systemsoftware
/
Programming-Guides
37
1
Fork 0
Code Issues 17 Pull Requests Projects Releases Wiki Activity

Improve section 2.7.3 with tables

Browse Source 
Fixes #12.

Signed-off-by: Bill Schmidt <wschmidt@linux.ibm.com>
pull/69/head
Bill Schmidt 5 years ago
parent 5ab9ef6cce
commit c952a73bb4
1 changed files with 949 additions and 3 deletions
Show Stats Download Patch File Download Diff File

952
Intrinsics_Reference/ch_biendian.xml
Unescape Escape View File

@ -1505,6 +1505,245 @@ a[3] = c;</programlisting>
and the second integer element of <code>b</code>, in that
order.
</para>
<para>
The big endian result is {0x00010203, 0x1c1d1e1f, 0x0c0d0e0f,
0x14151617}, as shown here:
</para>
<informaltable frame="all">
<tgroup cols="17">
<colspec colname="c1" colwidth="1*" />
<colspec colname="c2" colwidth="1*" />
<colspec colname="c3" colwidth="1*" />
<colspec colname="c4" colwidth="1*" />
<colspec colname="c5" colwidth="1*" />
<colspec colname="c6" colwidth="1*" />
<colspec colname="c7" colwidth="1*" />
<colspec colname="c8" colwidth="1*" />
<colspec colname="c9" colwidth="1*" />
<colspec colname="c10" colwidth="1*" />
<colspec colname="c11" colwidth="1*" />
<colspec colname="c12" colwidth="1*" />
<colspec colname="c13" colwidth="1*" />
<colspec colname="c14" colwidth="1*" />
<colspec colname="c15" colwidth="1*" />
<colspec colname="c16" colwidth="1*" />
<colspec colname="c17" colwidth="1*" />
<tbody>
<row>
<entry align="center">
<para><emphasis role="bold">a</emphasis></para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>01</para>
</entry>
<entry align="center">
<para>02</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
<entry align="center">
<para>04</para>
</entry>
<entry align="center">
<para>05</para>
</entry>
<entry align="center">
<para>06</para>
</entry>
<entry align="center">
<para>07</para>
</entry>
<entry align="center">
<para>08</para>
</entry>
<entry align="center">
<para>09</para>
</entry>
<entry align="center">
<para>0A</para>
</entry>
<entry align="center">
<para>0B</para>
</entry>
<entry align="center">
<para>0C</para>
</entry>
<entry align="center">
<para>0D</para>
</entry>
<entry align="center">
<para>0E</para>
</entry>
<entry align="center">
<para>0F</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">b</emphasis></para>
</entry>
<entry align="center">
<para>10</para>
</entry>
<entry align="center">
<para>11</para>
</entry>
<entry align="center">
<para>12</para>
</entry>
<entry align="center">
<para>13</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>18</para>
</entry>
<entry align="center">
<para>19</para>
</entry>
<entry align="center">
<para>1A</para>
</entry>
<entry align="center">
<para>1B</para>
</entry>
<entry align="center">
<para>1C</para>
</entry>
<entry align="center">
<para>1D</para>
</entry>
<entry align="center">
<para>1E</para>
</entry>
<entry align="center">
<para>1F</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">c</emphasis></para>
</entry>
<entry align="center">
<para>0</para>
</entry>
<entry align="center">
<para>1</para>
</entry>
<entry align="center">
<para>2</para>
</entry>
<entry align="center">
<para>3</para>
</entry>
<entry align="center">
<para>28</para>
</entry>
<entry align="center">
<para>29</para>
</entry>
<entry align="center">
<para>30</para>
</entry>
<entry align="center">
<para>31</para>
</entry>
<entry align="center">
<para>12</para>
</entry>
<entry align="center">
<para>13</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>20</para>
</entry>
<entry align="center">
<para>21</para>
</entry>
<entry align="center">
<para>22</para>
</entry>
<entry align="center">
<para>23</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">t</emphasis></para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>01</para>
</entry>
<entry align="center">
<para>02</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
<entry align="center">
<para>1C</para>
</entry>
<entry align="center">
<para>1D</para>
</entry>
<entry align="center">
<para>1E</para>
</entry>
<entry align="center">
<para>1F</para>
</entry>
<entry align="center">
<para>0C</para>
</entry>
<entry align="center">
<para>0D</para>
</entry>
<entry align="center">
<para>0E</para>
</entry>
<entry align="center">
<para>0F</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>
For little endian, the modified PCV is elementwise subtracted
from 31, giving {31,30,29,28,3,2,1,0,19,18,17,16,11,10,9,8}.
