Chapel Changelog

What's new in Chapel 1.12.0

Jan 18, 2016

Highlights:
significantly expanded the coverage of our online documentation (see http://chapel.cray.com/docs/1.12/ and "Documentation" below)
added new 'Barrier', 'Spawn', and 'LAPACK' modules to the standard set (see "Standard Library/Modules" section below)
added chplvis: a new tool for visualizing Chapel communication and concurrency (see http://chapel.cray.com/docs/1.12/tools/chplvis/index.html)
added a new chapter describing Chapel's memory consistency model in detail (see 'Memory Consistency Model' in the language spec)
added a 'vectorizeOnly()' iterator that vectorizes without task creation (http://chapel.cray.com/docs/1.12/modules/internal/ChapelIteratorSupport.html)
new performance optimizations, particularly intra- and inter-node locality (see "Performance Improvements" section below)
removed the 'local' block from stream-ep based on the above optimizations (see examples/benchmarks/hpcc/stream-ep.chpl)
changed the default tasking layer on 'cray-x*' to 'qthreads' for performance
added support for type methods and iterators (see 'Classes::Class Method Calls::The Method Receiver and the this Argument')
added support for public/private module-level variables, functions, modules) (see 'Modules:Access of Module Contents::Visibility of Module's Symbols')
domains in formal array arguments are now interpreted as a constraint (see 'Arrays::Array Arguments to Functions' in the language spec)
significantly revamped and improved correctness and performance testing system
improved how internal error messages are displayed to users
added Chapel Improvement Proposals (CHIPs) framework for proposing changes (see https://github.com/chapel-lang/chapel/blob/master/doc/chips/1.rst)
made more bug fixes than any release since version 1.1 (see "Bug Fixes" section below)
addressed portability issues for a number of platforms and compilers
Process Improvements:
added Chapel Improvement Proposals (CHIPs) framework for proposed changes (see https://github.com/chapel-lang/chapel/blob/master/doc/chips/1.rst)
Environment/Configuration Changes:
'printchplenv' now indicates which settings come from environment variables
made the quickstart scripts turn CHPL_LLVM off by default
removed dependencies on 'bc' and 'patch'
Tool Changes:
added chplvis: a new tool for visualizing Chapel communication and concurrency (see http://chapel.cray.com/docs/1.12/tools/chplvis/index.html)
chpldoc improvements: - improved handling of enum, real, imag, and complex initializers - 'chpldoc' now generates values for enum symbols - automatically skip documentation of 'private' symbols - squashed generation of 'inline' in output - added support for --print-commands with chpldoc
chpl-ipe: - added a quit() primitive for clean exits from the environment
Syntactic/Naming Changes:
changed 'use' to 'require' for header files and external libraries (see http://chapel.cray.com/docs/1.12/technotes/extern.html)
replaced the standalone format() routine, with string.format() (http://chapel.cray.com/docs/1.12/modules/standard/IO.html#IO.string.format)
renamed memory diagnostics capabilities for clarity (see http://chapel.cray.com/docs/1.12/modules/standard/Memory.html)
changed the '##.##' writef() pattern so that it requires '%{...}' around it (see http://chapel.cray.com/docs/1.12/modules/standard/IO.html#specifiers)
added support for form-feed characters ('\f') as whitespace (see 'Lexical Structure::White Space' in the language specification)
changed the term 'blank intent' to 'default intent' (see 'Functions::Argument Intents::Abstract Intents::The Default Intent')
Semantic Changes / Changes to Chapel Language:
domains in formal array arguments are now interpreted as a constraint (see 'Arrays::Array Arguments to Functions' in the language spec)
Chapel no longer keeps referenced variables alive past their lexical scope
c_strings are no longer made into strings when passed to generic extern args
'select' statements now only evaluate their argument expression once
New Features:
added a 'vectorizeOnly()' iterator that vectorizes without using multitasking (http://chapel.cray.com/docs/1.12/modules/internal/ChapelIteratorSupport.html)
added support for type methods and iterators (see 'Classes::Class Method Calls::The Method Receiver and the this Argument')
added support for public/private module-level variables, functions, modules) (see 'Modules:Access of Module Contents::Visibility of Module's Symbols')
added support for methods on enumerated types (e.g., 'enum color {red};' permits 'proc color.foo() { ... } color.red.foo();')
added support for hexadecimal floating point literals (see 'Lexical Structure::Tokens::Literals' in the language specification)
added the ability to rename extern records for use within Chapel (see 'Interoperation::...::Shared Types::Referring to External C Structs')
added support for -lchplmalloc for compilers supporting weak symbols (see http://chapel.cray.com/docs/1.12/technotes/allocators.html))
added the ability to use 'continue' statements in 'param' for-loops
added support for == and != operators on domain maps
Standard Library/Modules:
added a new 'Barrier' module defining a simple collective barrier capability (see http://chapel.cray.com/docs/1.12/modules/standard/Barrier.html)
added a new 'Spawn' module for creating new subprocesses (see http://chapel.cray.com/docs/1.12/modules/standard/Spawn.html)
added a new 'LAPACK' module that provides an interface to LAPACK (see http://chapel.cray.com/docs/1.12/modules/standard/LAPACK.html)
added support for common mathematical constants to 'Math.chpl' (see http://chapel.cray.com/docs/1.12/modules/standard/Math.html#Math.e)
replaced standalone format() routine with string.format() in 'IO' (http://chapel.cray.com/docs/1.12/modules/standard/IO.html#IO.string.format)
unified string.format() format strings with writef() (http://chapel.cray.com/docs/1.12/modules/standard/IO.html#formatted-i-o)
added a getFileSize() routine to the 'FileSystem' module (see http://chapel.cray.com/docs/1.12/modules/standard/FileSystem.html)
merged the contents of the 'UtilMath' module into 'Math' (see http://chapel.cray.com/docs/1.12/modules/standard/Math.html)
improved the 'Memory' module: - renamed memory diagnostics capabilities for clarity - added a --memLeaksByDesc flag to track only certain types of leaks - stopped tracking memory allocations not related to Chapel code by default (see http://chapel.cray.com/docs/1.12/modules/standard/Memory.html)
errorToString(ENOERR) now portably returns "No error" in 'Error' module (see http://chapel.cray.com/docs/1.12/modules/standard/Error.html)
applied the 'private' keyword to standard modules as appropriate/possible
Performance Improvements:
parallelized large numeric array initialization for better first-touch
improved analysis and optimization of variables that are provably local
fixed a bug in which non-blocking 'on's were counted as local running tasks
improved task counting when one task is waiting for others to complete
optimized task counts to use processor atomics when profitable
made 'cray-x*' systems default to 'qthreads' over 'muxed'
moved polling threads to the last available CPU to avoid contention
made array allocation use calloc(), not malloc() for better first-touch
enabled more optimizations and streamlined code when using the LLVM back-end
Memory Improvements:
stopped leaking sync and single variables on all platforms except Cygwin
eliminated leaks for heap allocated variables used in cobegin/coforall
Documentation:
mirrored many of the READMEs from the release onto our online documentation (see http://chapel.cray.com/docs/1.12/usingchapel/ and .../1.12/technotes)
added online documentation for built-in types, functions, methods (see http://chapel.cray.com/docs/1.12/modules/builtins.html)
added online documentation for standard domain maps (layouts and distributions) (http://chapel.cray.com/docs/1.12/modules/distributions.html and layouts.html)
added a copy of the online html documentation to the release itself (see $CHPL_HOME/doc/html)
converted most READMEs to ReStructured Text (.rst) or markdown (.md) (for example, see $CHPL_HOME/doc/and $CHPL_HOME/doc/technotes/*)
refreshed the contents of most former READMEs as part of this effort
language specification updates: - added a new chapter on Chapel's memory consistency model - added documentation of the I/O operator, - improved the specification's page numbering and format - retired standard library chapters from the spec now that they're online (see http://chapel.cray.com/spec/spec-0.98.pdf)
standard module documentation improvements - added a "Formatted I/O for C Programmers" table to the IO module (see http://chapel.cray.com/docs/1.12/modules/standard/IO.html#formatted-i-o) - refreshed the documentation of other standard modules
refreshed the contents of the C interoperability technical note (see http://chapel.cray.com/docs/1.12/technotes/extern.html)
