From e8af787a7af30e7d132b40a278b1d131032f3b88 Mon Sep 17 00:00:00 2001
From: michaelh <michaelh@4a8a32a2-be11-0410-ad9d-d568d2c75423>
Date: Mon, 8 May 2000 03:12:19 +0000
Subject: [PATCH] Began adding float support

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@245 4a8a32a2-be11-0410-ad9d-d568d2c75423
---
 src/z80/support.c | 34 ++++++++++++++++++++++++++++++++++
 src/z80/support.h | 18 ++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 src/z80/support.c
 create mode 100644 src/z80/support.h

diff --git a/src/z80/support.c b/src/z80/support.c
new file mode 100644
index 00000000..01bbe845
--- /dev/null
+++ b/src/z80/support.c
@@ -0,0 +1,34 @@
+/** @file z80/support.c
+ */
+#include "z80.h"
+#include <math.h>
+
+int convertFloat(Z80_FLOAT *f, double native)
+{
+    unsigned long mantissa, exponent;
+    double f2;
+    wassert(f);
+    if (native!=0) {
+	f2 = floor(log(fabs(native))/log(2))+1;
+	mantissa = 0x1000000*fabs(native)/exp(f2*log(2));
+	mantissa &= 0xffffff;
+	exponent = f2 + 0x40;
+	if (native<0)
+	    exponent |= 0x80;
+    }
+    else {
+	mantissa = 0;
+	exponent = 0;
+    }
+
+    f->w[0] = (WORD)mantissa;
+    f->w[1] = (BYTE)(mantissa>>16);
+    f->w[1] |= exponent << 8;
+    
+    f->b[0] = (BYTE)f->w[0];
+    f->b[1] = (BYTE)(f->w[0]>>8);
+    f->b[2] = (BYTE)f->w[1];
+    f->b[3] = (BYTE)(f->w[1]>>8);
+
+    return 0;
+}
diff --git a/src/z80/support.h b/src/z80/support.h
new file mode 100644
index 00000000..cb519126
--- /dev/null
+++ b/src/z80/support.h
@@ -0,0 +1,18 @@
+/** @file z80/support.h
+    Support functions for the z80 port.
+*/
+#ifndef Z80_SUPPORT_INCLUDE
+#define Z80_SUPPORT_INCLUDE
+
+typedef unsigned short WORD;
+typedef unsigned char BYTE;
+
+typedef struct {
+    WORD w[2];
+    BYTE b[4];
+} Z80_FLOAT;
+
+/** Convert a native float into 'z80' format */
+int convertFloat(Z80_FLOAT *f, double native);
+
+#endif
-- 
2.30.2