--------------------------------------------------------------------------------------
                      [ENHANCED] VFP 9.0 FIX - SYS(9072) ENABLES OR DISABLES FAST STRING FUNCTIONS
                                 January 2026
                 --------------------------------------------------------------------------------------
                                     CCB



1. THE SYS(9072) FUNCTION:

     SYS(9072) - Enables or disables fast string functions

     Enables or disables fast string functions.

     SYS(9072 [, 0 | 1 | 2])

     Parameters
     0
     Disables fast string functions.
     0 is the startup default for Visual FoxPro Advanced 10.0 and 10.1.
     1
     Enables fast string functions if the functions are not called in SQL statements,
     and disables fast string functions if the functions are called in SQL statements.
     2
     Enables fast string functions.
     2 is the startup default for Visual FoxPro Advanced 10.2 or later.

     Return Value
     Character

     Remarks
     If we enable fast string functions in Visual FoxPro Advanced, it is the same as enabling the SYS(9900,9010-9073) functions,
     Visual FoxPro Advanced will be faster.

     There are some test results:

     LEN(): 10 MB
     LOOP COUNT: 10000
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9010-9073) Functions                                              | Optimized Parameters | Disable  | Enable  |  Rate    |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9010,0|1) - Enables or disables fast SUBSTR(), SUBSTRC() functions.              | p1    |     32   |  0.02   | 1500 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9011,0|1) - Enables or disables fast LEFT(), LEFTC() functions.                  | p1    |     36   |  0.01   | 3600 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9012,0|1) - Enables or disables fast RIGHT(), RIGHTC() functions.                | p1    |     32   |  0.02   | 1500 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9013,0|1) - Enables or disables fast UPPER() function.                           | p1    |    270   |   250   |  1.1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9014,0|1) - Enables or disables fast LOWER() function.                           | p1    |    270   |   250   |  1.1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9015,0|1) - Enables or disables fast PROPER() function.                          | p1    |    340   |   420   |  0.8 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9016,0|1) - Enables or disables fast LEN(), LENC() functions.                    | p1    |     63   |  0.01   | 6300 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9017,0|1) - Enables or disables fast EMPTY() function.                           | p1    |     52   |  0.01   | 5200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9018,0|1) - Enables or disables fast VARTYPE() function.                         | p1    |     52   |  0.01   | 5200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9019,0|1) - Enables or disables fast LTRIM() function.                           | p1    |    111   |    87   |  1.3 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9020,0|1) - Enables or disables fast RTRIM(), TRIM() functions.                  | p1    |     93   |    87   |  1.1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9021,0|1) - Enables or disables fast ALLTRIM() function.                         | p1    |    110   |    87   |  1.3 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9022,0|1) - Enables or disables fast PADL(), PADR(), PADC() functions.           | p1    |    108   |   107   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9023,0|1) - Enables or disables fast STUFF(), STUFFC() functions.                | p1    |     81   |    77   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9024,0|1|2) - Enables or disables fast CHRTRAN(), CHRTRANC() functions.          | p1    |    554   | 492|492 |  1.1:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9025,0|1|2) - Enables or disables fast STRTRAN() function.                       | p1    |  51000|50000|1950  |  25:25:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9026,0|1|2) - Enables or disables fast AT(), AT_C(), ATC(), ATCC() functions.    | p2    |     16   |0.02|0.02|  800:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9027,0|1|2) - Enables or disables fast RAT(), RATC() functions.                  | p2    |     20   |0.02|0.02| 1000:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9028,0|1|2) - Enables or disables fast ATLINE(), ATCLINE(), RATLINE() functions. | p2    |     19   |0.02|0.02|  950:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9029,0|1|2) - Enables or disables fast OCCURS() function.                        | p2    |   2100   |1900|1900|  1.1:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9030,0|1) - Enables or disables fast GETWORDCOUNT() function.                    | p1    |   4100   |  3900   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9031,0|1) - Enables or disables fast GETWORDNUM() function.                      | p1    |     27   |  0.01   | 2700 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9032,0|1) - Enables or disables fast TRANSFORM() function.                       | p1    |     21   |  0.03   |  700 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9033,0|1|2) - Enables or disables fast TEXTMERGE() function.                     | p1    |    167   | 147|147 |  1.1:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9034,0|1|2) - Enables or disables fast STREXTRACT() function.                    | p1    |   1800   |1800|1800|    1:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9035,0|1) - Enables or disables fast STRCONV() function.                         | p1    |    207   |   205   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9036,0|1) - Enables or disables fast STRTOFILE() function.                       | p1    |    117   |    67   |  1.7 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9037,0|1) - Enables or disables fast SYS(2007) function.                         | p1    |    877   |   866   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9038,0|1) - Enables or disables fast TYPE() function.                            | p1    |     16   |  0.01   | 1600 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9039,0|1) - Enables or disables fast FWRITE(), FPUTS() functions.                | p2    |     62   |    19   |    3 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9040,0|1) - Enables or disables fast XMLTOCURSOR() function.                     | p1    |  47550   | 47220   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9041,0|1) - Enables or disables fast ALINES() function.                          | p2    |     38   |    36   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9042,0|1) - Enables or disables fast ISNULL() function.                          | p1    |     42   |  0.01   | 4200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9043,0|1) - Enables or disables fast ISBLANK() function.                         | p1    |     42   |  0.01   | 4200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9044,0|1) - Enables or disables fast ISALPHA() function.                         | p1    |     43   |  0.01   | 4300 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9045,0|1) - Enables or disables fast ISDIGIT() function.                         | p1    |     43   |  0.01   | 4300 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9046,0|1) - Enables or disables fast ISUPPER() function.                         | p1    |     43   |  0.01   | 4300 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9047,0|1) - Enables or disables fast ISLOWER() function.                         | p1    |     43   |  0.01   | 4300 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9048,0|1) - Enables or disables fast ISLEADBYTE() function.                      | p1    |     43   |  0.01   | 4300 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9049,0|1) - Enables or disables fast NVL() function.                             | p1    |     32   |    31   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9050,0|1) - Enables or disables fast EVL() function.                             | p1    |     34   |    32   |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9051,0|1) - Enables or disables fast BETWEEN() function.                         | p1    |     42   |  0.01   | 4200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9052,0|1) - Enables or disables fast INLIST() function.                          | p1    |     42   |  0.01   | 4200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9053,0|1) - Enables or disables fast LIKE(), LIKEC() functions.                  | p2    |     42   |  0.01   | 4200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9054,0|1|2) - Enables or disables fast $ operator.                               | p1,p2 |     16   |0.01|0.01| 1600:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9055,0|1) - Enables or disables fast + operator.                                 | p1,p2 |     53   |    35   |  1.5 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9056,0|1) - Enables or disables fast - operator.                                 | p1,p2 |     50   |    34   |  1.5 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9057,0|1) - Enables or disables fast < operator.                                 | p1,p2 |     42   |  0.01   | 4200 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9058,0|1) - Enables or disables fast <= operator.                                | p1,p2 |     39   |  0.01   | 3900 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9059,0|1) - Enables or disables fast != operator.                                | p1,p2 |     40   |  0.01   | 4000 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9060,0|1) - Enables or disables fast = operator.                                 | p1,p2 |     44   |  0.01   | 4400 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9061,0|1) - Enables or disables fast > operator.                                 | p1,p2 |     45   |  0.01   | 4500 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9062,0|1) - Enables or disables fast >= operator.                                | p1,p2 |     44   |  0.01   | 4400 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9063,0|1) - Enables or disables fast == operator.                                | p1,p2 |     16   |  0.01   | 1600 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9064,0|1) - Enables or disables fast REPLICATE() function.                       | p1    |    200   |   168   |  1.2 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9065,0|1) - Enables or disables fast += operator.                                        |  0.00275 | 0.00139 |    2 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9066,0|1) - Enables or disables fast -= operator.                                        |  0.00275 | 0.00139 |    2 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9067,0|1) - Enables or disables fast *= operator.                                        |  0.00632 | 0.00632 |    1 : 1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9068,0|1) - Enables or disables fast /= operator.                                        |    ---   |   ---   |    ---   |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9069,0|1) - Enables or disables fast %= operator.                                        |    ---   |   ---   |    ---   |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9070,0|1|2) - Enables or disables fast memcpy(), memmove() functions (SUBSTR()).         |     15   |  15|11  |1.3:1.3:1 |
     | SYS(9900,9070,0|1|2) - Enables or disables fast memcpy(), memmove() functions (LEFT()).           |     15   |  15|11  |1.3:1.3:1 |
     | SYS(9900,9070,0|1|2) - Enables or disables fast memcpy(), memmove() functions (RIGHT()).          |     15   |  15|11  |1.3:1.3:1 |
     | SYS(9900,9070,0|1|2) - Enables or disables fast memcpy(), memmove() functions (LEN()).            |     40   |  40|32  |1.3:1.3:1 |
     | SYS(9900,9070,0|1|2) - Enables or disables fast memcpy(), memmove() functions (STRTRAN()).        |  48000|48000|48000 |    1:1:1 |
     | SYS(9900,9070,0|1|2) - Enables or disables fast memcpy(), memmove() functions (STREXTRACT()).     |   1850   |1850|1850|    1:1:1 |
     | SYS(9900,9070,0|1|2) - Enables or disables fast memcpy(), memmove() functions (XMLTOCURSOR()).    |  15500|15100|15100 |    1:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9071,0|1|2) - Enables or disables fast strchr(), strchri() functions (CHRTRAN()).        |    583   | 555|550 |    1:1:1 |
     | SYS(9900,9071,0|1|2) - Enables or disables fast strchr(), strchri() functions (GETWORDCOUNT()).   |   2560   | 660|690 |  3.7:1:1 |
     | SYS(9900,9071,0|1|2) - Enables or disables fast strchr(), strchri() functions (GETWORDNUM()).     |     19   |  19|19  |    1:1:1 |
     | SYS(9900,9071,0|1|2) - Enables or disables fast strchr(), strchri() functions (TEXTMERGE()).      |    137   |  94|83  |  1.6:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9072,0|1|2) - Enables or disables fast strstr(), strstri() functions (STRTRAN()).        |  51200|50000|50000 |    1:1:1 |
     | SYS(9900,9072,0|1|2) - Enables or disables fast strstr(), strstri() functions (ATLINE()).         |     19   |  19|19  |    1:1:1 |
     | SYS(9900,9072,0|1|2) - Enables or disables fast strstr(), strstri() functions (OCCURS()).         |   1900   | 160|160 |   12:1:1 |
     | SYS(9900,9072,0|1|2) - Enables or disables fast strstr(), strstri() functions (STREXTRACT()).     |   1850   |  65|65  |   28:1:1 |
     -------------------------------------------------------------------------------------------------------------------------------------
     | SYS(9900,9073,0|1|2) - Enables or disables fast strlen() function.                                |    ---   |    ---  |    ---   |
     -------------------------------------------------------------------------------------------------------------------------------------


