1 | SUBROUTINE ZTRMM(SIDE,UPLO,TRANSA,DIAG,M,N,ALPHA,A,LDA,B,LDB) |
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2 | * .. Scalar Arguments .. |
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3 | DOUBLE COMPLEX ALPHA |
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4 | INTEGER LDA,LDB,M,N |
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5 | CHARACTER DIAG,SIDE,TRANSA,UPLO |
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6 | * .. |
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7 | * .. Array Arguments .. |
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8 | DOUBLE COMPLEX A(LDA,*),B(LDB,*) |
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9 | * .. |
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10 | * |
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11 | * Purpose |
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12 | * ======= |
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13 | * |
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14 | * ZTRMM performs one of the matrix-matrix operations |
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15 | * |
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16 | * B := alpha*op( A )*B, or B := alpha*B*op( A ) |
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17 | * |
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18 | * where alpha is a scalar, B is an m by n matrix, A is a unit, or |
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19 | * non-unit, upper or lower triangular matrix and op( A ) is one of |
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20 | * |
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21 | * op( A ) = A or op( A ) = A' or op( A ) = conjg( A' ). |
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22 | * |
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23 | * Arguments |
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24 | * ========== |
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25 | * |
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26 | * SIDE - CHARACTER*1. |
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27 | * On entry, SIDE specifies whether op( A ) multiplies B from |
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28 | * the left or right as follows: |
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29 | * |
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30 | * SIDE = 'L' or 'l' B := alpha*op( A )*B. |
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31 | * |
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32 | * SIDE = 'R' or 'r' B := alpha*B*op( A ). |
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33 | * |
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34 | * Unchanged on exit. |
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35 | * |
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36 | * UPLO - CHARACTER*1. |
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37 | * On entry, UPLO specifies whether the matrix A is an upper or |
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38 | * lower triangular matrix as follows: |
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39 | * |
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40 | * UPLO = 'U' or 'u' A is an upper triangular matrix. |
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41 | * |
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42 | * UPLO = 'L' or 'l' A is a lower triangular matrix. |
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43 | * |
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44 | * Unchanged on exit. |
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45 | * |
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46 | * TRANSA - CHARACTER*1. |
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47 | * On entry, TRANSA specifies the form of op( A ) to be used in |
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48 | * the matrix multiplication as follows: |
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49 | * |
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50 | * TRANSA = 'N' or 'n' op( A ) = A. |
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51 | * |
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52 | * TRANSA = 'T' or 't' op( A ) = A'. |
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53 | * |
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54 | * TRANSA = 'C' or 'c' op( A ) = conjg( A' ). |
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55 | * |
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56 | * Unchanged on exit. |
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57 | * |
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58 | * DIAG - CHARACTER*1. |
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59 | * On entry, DIAG specifies whether or not A is unit triangular |
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60 | * as follows: |
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61 | * |
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62 | * DIAG = 'U' or 'u' A is assumed to be unit triangular. |
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63 | * |
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64 | * DIAG = 'N' or 'n' A is not assumed to be unit |
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65 | * triangular. |
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66 | * |
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67 | * Unchanged on exit. |
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68 | * |
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69 | * M - INTEGER. |
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70 | * On entry, M specifies the number of rows of B. M must be at |
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71 | * least zero. |
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72 | * Unchanged on exit. |
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73 | * |
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74 | * N - INTEGER. |
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75 | * On entry, N specifies the number of columns of B. N must be |
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76 | * at least zero. |
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77 | * Unchanged on exit. |
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78 | * |
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79 | * ALPHA - COMPLEX*16 . |
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80 | * On entry, ALPHA specifies the scalar alpha. When alpha is |
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81 | * zero then A is not referenced and B need not be set before |
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82 | * entry. |
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83 | * Unchanged on exit. |
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84 | * |
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85 | * A - COMPLEX*16 array of DIMENSION ( LDA, k ), where k is m |
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86 | * when SIDE = 'L' or 'l' and is n when SIDE = 'R' or 'r'. |
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87 | * Before entry with UPLO = 'U' or 'u', the leading k by k |
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88 | * upper triangular part of the array A must contain the upper |
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89 | * triangular matrix and the strictly lower triangular part of |
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90 | * A is not referenced. |
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91 | * Before entry with UPLO = 'L' or 'l', the leading k by k |
