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Add examples to vec_vslv and vec_vsrv

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vec_vslv and vec_vsrv are confusing in their own right and even more
so because they operate only with big-endian semantics.

Some examples are warranted.

Note that the respective examples are arranged such that the impact of
shifting in zero bits has a visible impact.

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
pull/69/head
Paul Clarke 5 years ago committed by Bill Schmidt
parent 1dcb7e348e
commit 3d79fb03c1
1 changed files with 371 additions and 2 deletions
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373
Intrinsics_Reference/ch_vec_reference.xml
Unescape Escape View File

@ -29410,12 +29410,197 @@ xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="VIPR.vec-ref">
Then each byte element <emphasis>i</emphasis> of <emphasis
role="bold">r</emphasis> is determined as follows. The start bit
<emphasis>sb</emphasis> is obtained from bits 5:7 of byte element
<emphasis>i</emphasis> of <emphasis role="bold">a</emphasis>. Then
<emphasis>i</emphasis> of <emphasis role="bold">b</emphasis>. Then
the contents of bits <emphasis>sb</emphasis>:<emphasis>sb+7</emphasis>
of the halfword in byte elements
<emphasis>i</emphasis>:<emphasis>i+1</emphasis> of <emphasis
role="bold">v</emphasis> are placed into byte element
<emphasis>i</emphasis> of <emphasis role="bold">r</emphasis>.</para>
<para>An example follows:
<informaltable frame="none">
<tgroup cols="17">
<colspec colname="c0" colwidth="10*" />
<colspec colname="c1" colwidth="10*" />
<colspec colname="c2" colwidth="10*" />
<colspec colname="c3" colwidth="10*" />
<colspec colname="c4" colwidth="10*" />
<colspec colname="c5" colwidth="10*" />
<colspec colname="c6" colwidth="10*" />
<colspec colname="c7" colwidth="10*" />
<colspec colname="c8" colwidth="10*" />
<colspec colname="c9" colwidth="10*" />
<colspec colname="c10" colwidth="10*" />
<colspec colname="c11" colwidth="10*" />
<colspec colname="c12" colwidth="10*" />
<colspec colname="c13" colwidth="10*" />
<colspec colname="c14" colwidth="10*" />
<colspec colname="c15" colwidth="10*" />
<colspec colname="c16" colwidth="10*" />
<tbody>
<row>
<entry align="center" valign="middle">
<para> <emphasis role="bold">a</emphasis> </para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
</row>
<row>
<entry align="center" valign="middle">
<para> <emphasis role="bold">b</emphasis> </para>
</entry>
<entry align="center" valign="middle">
<para>00</para>
</entry>
<entry align="center" valign="middle">
<para>01</para>
</entry>
<entry align="center" valign="middle">
<para>02</para>
</entry>
<entry align="center" valign="middle">
<para>03</para>
</entry>
<entry align="center" valign="middle">
<para>04</para>
</entry>
<entry align="center" valign="middle">
<para>05</para>
</entry>
<entry align="center" valign="middle">
<para>06</para>
</entry>
<entry align="center" valign="middle">
<para>07</para>
</entry>
<entry align="center" valign="middle">
<para>08</para>
</entry>
<entry align="center" valign="middle">
<para>09</para>
</entry>
<entry align="center" valign="middle">
<para>0A</para>
</entry>
<entry align="center" valign="middle">
<para>0B</para>
</entry>
<entry align="center" valign="middle">
<para>0C</para>
</entry>
<entry align="center" valign="middle">
<para>0D</para>
</entry>
<entry align="center" valign="middle">
<para>0E</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
</row>
<row>
<entry align="center" valign="middle">
<para> <emphasis role="bold">r</emphasis> </para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>1E</para>
</entry>
<entry align="center" valign="middle">
<para>3C</para>
</entry>
<entry align="center" valign="middle">
<para>78</para>
</entry>
<entry align="center" valign="middle">
<para>F0</para>
</entry>
<entry align="center" valign="middle">
<para>E1</para>
</entry>
<entry align="center" valign="middle">
<para>C3</para>
</entry>
<entry align="center" valign="middle">
<para>87</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>1E</para>
</entry>
<entry align="center" valign="middle">
<para>3C</para>
</entry>
<entry align="center" valign="middle">
<para>78</para>
</entry>
<entry align="center" valign="middle">
<para>F0</para>
</entry>
<entry align="center" valign="middle">
<para>E1</para>
</entry>
<entry align="center" valign="middle">
<para>C3</para>
</entry>
<entry align="center" valign="middle">
<para>80</para>
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>

