (fl1.l) ^ SIGN (fl2.l);
+
+  /* divide by zero??? */
+  if (!fl2.l)
+    {/* return NaN or -NaN */
+      fl2.l = 0x7FC00000;
+      return (fl2.f);
+    }
+
+  /* numerator zero??? */
+  if (!fl1.l)
+    return (0);
+
+  /* now get mantissas */
+  mant1 = MANT (fl1.l);
+  mant2 = MANT (fl2.l);
+
+  /* this assures we have 25 bits of precision in the end */
+  if (mant1 < mant2)
+    {
+      mant1 <<= 1;
+      exp--;
+    }
+
+  /* now we perform repeated subtraction of fl2.l from fl1.l */
+  mask = 0x1000000;
+  result = 0;
+  while (mask)
+    {
+      if (mant1 >= mant2)
+	{
+	  result |= mask;
+	  mant1 -= mant2;
+	}
+      mant1 <<= 1;
+      mask >>= 1;
+    }
+
+  /* round */
+  result += 1;
+
+  /* normalize down */
+  exp++;
+  result >>= 1;
+
+  result &= ~HIDDEN;
+
+  /* pack up and go home */
+  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);
+}
+
+float __fsdiv (float a1, float a2)
+{
+  float f;
+  unsigned long *p = (unsigned long *) &f;
+
+  if (a2 == 0.0f && a1 > 0.0f)
+    *p = 0x7f800000; // inf
+  else if (a2 == 0.0f && a1 < 0.0f)
+    *p = 0xff800000; // -inf
+  else if (a2 == 0.0f && a1 == 0.0f)
+    *p = 0xffc00000; // nan
+  else
+    f = __fsdiv_org (a1, a2);
+
+  return f; 
+}
+
+#endif