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92 | * lower triangular part of the array A must contain the lower |
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93 | * triangular matrix and the strictly upper triangular part of |
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94 | * A is not referenced. |
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95 | * Note that when DIAG = 'U' or 'u', the diagonal elements of |
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96 | * A are not referenced either, but are assumed to be unity. |
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97 | * Unchanged on exit. |
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98 | * |
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99 | * LDA - INTEGER. |
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100 | * On entry, LDA specifies the first dimension of A as declared |
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101 | * in the calling (sub) program. When SIDE = 'L' or 'l' then |
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102 | * LDA must be at least max( 1, m ), when SIDE = 'R' or 'r' |
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103 | * then LDA must be at least max( 1, n ). |
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104 | * Unchanged on exit. |
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105 | * |
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106 | * B - COMPLEX*16 array of DIMENSION ( LDB, n ). |
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107 | * Before entry, the leading m by n part of the array B must |
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108 | * contain the matrix B, and on exit is overwritten by the |
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109 | * transformed matrix. |
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110 | * |
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111 | * LDB - INTEGER. |
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112 | * On entry, LDB specifies the first dimension of B as declared |
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113 | * in the calling (sub) program. LDB must be at least |
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114 | * max( 1, m ). |
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115 | * Unchanged on exit. |
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116 | * |
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117 | * |
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118 | * Level 3 Blas routine. |
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119 | * |
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120 | * -- Written on 8-February-1989. |
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121 | * Jack Dongarra, Argonne National Laboratory. |
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122 | * Iain Duff, AERE Harwell. |
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123 | * Jeremy Du Croz, Numerical Algorithms Group Ltd. |
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124 | * Sven Hammarling, Numerical Algorithms Group Ltd. |
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125 | * |
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126 | * |
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127 | * .. External Functions .. |
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128 | LOGICAL LSAME |
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129 | EXTERNAL LSAME |
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130 | * .. |
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131 | * .. External Subroutines .. |
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132 | EXTERNAL XERBLA |
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133 | * .. |
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134 | * .. Intrinsic Functions .. |
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135 | INTRINSIC DCONJG,MAX |
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136 | * .. |
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137 | * .. Local Scalars .. |
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138 | DOUBLE COMPLEX TEMP |
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139 | INTEGER I,INFO,J,K,NROWA |
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140 | LOGICAL LSIDE,NOCONJ,NOUNIT,UPPER |
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141 | * .. |
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142 | * .. Parameters .. |
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143 | DOUBLE COMPLEX ONE |
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144 | PARAMETER (ONE= (1.0D+0,0.0D+0)) |
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145 | DOUBLE COMPLEX ZERO |
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146 | PARAMETER (ZERO= (0.0D+0,0.0D+0)) |
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147 | * .. |
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148 | * |
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149 | * Test the input parameters. |
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150 | * |
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151 | LSIDE = LSAME(SIDE,'L') |
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152 | IF (LSIDE) THEN |
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153 | NROWA = M |
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154 | ELSE |
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155 | NROWA = N |
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156 | END IF |
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157 | NOCONJ = LSAME(TRANSA,'T') |
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158 | NOUNIT = LSAME(DIAG,'N') |
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159 | UPPER = LSAME(UPLO,'U') |
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160 | * |
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161 | INFO = 0 |
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162 | IF ((.NOT.LSIDE) .AND. (.NOT.LSAME(SIDE,'R'))) THEN |
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163 | INFO = 1 |
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164 | ELSE IF ((.NOT.UPPER) .AND. (.NOT.LSAME(UPLO,'L'))) THEN |
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165 | INFO = 2 |
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166 | ELSE IF ((.NOT.LSAME(TRANSA,'N')) .AND. |
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167 | + (.NOT.LSAME(TRANSA,'T')) .AND. |
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168 | + (.NOT.LSAME(TRANSA,'C'))) THEN |
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169 | INFO = 3 |
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170 | ELSE IF ((.NOT.LSAME(DIAG,'U')) .AND. (.NOT.LSAME(DIAG,'N'))) THEN |
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171 | INFO = 4 |
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172 | ELSE IF (M.LT.0) THEN |
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173 | INFO = 5 |
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174 | ELSE IF (N.LT.0) THEN |
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175 | INFO = 6 |
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176 | ELSE IF (LDA.LT.MAX(1,NROWA)) THEN |
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177 | INFO = 9 |
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178 | ELSE IF (LDB.LT.MAX(1,M)) THEN |
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179 | INFO = 11 |
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180 | END IF |
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181 | IF (INFO.NE.0) THEN |
