SGI Varsity Update 1998 August

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- 1 - 7.2.1 MIPSpro Fortran 90 Front End Release Notes - 2 - 5. _N_e_w__F_e_a_t_u_r_e_s__o_f__T_h_i_s__R_e_l_e_a_s_e This chapter contains the differences between this release and the 7.2 release of the MIPSpro Fortran 90 compiler. It also summarizes the differences between the 7.2 release and the 7.1 release of MIPSpro Fortran 90. 5.1 _N_e_w__F_e_a_t_u_r_e_s__i_n__M_I_P_S_p_r_o__7_._2_._1 5.1.1 _O_p_e_n_M_P__S_u_p_p_o_r_t MIPSpro Fortran 90 7.2.1 now supports the OpenMP application programming interface (API) when used in conjunction with the -_m_p flag. The -_m_p flag enables the processing of the parallel (MP) directives, including the original SGI/PCF directives as well as the OpenMP directives. To selectively disable one or the other set of directives, add the following -MP option group flag to the -_m_p flag: -MP:old_mp=off disable processing of the original SGI/PCF directives, but retain the processing of OpenMP directives. -MP:open_mp=off disable processing of the OpenMP directives, but retain processing of the original SGI/PCF directives. You must have libmp from patchSG0002773 installed if you plan to work with OpenMP support. For more information about OpenMP support in MIPSpro Fortran 90, please refer to the MIPSPro 7 Fortran 90 Commands and Directives Reference Manual. For general information about OpenMP please refer to the following web page: http://www.openmp.org/ - 3 - 5.1.2 _I_G_N_O_R_E___T_Y_P_E___A_N_D___K_I_N_D__D_i_r_e_c_t_i_v_e The directive causes the compiler to ignore type and kind of the specified dummy argument when resolving a generic interface name to a specific procedure. The syntax for the directive is given below. The compiler also ignores type and kind on the specified dummy argument[s] when checking all the specific interfaces in a generic interface for ambiguous interfaces. Use of this directive allows different invocations of a procedure to pass different actual argument types to the same dummy argument. Use of this directive effectively turns off the strong type checking for the specified dummy argument(s) when resolving interfaces. This is useful when a single routine (a copy routine for example) is used with different argument types. !DIR$ IGNORE_TYPE_AND_KIND [darg_name[,darg_name]] If nothing is specified following the directive, the directive applies to all dummy arguments specified in the procedure. Otherwise, the directive applies just to the specified dummy arguments. 5.1.3 -_a_u_t_o__u_s_e _m_o_d_u_l_e__n_a_m_e[,_m_o_d_u_l_e__n_a_m_e] _c_o_m_m_a_n_d_l_i_n_e _o_p_t_i_o_n When the user specifies this on the commandline, it is the same as if the user specified USE module_name in every program unit, module procedure, internal procedure and interface body in the file(s) being compiled. This is useful when an application contains hundreds of routines and interface bodies and a programmer wishes to include the same module in each procedure and interface body. For example, a module may be written to provide explicit interfaces for a library used by the application. In order to enable compile time interface checking at each call to the library, each procedure and interface body must have a USE module_name inserted in it. This directive allows for a module to be implicitly used in all program units and interface bodies compiled without requiring source modification. - 4 - Note: Use of this option may significantly increase compile time. 5.1.4 _A_d_d_i_t_i_o_n_a_l__I_n_t_r_i_n_s_i_c__E_x_t_e_n_s_i_o_n_s Provided in this release are the following intrinsic extensions: SIND, TAND, COSD, ATAND, ATAN2D, ACOSD, ASIND. They use and return degree values rather than radians. 