retired README.format due to its documentation as part of a standard module (http://chapel.cray.com/docs/1.12/modules/standard/IO.html#IO.string.format)
removed Tilera-specific documentation due to lack of use and testing
Example Codes:
rewrote the 'stream-ep' example to remove the now unnecessary 'local' block (see examples/benchmarks/hpcc/stream-ep.chpl)
added a copy of Chapel code from learnXInYMinutes site to examples/primers (see examples/primers/learnChapelInYMinutes.chpl)
added a primer for the new 'chplvis' tool (see examples/primers/chplvis/README)
added a primer for the new LAPACK module (see examples/primers/LAPACKlib.chpl)
added a new examples/patterns directory for storing common code patterns (see examples/patterns/README)
added patterns/recordio.chpl to demonstrate reading tab-delimited records (see examples/patterns/recordio.chpl)
updated shootout/nbody.chpl to use 'ref's rather than nested procedures (see examples/benchmarks/shootout/nbody.chpl)
replaced uses of format() with writef() in SSCA2 benchmark (see examples/benchmarks/ssca2/)
made the fileIO primer more tolerant of floating point roundoff (see examples/primers/fileIO.chpl)
made the FFTW primer self-validating w.r.t. numerical differences (see examples/primers/FFTWlib.chpl)
removed 'param' from lulesh loops that probably don't want/need it (see examples/benchmarks/lulesh/)
Compiler Flags (see 'man chpl' for details):
redefined --fast to no longer imply --no-ieee-float
added --[no-]ieee-float support for CHPL_TARGET_COMPILER 'clang' and 'intel'
made --ccflags arguments stack rather than override one another
added support for --print-emitted-code-size for the LLVM back-end
Execution Flags:
added a --memLeaksByDesc flag to track only certain memory categories
made --memLeaks[ByDesc] be governed by the --memTreshold flag
Error Message Improvements:
improved how internal error messages are displayed to users
improved error messages for runaway comments
improved source location provided by 'noinit' warnings
Bug Fixes:
forall loops over a single array now correctly use the standalone iterator
fixed bugs with applying reduce intents to forall loops over domains/arrays
fixed bugs with scope resolution's choice of which symbol to resolve to
fixed a bug in which overloads of '|' broke internal modules
fixed a bug related to extern variables of types like c_ptr(c_int))
fixed an internal error when a class calls its parent class's destructor
fixed a bug in which large array copies could overflow runtime arguments
fixed a bug in which calls of the form '(x)' would cause internal errors
fixed a bug in I/O when skipping whitespace encountered illegal characters
fixed printing/reading of integers with '%{##.##}' format
made readf() calls without error arguments halt on mismatches
fixed a bug in which trailing whitespace was being consumed too aggressively
made default rectangular arrays print in JSON as arrays-of-arrays
fixed EOF-related bugs in Reader/Writer
fixed a bug in which channel.read(style) was ignoring its style argument
fixed a bug in which non-blocking 'on's were counted as local running tasks
fixed a compiler exception caused by dividing by param '0'
fixed a bug in the is*() FileSystem functions when given an invalid path/link
improved chpldoc's handling of failure to create output and tmp directories
added an error message for too-long compiler flags rather than truncating
fixed a bug in which calls to malloc/free/etc in extern blocks caused errors
fixed 'text file busy' errors in certain situations when invoking 'chpl'
fixed a bug in which overloading was being permitted based on argument intents
fixed a segfault in the glob() iterator when following 0..0 with 0 matches
fixed a bug in which bad source location info was passed to string routines
preserved source location information for cobegins
fixed a bug relating to inlined iterators and generic array fields
fixed a bug relating to passing c_strings to extern C functions
Platform-specific Changes:
made 'cray-x*' systems default to 'qthreads' over 'muxed'
'muxed' tasking now supports stack guard pages for non-hugepage heaps (see http://chapel.cray.com/docs/1.12/platforms/cray.html)
added support for 'clang-included' to work with GASNet on Cray systems
removed support for cray-prgenv-pgi from the module build on 'cray-x*'
for cray-prgenv-cray compilations, stopped throwing -hipa2 by default
Platform-specific bug fixes:
fixed a stack underflow problem with 'muxed' tasking causing segfaults
fixed a race in stack management for 'muxed' tasking
Portability Improvements:
eliminated warnings related to [_BSD|_SVID]_SOURCE being deprecated
improved portability of building the SysCTypes.chpl for Fedora 22
removed symmetric address assumptions from error-handling code in the runtime
fixed a number of I/O portability errors on cygwin
fixed tcmalloc when compiled with clang 3.6 and used from C++
fixed I/O for 32-bit Ubuntu 14.04
added support for building GASNet with segment=fast on OS X
fixed hwloc's cairo detection for certain OS X installations
eliminated some Xcode-specific warnings
Third-Party Software Changes:
added 'fltk' to the third-party directory for use by 'chplvis'
enabled the use of GMP with the LLVM back-end
made LLVM build in non-debug mode and without asserts by default
improved cross-compilation of third-party packages for 'cray-x*' platforms
we're now storing RE2 in an unpacked form due to all of our local changes
fixed a valgrind issue in RE2
Launcher-specific Changes:
improved 'slurm' launcher's handling of non-zero exit() codes
changed how the 'amudprun' launcher deals with quoted arguments
Runtime Library Changes:
added support for out-of-segment put()/get() calls
changed I/O to allocate buffer space out of the Chapel heap
Testing System:
rewrote 'start_test' and 'computePerfStats' in python
replaced --suppress feature with .suppressif files
added ability to write chpldoc tests using the .doc.chpl extension
updated testing system to support testing of 'chpl-ipe'
made the parallel testing system print an estimated end time
added support for a -valgrindexe flag to 'paratest.server'
made 'start_test' work when it's located outside of $CHPL_HOME/util
added the ability to have multi-line COMPOPTS file
improved support for #defines with quotes for C testing
made C testing system more accepting of C compilers that print filenames
specialized testing system to recognize some common launcher errors
improved ability to use chpl_launchcmd.py from NFS-mounted Lustre filesystems
extended timeout mechanism to work under Cygwin
Makefile Changes:
rewrote 'make check' to remove reliance on start_test/tcsh/python
Performance Testing/Graphing System:
added a 'screenshot' capability for performance graphs
added the ability to annotate cray-xc performance graphs
retired the old gnuplot-based graphing system
reduced graphing system's reliance on CHPL_HOME being set
improved graphing system's stability when there is no ANNOTATIONS.yaml file
Developer-oriented changes: Process Improvements:
began using Jira for issue tracking
Developer-oriented changes: Documentation Improvements:
added notes about testing nightly scripts to util/cron/README
Developer-oriented changes: Compiler Flags:
added a --break-on-resolve-id flag for stopping when calling a function
Developer-oriented changes: Module improvements:
cleaned up how filename/line# information is attached to network atomics
added support for casting directly to c_strings
started using specific I/O read/write functions for int/real/imag types
cleaned up handling of bool values in IO.chpl
made initOnLocales() a standalone parallel iterator and added 'chpl_' prefix
Developer-oriented changes: Makefile improvements:
added a top-level Makefile rule for building the parser
Developer-oriented changes: Compiler improvements/changes:
rewrote the compiler passes that widen references as necessary
rewrote major portions of the scope resolution pass
reduced reliance on homegrown ADTs with their STL equivalents
improved the sharing of flags between 'chpl' and 'chpldoc'
turned off sugaring of type names in --devel mode
internal improvements to how tuples are handled
removed unused flag FLAG_NO_USE_CHAPELSTANDARD
renamed FLAG_PRIVATE to FLAG_LOCALE_PRIVATE for clarity
retired the "auto destroy fn" pragma
added tracking of zippered loops throughout compilation
ensured the lexer returns a heap-allocated const charfor each literal
Developer-oriented changes: Runtime improvements:
added support for task callbacks in the runtime
eliminated reliance on __always_inline
added chpl_mem_goodAllocSize() to runtime to support minimizing wasted memory
added the ability to flag certain memory types to avoid tracking them
added a capability to generate a header file #defining CHPL_variables
turned off remote caching for tasking layers where migration can occur
Developer-oriented changes: Third-party improvements:
cleaned up local modifications to Qthreads for contribution back to master
updated third-party GMP/RE2 READMEs to refer to online module documentation

New in Chapel 1.11.0 (Apr 3, 2015)