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182 | CALL XERBLA('ZTRMM ',INFO) |
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183 | RETURN |
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184 | END IF |
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185 | * |
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186 | * Quick return if possible. |
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187 | * |
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188 | IF (M.EQ.0 .OR. N.EQ.0) RETURN |
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189 | * |
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190 | * And when alpha.eq.zero. |
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191 | * |
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192 | IF (ALPHA.EQ.ZERO) THEN |
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193 | DO 20 J = 1,N |
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194 | DO 10 I = 1,M |
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195 | B(I,J) = ZERO |
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196 | 10 CONTINUE |
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197 | 20 CONTINUE |
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198 | RETURN |
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199 | END IF |
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200 | * |
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201 | * Start the operations. |
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202 | * |
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203 | IF (LSIDE) THEN |
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204 | IF (LSAME(TRANSA,'N')) THEN |
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205 | * |
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206 | * Form B := alpha*A*B. |
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207 | * |
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208 | IF (UPPER) THEN |
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209 | DO 50 J = 1,N |
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210 | DO 40 K = 1,M |
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211 | IF (B(K,J).NE.ZERO) THEN |
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212 | TEMP = ALPHA*B(K,J) |
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213 | DO 30 I = 1,K - 1 |
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214 | B(I,J) = B(I,J) + TEMP*A(I,K) |
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215 | 30 CONTINUE |
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216 | IF (NOUNIT) TEMP = TEMP*A(K,K) |
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217 | B(K,J) = TEMP |
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218 | END IF |
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219 | 40 CONTINUE |
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220 | 50 CONTINUE |
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221 | ELSE |
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222 | DO 80 J = 1,N |
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223 | DO 70 K = M,1,-1 |
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224 | IF (B(K,J).NE.ZERO) THEN |
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225 | TEMP = ALPHA*B(K,J) |
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226 | B(K,J) = TEMP |
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227 | IF (NOUNIT) B(K,J) = B(K,J)*A(K,K) |
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228 | DO 60 I = K + 1,M |
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229 | B(I,J) = B(I,J) + TEMP*A(I,K) |
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230 | 60 CONTINUE |
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231 | END IF |
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232 | 70 CONTINUE |
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233 | 80 CONTINUE |
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234 | END IF |
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235 | ELSE |
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236 | * |
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237 | * Form B := alpha*A'*B or B := alpha*conjg( A' )*B. |
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238 | * |
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239 | IF (UPPER) THEN |
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240 | DO 120 J = 1,N |
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241 | DO 110 I = M,1,-1 |
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242 | TEMP = B(I,J) |
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243 | IF (NOCONJ) THEN |
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244 | IF (NOUNIT) TEMP = TEMP*A(I,I) |
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245 | DO 90 K = 1,I - 1 |
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246 | TEMP = TEMP + A(K,I)*B(K,J) |
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247 | 90 CONTINUE |
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248 | ELSE |
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249 | IF (NOUNIT) TEMP = TEMP*DCONJG(A(I,I)) |
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250 | DO 100 K = 1,I - 1 |
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251 | TEMP = TEMP + DCONJG(A(K,I))*B(K,J) |
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252 | 100 CONTINUE |
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253 | END IF |
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254 | B(I,J) = ALPHA*TEMP |
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255 | 110 CONTINUE |
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256 | 120 CONTINUE |
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257 | ELSE |
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258 | DO 160 J = 1,N |
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259 | DO 150 I = 1,M |
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260 | TEMP = B(I,J) |
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261 | IF (NOCONJ) THEN |
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262 | IF (NOUNIT) TEMP = TEMP*A(I,I) |
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263 | DO 130 K = I + 1,M |
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264 | TEMP = TEMP + A(K,I)*B(K,J) |
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265 | 130 CONTINUE |
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266 | ELSE |
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267 | IF (NOUNIT) TEMP = TEMP*DCONJG(A(I,I)) |
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268 | DO 140 K = I + 1,M |
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269 | TEMP = TEMP + DCONJG(A(K,I))*B(K,J) |
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270 | 140 CONTINUE |
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271 | END IF |
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272 | B(I,J) = ALPHA*TEMP |
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273 | 150 CONTINUE |
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274 | 160 CONTINUE |
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275 | END IF |
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276 | END IF |
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277 | ELSE |
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278 | IF (LSAME(TRANSA,'N')) THEN |
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279 | * |
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280 | * Form B := alpha*B*A. |
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281 | * |
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282 | IF (UPPER) THEN |
