X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=device%2Flib%2F_fsdiv.c;h=7bf1c48f010293a75054c269f0f63a06bcb0ac53;hb=a8a7fc8a514bc79114c6d76d6a6aeb885387478c;hp=1768ec46a9b21c9ee3d2e5c0b29d6f833e2f3e2a;hpb=bf1925f901a9f45ad2529874f41e1e2b01f5bc9f;p=fw%2Fsdcc

diff --git a/device/lib/_fsdiv.c b/device/lib/_fsdiv.c
index 1768ec46..7bf1c48f 100644
--- a/device/lib/_fsdiv.c
+++ b/device/lib/_fsdiv.c
@@ -23,10 +23,10 @@
 
 #ifdef FLOAT_ASM_MCS51
 
-// float __fsdiv (float a, float b) reentrant
-static void dummy(void) _naked
+// float __fsdiv (float a, float b) __reentrant
+static void dummy(void) __naked
 {
-	_asm
+	__asm
 	.globl	___fsdiv
 ___fsdiv:
 	// extract the two inputs, placing them into:
@@ -42,20 +42,52 @@ ___fsdiv:
 	cpl	sign_a
 00001$:
 
-	// if divisor is zero, return infinity
-	cjne	r7, #0, 00002$
-	ljmp	fs_return_inf
+	// 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, 00003$
+	cjne	r4, #0, 00004$
 	ljmp	fs_return_zero
-00003$:
+00004$:
+	// 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
-	mov	a, exp_a
 	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
@@ -67,7 +99,7 @@ ___fsdiv:
 	subb	a, r3
 	mov	a, r7
 	subb	a, r4
-	jc	00005$
+	jc	00010$
 	dec	exp_a
 	clr	c
 	mov	a, r2
@@ -82,15 +114,15 @@ ___fsdiv:
 	clr	a
 	rlc	a
 	mov	r4, a
-	sjmp	00006$
-00005$:
+	sjmp	00011$
+00010$:
 #endif
 	clr	a
 	xch	a, r4
 	xch	a, r3
 	xch	a, r2
 	mov	r1, a
-00006$:
+00011$:
 
 	// begin long division
 	push	exp_a
@@ -99,7 +131,7 @@ ___fsdiv:
 #else
 	mov	b, #24
 #endif
-00010$:
+00012$:
 	// compare
 	clr	c
 	mov	a, r1
@@ -112,11 +144,11 @@ ___fsdiv:
 	subb	a, #0		// carry==0 if mant1 >= mant2
 
 #ifdef FLOAT_FULL_ACCURACY
-	djnz	b, 00011$
+	djnz	b, 00013$
 	sjmp	00015$
-00011$:
+00013$:
 #endif
-	jc	00012$
+	jc	00014$
 	// subtract
 	mov	a, r1
 	subb	a, r5
@@ -132,7 +164,7 @@ ___fsdiv:
 	mov	r4, a
 	clr	c
 
-00012$:
+00014$:
 	// shift result
 	cpl	c
 	mov	a, r0
@@ -161,10 +193,10 @@ ___fsdiv:
 	mov	r4, a
 
 #ifdef FLOAT_FULL_ACCURACY
-	sjmp	00010$
+	sjmp	00012$
 00015$:
 #else
-	djnz	b, 00010$
+	djnz	b, 00012$
 #endif
 
 	// now we've got a division result, so all we need to do
@@ -185,6 +217,7 @@ ___fsdiv:
 	pop	exp_a
 	jnc	00016$
 	inc	exp_a
+	// incrementing exp_a without checking carry is dangerous
 	mov	r4, #0x80
 00016$:
 #else
@@ -198,14 +231,11 @@ ___fsdiv:
 
 	lcall	fs_normalize_a
 	ljmp	fs_zerocheck_return
-	_endasm;
+	__endasm;
 }
 
 #else
 
-
-
-
 /*
 ** libgcc support for software floating point.
 ** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
@@ -224,7 +254,6 @@ ___fsdiv:
 
 /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
 
-
 union float_long
   {
     float f;
@@ -238,7 +267,7 @@ float __fsdiv (float a1, float a2)
   volatile long result;
   volatile unsigned long mask;
   volatile long mant1, mant2;
-  volatile int exp ;
+  volatile int exp;
   char sign;
 
   fl1.f = a1;
@@ -254,8 +283,10 @@ float __fsdiv (float a1, float a2)
 
   /* divide by zero??? */
   if (!fl2.l)
-    /* return NaN or -NaN */
-    return (-1.0);
+    {/* return NaN or -NaN */
+      fl2.l = 0x7FC00000;
+      return (fl2.f);
+    }
 
   /* numerator zero??? */
   if (!fl1.l)
@@ -296,9 +327,13 @@ float __fsdiv (float a1, float a2)
   result &= ~HIDDEN;
 
   /* pack up and go home */
-  fl1.l = PACK (sign ? 1ul<<31 : 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
-