<para><emphasis role="bold">Endian considerations:</emphasis>
All bit and byte element numbers are specified in big-endian order.
This intrinsic is <emphasis>not</emphasis> endian-neutral.
@ -31644,11 +31829,195 @@ xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="VIPR.vec-ref">
<emphasis role="bold">r</emphasis> is determined as follows. The
start bit <emphasis>sb</emphasis> is obtained from bits 5:7 of
byte element <emphasis>i</emphasis> of <emphasis
role="bold">a</emphasis>. Then the contents of bits
role="bold">b</emphasis>. Then the contents of bits
(8 &#8211; <emphasis>sb</emphasis>):(15 &#8211; <emphasis>sb</emphasis>) of the
halfword in byte elements <emphasis>i</emphasis>:<emphasis>i</emphasis>+1
of <emphasis role="bold">v</emphasis> are placed into byte element
<emphasis>i</emphasis> of <emphasis role="bold">r</emphasis>.</para>
<para>An example follows:
<informaltable frame="none">
<tgroup cols="17">
<colspec colname="c0" colwidth="10*" />
<colspec colname="c1" colwidth="10*" />
<colspec colname="c2" colwidth="10*" />
<colspec colname="c3" colwidth="10*" />
<colspec colname="c4" colwidth="10*" />
<colspec colname="c5" colwidth="10*" />
<colspec colname="c6" colwidth="10*" />
<colspec colname="c7" colwidth="10*" />
<colspec colname="c8" colwidth="10*" />
<colspec colname="c9" colwidth="10*" />
<colspec colname="c10" colwidth="10*" />
<colspec colname="c11" colwidth="10*" />
<colspec colname="c12" colwidth="10*" />
<colspec colname="c13" colwidth="10*" />
<colspec colname="c14" colwidth="10*" />
<colspec colname="c15" colwidth="10*" />
<colspec colname="c16" colwidth="10*" />
<tbody>
<row>
<entry align="center" valign="middle">
<para> <emphasis role="bold">a</emphasis> </para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
</row>
<row>
<entry align="center" valign="middle">
<para> <emphasis role="bold">b</emphasis> </para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>0E</para>
</entry>
<entry align="center" valign="middle">
<para>0D</para>
</entry>
<entry align="center" valign="middle">
<para>0C</para>
</entry>
<entry align="center" valign="middle">
<para>0B</para>
</entry>
<entry align="center" valign="middle">
<para>0A</para>
</entry>
<entry align="center" valign="middle">
<para>09</para>
</entry>
<entry align="center" valign="middle">
<para>08</para>
</entry>
<entry align="center" valign="middle">
<para>07</para>
</entry>
<entry align="center" valign="middle">
<para>06</para>
</entry>
<entry align="center" valign="middle">
<para>05</para>
</entry>
<entry align="center" valign="middle">
<para>04</para>
</entry>
<entry align="center" valign="middle">
<para>03</para>
</entry>
<entry align="center" valign="middle">
<para>02</para>
</entry>
<entry align="center" valign="middle">
<para>01</para>
</entry>
<entry align="center" valign="middle">
<para>00</para>
</entry>
</row>
<row>
<entry align="center" valign="middle">
<para> <emphasis role="bold">r</emphasis> </para>
</entry>
<entry align="center" valign="middle">
<para>00</para>
</entry>
<entry align="center" valign="middle">
<para>3C</para>
</entry>
<entry align="center" valign="middle">
<para>78</para>
</entry>
<entry align="center" valign="middle">
<para>F0</para>
</entry>
<entry align="center" valign="middle">
<para>E1</para>
</entry>
<entry align="center" valign="middle">
<para>C3</para>
</entry>
<entry align="center" valign="middle">
<para>87</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
<entry align="center" valign="middle">
<para>1E</para>
</entry>
<entry align="center" valign="middle">
<para>3C</para>
</entry>
<entry align="center" valign="middle">
<para>78</para>
</entry>
<entry align="center" valign="middle">
<para>F0</para>
</entry>
<entry align="center" valign="middle">
<para>E1</para>
</entry>
<entry align="center" valign="middle">
<para>C3</para>
</entry>
<entry align="center" valign="middle">
<para>87</para>
</entry>
<entry align="center" valign="middle">
<para>0F</para>
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
<para><emphasis role="bold">Endian considerations:</emphasis>
All bit and byte element numbers are specified in big-endian order.
This intrinsic is <emphasis>not</emphasis> endian-neutral.

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