HIGHLIGHTS:
revamped 'chpldoc' and used it to create web docs for all standard modules
(see http://chapel.cray.com/docs/latest/)
added a new FileSystem standard module supporting operations on files/dirs
(see http://chapel.cray.com/docs/latest/modules/standard/FileSystem.html)
added a new FFTW standard module supporting key FFTW routines
(see http://chapel.cray.com/docs/latest/modules/standard/FFTW.html)
added task intents to forall loops, plus new intents such as 'in' and 'reduce'
(see 'Semantic Changes' and 'New Features' sections below)
added support for standalone parallel iterators, used by non-zippered foralls
(see examples/primers/parIters.chpl)
added support for vectorization of data parallel loops and operations
(see '--vectorize' flag in 'man chpl')
optimized away communication code for module-scope variables and local arrays
(see release note slides at http://chapel.cray.com/download.html#releaseNotes)
added an early prototype interactive/interpreted mode for writing Chapel code
(see doc/technotes/README.chpl-ipe.rst for more details)
initial support for Python->Chapel interoperability via PyChapel
(see http://pychapel.readthedocs.org/ for more details)
made 'ugni'/'muxed' the default comm/tasking choices for cray-xmodule users
(see doc/platforms/README.cray and doc/README.chplenv)
added a new 'chpltags' utility to generate emacs/vim tags for Chapel code
(see 'util/chpltags --help' and 'util/README')
numerous other improvements for better performance and cleaner generated code
(see 'Performance Improvements' section below)
improved portability to NetBSD and additional flavors of Linux
(see 'Portability Improvements' section below)
upgraded the bundled versions of GASNet, hwloc, llvm, and dygraphs
(see 'Third-Party Software Changes' section below)
numerous bug fixes
(see 'Bug Fixes' section below)
ENVIRONMENT/CONFIGURATION CHANGES:
made the setchplenv.scripts prepend to PATH and MANPATH rather than append
made the "quickstart" scripts set CHPL_COMM to 'none' and not set CHPL_MEM
improved the logic for auto-detecting when CHPL_ATOMICS should be 'intrinsics'
added auto-detection of CHPL_*_PLATFORM for 'cray-xc'/'cray-xe' systems
added support for building runtime/third-party with the bundled clang version
(see references to 'clang-included' in README.chplenv)
split the 'cygwin' CHPL_*_PLATFORM value into 'cygwin32' and 'cygwin64'
added new 'netbsd32' and 'netbsd64' values for CHPL_*_PLATFORM
changed CHPL_COMM/TASKS to default to ugni/muxed when using the cray-xmodule
(see doc/README.chplenv, doc/platforms/README.cray, and/or doc/README.tasks)
made CHPL_TASKS default to 'fifo' for 'cray-prgenv-cray' CHPL_TARGET_COMPILER
PACKAGING CHANGES:
updated Makefiles to support building Chapel in parallel via 'make -j'
avoid rebuilding gmp and re2 speculatively when previous builds have failed
TOOL CHANGES:
added an early prototype interactive/interpreted mode for writing Chapel code
(see doc/technotes/README.chpl-ipe.rst for more details)
revamped 'chpldoc' to create HTML files via Sphinx for documenting Chapel code
(see doc/technotes/README.chpldoc.rst and 'man chpldoc' for more details)
added a new 'chpltags' utility to generate emacs/vim tags for Chapel code
(see 'util/chpltags --help' and 'util/README' for more information)
SYNTACTIC/NAMING CHANGES:
removed the placeholder keyword 'refvar' in favor of the new keyword 'ref'
removed support for the use of 'var' as a return intent (use 'ref' instead)
SEMANTIC CHANGES / CHANGES TO CHAPEL LANGUAGE:
added support for task intent clauses and semantics to forall loops
(see 'Data Parallelism: Forall Intents' in the language specification)
added initial support for 'reduce' intents on forall loops
(see doc/technotes/README.reduceIntents)
removed the 'type select x' syntax in favor of simply using 'select x.type'
made read()s of sync/single variables result in a compiler error
NEW FEATURES:
added "blank", 'const', 'in', 'const in' and 'const ref' task intents
(see 'Task Parallelism: Task Intents' in the language specification)
added "standalone parallel iterators", used by non-zippered forall loops
(see examples/primers/parIters.chpl)
added support for aliasing of domains via the '=>' operator
NEW INTEROPERABILITY FEATURES:
inital support for Python->Chapel interoperability via PyChapel
(see http://pychapel.readthedocs.org/ for more details)
added a prototype capability to embed external dependences to source via 'use'
(e.g., use "foo.h", "-lfoo"; is like adding these to the 'chpl' command-line)
added support for passing multidimensional arrays to external routines
(see doc/technotes/README.extern)
added munging of all user identifiers by default to avoid naming conflicts
(see --[no-]munge-user-idents in 'man chpl' and doc/README.executing)
added an error when passing Chapel strings to C routines; use c_string instead
STANDARD LIBRARY/MODULES:
added a new module, FileSystem, containing numerous file system operations
(see http://chapel.cray.com/docs/latest/modules/standard/FileSystem.html)
added support for key 64-bit FFTW routines (single- and multi-threaded)
(see http://chapel.cray.com/docs/latest/modules/standard/FFTW.html and
http://chapel.cray.com/docs/latest/modules/standard/FFTW_MT.html)
added parity() and rotate() operations to the BitOps module
(see http://chapel.cray.com/docs/latest/modules/standard/BitOps.html)
added parallel versions of the glob(), walkdirs(), and findfiles() iterators
(see http://chapel.cray.com/docs/latest/modules/standard/FileSystem.html)
started a new module, Path, supporting realPath(), curDir, parentDir, pathSep
(see http://chapel.cray.com/docs/latest/modules/standard/Path.html)
added a new module, Assert, defining a simple assertion capability
(see http://chapel.cray.com/docs/latest/modules/standard/Assert.html)
added support for C types c_ptrdiff, c_uintptr, and c_intptr to SysCTypes.chpl
(see http://chapel.cray.com/docs/latest/modules/standard/gen/doc/SysCTypes.html)
changed cwd() and chdir() from standalone functions to locale methods
(see http://chapel.cray.com/docs/latest/modules/standard/FileSystem.html)
made mkdir(parents=true) behave more like 'mkdir -p'
added a .safeCast() method to integer types to value-check downcasts
(see http://chapel.cray.com/docs/latest/modules/standard/Types.html)
changed min(t) and max(t) to return 'param' values for integral types 't'
(see http://chapel.cray.com/docs/latest/modules/standard/Types.html)
parameterized RandomStream by an 'eltType' and updated its methods accordingly
(see http://chapel.cray.com/docs/latest/modules/standard/Random.html)
removed the parSafe arguments from RandomStream's methods in the Random module
(see http://chapel.cray.com/docs/latest/modules/standard/Random.html)
added support for escaping pattern-style format strings using %{}
(e.g., "writef("#%{##}", 10)" => "#10")
added support for readf()/writef() of octal values
changed 'BigInt' methods to use Chapel types rather than C types
folded the prototypical 'Filerator' module into the new 'FileSystem' module
retired the 'Containers' module in favor of vector operations on arrays
(see examples/primers/arrayVectorOps.chpl)
PERFORMANCE IMPROVEMENTS:
added support for vectorization of data parallel loops and operations
(see '--vectorize' flag in 'man chpl')
optimized away the creation of anonymous ranges in loops
(e.g., 'for i in 1..10' no longer creates an anonymous range object for 1..10)
optimized away communication code for module-scope variables and local arrays
optimized iterations over ranges in data parallel constructs like 'forall'
added standalone parallel iterators for ranges and default domain maps
extended loop-invariant code motion to include certain global variables
added an 'assertNoSlicing' config that can be used to optimize array accesses
(see $CHPL_HOME/PERFORMANCE)
avoided creating new singleton tasks within serial execution contexts
MEMORY IMPROVEMENTS:
reduced memory leaks due to compilerWarning()s and runtime string arguments
distinguished between "owned" and "unowned" c_strings in implementation
improved the handling of strings across multiple locales
LAUNCHER-SPECIFIC CHANGES:
in the 'pbs-aprun' launcher, removed reliance on the mppoptions
added a --nodelist option to the 'slurm-srun' launcher
in the 'slurm-srun' launcher, stopped using expect scripts
PLATFORM-SPECIFIC CHANGES:
fixed an issue in which Qthreads would not handle sleep() correctly for darwin
added a micro-sleep when yielding threads on Cygwin to improve throughput
changed CHPL_COMM/TASKS to default to ugni/muxed when using the cray-xmodule
(see doc/README.chplenv, doc/platforms/README.cray, and/or doc/README.tasks)
enabled 'ugni' tasking to be usable with 'qthreads' as well as 'muxed'
reduced default heap size used for CHPL_COMM='ugni' to 2/3 free node memory
(see doc/platforms/README.cray)
changed 'muxed' tasking to use # of threads equal to the # of CPUs by default
(see doc/platforms/README.cray)
disabled optimizations by default for cray-prgenv-cray compilations
split the 'cygwin' platform value into 'cygwin32' and 'cygwin64'
split the 'netbsd' platform value into 'netbsd32' and 'netbsd64'
made CHPL_TASKS default to 'fifo' for 'cray-prgenv-cray' CHPL_TARGET_COMPILER
PORTABILITY IMPROVEMENTS:
fixed several portability issues on NetBSD platforms
fixed the use of the --llvm flag on Mac OS X ('darwin') platforms
fixed some portability issues with the use of hwloc and -lnuma for 'qthreads'
fixed some static/dynamic linking issues with certain platforms/compilers
fixed a gmp build issue for 32-bit platforms
THIRD-PARTY SOFTWARE CHANGES:
updated the bundled version of GASNet to 1.24.0
updated the bundled version of hwloc to 1.10.1
updated the bundled version of llvm to 3.6.0
upgraded the bundled version of dygraphs to version 1.1.0
added support for dynamically installing Python packages required by 'chpldoc'
(see 'chpldov-venv' in third-party/README)
rearchitected scripting framework for third-party dependences
made the re2 build do a better job of propagating errors back to the Makefiles
changed Qthreads to avoid using guard pages when mprotect() won't work
fixed a bug in limiting the maximum size of Qthreads memory pools
DOCUMENTATION:
added web-based docs for all standard modules and removed from spec/READMEs
(see http://chapel.cray.com/docs/latest/)
made some minor improvements to the Quick Reference document
added documentation for class and record destructors to the spec
removed an outdated distinction between function calls using () vs. [] in spec
