0.15.5

Added

• reduce_by_index with f32-addition is now approximately 2x
  faster in the CUDA backend.

Fixed

• Fixed kernel extractor bug in if-interchange (#921).

• Fixed some cases of malformed kernel code generation (#922).

• Fixed rare memory corruption bug involving branches returning
  arrays (#923).

• Fixed spurious warning about entry points involving opaque return
  types, where the type annotations are put on a higher-order return
  type.

• Fixed incorrect size type checking for sum types in negative
  position with unknown constructors (#927).

• Fixed loop interchange for permuted sequential loops with more
  than one outer parallel loop (#928).

• Fixed a type checking bug for branches returning incomplete sum
  types (#931).

0.15.4

Added

• futhark pkg now shells out to curl for HTTP requests.

• futhark doc now supports proper GitHub-flavored Markdown, as it
  uses the cmark-gfm library internally.

• Top-level constants are now executed only once per program
  instance. This matters when Futhark is used to generate library
  code.

• futhark autotune is better at handling degrees of parallelism
  that assume multiple magnitudes during a single run.

• futhark pkg now uses curl to retrieve packages.

• Type errors are now printed in red for better legibility (thanks
  to @mxxo!).

Fixed

• Fixed incorrect handling of opaques in entry point return types.

• futhark pkg now works properly with GitLab (#899).

0.15.3

Added

• scan now supports operators whose operands are arrays. They are
  significantly slower than primitive-typed scans, so avoid them if
  at all possible.

• Precomputed constants are now handled much more efficiently.

• Certain large programs that rely heavily on inlining now compile
  orders of magnitude faster.

Fixed

• Some fixes to complicated module expressions.

• futhark pkg should no longer crash uncontrollably on network
  errors (#894).

• Fixed local open in interpreter (#887).

• Fix error regarding entry points that called other entry points
  which contained local functions (#895).

• Fix loading OpenCL kernels from a binary.

0.15.2

Fixed

• Fix a REPL regression that made it unable to handle overloaded
  types (such as numeric literals, oops).

• The uniqueness of a record is now the minimum of the uniqueness of
  any of its elements (#870).

• Bug in causality checking has been fixed (#872).

• Invariant memory allocations in scan/reduce operators are now supported.

• futhark run now performs more type checking on entry point input (#876).

• Compiled Futhark programs now check for EOF after the last input
  argument has been read (#877).

• Fixed a bug in loop type checking that prevented the result from
  ever aliasing the initial parameter values (#879).

0.15.1

Added

• Futhark now type-checks size annotations using a size-dependent
  type system.

• The parallel code generators can now handle bounds checking and
  other safety checks.

• Integer division by zero is now properly safety-checked and
  produces an error message.

• Integer exponentiation with negative exponent is now properly
  safety-checked and produces an error message.

• Serious effort has been put into improving type errors.

• reduce_by_index may be somewhat faster for complex operators on
  histograms that barely fit in local memory.

• Improved handling of in-place updates of multidimensional arrays
  nested in map. These are now properly parallelised.

• Added concat_to and flatten_to functions to prelude.

• Added indices function to the prelude.

• futhark check and all compilers now take a -w option for
  disabling warnings.

• futhark bench now accepts --pass-compiler-option.

• The integer modules now have mad_hi and mul_hi functions for
  getting the upper part of multiplications. Thanks to @porcuquine for the contribution!

• The f32 and f64 modules now also define sinh, cosh,
  tanh, asinh, acosh, and atanh functions.

• The f32 and f64 modules now also define fma and mad
  functions.

Removed

• Removed update, split2, intersperse, intercalate, pick,
  steps, and range from the prelude.

Changed

• "futlib" is now called "prelude", and it is now an error to
  import it explicitly.

Fixed

• Corrected address calculations in csharp backend.

• The C backends are now more careful about generating overflowing
  integer operations (since this is undefined behaviour in C, but
  defined in Futhark).

• futhark dataset no longer crashes uncontrollably when used
  incorrectly (#849).

0.14.1

Added

• The optimiser is now somewhat better at removing unnecessary
  copies of array slices.