@ -1515,10 +1754,247 @@ a[3] = c;</programlisting>
<code>vperm</code> instruction will again select entire
elements using the groups of 4 contiguous bytes, and the
values of the integers will be reordered without compromising
each integer's contents. The fact that the little-endian
result matches the big-endian result is left as an exercise
for the reader.
each integer's contents. The little-endian result matches the
big-endian result, as shown. Observe that <emphasis
role="bold">a</emphasis> and <emphasis
role="bold">b</emphasis> switch positions for little endian
code generation.
</para>
<informaltable frame="all">
<tgroup cols="17">
<colspec colname="c1" colwidth="1*" />
<colspec colname="c2" colwidth="1*" />
<colspec colname="c3" colwidth="1*" />
<colspec colname="c4" colwidth="1*" />
<colspec colname="c5" colwidth="1*" />
<colspec colname="c6" colwidth="1*" />
<colspec colname="c7" colwidth="1*" />
<colspec colname="c8" colwidth="1*" />
<colspec colname="c9" colwidth="1*" />
<colspec colname="c10" colwidth="1*" />
<colspec colname="c11" colwidth="1*" />
<colspec colname="c12" colwidth="1*" />
<colspec colname="c13" colwidth="1*" />
<colspec colname="c14" colwidth="1*" />
<colspec colname="c15" colwidth="1*" />
<colspec colname="c16" colwidth="1*" />
<colspec colname="c17" colwidth="1*" />
<tbody>
<row>
<entry align="center">
<para><emphasis role="bold">b</emphasis></para>
</entry>
<entry align="center">
<para>1C</para>
</entry>
<entry align="center">
<para>1D</para>
</entry>
<entry align="center">
<para>1E</para>
</entry>
<entry align="center">
<para>1F</para>
</entry>
<entry align="center">
<para>18</para>
</entry>
<entry align="center">
<para>19</para>
</entry>
<entry align="center">
<para>1A</para>
</entry>
<entry align="center">
<para>1B</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>10</para>
</entry>
<entry align="center">
<para>11</para>
</entry>
<entry align="center">
<para>12</para>
</entry>
<entry align="center">
<para>13</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">a</emphasis></para>
</entry>
<entry align="center">
<para>0C</para>
</entry>
<entry align="center">
<para>0D</para>
</entry>
<entry align="center">
<para>0E</para>
</entry>
<entry align="center">
<para>0F</para>
</entry>
<entry align="center">
<para>08</para>
</entry>
<entry align="center">
<para>09</para>
</entry>
<entry align="center">
<para>0A</para>
</entry>
<entry align="center">
<para>0B</para>
</entry>
<entry align="center">
<para>04</para>
</entry>
<entry align="center">
<para>05</para>
</entry>
<entry align="center">
<para>06</para>
</entry>
<entry align="center">
<para>07</para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>01</para>
</entry>
<entry align="center">
<para>02</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">c</emphasis></para>
</entry>
<entry align="center">
<para>8</para>
</entry>
<entry align="center">
<para>9</para>
</entry>
<entry align="center">
<para>10</para>
</entry>
<entry align="center">
<para>11</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>18</para>
</entry>
<entry align="center">
<para>19</para>
</entry>
<entry align="center">
<para>0</para>
</entry>
<entry align="center">
<para>1</para>
</entry>
<entry align="center">
<para>2</para>
</entry>
<entry align="center">
<para>3</para>
</entry>
<entry align="center">
<para>28</para>
</entry>
<entry align="center">
<para>29</para>
</entry>
<entry align="center">
<para>30</para>
</entry>
<entry align="center">
<para>31</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">t</emphasis></para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>0C</para>
</entry>
<entry align="center">
<para>0D</para>
</entry>
<entry align="center">
<para>0E</para>
</entry>
<entry align="center">
<para>0F</para>
</entry>
<entry align="center">
<para>1C</para>
</entry>
<entry align="center">
<para>1D</para>
</entry>
<entry align="center">
<para>1E</para>
</entry>
<entry align="center">
<para>1F</para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>01</para>
</entry>
<entry align="center">
<para>02</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>
Now, suppose instead that the original PCV does not reorder