clarified that integer literals may be 'int' or 'uint' in the spec
added a note for 'zsh' users to the top-level README
added a note to CONTRIBUTORS noting mis-attributed code authors within GitHub
improved the documentation of the slurmlaunchers
(see doc/README.launcher, doc/platforms/README.cray)
added a note about ugni memory registration and concurrency with slurm
(see doc/platforms/README.cray)
added a note about a longstanding undocumented feature to squash ref counting
(see $CHPL_HOME/PERFORMANCE)
EXAMPLE CODES:
added a new primer example demonstrating use of the FFTW module
(see examples/primers/FFTWlib.chpl)
added standalone parallel iterators to the leader-follower primer and renamed
(see examples/primers/parIters.chpl)
updated and renamed the chpldoc primer example to reflect chpldoc's changes
(see examples/primers/chpldoc.doc.chpl)
updated the random numbers primer to reflect changes to the interface
(see examples/primers/randomNumbers.chpl)
fixed a bug in our lulesh implementation when using the 3D representation
updated miniMD's Stencil distribution to track changes in BlockDist
changed miniMD to work around a bug in passing remote records by blank intent
updated the HPCC FFT example to use new BitOps
updated SSCA2 to reflect new intent semantics for forall-loops
updated the regexdna shootout to accept extra arguments as used by framework
made stream and ra save their problem sizes when performance testing
replaced the use of format() in example codes with writef()
COMPILER FLAGS (SEE 'MAN CHPL' FOR DETAILS):
added --[no-]use-noinit to permit 'noinit' to be ignored
added support for setting --fast via environment variable CHPL_FAST
added --[no-]ignore-classes to disable local class optimizations
added --[no-]vectorize to enable/disable generation of vectorization hints
added --[no-]cast-checks to enable/disable value checking in safeCast methods
added --[no-]munge-user-idents to control munging of generated identifiers
removed all documentation-related options; use 'chpldoc' instead
added a flag --[no-]task-tracking to enable/disable runtime task tracking
NEW SEMANTIC CHECKS (FOR OLD SEMANTICS):
Improved 'const' checking for array/tuple fields and array/domain aliases
ERROR MESSAGE IMPROVEMENTS:
added an error when compiling for a configuration whose runtime is not built
improved error messages for several range overflow conditions
BUG FIXES:
fixed a bug with dynamically dispatched iterators
fixed a bug with parallel iteration over non-naturally-aligned ranges
fixed a bug in which record variables did not call user-defined constructors
fixed a bug in which arrays of associative domains could cause a segfault
fixed a bug in which user identifiers could easily conflict with C identifiers
fixed a bug with formatted writes of integers using "###."
fixed an infinite loop in binary reads of strings when EOF is reached
fixed a bug preventing sparse domains from having 'uint' indices
fixed a bug when casting param 'int(64)' and 'uint(?)' to 'c_string'
fixed a bug in which secondary parentheses-less methods did not work well
fixed a buffer overrun issue in certain I/O routines
fixed a bug in which defining multiple destructors caused a segfault
fixed some bugs in the standard Buffers module
fixed a bug in which filenames generated by --cpp-lines would get corrupted
fixed a bug in --cache-remote for 32-bit platforms
fixed a bug with loop invariant code motion in the context of nested functions
fixed a crash when using multiple formal type queries for primitives types
fixed a bug in which iterators yielding locale types caused an internal error
fixed a bug in which --no-remove-copy-calls would break certain extern records
fixed a bug in the parser causing issues with &&= and ||= for --baseline
fixed a bug in which developer pragmas were only attached to the first symbol
PLATFORM-SPECIFIC BUG FIXES:
fixed a bug in which I/O errors would print "unknown" for paths for 'cygwin'
fixed a warning in our calls to glob() when compiling with 'prgenv-cray'
fixed an issue in which generated identifiers could be too long for 'pgi'
fixed a bug in which 'gmp' would not build cleanly for 32-bit Ubuntu systems
fixed a bug in atomic operations on 'real' types for CHPL_COMM='ugni'
RUNTIME LIBRARY CHANGES:
enabled 'ugni' tasking to be usable with 'qthreads' as well as 'muxed'
changed Qthreads to yield after uncontested sync var locks to avoid starvation
COMPILER PERFORMANCE:
accelerated compilation times by disabling the task table by default
(see '--[no-]task-tracking' on the 'chpl' man page and doc/README.executing)
TESTING SYSTEM:
added support for specifying 'skipif' files as executable scripts
added a mode in which only futures with .skipif files are tested
check for .skipif conditions before wasting any effort on a test
switched to a consistent and simpler naming scheme for test configurations
added timing measurements to the log for various aspects of testing
revamped emails sent by testing scripts for maintainability and spam avoidance
made the test system less sensitive to line/versions #s in .bad comparisons
added a --test-root flag, improving start_test when run from outside CHPL_HOME
fixed a bug in which '-nl' was passed to C tests for multilocale testing
added support for jUnit XML-style report generation to start_test and paratest
made paratest.server's compopts/execopts accumulate rather than overwrite
added CHPL_TEST_UNIQUIFY_EXE to support simultaneous test runs on a directory
added the ability to set the default testing timeout via CHPL_TEST_TIMEOUT
added support for CHPL_TEST_NUM_TRIALS to be set by a user's environment
squashed duplicate error messages due to sub_test failures
fixed a bug with stdin redirects for tests with multiple .execopts
made start_test smarter about stdin and launchers for multilocale testing
improved the testing system's handling of timeouts when launchers are used
added validation for CHPL_NIGHTLY_LOGDIR in nightly testing
fixed a bug for tests with multiple execopts settings that timed out
permitted suppression files to contain blank lines
fix bug in which suppression-based issues only appeared in the test summary
fixed a bad interaction between env. vars. set in sub_test vs. execenv files
made sub_test ignore OS errors during unlinking to quiet false negatives
PERFORMANCE TESTING/GRAPHING SYSTEM:
allow scrolling of the list of graphs independently from graphs themselves
embed more information in the URL of performance graphs for sharing purposes
improved the portability of URLs from the performance graphing system
added support for 'today' as a date in the perf graph system's URL encodings
accelerated graphs by moving sorting of graphs' legends into genGraphs script
track top processes between performance runs to look for causes of noise
improved support for comparing multiple performance testing configurations
started logging the sha values for performance runs, for historical reference
changed performance graphs to use json rather than csv
automatically strip punctuation characters from the end of graph keys
DEVELOPER-ORIENTED CHANGES - UTILITY CHANGES:
added a new compiler gdb command 'locid' which prints an AST's source location
made build_configs.py support parallel execution
DEVELOPER-ORIENTED CHANGES - COMPILER FLAGS:
added --report-order-independent-loops to note loops with vectorization hints
added --remove-unreachable-blocks to attempt early removal of dead code
fixed a code pointer in the --help message for --log
DEVELOPER-ORIENTED CHANGES - MODULE IMPROVEMENTS:
added a pragma for asserting that a class field is local to the object
moved routines in support of iterators to a new module ChapelIteratorSupport
split _build_range() into several routines with better names
refactored overloads of range operator definitions
changed Filerator routines to use new isLink(), isDir(), and isFile() routines
removed requirement to add 'no ChapelStandard' pragma to internal modules
DEVELOPER-ORIENTED CHANGES - MAKEFILE IMPROVEMENTS:
added a "WARNINGS" macro that can be used to turn on C-level warnings
moved check for standard C headers into the post-commit smoke test
simplified and regularized third-party Makefiles
DEVELOPER-ORIENTED CHANGES - COMPILER IMPROVEMENTS/CHANGES:
changed the parser to a "pure push" style of parser
changed the compiler to require bison 2.5 (or later)
dramatically reworked representation and manipulation of loop AST nodes
made more AST members private and increased the use of query methods
added a new, prototype AST pretty-printer for Chapel-oriented output
made improvements to list_view()
made flags on a symbol print in a deterministic order
extended DeadCodeElimination to reclaim degenerate C for loops
made 'narrowWideReferences' its own compiler pass and refactor it
moved the 'docs' pass earlier in compilation
reorder localCopyPropagation to avoid a ref-before-def bug
improved verification of expressions to check correctness of AList links
fixed a bug in which failed chpl__tryToken resolutions could roll back too far
removed flags: FLAG_LABEL_BREAK, FLAG_LABEL_CONTINUE, FLAG_USER_NAMED
distinguished FLAG_WIDE from FLAG_WIDE_REF
deprecated the use of the MOD_MAIN tag
simplified code related to calling user-defined constructors vs. _defaultOf
converted the collapsing of nested BlockStmts to use a visitor
added a predicate to determine if an expression is a "statement expression"
converted some uses of C arrays to std::vector in compiler
added binary operators to the BitVec implementation
replaced the basic block macros with private static functions
fixed a bug in basic block analysis
moved the handling of boolean short-circuiting from 'parse' to 'normalize'
renamed 'by' operators in the compiler's IR to avoid naming conflicts
refactored fix_def_expr() in the normalize pass
refactored constant folding vs. dead code elimination for CondStmts
fixed several code issues identified by coverity scan
many other code refactorings and improvements
DEVELOPER-ORIENTED CHANGES - RUNTIME IMPROVEMENTS:
simplified interactions between locale models and the runtime
improved the non-blocking communication interface
added support for the main process to run Chapel tasks
guarded against some src==dst calls to memcpy()
for optimized builds of the runtime, set NDEBUG to turn off assertions
fixed several code issues identified by coverity scan
DEVELOPER-ORIENTED CHANGES: GENERATED CODE IMPROVEMENTS:
improved the spacing when printing IDs via --gen-ids

