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| 2 | 1 | equemene | <HEAD>
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| 3 | 1 | equemene | <TITLE>HPL_logsort HPL 2.0 Library Functions September 10, 2008</TITLE> |
| 4 | 1 | equemene | </HEAD>
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| 5 | 1 | equemene | |
| 6 | 1 | equemene | <BODY BGCOLOR="WHITE" TEXT = "#000000" LINK = "#0000ff" VLINK = "#000099" |
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| 8 | 1 | equemene | |
| 9 | 1 | equemene | <H1>Name</H1> |
| 10 | 1 | equemene | <B>HPL_logsort</B> Sort the processes in logarithmic order. |
| 11 | 1 | equemene | |
| 12 | 1 | equemene | <H1>Synopsis</H1> |
| 13 | 1 | equemene | <CODE>#include "hpl.h"</CODE><BR><BR> |
| 14 | 1 | equemene | <CODE>void</CODE> |
| 15 | 1 | equemene | <CODE>HPL_logsort(</CODE> |
| 16 | 1 | equemene | <CODE>const int</CODE> |
| 17 | 1 | equemene | <CODE>NPROCS</CODE>, |
| 18 | 1 | equemene | <CODE>const int</CODE> |
| 19 | 1 | equemene | <CODE>ICURROC</CODE>, |
| 20 | 1 | equemene | <CODE>int *</CODE> |
| 21 | 1 | equemene | <CODE>IPLEN</CODE>, |
| 22 | 1 | equemene | <CODE>int *</CODE> |
| 23 | 1 | equemene | <CODE>IPMAP</CODE>, |
| 24 | 1 | equemene | <CODE>int *</CODE> |
| 25 | 1 | equemene | <CODE>IPMAPM1</CODE> |
| 26 | 1 | equemene | <CODE>);</CODE> |
| 27 | 1 | equemene | |
| 28 | 1 | equemene | <H1>Description</H1> |
| 29 | 1 | equemene | <B>HPL_logsort</B> |
| 30 | 1 | equemene | computes an array IPMAP and its inverse IPMAPM1 that |
| 31 | 1 | equemene | contain the logarithmic sorted processes id with repect to the local |
| 32 | 1 | equemene | number of rows of U that they own. This is necessary to ensure that |
| 33 | 1 | equemene | the logarithmic spreading of U is optimal in terms of number of steps |
| 34 | 1 | equemene | and communication volume as well. In other words, the larget pieces |
| 35 | 1 | equemene | of U will be sent a minimal number of times. |
| 36 | 1 | equemene | |
| 37 | 1 | equemene | <H1>Arguments</H1> |
| 38 | 1 | equemene | <PRE>
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| 39 | 1 | equemene | NPROCS (global input) const int |
| 40 | 1 | equemene | On entry, NPROCS specifies the number of process rows in the |
| 41 | 1 | equemene | process grid. NPROCS is at least one. |
| 42 | 1 | equemene | </PRE>
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| 43 | 1 | equemene | <PRE>
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| 44 | 1 | equemene | ICURROC (global input) const int |
| 45 | 1 | equemene | On entry, ICURROC is the source process row. |
| 46 | 1 | equemene | </PRE>
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| 47 | 1 | equemene | <PRE>
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| 48 | 1 | equemene | IPLEN (global input/output) int * |
| 49 | 1 | equemene | On entry, IPLEN is an array of dimension NPROCS+1, such that |
| 50 | 1 | equemene | IPLEN[0] is 0, and IPLEN[i] contains the number of rows of U, |
| 51 | 1 | equemene | that process i-1 has. On exit, IPLEN[i] is the number of |
| 52 | 1 | equemene | rows of U in the processes before process IPMAP[i] after the |
| 53 | 1 | equemene | sort, with the convention that IPLEN[NPROCS] is the total |
| 54 | 1 | equemene | number of rows of the panel. In other words, IPLEN[i+1] - |
| 55 | 1 | equemene | IPLEN[i] is the number of rows of A that should be moved to |
| 56 | 1 | equemene | the process IPMAP[i]. IPLEN is such that the number of rows |
| 57 | 1 | equemene | of the source process row is IPLEN[1] - IPLEN[0], and the |
| 58 | 1 | equemene | remaining entries of this array are sorted so that the |
| 59 | 1 | equemene | quantities IPLEN[i+1]-IPLEN[i] are logarithmically sorted. |
| 60 | 1 | equemene | </PRE>
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| 61 | 1 | equemene | <PRE>
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| 62 | 1 | equemene | IPMAP (global output) int * |
| 63 | 1 | equemene | On entry, IPMAP is an array of dimension NPROCS. On exit, |
| 64 | 1 | equemene | array contains the logarithmic mapping of the processes. In |
| 65 | 1 | equemene | other words, IPMAP[myroc] is the corresponding sorted process |
| 66 | 1 | equemene | coordinate. |
| 67 | 1 | equemene | </PRE>
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| 68 | 1 | equemene | <PRE>
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| 69 | 1 | equemene | IPMAPM1 (global output) int * |
| 70 | 1 | equemene | On entry, IPMAPM1 is an array of dimension NPROCS. On exit, |
| 71 | 1 | equemene | this array contains the inverse of the logarithmic mapping |
| 72 | 1 | equemene | contained in IPMAP: IPMAPM1[ IPMAP[i] ] = i, for all i in |
| 73 | 1 | equemene | [0.. NPROCS) |
| 74 | 1 | equemene | </PRE>
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| 75 | 1 | equemene | |
| 76 | 1 | equemene | <H1>See Also</H1> |
| 77 | 1 | equemene | <A HREF="HPL_plindx1.html">HPL_plindx1</A>, |
| 78 | 1 | equemene | <A HREF="HPL_plindx10.html">HPL_plindx10</A>, |
| 79 | 1 | equemene | <A HREF="HPL_pdlaswp01N.html">HPL_pdlaswp01N</A>, |
| 80 | 1 | equemene | <A HREF="HPL_pdlaswp01T.html">HPL_pdlaswp01T</A>. |
| 81 | 1 | equemene | |
| 82 | 1 | equemene | </BODY>
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| 83 | 1 | equemene | </HTML> |