• futhark bench and futhark test now take a --concurrency
  option for limiting how many threads are used for housekeeping
  tasks. Set this to a low value if you run out of memory.

• random test blocks are now allowed to contain integer literals
  with type suffixes.

• :frame <n> command for futhark repl for inspecting the stack.

• e :> t notation, which means the same as e : t for now, but
  will have looser constraints in the future.

• Size-lifted type abbreviations can be declared with type~ and
  size-lifted type parameters with '~. These currently have no
  significant difference from fully lifted types.

Changed

• Tuples are now 0-indexed (#821, which also includes a conversion
  script).

• Invalid ranges like 1..<0 now produce a run-time error instead
  of an empty array.

• Record updates (r with f = e) now require r to have a
  completely known type up to f. This is a restriction that will
  hopefully be lifted in the future.

• The backtrace format has changed to be innermost-first, like
  pretty much all other languages.

• Value specs must now explicitly quantify all sizes of function
  parameters. Instead of

  val sum: []t -> t
  

  you must write

  val sum [n]: [n]t -> t
  

• futhark test now once again numbers un-named data sets from 0
  rather than from 1. This fits a new general principle of always
  numbering from 0 in Futhark.

• Type abbreviations declared with type may no longer contain
  functions or anonymous sizes in their definition. Use type^ for
  these cases. Just a warning for now, but will be an error in the
  future.

Fixed

• Work around (probable) AMD OpenCL compiler bug for
  reduce_by_index operations with complex operators that require
  locking.

• Properly handle another ICE on parse errors in test stanzas (#819).

• futhark_context_new_with_command_queue() now actually works. Oops.

• Different scopes are now properly addressed during type inference
  (#838). Realistically, there will still be some missing cases.

0.13.2

Added

• New subcommand, futhark query, for looking up information about
  the name at some position in a file. Intended for editor
  integration.

• (Finally) automatic support for compute model 7.5 in the CUDA backend.

• Somewhat better performance for very large target arrays for
  reduce_by_index..

Fixed

• Fixed a slice-iota simplification bug (#813).

• Fixed defunctionalisation crash involving intrinsics (#814).

0.13.1

Added

• Stack traces are now multiline for better legibility.

Changed

• The empty(t) notation now specifies the type of the entire
  value (not just the element type), and requires dimension sizes
  when t is an array (e.g. empty(i32) is no longer allowed, you
  need for example empty([0]i32)).

• All input files are now assumed to be in UTF-8.

Fixed

• Fixed exponential-time behaviour for certain kernels with large
  arithmetic expressions (#805).

• futhark test and friends no longer crash when reporting some
  errors (#808).

• Fix uniqueness of loop results (#810).

0.12.3

Added

• Character literals can now be any integer type.

• The integer modules now have popc and clz functions.

• Tweaked inlining so that larger programs may now compile faster
  (observed about 20%).

• Pattern-matching on large sum typed-values taken from arrays may
  be a bit faster.

Fixed

• Various small fixes to type errors.

• All internal functions used in generated C code are now properly
  declared static.

• Fixed bugs when handling dimensions and aliases in type ascriptions.

0.12.2

Added

• New tool: futhark autotune, for tuning the threshold parameters
  used by incremental flattening. Based on work by Svend Lund
  Breddam, Simon Rotendahl, and Carl Mathias Graae Larsen.

• New tool: futhark dataget, for extracting test input data. Most
  will probably never use this.

• Programs compiled with the cuda backend now take options
  --default-group-size, --default-num-groups, and
  --default-tile-size.

• Segmented reduce_by_index are now substantially fasted for small
  histograms.

• New functions: f32.lerp and f64.lerp, for linear interpolation.

Fixed

• Fixes to aliasing of record updates.

• Fixed unnecessary array duplicates after coalescing optimisations.

• reduce_by_index nested in maps will no longer sometimes
  require huge amounts of memory.

• Source location now correct for unknown infix operators.

• Function parameters are no longer in scope of themselves (#798).

• Fixed a nasty out-of-bounds error in handling of irregular allocations.

• The floor/ceil functions in f32/f64 now handle infinities
  correctly (and are also faster).

• Using % on floats now computes fmod instead of crashing the compiler.