New in Chapel 1.10.0 (Oct 3, 2014)

The runtime tasking layer has switched to the lighter-weight Qthreads-based implementation by default, resulting in performance improvements for most computations. This release also includes initial support for Intel Xeon Phi Knights Corner (KNC) processors using the 'fifo' tasking layer.
New capabilities on arrays and domains include: support for set-based operations on associative domains and arrays; draft support for vector methods on 1D arrays that have their own individual domain; the ability to query distributed arrays to determine the subdomain that a given locale owns; and the ability to pass contiguous Chapel arrays to external procedures.
The standard library has been expanded to support library routines for bit operations, utility functions for files and directories, and prefetch; regular expression and multiple precision arithmetic support has also been enabled when using a back-end C compiler that supports re2 and GMP, respectively.
The compiler has been improved to implement better const-ness checking, to fix the semantics for passing sync/single variables to generic arguments, and to improve the support for constructor calls. More generally, the release includes improvements to performance, the quality of the generated code, error messages, and numerous bug fixes.
The example code section has been expanded to include new primer examples for associative domains and arrays, for vector operations, and for random numbers; in addition, two new Computer Language Benchmark Game computations have been added, and several others have been improved.
The auxiliary file system features now include web requests with libcurl and Lustre, in addition to better integration of HDFS.
This release of Chapel contains stable support for the base language, and for task and regular data parallelism using one or more locales. Data parallel operations on irregular domains and arrays are currently supported in a single-locale implementation. While performance has received a great deal of attention in Chapel's design and is generally improving from release-to-release, this release is lacking a number of crucial performance optimizations. See $CHPL_HOME/PERFORMANCE for additional notes on Chapel performance.

New in Chapel 1.9.0 (Apr 18, 2014)

New in Chapel 1.8.0 (Oct 19, 2013)