5.2 _M_I_P_S_p_r_o _7._2._1 _F_o_r_t_r_a_n _a_n_d _F_F_I_O _L_I_B_R_A_R_Y _F_e_a_t_u_r_e_s 5.2.1 _E_x_p_l_i_c_i_t _M_I_P_S-_t_o-_C_R_A_Y _a_n_d _C_R_A_Y-_t_o-_M_I_P_S _c_o_n_v_e_r_s_i_o_n _r_o_u_t_i_n_e_s Provided in this release are interfaces for converting Cray floating point data to and from MIPS IEEE data. Two interfaces are provided: +o A subroutine interface which Fortran 90 and C users can call explicitly +o An assign -N cray interface which allows IRIX Fortran 90 users to access Cray floating files implicitly (without changing their program). See the intro_conversion manpage for more information. 5.2.2 _G_l_o_b_a_l__F_F_I_O__L_a_y_e_r These routines have been ported directly from the T3E platform. See the intro_ffio manpage for more information. 5.2.3 _A_d_d_i_t_i_o_n_a_l__P_O_S_I_X_._9__i_n_t_e_r_f_a_c_e__r_o_u_t_i_n_e These are Fortran 90 subroutine interfaces to signal handling system calls on all IRIX platforms. They include: - 5 - IPXFWIFEXITSTATUS IPXFWTERMSIG IPXFWSTOPSIG PXFALARM PXFCALLSUBHANDLE PXFGETSUBHANDLE PXFKILL PXFSIGACTION PXFSIGADDSET PXFSIGDELSET PXFSIGEMPTYSET PXFSIGFILLSET PXFSIGISMEMBER PXFSIGPENDING PXFSIGSUSPEND PXFSLEEP PXFWIFEXITED PXFWIFSIGNALED PXFWIFSTOPPED See the intro_pxf manpage for more information. 5.3 _N_e_w__F_e_a_t_u_r_e_s__i_n__M_I_P_S_p_r_o__7_._2 5.3.1 _N_e_w__C_o_m_p_i_l_e_r__F_r_o_n_t_-_e_n_d MIPSpro 7.2 Fortran 90 uses version 3.0 of the Cray Fortran90 compiler front-end. It is source compatible with the Cray Fortran90 compiler, with minor exceptions noted below. MIPSpro 7.2 Fortran 90 now supports Cray Pointers and Cray's Flexible File I/O. 5.3.1.1 _C_r_a_y__T_a_s_k_i_n_g__D_i_r_e_c_t_i_v_e_s MIPSpro 7.2 Fortran 90 supports many of the CMIC$ directives found in Cray Fortran 90 including: !MIC$ NUMCPUS, !MIC$CNCALL, !MIC$ PARALLEL, !MIC$ DO PARALLEL, !MIC$ ENDDO, !MIC$ DO ALL, !MIC$ GUARD, !MIC$ END GUARD, along with these parameters: SHARED,PRIVATE, IF, MAXCPUS, CHUNKSIZE, GUIDED, and SAVELAST. - 6 - 5.3.1.2 _!_D_I_R__d_i_r_e_c_t_i_v_e_s_. MIPSPro 7.2 Fortran 90 also supports these CDIR$ directives from Cray Fortran90: !DIR$ BOUNDS, !DIR$ NOBOUNDS, !DIR$ FREE, !DIR$ FIXED !DIR$ ID, !DIR$ IVDEP, !DIR$ NAME. The !DIR$TASK and !DIR$NOTASK directives can be used to control automatic parallelization using -pfa. The TASK and NOTASK directives are ignored unless the -cray_mp switch is specified to enable Cray-style tasking directives. 5.3.2 _N_e_w__C_o_m_p_i_l_e_r__B_a_c_k_-_e_n_d MIPSpro 7.2 Fortran 90 uses the same optimizing back-end as the other MIPSpro 7.2 compilers. As such it now supports the newer command-line options for controlling optimizations (-OPT, -LNO, -IPA, etc.) See the f90(1) and ipa(5) man pages for more information about these options. 5.3.2.1 _L_o_o_p__N_e_s_t__O_p_t_i_m_i_z_e_r MIPSpro Fortran 90 7.2 introduces a new flag group (-LNO: ...) that controls optimization of loops. This flag replaces the -sopt ... flags that performed similar functionality in the 7.1 compiler. LNO performs loop fission, loop fusion, cache blocking, loop unrolling and other optimizations. For an overview of this functionality, please refer to the MIPSpro Compiling, Debugging and Performance Tuning Guide and f90(1) man pages. 