2. CAUSE:

     There are some BUGs in the following code.


3. RESOLUTION:

     We can write some code to fix the BUG.

     Fun529fca :: ; proc near
             push ebp                                                        ;0x00529fca :        55
             mov ebp , esp                                                   ;0x00529fcb :        8bec
             pushd 0FFFFFFFFh                                                ;0x00529fcd :        6aff
             pushd offset Data922268                                                  ;0x00529fcf :        6868229200
             pushd offset Label9160f9                                                  ;0x00529fd4 :        68f9609100
             mov eax ,  dword ptr fs:[00h]                                   ;0x00529fd9 :        64a100000000
             push eax                                                        ;0x00529fdf :        50
             mov  dword ptr fs:[00h] , esp                                   ;0x00529fe0 :        64892500000000
             push ecx                                                        ;0x00529fe7 :        51
             push ecx                                                        ;0x00529fe8 :        51
             mov eax , 02FBCh                                                ;0x00529fe9 :        b8bc2f0000
             call Fun42c118                                                  ;0x00529fee :        e82521f0ff
             mov eax ,  dword ptr [ Data937090 ]                             ;0x00529ff3 :        a190729300
             mov  dword ptr [ ebp - 28 ] , eax                               ;0x00529ff8 :        8945e4
             push ebx                                                        ;0x00529ffb :        53
             push esi                                                        ;0x00529ffc :        56
             push edi                                                        ;0x00529ffd :        57
             mov  dword ptr [ ebp - 24 ] , esp                               ;0x00529ffe :        8965e8
             xor edi , edi                                                   ;0x0052a001 :        33ff
             mov  dword ptr [ ebp + 0FFFFD114h ] , edi                       ;0x0052a003 :        89bd14d1ffff
             push edi                                                        ;0x0052a009 :        57
             pushd 02710h                                                    ;0x0052a00a :        6810270000
             push edi                                                        ;0x0052a00f :        57
             mov  ebx , dword ptr [ ebp + 8 ]                                ;0x0052a010 :        8b5d08
             mov eax , ebx                                                   ;0x0052a013 :        8bc3
             call Fun529bc5                                                  ;0x0052a015 :        e8abfbffff
             mov  dword ptr [ ebp + 0FFFFD0E4h ] , eax                       ;0x0052a01a :        8985e4d0ffff
             mov  dword ptr [ ebp + 0FFFFD10Ch ] , edi                       ;0x0052a020 :        89bd0cd1ffff
             lea ecx ,  dword ptr [ ebp + 0FFFFFDE0h ]                       ;0x0052a026 :        8d8de0fdffff
             mov  dword ptr [ ebp + 0FFFFD100h ] , ecx                       ;0x0052a02c :        898d00d1ffff
             mov  byte ptr [ ebp + 0FFFFFDE0h ] , 00h                        ;0x0052a032 :        c685e0fdffff00
             movsx eax , ax                                                  ;0x0052a039 :        0fbfc0