Highlights:
added initial support for user-defined locale models and a NUMA locale model
added initial support for accessing HDFS file systems via files/channels
improved tasking semantics w.r.t. references to variables from outer scopes
added new example codes for MiniMD and the Computer Language Benchmark Game
performance optimizations related to array base pointers, loop-invariant code
removed a number of compiler-generated memory leaks
added new types for interoperating with C: c_string, c_ptr(type), c_void_ptr
improved support for small-int computations, ranges, domains, and arrays
support for dygraph-based performance monitoring in the testing system
updates to the GASNet, Qthreads, MassiveThreads, LLVM, and CLANG packages
added a new 'cray-cs' platform to represent Cray Cluster Supercomputers
made 'gemini' the default GASNet conduit for 'cray-xe' and 'cray-xk'
added support for a SLURM + GASNet-over-Infiniband launcher
New Features:
added initial support for specifying locale models ('hierarchical locales')
(see doc/technotes/README.localeModels)
added support for a prototype NUMA locale model
(see doc/technotes/README.localeModels)
added initial support for accessing HDFS file systems via files/channels
(see doc/technotes/README.hdfs)
added new 'const in' and 'const ref' argument intents
(see the 'Argument Intents' section in the language specification)
added built-in config params for all CHPL_* environment settings
Semantic Changes / Changes to Chapel Language:
improved tasking semantics w.r.t. references to variables from outer scopes
(e.g., in 'var x=0; begin { ...x... }', 'x' is a const copy within the task)
(see 'Task Intents' section in the language specification)
added 'ref' clauses to obtain the previous reference tasking semantics
(e.g., 'var x: int; begin ref(x) { ...x... }' causes '...x...' to refer to x)
(see 'Task Intents' section in the language specification)
made blank intents for atomic variables get interpreted as 'ref'
(see the 'Argument Intents' section in the language specification)
added support for ranges, domains/arrays with small-int index types
(e.g., 'range(int(8))' is now a supported type)
added operator support for pairs of small int/uint types
(e.g., 'int(8) + int(8)' now generates an int(8) rather than int(32))
added operator support for homogenous tuple/scalar pairs
(e.g., (1,2,3) + 1 => (2,3,4))
extended the member() method on domains to support varargs as well as tuples
(e.g., 'var D = {1..n, 1..n};' supports 'D.member(i,j)' and 'D.member((i,j))')
the compiler now only creates '==' operators for matching record types
made 'bool' types prefer dispatching to 'int' args over smaller-int options
(e.g., foo(true) will prefer to dispatch to foo(x:int) over foo(x:int(8)))
New Interoperability Features:
added support for 'c_ptr(type)' and 'c_void_ptr' to refer to local C pointers
(see doc/technotes/README.extern)
added support for a 'c_string' type to refer to local C char* pointers
(see doc/technotes/README.extern)
Deprecated Features:
removed experimental GPU work to prepare for a revised approach to GPU support
removed the callStackSize() query from the locale type
removed certain config consts to control runtime arguments
(see "Flags on Generated Executables" section below)
Standard Modules:
added a new 'UtilReplicatedVar.chpl' standard module for replicated variables
new 'HDFSiterator' and 'RecordParser' modules to help with parsing HDFS files
Documentation:
added a new README to describe the new locale model concept and NUMA model
(see doc/technotes/README.localeModels)
added a new README.hdfs file to describe HDFS file system access in Chapel
(see doc/technotes/README.hdfs)
made significant improvements to the README.cray file
(see doc/platforms/README.cray)
refreshed the 'chpl' man page, particularly the SYNOPSIS/ENVIRONMENT sections
refreshed the Chapel Quick Reference document
major updates to the 'Task Parallelism' section of the spec for task intents
made minor updates to several chapters in the language specification
updated README.chplenv to reflect new CHPL_* environment variables
minor updates to various README files
Example Codes:
added an initial port of the Mantevo MiniMD miniapp to Chapel
(see examples/benchmarks/miniMD)
added Chapel ports of four codes from the Computer Language Benchmark Game
(see examples/benchmarks/shootout)
fixed a bug in the atomics.chpl primer example
cleaned up the beer.chpl example
Cray-specific Notes:
added a new 'cray-cs' platform to represent Cray Cluster Supercomputers (CS)
(see doc/platforms/README.cray for more information)
made 'gasnet' the default CHPL_COMM setting for all Cray platforms
made 'gemini' the default GASNet conduit for 'cray-xe' and 'cray-xk' platforms
(see doc/platforms/README.cray)
added support for the GASNet 'aries' conduit for the 'cray-xc' platform
(see doc/platforms/README.cray)
made 'aprun' the default launcher for 'cray-x*' systems when available
removed support for the 'xmt', 'x1', and 'x2' platforms and related features
generated warning messages on cray-x* systems when no PrgEnv is loaded
removed -target=linux flag from cray-prgenv-* compiler options
Launcher-specific Notes:
added support for a SLURM + GASNet-over-Infiniband launcher
(see 'slurm-gasnetrun_ibv' in doc/README.launcher)
made the aprun-based launchers use the system's default number of CPUs
brought the pbs launchers up-to-date with the current NCCS wrapper of qsub
Portability of code base:
worked around a PGI portability issue with C structs in the generated code
improved const checking for actuals passed to out/inout/const ref/ref intents
improved error messages for programs with bad type resolution cycles
added a warning for while loops over constants
errors for assignments to non-lvalues no longer halt compilation immediately
Performance Improvements:
improved performance of local arrays by storing a shifted base pointer
added a loop-invariant code motion optimization
passed more things by value ('this', array/domain/domain map wrappers)
made some improvements to the bulk copy optimization
Memory Leak Improvements:
reduced memory leaked by strings by sharing them more aggressively
improved support for destroying more automatic variables as they leave scope
fixed a memory leak relating to inlining of iterators
plugged memory leaks related to file types
freed temporary buffers used for formatted I/O on complex values
Bug Fixes / New Semantic Checks (for old semantics):
fixed bugs in extern blocks containing #define's
fixed a bug when reading string literals that began with whitespace
fixed a bug in which whitespace was written to binary files for array output
fixed bugs related to writef() for complex values
fixed size mismatches in IO code for 32-bit linux systems
fixed a bug in the compareExchange implementation for atomic reals
fixed bugs in Regexp convenience functions and the naming of string.split()
fixed some bugs in BigInt functions in the GMP module
fixed a bug in which AdvancedIterators would serialize if #chunks < #tasks
fixed a bug related to 'ref' intents and the fast segment for GASNet
fixed a bug related to using --make on the chpl command line
bug fix for lost updates to fields of 'this' in certain scenarios
fixed dead code elimination for blocks that are their own sole in-arc
Third-Party Software Changes:
updated to GASNet version 1.20.2 which improves the Cray native conduits
updated to Qthreads version 1.10 and turned on support for stack overflow
(see reference to QT_GUARD_PAGES in doc/README.tasks for more information)
updated to MassiveThreads version 0.95 with support for task-private data
updated the LLVM back-end to use version 3.3 and packaged it with the release
packaged CLANG 3.3 with the release rather than requiring a separate download
Runtime Library Changes:
made several interface changes to support locale models/hierarchical locales
Generated Code Cleanups:
declared non-exported symbols 'static' in generated code
added support for targeting 'op=' operators in the back-end
removed chains of unnecessary autocopy/autodestroy calls
Compiler Performance:
disabled compiler internal verification by default to improve compile time
LLVM Back-end Changes:
added wide pointer support for the LLVM back-end via CHPL_WIDE_POINTERS
(see doc/technotes/README.llvm and doc/README.chplenv)
added support for LLVM-based communication optimizations via --llvm-wide-opt
(see doc/technotes/README.llvm)
Testing System:
changed performance graphing to use dygraphs
added support for filing .bad files against futures to track behavior changes
added support for setting environment variables on a per-test/-directory basis
added the ability to use an external 'time -p' command for performance tests
added directory-level PERFCOMPOPTS/PERFEXECOPTS files
added a timeout feature for performance testing (separate from correctness)
fixed a bug in which spec tests weren't being generated correctly
added the capability for the test directory to clean itself up more thoroughly
Makefile Changes:
changed the naming scheme for intermediate object file directories
added a 'cleanall' target between 'clean' and 'clobber'
(see README.building)
made the 'clean' and 'cleanall' targets preserve a working installation
accelerated the Makefile framework, particularly for no-op re-builds
made the Makefiles smarter about rebuilding the compiler when necessary
Internal/Developer-oriented:
added a new 'createTaskFunctions' pass that creates functions defining tasks
added a new 'resolveIntents' pass which resolves 'blank' and 'const' intents
added a per-pass consistency/verification framework
added a --verify compiler flag for running optional verification steps
added an --ignore-errors-for-pass compiler flag for developers
added a compiler analysis to compute dominators
fixed a bug in isDefAndOrUse() for op= primitives
rearchitected the QIO framework to support multiple file systems
refactored the memory interface to better separate checking/tracking concerns
switched to using 'ref' intents rather than 'inout' for I/O routines
added "atomic type" flag for identifying atomic types to the compiler
added "donor" function concept, making the callee responsible for deletion
added "runtime type init fn" pragma to clarify overloaded "has runtime type"
fixed a bug in which 'begin's in internal modules broke compilation
restructured iterators so that not all yields would share the same variable
improved cases where filename/line numbers aren't set correctly
continued transition toward STL collections within the compiler
added new capabilities to the bit vector class
removed several instances of strcpy()s in the compiler
added a functional interface for invoking remote functions by ID
restructured #includes to avoid reliance on compiler-specific search policies
added new features for debugging the compiler
Changes In Support of Hierarchical Locales:
made ranges and default rectangular domains/arrays use sublocales, if present
made on-clauses get invoked through locale model module code in Chapel
moved optimization of local on-clauses from the compiler to locale model code
made task invocation flow through locale model module code written in Chapel
mapped the tasking interface's support for hierarchical locales to Qthreads
made hierarchical locale model compilations use wide pointers and on-clauses

New in Chapel 1.7.0 (Apr 19, 2013)

