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9<title>OSSetGQR[n]</title>
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13
14<h1>OSSetGQR[n]</h1>
15
16
17<h2>C Specification</h2>
18
19<dl>
20<dd><pre><code>#include &lt;revolution/os.h&gt;
21
22// GQR type formats
23#define OS_GQR_F32 0x0000
24#define OS_GQR_U8  0x0004
25#define OS_GQR_U16 0x0005
26#define OS_GQR_S8  0x0006
27#define OS_GQR_S16 0x0007
28
29// GQR scale factors
30#define OS_GQR_SCALE_NONE   0
31#define OS_GQR_SCALE_2      1
32#define OS_GQR_SCALE_4      2
33#define OS_GQR_SCALE_8      3
34#define OS_GQR_SCALE_16     4
35#define OS_GQR_SCALE_32     5
36#define OS_GQR_SCALE_64     6
37#define OS_GQR_SCALE_128    7
38#define OS_GQR_SCALE_256    8
39#define OS_GQR_SCALE_512    9
40#define OS_GQR_SCALE_1024   10
41#define OS_GQR_SCALE_2048   11
42#define OS_GQR_SCALE_4096   12
43#define OS_GQR_SCALE_8192   13
44#define OS_GQR_SCALE_16384  14
45#define OS_GQR_SCALE_32768  15
46#define OS_GQR_SCALE_65536  16
47#define OS_GQR_SCALE_MAX    31
48
49#define OS_GQR_DIVIDE_2     63
50#define OS_GQR_DIVIDE_4     62
51#define OS_GQR_DIVIDE_8     61
52#define OS_GQR_DIVIDE_16    60
53#define OS_GQR_DIVIDE_32    59
54#define OS_GQR_DIVIDE_64    58
55#define OS_GQR_DIVIDE_128   57
56#define OS_GQR_DIVIDE_256   56
57#define OS_GQR_DIVIDE_512   55
58#define OS_GQR_DIVIDE_1024  54
59#define OS_GQR_DIVIDE_2048  53
60#define OS_GQR_DIVIDE_4096  52
61#define OS_GQR_DIVIDE_8192  51
62#define OS_GQR_DIVIDE_16384 50
63#define OS_GQR_DIVIDE_32768 49
64#define OS_GQR_DIVIDE_65536 48
65#define OS_GQR_DIVIDE_MAX   32
66
67inline void OSSetGQR2(u32 type, u32 scale);
68</code><code>inline void OSSetGQR3(u32 <em>type</em>, u32 <em>scale</em>);
69</code><code>inline void OSSetGQR4(u32 <em>type</em>, u32 <em>scale</em>);
70</code><code>inline void OSSetGQR5(u32 <em>type</em>, u32 <em>scale</em>);
71</code><code>inline void OSSetGQR6(u32 <em>type</em>, u32 <em>scale</em>);
72</code><code>inline void OSSetGQR7(u32 <em>type</em>, u32 <em>scale</em>);
73</code></pre>
74  </dd>
75</dl>
76<h2>Arguments</h2>
77<TABLE border="1" cellpadding="3" cellspacing="0.1">
78  <tr>
79<TD width="120" bgcolor="#ffffe8"><em><strong><code><code><EM><STRONG>type</STRONG></EM></code></code></strong></em></TD>
80<TD width="520">Data Types Can specify the following values: <code>OS_GQR_F32, OS_GQR_S8, OS_GQR_S16, OS_GQR_U8, OS_GQR_U16</code>.</TD>
81    </tr>
82  <tr>
83<TD width="120" bgcolor="#ffffe8"><strong><em><code><strong><em><code>scale</code></em></strong></code></em></strong></TD>
84<TD width="520">Scaling factor. Can specify the following values: <code>OS_GQR_SCALE_*</code> or <code>OS_GQR_DIVIDE_*</code>.</TD>
85    </tr>
86</TABLE>
87<h2>Return Values</h2>
88<P>None.</P>
89<h2>Description</h2>
90<P>Sets value to a quantization register GQR in the Broadway CPU. These register values are used by a single floating-point paired load/store instructions to convert from float to integer or vice versa.</P>
91<P>The <strong><em><code>type</code></em></strong> argument defines the data type used to load float values from memory or store float values into memory. The <strong><em><code>scale</code></em></strong> argument defines the scale factor when a value is stored into memory as an integer value. For loading a value from memory, the inverted scale factor is applied. (For example, if you use <code>OS_GQR_SCALE_4</code>,&nbsp;the value will be multiplied by 4 when stored and divided by 4 when loaded.)</P>
92<P>The Broadway CPU has 8 GQRs. Since GQR0 and GQR1 are reserved for the system, no APIs to modify them are available.</P>
93<P><STRONG>Note:</STRONG> OS fast cast functions use GQR2 to GQR5. If you change these registers after the <a href="OSInitFastCast.html"><code>OSInitFastCast</code></a> function is called, OS fast cast functions (<code><a href="OSf32tos16.html">OSf32tos16</a>, <a href="OSf32tos8.html">OSf32tos8</a>,</code> etc.) do not function properly. In such cases, call the <a href="OSInitFastCast.html"><code>OSInitFastCast</code></a> function again to reinitialize these four registers.</P>
94
95<h2>See Also</h2>
96
97<p><code><a href="OSInitFastCast.html">OSInitFastCast</a>, <a href="OSf32tos16.html">OSf32tos16</a>, <a href="OSf32tos8.html">OSf32tos8</a>, <a href="OSf32tou16.html">OSf32tou16</a>, <a href="OSf32tou8.html">OSf32tou8</a>, <a href="OSs16tof32.html">OSs16tof32</a>, <a href="OSs8tof32.html">OSs8tof32</a>, <a href="OSu16tof32.html">OSu16tof32</a>, <a href="OSu8tof32.html">OSu8tof32</a></code></p>
98<H2>Revision History</H2>
99<P>2006/03/01 Initial version.</P>
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