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283 | DO 200 J = N,1,-1 |
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284 | TEMP = ALPHA |
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285 | IF (NOUNIT) TEMP = TEMP*A(J,J) |
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286 | DO 170 I = 1,M |
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287 | B(I,J) = TEMP*B(I,J) |
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288 | 170 CONTINUE |
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289 | DO 190 K = 1,J - 1 |
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290 | IF (A(K,J).NE.ZERO) THEN |
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291 | TEMP = ALPHA*A(K,J) |
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292 | DO 180 I = 1,M |
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293 | B(I,J) = B(I,J) + TEMP*B(I,K) |
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294 | 180 CONTINUE |
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295 | END IF |
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296 | 190 CONTINUE |
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297 | 200 CONTINUE |
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298 | ELSE |
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299 | DO 240 J = 1,N |
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300 | TEMP = ALPHA |
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301 | IF (NOUNIT) TEMP = TEMP*A(J,J) |
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302 | DO 210 I = 1,M |
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303 | B(I,J) = TEMP*B(I,J) |
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304 | 210 CONTINUE |
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305 | DO 230 K = J + 1,N |
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306 | IF (A(K,J).NE.ZERO) THEN |
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307 | TEMP = ALPHA*A(K,J) |
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308 | DO 220 I = 1,M |
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309 | B(I,J) = B(I,J) + TEMP*B(I,K) |
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310 | 220 CONTINUE |
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311 | END IF |
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312 | 230 CONTINUE |
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313 | 240 CONTINUE |
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314 | END IF |
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315 | ELSE |
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316 | * |
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317 | * Form B := alpha*B*A' or B := alpha*B*conjg( A' ). |
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318 | * |
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319 | IF (UPPER) THEN |
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320 | DO 280 K = 1,N |
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321 | DO 260 J = 1,K - 1 |
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322 | IF (A(J,K).NE.ZERO) THEN |
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323 | IF (NOCONJ) THEN |
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324 | TEMP = ALPHA*A(J,K) |
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325 | ELSE |
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326 | TEMP = ALPHA*DCONJG(A(J,K)) |
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327 | END IF |
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328 | DO 250 I = 1,M |
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329 | B(I,J) = B(I,J) + TEMP*B(I,K) |
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330 | 250 CONTINUE |
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331 | END IF |
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332 | 260 CONTINUE |
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333 | TEMP = ALPHA |
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334 | IF (NOUNIT) THEN |
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335 | IF (NOCONJ) THEN |
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336 | TEMP = TEMP*A(K,K) |
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337 | ELSE |
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338 | TEMP = TEMP*DCONJG(A(K,K)) |
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339 | END IF |
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340 | END IF |
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341 | IF (TEMP.NE.ONE) THEN |
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342 | DO 270 I = 1,M |
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343 | B(I,K) = TEMP*B(I,K) |
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344 | 270 CONTINUE |
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345 | END IF |
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346 | 280 CONTINUE |
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347 | ELSE |
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348 | DO 320 K = N,1,-1 |
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349 | DO 300 J = K + 1,N |
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350 | IF (A(J,K).NE.ZERO) THEN |
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351 | IF (NOCONJ) THEN |
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352 | TEMP = ALPHA*A(J,K) |
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353 | ELSE |
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354 | TEMP = ALPHA*DCONJG(A(J,K)) |
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355 | END IF |
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356 | DO 290 I = 1,M |
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357 | B(I,J) = B(I,J) + TEMP*B(I,K) |
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358 | 290 CONTINUE |
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359 | END IF |
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360 | 300 CONTINUE |
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361 | TEMP = ALPHA |
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362 | IF (NOUNIT) THEN |
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363 | IF (NOCONJ) THEN |
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364 | TEMP = TEMP*A(K,K) |
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365 | ELSE |
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366 | TEMP = TEMP*DCONJG(A(K,K)) |
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367 | END IF |
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368 | END IF |
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369 | IF (TEMP.NE.ONE) THEN |
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370 | DO 310 I = 1,M |
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371 | B(I,K) = TEMP*B(I,K) |
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372 | 310 CONTINUE |
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373 | END IF |
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374 | 320 CONTINUE |
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375 | END IF |
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376 | END IF |
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377 | END IF |
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378 | * |
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379 | RETURN |
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380 | * |
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381 | * End of ZTRMM . |
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382 | * |
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383 | END |
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