Environment Changes:
renamed the platform 'cray-cascade' to 'cray-xc'
renamed the platforms 'xmt'/'xmt-sim' to 'cray-xmt'/'cray-xmt-sim'
enabled GMP support by default if it is already built in the third-party dir
Syntactic/Naming Changes:
added support for associative domain/array literals
(e.g., {"red", "blue"} is an associative domain of strings)
(e.g., ["red" => 0, "blue => 1] is an assoc. array from strings to ints)
Semantic Changes / Changes to Chapel Language:
added support for injecting C declarations into Chapel via "extern blocks"
(see "Support for Extern Blocks" section of doc/technotes/README.extern)
added support for iteration over homogenous tuples
(see "Tuples" section of the Chapel spec)
added a capability for main() to take arguments and return a status value
(see doc/technotes/README.main)
added a 'requestCapacity()' capability to pre-size associative domains
(see "Domains:Predefined Functions" section of the Chapel spec)
added a warning() routine to generate warnings, similar to halt(), assert()
(see "Standard Modules" section of the Chapel spec)
Newly Implemented Features:
added support for the .localSlice() method to take a domain argument
(e.g., A.localSlice({loRow..hiRow, loCol..hiCol}))
Deprecated Features:
removed the tuple() function
(i.e., instead of tuple(x) or tuple(x,y,z), use (x,) or (x,y,z) instead)
deprecated warning for old-style domain literals by default
(i.e., [1..m, 1..n] is an array of ranges; re-enable w/ --warn-domain-literal)
Standard Modules:
added support for regular expression operations on strings and channels
(see doc/technotes/README.regexp for details)
added support for readf()/writef() routines for formatted I/O
(see doc/technotes/README.formattedIO for details)
refactored communication diagnostics into its own module (CommDiagnostics)
(see doc/technotes/README.comm-diagnostics for documentation)
added isDomainType(type t)/isArrayType(type t)/isRecordType(type t) queries
Documentation:
added README.formattedIO to describe support for writef()/readf() routines
(see doc/technotes/README.formattedIO)
added README.regexp to describe support for regular expression operations
(see doc/technotes/README.regexp)
added README.main to describe support for arguments/return values for main()
(see doc/technotes/README.main)
updated README.extern to describe C type aliases and extern blocks
changed READMEs that used csh-style syntax to use bash-style consistently
fixed a semantic typo in README.atomics
minor updates and fixes to various chapters in the language specification
minor updates to several READMEs
Example Codes:
improvements to the Chapel implementation of LULESH
(see examples/benchmarks/lulesh/ for more details)
configuration improvements (see README for details):
added ability to compute the cube input set rather than reading from disk
support for 3D vs. 1D representations via 'use3DRepresentation'
support sparse vs. dense material representations via --sparseMaterials
added a --maxcycles config that can be used to stop the computation early
converted 'dtfixed' into a config const
added a per-iteration timing when doTiming and showProgress are enabled
code improvements:
refactored setup code into a helper module: luleshInit.chpl
changed the representation of nodesets to use a sparse subdomain
switched to using 'ref' intents rather than 'in' or 'inout'
converted vars to consts where appropriate
general code cleanup
performance improvements:
improved performance by avoiding an unnecessary reindexing operation
made some unnecessarily serial loops parallel
replaced error-oriented reductions with forall loops + halt
param-unrolled the loop in localizeNeighborNodes() for performance reasons
removed a redundant zero-initialization of an array
documentation improvements:
updated README to document new configuration options
added the LULESH callgraph to the README
improved the Chapel implementation of RA:
added the ability to use an LCG random number generator via 'useLCG'
added a config const 'verify' that permits verification to be skipped
fixed a typo in HPL that inflated the calculated GFLOPs by 10x
improvements to the Chapel implementation of SSCA2:
fixed a bug in the torus representation
fixed a bug with VALIDATE_BC=true
Platform-specific Notes:
enabled GMP using the system-installed version on cray-x* platforms by default
Portability of code base:
fixed an issue related to vsnprintf on OS X Lion
fixed an assumption that platforms defining INT8_MIN will also define INT*_MIN
Launcher-specific Notes:
improved use of cnselect in launchers that use 'aprun'
Compiler Flags:
added --novariants of the following compiler flags: --count-tokens, --llvm,
--print-code-size, --print-commands, --print-passes, --print-search-dirs,
added --[no-]warn-tuple-iteration to warn against old-style zipper iteration
(see man page for details)
added --[no-]warn-special as a meta-flag for all old-style syntax uses
(see man page for details)
improved support for environment variable setting of '--no-'style flags
(see man page for details)
Error Message Improvements:
improved type mismatch error messages when assigning scalars to arrays
added an error for extern functions with formal arguments of array type
made Ctrl-C and the like result in a user, rather than internal, error
added an error for associative domains with unsupported index types
Bug Fixes / New Semantic Checks (for old semantics):
fixed a bug in which sizeof() had leaked into the user namespace in v1.6
fixed a regression in v1.6 in which type aliases of arrays were broken
fixed a bug in which 0-element arrays of arrays would free domains prematurely
fixed a bug related to writing out instances of the RandomStream class
I/O bug fixes:
QIO_HINT_PARALLEL now works for new/zero length files
fixed bugs related to bit-oriented reads and writes
fixed a bug w.r.t. EOF and preemptive mmap
fixed portability bug related to Intel compilers
changed channels so that once EOF is hit, it will never read further
fixed issues related to ssize_t/int(64) mismatches on 32-bit platforms
fixed an issue related to reading empty strings
fixed some bugs in the implementation of atomic variables
fixed a bug in which AdvancedIters didn't default 'numTasks' as documented
improved shape checking for array assignment
restricted reshape() to be applied for rectangular domains only
restricted reshape() to only work when the source and destination sizes match
improved support for Cyclic distributions of idxType uint(64)
fixed INFINITY and NAN to be of type 'real' rather than 'real(32)'
fixed a bug with '/*/' within a nested comment
fixed a bug in which uses of ** would dispatch to a user's pow() overload
fixed a few bugs in the Buffers.chpl module
fixed a bug in which memory leak tracking would mislabel some allocations
fixed a bug with recursive iterator inlining
fixed a bug in broadcasting large values at program startup
Packaging Changes:
added Chapel mode support for emacs version 23.x (see etc/emacs/README)
Performance Improvements:
switched to using processor atomics for reference counting on Cray systems
improved bulk transfer optimization (use -s useBulkTransferStride to enable)
put fewer variables on the heap in the presence of nested functions
enabled remote value forwarding for more constants/arguments than before
made atomic variables use compiler intrinsics for cray-prgenv-intel
made associative domains of 'imag' indices more efficient
Runtime Library Changes:
split chpl_task_begin() to distinguish between new tasks and migrating ones
improved the ability to build the Chapel runtime with a C++ compiler
Third-Party Software Changes:
updated to version 1.20 of GASNet
updated to version 1.9 of Qthreads
made the LLVM checkout script grab version 3.2 to ensure compatability
removed the nanox tasking layer due to lack of support/champion
Testing System
extended the 'skipif' capability to support the ability to skip a subdirectory
improved the robustness of start_test in cross-compiled environments
added support for .no-local.good files for --no-local-specific test output
fixed a bug in which the test system looked at incorrect .future files
removed artificial limiting of stacksize in start_test
refactored test system environment setup into util/test/testEnv
made the test system use $cwd rather than 'pwd'
made 'nightly' compopts/execopts get added to end of the command line
made 'nightly' support a --no-futures option
Internal/Developer-oriented
--------added some code that sets the groundwork for supporting hierarchical locales
fixed portability of bswap.h (for once and for all?)
restructured internal modules corresponding to specific runtime layers
removed uses of alloca()
removed PRIM_CHPL_ALLOC_PERMIT_ZERO
deprecated 'make depend' and made use of gcc -MMD/-MP instead
made 'rm -rf' commands a little safer in Makefile clean/clobber rules
refactored Makefiles for Cray systems/compilers to avoid repetition
added a map_view() function for printing out SymbolMaps
removed some dead and possibly incorrect methods from Map and Vec classes
refactored _cast functions for booleans
made the _isPrimitiveType test more concise
improved the mechanism by which line numbers are assigned to AST nodes
factored sync/single out of ChapelBase.chpl and into ChapelSyncvar.chpl
fixed the --gen-extern-prototypes flag
improved the correspondence of FLAG_* and string forms of AST flags
improved the correspondence of PRIM_* and string forms of primitives
refactored chplrt.h
added initial support for a .localAccess accessor to Block/Default arrays
renamed compiler-generated types for classes in generated code
refactored QIO code in the runtime
converted macros in the compiler to inline functions for sanity/performance
cleaned up the functions that build array/domain literals
refactored and commented lowerIterators.cpp
keep dtObject alive even if unused after function resolution
added EOF to the list of reserved symbol names
protected some C identifiers introduced by PGI when compiling with -Kieee

New in Chapel 1.5.0 (Apr 20, 2012)

New in Chapel 1.3.0 (Apr 22, 2011)

New in Chapel 1.1.1 (Sep 23, 2010)

