Owen Edwards / TwosComplement

Handle two\'s complement numbers.

Files at this revision

API Documentation at this revision

Revision 0:b495118be5a7, committed 2011-01-20

Comitter:
Owen
Date:
Thu Jan 20 20:01:36 2011 +0000
Commit message:

Changed in this revision

SignExtend.cpp Show annotated file Show diff for this revision Revisions of this file
SignExtend.h Show annotated file Show diff for this revision Revisions of this file 
diff -r 000000000000 -r b495118be5a7 SignExtend.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SignExtend.cpp	Thu Jan 20 20:01:36 2011 +0000
@@ -0,0 +1,17 @@
+#include "mbed.h"
+#include "assert.h"
+
+int SignExtend( int value, const int bit_width )
+{
+    assert( ( bit_width > 1) && ( bit_width < (8*sizeof(int)) ) );
+
+    value &= ( (1<<(bit_width)) - 1 ); /* Clear out any extra MSB data */
+
+    if ( ( value & ( 1 << (bit_width-1) ) ) != 0 )
+    {
+        /* value IS negative */
+        value -= (1<<bit_width);
+    }
+
+    return value;
+}

diff -r 000000000000 -r b495118be5a7 SignExtend.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SignExtend.h	Thu Jan 20 20:01:36 2011 +0000
@@ -0,0 +1,1 @@
+int SignExtend( int value, const int bit_width );
\ No newline at end of file