5.3.2.2 _N_e_wSymbol Two new directives have been added in MIPSpro 7.2 to control the way symbols (i.e. variables that may be a Fortran COMMON, or an automatic variable, but not a formal and not an element of a structured type like a struct or an array). are stored: ALIGN_SYMBOL and FILL_SYMBOL. Their syntax is as follows: - 7 - C*$* ALIGN_SYMBOL (symbol, L1cacheline) C*$* ALIGN_SYMBOL (symbol, L2cacheline) C*$* ALIGN_SYMBOL (symbol, page) C*$* ALIGN_SYMBOL (symbol, <user-specified-power-of-two>) C*$* FILL_SYMBOL (symbol, L1cacheline) C*$* FILL_SYMBOL (symbol, L2cacheline) C*$* FILL_SYMBOL (symbol, page) C*$* FILL_SYMBOL (symbol, <user-specified-power-of-two>) The ALIGN_SYMBOL directive aligns the start of <symbol> at a specified alignment boundary. The second argument in the directive may be one of the keywords L1cacheline (machine specific first-level cache line size, typically 32 bytes), L2cacheline (machine specific second- level cache line size, typically 128 bytes), page (machine specific page size, typically 16 Kbytes), or a user-specified power-of-two value. The FILL_SYMBOL directive pads <symbol> with additional storage so that the symbol is assured not to overlap with any other data item within the storage of the specified size. The additional padding required is divided between each end of the specified symbol. 5.3.2.3 _A_d_d_i_t_i_o_n_a_l _O_p_t_i_o_n_s _f_o_r _D_O_A_C_R_O_S_S _a_n_d _P_C_F _D_i_r_e_c_t_i_v_e_s There are two additional options, NEST and AFFINTY, to !$PAR PDO and !$DOACROSS in MIPSpro 7.2 which can improve parallel performance on Origin2000 distributed shared memory architecture. Refer to the MIPSpro F90 Commands and Directives Manual for more information. 5.3.2.4 _D_a_t_a__D_i_s_t_r_i_b_u_t_i_o_n__D_i_r_e_c_t_i_v_e_s The 7.2 F90 compiler supports data distribution directives data distribution pragmas such as distribute, and distribute-reshape, which allow for explicit data parallelism to be exploited in a multi-processing environment. This is in addition to the multi- processing MP pragmas for which support has been provided since 7.1. The programmer's guide describes the data distribution pragmas and their use on multiprocessing machines such as the Origin series. - 8 - 5.3.2.5 _I_n_t_e_r _P_r_o_c_e_d_u_r_a_l _A_n_a_l_y_s_i_s (_I_P_A) _O_p_t_i_m_i_z_a_t_i_o_n_s The 7.2 compiler introduces a new flag group (-IPA: ...) that enables interprocedural optimizations. Another flag group (-INLINE: ...) controls the application of subroutine inlining done within a file by the standalone inliner, or by the main inliner if -IPA options are enabled. IPA can be used with optimization levels -O2 and -O3, and will perform cross-file constant propagation, cross-file inlining, and generate information used by other optimization passes. If you use separate steps to compile and link (i.e. using -c when you compile and then linking the .o files produced with a separate cc(1), f90(1), or ld(1) command), then you need to use -IPA (with or without any individual options) for both the compile step and the link step. For more information, please consult the ipa(5) man page. 5.3.2.6 _N_e_w__-_O_P_T__c_o_n_t_r_o_l__g_r_o_u_p__o_p_t_i_o_n_s The fast_complex, fast_trunc and fast_nint controls have been added to the -OPT: ... control group. For more information, please consult the f90(1) man pages. 5.3.2.7 _N_e_w__D_E_B_U_G__o_p_t_i_o_n The -DEBUG option control group has been implemented. - DEBUG:div_check inserts runtime checks for divide by zero. -DEBUG:trap_uninitialized (- trapuv) inserts checks for uninitialized variables. -DEBUG:subscript_check inserts checks for out of bounds subscripts. For more information, please refer to DEBUG_group(5). 