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<title>13.1.1 Scalar types </title>
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<a name="1204501"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">13.1.1 Scalar types</font>
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<a name="1204571"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">C scalar type representations are described in the following table.
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<caption><b><i><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204568"> </a><font face="Helvetica">Table 42: Scalar types</font></font></i></b></caption>
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<th><font face="Verdana, Arial, Helvetica, sans-serif" color="#003366"><a name="1208948"> </a><font face="Verdana, Arial, Helvetica, sans-serif">C Type</font></font></th>
<th><font face="Verdana, Arial, Helvetica, sans-serif" color="#003366"><a name="1208950"> </a><font face="Verdana, Arial, Helvetica, sans-serif">Description</font></font></th>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204509"> </a><div ><font size=2><font size=2 face=Courier><strong>unsigned char</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204511"> </a><div ><font size=2>Represented in a word in which the lower eight bits are significant, the upper bits are zero.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204514"> </a><div ><font size=2><font size=2 face=Courier><strong>signed char</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204516"> </a><div ><font size=2>Represented in a word in which the lower eight bits are significant, bit 7 is the sign-bit, the upper bits are zero. </font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204519"> </a><div ><font size=2><font size=2 face=Courier><strong>char</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204521"> </a><div ><font size=2>The representation of char differs depending on whether the <strong>st20cc</strong> option <font size=2 face=Courier><strong>fsignedchar</strong></font> is used to make plain <font size=2 face=Courier><strong>char</strong></font>s signed. When <font size=2 face=Courier><strong>fsignedchar</strong></font> is used, <font size=2 face=Courier><strong>char</strong></font> has the same representation as <font size=2 face=Courier><strong>signed char</strong></font>; without <font size=2 face=Courier><strong>fsignedchar</strong></font> the representation is the same as <font size=2 face=Courier><strong>unsigned char</strong></font>.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204523"> </a><div ><font size=2><font size=2 face=Courier><strong>unsigned short</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204526"> </a><div ><font size=2>Represented in a word in which the lower 16 bits are significant, the upper bits are zero.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204529"> </a><div ><font size=2><font size=2 face=Courier><strong>signed short</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204531"> </a><div ><font size=2>Represented in a word in which the lower 16 bits are significant, bit 15 is the sign bit, the upper bits are zero. </font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204534"> </a><div ><font size=2><font size=2 face=Courier><strong>unsigned int</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204536"> </a><div ><font size=2>Represented in a word in which all 32 bits are significant.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204539"> </a><div ><font size=2><font size=2 face=Courier><strong>signed int</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204541"> </a><div ><font size=2>Represented in a word in which all 32 bits are significant, bit 31 is the sign bit.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204544"> </a><div ><font size=2><font size=2 face=Courier><strong>unsigned long</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204546"> </a><div ><font size=2>Represented in a word in which all 32 bits are significant.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204549"> </a><div ><font size=2><font size=2 face=Courier><strong>signed long</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204551"> </a><div ><font size=2>Represented in a word in which all 32 bits are significant, bit 31 is the sign bit.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204554"> </a><div ><font size=2><font size=2 face=Courier><strong>float</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204556"> </a><div ><font size=2>Represented in a word, in IEEE single-precision format.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204559"> </a><div ><font size=2><font size=2 face=Courier><strong>double</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204561"> </a><div ><font size=2>Represented in two words, in IEEE double-precision format.</font></div></font></td>
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<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204564"> </a><div ><font size=2><font size=2 face=Courier><strong>enumeration</strong></font></font></div></font></td>
<td><font face="Verdana, Arial, Helvetica, sans-serif"><a name="1204566"> </a><div ><font size=2>Represented in a word in which all 32 bits are significant.</font></div></font></td>
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<a name="1204573"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">All signed integer types are represented in two's-complement form and all unsigned integer types in binary form.</font>
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<a name="1204574"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><em>Note: The <strong>st20cc</strong> command line option <font size=2 face=Courier><strong>fsignedchar</strong></font> makes plain chars and plain bit-fields signed.</em></font>
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<a name="1204578"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">All floating point types are represented in a form defined by the ANSI/IEEE standard 7541985 and conform to the operation of that standard with the following exceptions.</font>
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<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204579"> </a>The treatment of non numbers (NaNs and Infinities) in comparisons and arithmetic can be non-standard. For example, NaN==NaN should always return false, but depending on the error which generated the NaN, may not.</font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204580"> </a>Only "round to nearest" arithmetic is provided whereas IEEE also requires "round to zero", "round to -infinity" and "round to infinity".</font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1204581"> </a>There are no error flag registers for handling exceptions nor routines to manipulate or trap the errors.</font></p>
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