High-Level Themes
single- and multi-locale task parallelism
improved single- and multi-locale data parallelism
all data parallel operations on arithmetic arrays are now parallelized
improved control over task quantity and granularity for data parallelism
improved completeness and stability of Block and Cyclic distributions
bug fixes
Environment Changes
added CHPL_TASKS to select the tasking layer to use (was CHPL_THREADS)
(see doc/README.chplenv and doc/README.tasks for details)
CHPL_THREADS now describes lower-level threading and is typically inferred
(see doc/README.tasks)
changed the name of the default tasking layer from 'default' to 'fifo'
(see doc/README.chplenv and doc/README.tasks)
added CHPL_TIMERS to select between timer implementations
(see doc/README.chplenv)
changed the CHPL_*_PLATFORM string for 32-bit linux from 'linux' to 'linux32'
(see doc/README.chplenv)
Syntactic/Naming Changes
several changes related to the naming and syntax of distributions:
renamed "distributions" to "domain maps" (or 'dmap's in Chapel syntax)
redefined the term "distributions" to refer to multi-locale domain maps
defined the term "layouts" to refer to single-locale domain maps
replaced placeholder 'distributionType'/'distributionValue' with 'dmap'
(e.g., 'const D = distributionValue(...)' => 'const D = new dmap(...)'
changed the 'distributed' keyword to 'dmapped'
added a syntactic sugar to drop 'new dmap(new' for anonymous domain maps
(e.g., '...dmapped new dmap(new Block(...))...' => '...dmapped Block(...)')
(see 'Domain Maps' chapter of language specification for more information)
renamed maxThreads to maxThreadsPerLocale (see README.tasks)
renamed the 'ind2loc' method on domain maps to 'idxToLocale'
renamed the Cyclic constructor 'low' argument to 'startIdx'
(see 'Standard Distributions' chapter of the specification)
replaced the use of underscore (_) to ignore things to leaving the space blank
(e.g., '(_, x) = getTuple()' => '( , x) = getTuple()')
made underscore (_) a legal identifier
changed name of the Random module's SeedGenerator from clockMS to currentTime
(see 'Standard Modules' chapter of the specification)
added support for empty (no-op) statements within a class declaration
added ability to elide the # of arguments specification/query from varargs fns
(e.g., can now do 'def f(x...)' in addition to 'def f(x...?n)'/'def f(x...n)')

New in Chapel 1.02 (Nov 30, 2009)

replaced uses of "[unsigned] long long" with [u]int64_t for sane portability
some unification of reserved names, though more remains
improved Chapel's launcher runtime interface to be more general
added a mechanism for intercepting printf/fprintf calls if required
Makefile refactorings working toward supporting parallel make
refactored runtime/mem- directories to decrease duplicated code
renamed runtime files to improve standardization, though more remains
removed linked list pointers from memory tracking table
reduced amount of runtime code linked into the launcher binary
made the use of chpl_globals_registry more consistent across locales
relaxed compiler assumptions about classes with the "data class" pragma
added support for generating type and offset information for communications
some initial work toward supporting execution on heterogeneous architectures
some initial work toward supporting CPUGPU computations in Chapel
some initial work toward supporting profiling tools with Chapel
removed "valid var" pragma
made wrapper functions use blank intent rather than inheriting from wrappee
changed strategy for determining when value types should be copied/destroyed
made domain and array classes always have reindexed set to true by default
added a developer flag for disabling compiler-introduced memory frees
removed support for _init functions from the compiler
removed assumptions that replicated global constants are stored symmetrically
added thread cancel and join functions to the threading runtime interface
added a type, chpl_threadID_t to pass thread IDs between C and Chapel
changed point at which variables are put on the heap
made all built-in modules be filename based
refactored directory structure of $CHPL_HOME/modules into standard/internal...
added optimizations to remove unnecessary autocopy/autodestroy calls
improved robustness of internal modules that use standard ones
changed the scan implementation to generate an array rather than a list
changed array assignments to use array iteration rather than random access
made --no-cpp-lines the default for -g for developers
improved handling, robustness of built-in configuration variables
split chpl_comm_md.h into two files to permit platform- and comm- overrides

New in Chapel 0.9 (Apr 24, 2009)

High-Level Themes:
multi-locale task parallelism
very initial/limited support for data parallelism, distributed arrays
improved stability, portability, and performance
target audience: general public
Environment Changes:
added a script to print out set and inferred CHPL env vars
(see util/printchplenv.pl)
added support for the IBM xlc/xlC compilers by setting CHPL_*_COMPILER to ibm
added an environment variable for naming a queue for the PBS launcher
(see doc/platforms/README.xt-cle)
added an environment variable for specifying #cores/locale to pbs/aprun
(see doc/platforms/README.xt-cle)
improved the logic for inferring host and target compilers for xt-cle
Changes to Chapel Language:
added a typeToString() function for converting a static type into a string
Newly Implemented Features:
added queries for task/thread counts per locale for CHPL_THREADS=pthreads
(see doc/README.threads)
added a printMemTable() routine to the Memory module for use in Chapel
(see doc/README.executing)
added a prototype multidimensional Block distribution: MultiBlockDist.chpl
(see examples/tutorials/block2D.chpl)
Portability of code base:
improved our general method of building and using GASNet for portability
improved portability of GASNet configure + build steps for xt-cle
improved the heuristic for setting GASNET_MAX_SEGSIZE for xt-cle
(see doc/platforms/README.xt-cle)
added initial support for IBM Power5 and Power6 systems
(see doc/platforms/README.ibm)
made flex and bison generate .cpp files rather than .c files for portability
added capabilities to build Chapel on Macs using xcodebuild
(see doc/platforms/README.macosx)
added a -d option to our use of aprun in the aprun and pbs launchers
removed the assumption that function pointers are identical between nodes
Syntactic/Naming Changes:
disallowed identifiers that start with $
removed compilerError and compilerWarning as keywords
permitted binary and hex literals to be written using uppercase B/X
renamed classes used for defining distributions
Runtime Library Changes:
added support for communication diagnostics and debugging
(see doc/technotes/README.comm-diagnostics)
Documentation:
added a new ACKNOWLEDGEMENTS file for financial and machine time support
refactored the doc directory, pushing platform & technical notes into subdirs
minor changes and improvements to the language specification
minor edits to many of the README files
updated the man page
Example Codes:
pushed most top-level examples into tutorials/ and programs/ subdirectories
added new tutorial examples for variables, ranges, classes, generic classes
added new tutorial examples for timers and the prototype Block distribution
changed quicksort to ensure levels beyond thresh do not re-enable parallelism
Compiler Flags:
added a flag to disable/enable the remote value forwarding optimization
Bug Fixes/New Semantic Checks (for old semantics):
fixed a number of spurious errors caused by how we were using GASNet
fixed problems in how we terminated multithreaded GASNet programs
added the ability for _chpl_comm_fork[_nb] to handle large arguments
applied a GASNet patch that fixes an x86 alignment error
fixed a bug which had previously limited execution to 1024 locales
fixed a bug in which arrays could only store 2**31 elements
eliminated a race condition when two tasks initialize the same module
fixed a bug in which integer exponentiation was being computed using pow()
fixed a bug in which slicing via .. could only be done for int(32) indices
fixed a bug with Block1D domains that exceed the bounding box argument
added a check to ensure that return statements are not used at module scope
improved verification of formal/actual argument types
fixed a bug in which long program names broke the PBS launcher
fixed a bug with incorrectly spacing operators in generated code
fixed Chapel error messages that referred to C's errno variable
fixed a bug with accidentally shared state during parallel iterations
fixed a bug related to reductions involving forall expressions
Error Message Improvements:
added a runtime error message if the launcher binary can't find the _real one
Compiler Analysis and Optimizations/Performance of Generated Code:
improved the correctness and effectiveness of remote value forwarding
optimized performance of local communications
optimized parallel iteration for Block1D to minimize remote references
parallelized declarations of Block1D distributions, domains, and arrays
optimized implementation of broadcasts used to initialize private data
optimized away a thread per locale used for progress+termination
improved reclamation of compiler-allocated memory
improved the correctness and effectiveness of re-privatization optimizations
privatized the default distribution object
removed array/domain wrapper records
Compiler Performance and Cleanup:
removed hand-baked and occasionally incorrect integer types int32, int64
fixed an infinite loop when inlining recursive iterators
fixed cases in which compiler temps were used outside the variable's scope
Cleanup of Generated Code:
removed redundant reference types from the generated code
Internal:
switched iterator implementation to use records rather than classes
improved the naming of identifiers in the runtime and generated code
removed compiler support for (undocumented) anonymous record types