5.3.3 _l_i_b_f_o_r_t_r_a_n__l_i_b_r_a_r_y The libfortran library consists of those internally generated library procedures made by the Fortran 90 compiler as well as intrinsic procedures that users can invoke. All standard Fortran intrinsics are provided as well as a subset of Cray intrinsics which are extensions to the standard. The library also includes the I/O - 9 - library currently being used on Cray platforms. 5.3.4 _P_r_e_p_r_o_c_e_s_s_i_n_g__w_i_t_h__f_t_p_p In previous releases, all files were preprocessed using cpp. For 7.2, files with the .F and .F90 suffix are preprocessed with the ftpp preprocessor, by default. Ftpp is a Fortran-aware version of the standard cpp preprocessor. For example, ftpp is aware of the constraints on the line length of Fortran source files, and understands comments and continuation lines. There are several options which can be used to control preprocessing for Fortran 90 files: 5.3.4.1 _-_f_t_p_p Process all Fortran files with ftpp, regardless of suffix. 5.3.4.2 _-_c_p_p Process all Fortran files with cpp, regarless of suffix 5.3.4.3 _-_m_a_c_r_o___e_x_p_a_n_d With ftpp, expand preprocessor macros wherever they occur. By default, macro expansion only occurs in preprocessor directives. 5.3.5 _A_s_s_i_g_n__C_o_m_m_a_n_d The assign command provides the ability to specify I/O processing options for a file. Options include FFIO layer selection, data conversion properties, and buffer size. 5.4 _E_x_p_l_a_i_n__C_o_m_m_a_n_d__a_n_d__M_e_s_s_a_g_e__S_y_s_t_e_m__L_i_b_r_a_r_y Provided as patchSG0002052, the explain command provides the interface to retrieve and and display messages during the compilation, loading and execution of of a user's program. Currently, the message system library contains only those messages for the front-end and the runtime I/O library. The explain command can only be used for messages coming from the message system library. - 10 - 5.5 _C_r_a_y__M_o_d_u_l_e_s Packaged as a separate image on the IRIX Development Foundation CD, Modules is an experimental environment which allows you to install and use the 7.2 compilers under a location other than the root directory (/). For MIPSpro 7.2, only the compiler, dbx and SpeedShop images can be installed under this alternate location. Other product images, such as the Insight books, license manager and WorkShop should not be installed in this alternate location. For more information about modules please refer to the chapter on modules in the IRIX Development Foundation Release Notes, the modules release notes, or man modules(1). 5.6 _N_e_w__A_u_t_o_m_a_t_i_c__P_a_r_a_l_l_e_l_i_z_a_t_i_o_n__O_p_t_i_o_n The MIPSpro Auto Parallelizing Option (SC4-APO- 7.2) is a replacement product for the Power Fortran 90, Power Fortran 77 and Power C Analyzer products. It also works on C++ programs. When -pfa is specified on the command line, Fortran 77 or Fortran90 programs are automatically parallelized. When -pca is specified, C or C++ programs are automatically parallelized. The MIPSpro Automatic Parallelization Option only supports the 64-bit (-64) and new high performance 32-bit (-n32) ABI's. The old 32-bit ABI (-32) is not supported by this product. 5.7 _F_o_r__M_o_r_e__I_n_f_o_r_m_a_t_i_o_n Please refer to the following manuals for more detailed descriptions of of the features mentioned in these release notes. +o MIPSPro Fortran 90 Language Reference Manual (Volumes I-III) +o MIPSpro Fortran 90 Commands and Directives Manual. - 11 -