| 1 |
C $Header: /u/gcmpack/MITgcm/eesupp/src/global_max.F,v 1.11 2004/03/27 03:51:51 edhill Exp $ |
| 2 |
C $Name: $ |
| 3 |
|
| 4 |
#include "CPP_EEOPTIONS.h" |
| 5 |
|
| 6 |
C-- File global_max.F: Routines that perform global max reduction on an array |
| 7 |
C of thread values. |
| 8 |
C Contents |
| 9 |
C o GLOBAL_MAX_R4 |
| 10 |
C o GLOBAL_MAX_R8 |
| 11 |
|
| 12 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 13 |
CBOP |
| 14 |
C !ROUTINE: GLOBAL_MAX_R4 |
| 15 |
|
| 16 |
C !INTERFACE: |
| 17 |
SUBROUTINE GLOBAL_MAX_R4( |
| 18 |
U maxPhi, |
| 19 |
I myThid ) |
| 20 |
|
| 21 |
C !DESCRIPTION: |
| 22 |
C *==========================================================* |
| 23 |
C | SUBROUTINE GLOBAL\_MAX\_R4 |
| 24 |
C | o Handle max for real*4 data. |
| 25 |
C *==========================================================* |
| 26 |
C | Perform max on array of one value per thread and then |
| 27 |
C | max result of all the processes. |
| 28 |
C | Notes |
| 29 |
C | ===== |
| 30 |
C | Within a process only one thread does the max, each |
| 31 |
C | thread is assumed to have already maxed its local data. |
| 32 |
C | The same thread also does the inter-process max for |
| 33 |
C | example with MPI and then writes the result into a shared |
| 34 |
C | location. All threads wait until the max is avaiailable. |
| 35 |
C *==========================================================* |
| 36 |
|
| 37 |
C !USES: |
| 38 |
IMPLICIT NONE |
| 39 |
|
| 40 |
C == Global data == |
| 41 |
#include "SIZE.h" |
| 42 |
#include "EEPARAMS.h" |
| 43 |
#include "EESUPPORT.h" |
| 44 |
#include "GLOBAL_MAX.h" |
| 45 |
|
| 46 |
C !INPUT/OUTPUT PARAMETERS: |
| 47 |
C == Routine arguments == |
| 48 |
C maxPhi :: Result of max. |
| 49 |
C myThid :: My thread id. |
| 50 |
Real*4 maxPhi |
| 51 |
INTEGER myThid |
| 52 |
|
| 53 |
C !LOCAL VARIABLES: |
| 54 |
C == Local variables == |
| 55 |
C I :: Loop counters |
| 56 |
C mpiRC :: MPI return code |
| 57 |
INTEGER I |
| 58 |
Real*4 tmp |
| 59 |
#ifdef ALLOW_USE_MPI |
| 60 |
INTEGER mpiRC |
| 61 |
#endif /* ALLOW_USE_MPI */ |
| 62 |
CEOP |
| 63 |
|
| 64 |
C-- write local max into array |
| 65 |
phiGMR4(1,myThid) = maxPhi |
| 66 |
|
| 67 |
C-- Can not start until everyone is ready |
| 68 |
CALL BAR2( myThid ) |
| 69 |
|
| 70 |
C-- Max within the process first |
| 71 |
_BEGIN_MASTER( myThid ) |
| 72 |
tmp = phiGMR4(1,1) |
| 73 |
DO I=2,nThreads |
| 74 |
tmp = MAX(tmp,phiGMR4(1,I)) |
| 75 |
ENDDO |
| 76 |
maxPhi = tmp |
| 77 |
#ifdef ALLOW_USE_MPI |
| 78 |
#ifndef ALWAYS_USE_MPI |
| 79 |
IF ( usingMPI ) THEN |
| 80 |
#endif |
| 81 |
CALL MPI_Allreduce(tmp,maxPhi,1,MPI_REAL,MPI_MAX, |
| 82 |
& MPI_COMM_MODEL,mpiRC) |
| 83 |
#ifndef ALWAYS_USE_MPI |
| 84 |
ENDIF |
| 85 |
#endif |
| 86 |
#endif /* ALLOW_USE_MPI */ |
| 87 |
phiGMR4(1,0) = maxPhi |
| 88 |
_END_MASTER( myThid ) |
| 89 |
C-- |
| 90 |
CALL BAR2( myThid ) |
| 91 |
|
| 92 |
C-- set result for every process |
| 93 |
maxPhi = phiGMR4(1,0) |