entire integers at once:
@ -1528,6 +2004,241 @@ a[3] = c;</programlisting>
The result of the big-endian implementation would be:
</para>
<programlisting> t = {0x00141f04, 0x07110613, 0x1e030208, 0x090d0516};</programlisting>
<informaltable frame="all">
<tgroup cols="17">
<colspec colname="c1" colwidth="1*" />
<colspec colname="c2" colwidth="1*" />
<colspec colname="c3" colwidth="1*" />
<colspec colname="c4" colwidth="1*" />
<colspec colname="c5" colwidth="1*" />
<colspec colname="c6" colwidth="1*" />
<colspec colname="c7" colwidth="1*" />
<colspec colname="c8" colwidth="1*" />
<colspec colname="c9" colwidth="1*" />
<colspec colname="c10" colwidth="1*" />
<colspec colname="c11" colwidth="1*" />
<colspec colname="c12" colwidth="1*" />
<colspec colname="c13" colwidth="1*" />
<colspec colname="c14" colwidth="1*" />
<colspec colname="c15" colwidth="1*" />
<colspec colname="c16" colwidth="1*" />
<colspec colname="c17" colwidth="1*" />
<tbody>
<row>
<entry align="center">
<para><emphasis role="bold">a</emphasis></para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>01</para>
</entry>
<entry align="center">
<para>02</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
<entry align="center">
<para>04</para>
</entry>
<entry align="center">
<para>05</para>
</entry>
<entry align="center">
<para>06</para>
</entry>
<entry align="center">
<para>07</para>
</entry>
<entry align="center">
<para>08</para>
</entry>
<entry align="center">
<para>09</para>
</entry>
<entry align="center">
<para>0A</para>
</entry>
<entry align="center">
<para>0B</para>
</entry>
<entry align="center">
<para>0C</para>
</entry>
<entry align="center">
<para>0D</para>
</entry>
<entry align="center">
<para>0E</para>
</entry>
<entry align="center">
<para>0F</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">b</emphasis></para>
</entry>
<entry align="center">
<para>10</para>
</entry>
<entry align="center">
<para>11</para>
</entry>
<entry align="center">
<para>12</para>
</entry>
<entry align="center">
<para>13</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>18</para>
</entry>
<entry align="center">
<para>19</para>
</entry>
<entry align="center">
<para>1A</para>
</entry>
<entry align="center">
<para>1B</para>
</entry>
<entry align="center">
<para>1C</para>
</entry>
<entry align="center">
<para>1D</para>
</entry>
<entry align="center">
<para>1E</para>
</entry>
<entry align="center">
<para>1F</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">c</emphasis></para>
</entry>
<entry align="center">
<para>0</para>
</entry>
<entry align="center">
<para>20</para>
</entry>
<entry align="center">
<para>31</para>
</entry>
<entry align="center">
<para>4</para>
</entry>
<entry align="center">
<para>7</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>6</para>
</entry>
<entry align="center">
<para>19</para>
</entry>
<entry align="center">
<para>30</para>
</entry>
<entry align="center">
<para>3</para>
</entry>
<entry align="center">
<para>2</para>
</entry>
<entry align="center">
<para>8</para>
</entry>
<entry align="center">
<para>9</para>
</entry>
<entry align="center">
<para>13</para>
</entry>
<entry align="center">
<para>5</para>
</entry>
<entry align="center">
<para>22</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">t</emphasis></para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>1F</para>
</entry>
<entry align="center">
<para>04</para>
</entry>
<entry align="center">
<para>07</para>
</entry>
<entry align="center">
<para>11</para>
</entry>
<entry align="center">
<para>06</para>
</entry>
<entry align="center">
<para>13</para>
</entry>
<entry align="center">
<para>1E</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
<entry align="center">
<para>02</para>
</entry>
<entry align="center">
<para>08</para>
</entry>
<entry align="center">
<para>09</para>
</entry>
<entry align="center">
<para>0D</para>
</entry>
<entry align="center">
<para>05</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>
For little-endian, the modified PCV would be
{31,11,0,27,24,14,25,12,1,28,29,23,22,18,26,9}, appearing in
@ -1539,6 +2250,241 @@ a[3] = c;</programlisting>
<para>
which bears no resemblance to the big-endian result.