     ;
     ;                 ---------------------------------------------------------------------------
     ;                      VFP 9.0 FIX - SYS(9072) ENABLES OR DISABLES FAST STRING FUNCTIONS
     ;                                December 2021
     ;                 ---------------------------------------------------------------------------
     ;                                     CCB
     ;
     ; SYS(9072) - Enables or disables fast string functions.
     ;
     ; 2021/12/8, by ccb
     ;

             cmp eax,9072
             je vfpa_sys9072_start


             pushd 064h                                                      ;0x0052a03c :        6a64
             pop esi                                                         ;0x0052a03e :        5e
             cmp eax , esi                                                   ;0x0052a03f :        3bc6
             jle Label52a0d0                                                 ;0x0052a041 :        0f8e89067000
             mov ecx , 07EAh                                                 ;0x0052a047 :        b9ea070000
             cmp eax , ecx                                                   ;0x0052a04c :        3bc1
             jg Label52a164                                                  ;0x0052a04e :        0f8f10010000
             je Label609b33                                                  ;0x0052a054 :        0f84d9fa0d00
             mov ecx , 04F6h                                                 ;0x0052a05a :        b9f6040000
             cmp eax , ecx                                                   ;0x0052a05f :        3bc1
             jle Label52b6e0                                                 ;0x0052a061 :        0f8e79160000
             mov ecx , 07DBh                                                 ;0x0052a067 :        b9db070000
             cmp eax , ecx                                                   ;0x0052a06c :        3bc1
             jg Label51f355                                                  ;0x0052a06e :        0f8fe152ffff
             je Label609700                                                  ;0x0052a074 :        0f8486f60d00
             add ecx , 0FFFFFFF9h                                            ;0x0052a07a :        83c1f9
             cmp eax , ecx                                                   ;0x0052a07d :        3bc1
             jg Label4a4938                                                  ;0x0052a07f :        0f8fb3a8f7ff
             je Label4f6b07                                                  ;0x0052a085 :        0f847ccafcff
             sub eax , 04F7h                                                 ;0x0052a08b :        2df7040000
             je Label60951e                                                  ;0x0052a090 :        0f8488f40d00
             dec eax                                                         ;0x0052a096 :        48
             je Label60950f                                                  ;0x0052a097 :        0f8472f40d00
             sub eax , 0E4h                                                  ;0x0052a09d :        2de4000000
             je Label609492                                                  ;0x0052a0a2 :        0f84eaf30d00
             sub eax , 01F4h                                                 ;0x0052a0a8 :        2df4010000
             jne Label462026                                                 ;0x0052a0ad :        0f85737ff3ff
             lea eax ,  dword ptr [ ebp + 0FFFFFDE0h ]                       ;0x0052a0b3 :        8d85e0fdffff
             push eax                                                        ;0x0052a0b9 :        50
             push  dword ptr [ ebp + 12 ]                                    ;0x0052a0ba :        ff750c
             mov edx , ebx                                                   ;0x0052a0bd :        8bd3
             call Fun4dc923                                                  ;0x0052a0bf :        e85f28fbff


4. APPLIES TO:

     VFP 10 (VFP Advanced)


5. REFERENCE WEBSITES:

     1, baiyujia.com:
     http://www.baiyujia.com
     http://www.baiyujia.com/vfpdocuments/f_vfp9fix95.asp
     http://www.baiyujia.com/vfpdocuments/f_vfp9fix96.asp
     http://www.baiyujia.com/vfpdocuments/f_vfp9fix199.asp
     http://www.baiyujia.com/vfpdocuments/f_vfp9fix233.asp
     http://www.baiyujia.com/vfpdocuments/f_vfp9fix400.asp

     2, west-wind.com:
     https://west-wind.com/wconnect/weblog/ShowEntry.blog?id=962
     https://west-wind.com/wconnect/weblog/ShowEntry.blog?id=882

     3, stevenblack.com:
     http://stevenblack.com/articles/text-and-string-handling-in-VFP/

     4, agner.org:
     https://www.agner.org/optimize/


6. OTHER:

     For reference only, there is no guarantees.

     Any questions or suggestions, please send me an email at ccb2000@163.com.