CMAX Version 2.0 Bug Update Report for May 1994 For Connection Machine Systems FIXED BUGS The following bugs have been fixed in the current release, Version 2.0. For a description of any bug listed here, contact your Applications Engineer or the Customer Support group at Thinking Machines Corporation. TMCaa01837 MAXVAL of ABS doesn't convert TMCaa03295 Promoted scalar temporaries not reused TMCaa03377 Reductions into array elements not recognized TMCaa03381 COUNT of nontrivial expressions not recognized TMCaa03920 Incorrect ELSEWHERE generated TMCaa03936 Promoted scalars indexed incorrectly in I/O statements TMCaa04041 Segfault with NOVECTORIZE in IF TMCaa04047 Bad things recognized as reductions of intrinsics TMCaa04082 Non-integer loop bound expression convert to illegal CMF TMCaa04089 Segmentation fault during loop pushing TMCaa04090 Bad unpromoted scalars with loop pushing TMCaa04100 Promoted scalars sometimes given inefficient layouts TMCaa04155 Variable clobbered after use as loop index TMCaa04175 Block structure mangled TMCaa04178 -LineWidth doesn't help on long strings TMCaa04179 Names for CSHIFT functions are wrong. TMCaa04180 Loop around call to I/O causes segfault TMCaa04192 ENDWHERE inserted in wrong place TMCaa04193 translated CMF_SCAN_* incorrect on mixed data types TMCaa04194 Translated CMF_SCANS_* last value is not saved TMCaa04198 Variable loop bound computation gets fissioned badly TMCaa04286 Original variable referenced instead of promoted version TMCaa04321 Variable substitution and computed loop bounds broken TMCaa04334 Bus error with lots of ENTRY statements TMCaa04416 Incorrect code for stride -1 loop TMCaa04470 LAYOUT inserted before declaration because of DATA TMCaa04538 Logical IF mistranslated TMCaa04546 Cloned functions declared illegally TMCaa04553 Invariant MAXLOC index dropped TMCaa04582 Bad FORALL in array promotion broadcast TMCaa04583 Unterminated block IF created TMCaa04585 IF/ELSEIF/ELSE (with mixed invariance) causes segfault TMCaa04906 Intelligence intrinsics not recognized OUTSTANDING BUGS The following bugs are outstanding in the current release. TMCaa01824 Reductions nested in nonvectorizable loops not recognized TMCaa02988 Align propagation TMCaa03791 F90 keyword renaming does not work in include files TMCaa03799 FORALL generated instead of DO loop for serial function test TMCaa03873 Parameter values sometimes substituted in output code TMCaa03895 WHERE emitted too aggressively TMCaa03929 MAXVAL of promoted scalar does not convert TMCaa03975 using CMF$ALIGN cuases error without CMF$LAYOUT TMCaa04147 Arrays sometimes incorrectly recognized as "automatic" TMCaa04177 -ZeroArray creates bad code on program fragments Each of these bugs is detailed below. ********************************************************* ID: TMCaa01824 Title: Reductions nested in nonvectorizable loops not recognized Description: The MAXLOC idiom (and other idioms) are not always recognized when used inside other, nonvectorizable loops. Workaround: Use CMF$NOVECTORIZE around outer loops. Status: Outstanding. ********************************************************* ID: TMCaa02988 Title: Align propagation Description: CMF$ALIGN directives, and the relationships they establish between layouts of arrays, are not always propagated through function calls. Workaround: Use CMF$LAYOUT. Status: Outstanding. ********************************************************* ID: TMCaa03791 Title: F90 keyword renaming does not work in include files Description: F90 keyword renaming does not work in include files. For example, if a declaration of a variable "SUM" appears in an include file, uses of it will be renamed to be F90_KEYWORD_RENAME_SUM, but the declaration will not. The new variable F90_KEYWORD_RENAME_SUM will have whatever type it gets due to the user's IMPLICIT typing scheme. If the user used IMPLICIT NONE, the error will be caught by CMAX itself. CMAX prints a warning whenever it renames anything, whether it is in an include file or not. Workaround: Rename the variable manually to not conflict with F90 keywords, or include the include file inline. Status: Outstanding. ********************************************************* ID: TMCaa03799 Title: FORALL generated instead of DO loop for serial function test Description: If the test of an IF statement is a call to a function, CMAX may translate the IF (inside a loop) into a FORALL. This works for most cases, but leads to a CMF warning that the FORALL will be serialized. But if the test involves character arrays, then the code generated is not legal CM Fortran, because character arrays cannot have CM homes. Workaround: Use CMAX$NOVECTORIZE Status: Outstanding. ********************************************************* ID: TMCaa03873 Title: Parameter values sometimes substituted in output code Description: In some circumstances, values of named parameters are substituted in the output code. Workaround: Status: Outstanding. ********************************************************* ID: TMCaa03895 Title: WHERE emitted too aggressively Description: CMAX will sometimes too aggressively convert an IF inside a DO loop to a WHERE statement. If a variable used in the IF condition is assigned to in a branch of an IF/ELSEIF/ELSE chain, then the resulting WHERE construct will be incorrect. For example: do i = 1,100 if (a(i).eq.23) then b(i) = -a(i) else if (a(i).ne.b(i)) then b(i) = a(i) else if (a(i).lt.b(i)) then b(i) = a(i) * 2.0 else b(i) = 0.0 endif end do Translates to: WHERE (a .EQ. 23) b = -a ENDWHERE WHERE (.NOT.a .EQ. 23 .AND. a .NE. b) b = a ENDWHERE WHERE (.NOT.(a .EQ. 23 .OR. a .NE. b) .AND. a .LT. b) b = a * 2.0 ENDWHERE WHERE (.NOT.(a .EQ. 23 .OR. a .NE. b .OR. a .LT. b)) b = 0.0 ENDWHERE Because B is both assigned to and used in the conditions, the later tests are not equivalent to the serial code. Workaround: Use CMAX$NOVECTORIZE, or introduce a temporary variable to store the original value of any array both assigned to and used in a condition. Status: Outstanding. ********************************************************* ID: TMCaa03929 Title: MAXVAL of promoted scalar does not convert Description: MAXVAL of promoted scalar does not convert. Converted code will have to be editted. Workaround: Status: Outstanding. ********************************************************* ID: TMCaa03975 Title: using CMF$ALIGN cuases error without CMF$LAYOUT Description: Using CMF$ALIGN causes CMAX to generate a "defined in more than one directive" error message. If you want to align two arrays than in the subroutine that has the CMF$ALIGN directive make sure you include a CMF$LAYOUT directive for the array you are aligning. Workaround: The workaround is to add a layout directive for the array you are aligning to (u) in the same subr that has the align directive. This somehow prevents cmax from propagating the redundant layout directive for the other array (bdmask). Status: Outstanding. ********************************************************* ID: TMCaa04147 Title: Arrays sometimes incorrectly recognized as "automatic" Description: An array dimensionsioned with an expression containing a parameter with a floating point value will be incorrectly recognized as an "automatic" array. Workaround: Replace the floating point parameter with an integer parameter. Status: Outstanding. ********************************************************* ID: TMCaa04177 Title: -ZeroArray creates bad code on program fragments Description: -ZeroArray creates erroroneous code is used on only program fragment. The workaround is to gice CMAX the whole program or a dummy stub. Workaround: The workaround is to give CMAX either the whole program or a dummy stub that calls the program fragment. Status: Outstanding.