</para>
<informaltable frame="all">
<tgroup cols="17">
<colspec colname="c1" colwidth="1*" />
<colspec colname="c2" colwidth="1*" />
<colspec colname="c3" colwidth="1*" />
<colspec colname="c4" colwidth="1*" />
<colspec colname="c5" colwidth="1*" />
<colspec colname="c6" colwidth="1*" />
<colspec colname="c7" colwidth="1*" />
<colspec colname="c8" colwidth="1*" />
<colspec colname="c9" colwidth="1*" />
<colspec colname="c10" colwidth="1*" />
<colspec colname="c11" colwidth="1*" />
<colspec colname="c12" colwidth="1*" />
<colspec colname="c13" colwidth="1*" />
<colspec colname="c14" colwidth="1*" />
<colspec colname="c15" colwidth="1*" />
<colspec colname="c16" colwidth="1*" />
<colspec colname="c17" colwidth="1*" />
<tbody>
<row>
<entry align="center">
<para><emphasis role="bold">b</emphasis></para>
</entry>
<entry align="center">
<para>1C</para>
</entry>
<entry align="center">
<para>1D</para>
</entry>
<entry align="center">
<para>1E</para>
</entry>
<entry align="center">
<para>1F</para>
</entry>
<entry align="center">
<para>18</para>
</entry>
<entry align="center">
<para>19</para>
</entry>
<entry align="center">
<para>1A</para>
</entry>
<entry align="center">
<para>1B</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>16</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>10</para>
</entry>
<entry align="center">
<para>11</para>
</entry>
<entry align="center">
<para>12</para>
</entry>
<entry align="center">
<para>13</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">a</emphasis></para>
</entry>
<entry align="center">
<para>0C</para>
</entry>
<entry align="center">
<para>0D</para>
</entry>
<entry align="center">
<para>0E</para>
</entry>
<entry align="center">
<para>0F</para>
</entry>
<entry align="center">
<para>08</para>
</entry>
<entry align="center">
<para>09</para>
</entry>
<entry align="center">
<para>0A</para>
</entry>
<entry align="center">
<para>0B</para>
</entry>
<entry align="center">
<para>04</para>
</entry>
<entry align="center">
<para>05</para>
</entry>
<entry align="center">
<para>06</para>
</entry>
<entry align="center">
<para>07</para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>01</para>
</entry>
<entry align="center">
<para>02</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">c</emphasis></para>
</entry>
<entry align="center">
<para>9</para>
</entry>
<entry align="center">
<para>26</para>
</entry>
<entry align="center">
<para>18</para>
</entry>
<entry align="center">
<para>22</para>
</entry>
<entry align="center">
<para>23</para>
</entry>
<entry align="center">
<para>29</para>
</entry>
<entry align="center">
<para>28</para>
</entry>
<entry align="center">
<para>1</para>
</entry>
<entry align="center">
<para>12</para>
</entry>
<entry align="center">
<para>25</para>
</entry>
<entry align="center">
<para>14</para>
</entry>
<entry align="center">
<para>24</para>
</entry>
<entry align="center">
<para>27</para>
</entry>
<entry align="center">
<para>0</para>
</entry>
<entry align="center">
<para>11</para>
</entry>
<entry align="center">
<para>31</para>
</entry>
</row>
<row>
<entry align="center">
<para><emphasis role="bold">t</emphasis></para>
</entry>
<entry align="center">
<para>15</para>
</entry>
<entry align="center">
<para>06</para>
</entry>
<entry align="center">
<para>0E</para>
</entry>
<entry align="center">
<para>0A</para>
</entry>
<entry align="center">
<para>0B</para>
</entry>
<entry align="center">
<para>01</para>
</entry>
<entry align="center">
<para>00</para>
</entry>
<entry align="center">
<para>1D</para>
</entry>
<entry align="center">
<para>10</para>
</entry>
<entry align="center">
<para>05</para>
</entry>
<entry align="center">
<para>12</para>
</entry>
<entry align="center">
<para>04</para>
</entry>
<entry align="center">
<para>07</para>
</entry>
<entry align="center">
<para>1C</para>
</entry>
<entry align="center">
<para>17</para>
</entry>
<entry align="center">
<para>03</para>
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
<para>
The lesson here is to only use <code>vec_perm</code> to
reorder entire elements of a vector. If you must use vec_perm

Write Preview
Loading…
Cancel
Save