| 94 |
|
| 95 |
RETURN |
| 96 |
END |
| 97 |
|
| 98 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 99 |
CBOP |
| 100 |
C !ROUTINE: GLOBAL_MAX_R8 |
| 101 |
|
| 102 |
C !INTERFACE: |
| 103 |
SUBROUTINE GLOBAL_MAX_R8( |
| 104 |
O maxPhi, |
| 105 |
I myThid ) |
| 106 |
|
| 107 |
C !DESCRIPTION: |
| 108 |
C *==========================================================* |
| 109 |
C | SUBROUTINE GLOBAL\_MAX\_R8 |
| 110 |
C | o Handle max for real*8 data. |
| 111 |
C *==========================================================* |
| 112 |
C | Perform max on array of one value per thread and then |
| 113 |
C | max result of all the processes. |
| 114 |
C | Notes |
| 115 |
C | ===== |
| 116 |
C | Within a process only one thread does the max, each |
| 117 |
C | thread is assumed to have already maxed its local data. |
| 118 |
C | The same thread also does the inter-process max for |
| 119 |
C | example with MPI and then writes the result into a shared |
| 120 |
C | location. All threads wait until the max is avaiailable. |
| 121 |
C *==========================================================* |
| 122 |
|
| 123 |
C !USES: |
| 124 |
IMPLICIT NONE |
| 125 |
|
| 126 |
C === Global data === |
| 127 |
#include "SIZE.h" |
| 128 |
#include "EEPARAMS.h" |
| 129 |
#include "EESUPPORT.h" |
| 130 |
#include "GLOBAL_MAX.h" |
| 131 |
|
| 132 |
C !INPUT/OUTPUT PARAMETERS: |
| 133 |
C === Routine arguments === |
| 134 |
C maxPhi :: Result of max. |
| 135 |
C myThid :: My thread id. |
| 136 |
Real*8 maxPhi |
| 137 |
INTEGER myThid |
| 138 |
|
| 139 |
C !LOCAL VARIABLES: |
| 140 |
C === Local variables === |
| 141 |
C I :: Loop counters |
| 142 |
C mpiRC :: MPI return code |
| 143 |
INTEGER I |
| 144 |
Real*8 tmp |
| 145 |
#ifdef ALLOW_USE_MPI |
| 146 |
INTEGER mpiRC |
| 147 |
#endif /* ALLOW_USE_MPI */ |
| 148 |
CEOP |
| 149 |
|
| 150 |
C-- write local max into array |
| 151 |
phiGMR8(1,myThid) = maxPhi |
| 152 |
|
| 153 |
C-- Can not start until everyone is ready |
| 154 |
CALL BAR2( myThid ) |
| 155 |
|
| 156 |
C-- Max within the process first |
| 157 |
_BEGIN_MASTER( myThid ) |
| 158 |
tmp = phiGMR8(1,1) |
| 159 |
DO I=2,nThreads |
| 160 |
tmp = MAX(tmp,phiGMR8(1,I)) |
| 161 |
ENDDO |
| 162 |
maxPhi = tmp |
| 163 |
#ifdef ALLOW_USE_MPI |
| 164 |
#ifndef ALWAYS_USE_MPI |
| 165 |
IF ( usingMPI ) THEN |
| 166 |
#endif |
| 167 |
CALL MPI_Allreduce(tmp,maxPhi,1,MPI_DOUBLE_PRECISION,MPI_MAX, |
| 168 |
& MPI_COMM_MODEL,mpiRC) |
| 169 |
#ifndef ALWAYS_USE_MPI |
| 170 |
ENDIF |
| 171 |
#endif |
| 172 |
#endif /* ALLOW_USE_MPI */ |
| 173 |
C-- Write solution to place where all threads can see it |
| 174 |
phiGMR8(1,0) = maxPhi |
| 175 |
_END_MASTER( myThid ) |
| 176 |
|
| 177 |
C-- Do not leave until we are sure that the max is done |
| 178 |
CALL BAR2( myThid ) |
| 179 |
|
| 180 |
C-- set result for every process |
| 181 |
maxPhi = phiGMR8(1,0) |
| 182 |
|
| 183 |
RETURN |
| 184 |
END |
Parent Directory
| 
Revision Log
| 
Revision Graph