0.18.1

Added

• Experimental multi-threaded CPU backend, multicore.

Changed

• All sizes are now of type i64. This has wide-ranging
  implications and most programs will need to be updated (#134).

0.17.3

Added

• Improved parallelisation of futhark bench compilation.

Fixed

• Dataset generation for test programs now use the right futhark
  executable (#1133).

• Really fix NaN comparisons in interpreter (#1070, again).

• Fix entry points with a parameter that is a sum type where
  multiple constructors contain arrays of the same statically known
  size.

• Fix in monomorphisation of types with constant sizes.

• Fix in in-place lowering (#1142).

• Fix tiling inside multiple nested loops (#1143).

0.17.2

Added

• Obscure loop optimisation (#1110).

• Faster matrix transposition in C backend.

• Library code generated with CUDA backend can now be called from
  multiple threads.

• Better optimisation of concatenations of array literals and
  replicates.

• Array creation C API functions now accept const pointers.

• Arrays can now be indexed (but not sliced) with any signed integer
  type (#1122).

• Added --list-devices command to OpenCL binaries (#1131)

• Added --help command to C, CUDA and OpenCL binaries (#1131)

Removed

• The integer modules no longer contain iota and replicate
  functions. The top-level ones still exist.

• The size module type has been removed from the prelude.

Changed

• Range literals may no longer be produced from unsigned integers.

Fixed

• Entry points with names that are not valid C (or Python)
  identifiers are now pointed out as problematic, rather than
  generating invalid C code.

• Exotic tiling bug (#1112).

• Missing synchronisation for in-place updates at group level.

• Fixed (in a hacky way) an issue where reduce_by_index would use
  too much local memory on AMD GPUs when using the OpenCL backend.

0.16.4

Added

• #[unroll] attribute.

• Better error message when writing a[i][j] (#1095).

• Better error message when missing "in" (#1091).

Fixed

• Fixed compiler crash on certain patterns of nested parallelism
  (#1068, #1069).

• NaN comparisons are now done properly in interpreter (#1070).

• Fix incorrect movement of array indexing into branches ifs
  (#1073).

• Fix defunctorisation bug (#1088).

• Fix issue where loop tiling might generate out-of-bounds reads
  (#1094).

• Scans of empty arrays no longer result in out-of-bounds memory
  reads.

• Fix yet another defunctionalisation bug due to missing
  eta-expansion (#1100).

0.16.3

Added

• random input blocks for futhark test and futhark bench now
  support floating-point literals, which must always have either an
  f32 or f64 suffix.

• The cuda backend now supports the -d option for executables.

• The integer modules now contain a ctz function for counting
  trailing zeroes.

Fixed

• The pyopencl backend now works with OpenCL devices that have
  multiple types (most importantly, oclgrind).

• Fix barrier divergence when generating code for group-level
  colletive copies in GPU backend.

• Intra-group flattening now looks properly inside of branches.

• Intra-group flattened code versions are no longer used when the
  resulting workgroups would have less than 32 threads (with default
  thresholds anyway) (#1064).

0.16.2

Added

• futhark autotune: added --pass-option.

Fixed

• futhark bench: progress bar now correct when number of runs is
  less than 10 (#1050).

• Aliases of arguments passed for consuming parameters are now
  properly checked (#1053).

• When using a GPU backend, errors are now properly cleared.
  Previously, once e.g. an out-of-bounds error had occurred, all
  future operations would fail with the same error.

• Size-coercing a transposed array no longer leads to invalid code
  generation (#1054).

0.16.1

Added

• Incremental flattening is now performed by default. Use
  attributes to constrain and direct the flattening if you have
  exotic needs. This will likely need further iteration and
  refinement.

• Better code generation for reverse (and the equivalent explicit
  slice).

• futhark bench now prints progress bars.

• The cuda backend now supports similar profiling as the opencl
  option, although it is likely slightly less accurate in the
  presence of concurrent operations.

• A preprocessor macro FUTHARK_BACKEND_foo is now defined in
  generated header files, where foo is the name of the backend
  used.

• Non-inlined functions (via #[noinline]) are now supported in GPU
  code, but only for functions that exclusively operate on
  scalars.

• futhark repl now accepts a command line argument to load a
  program initially.

• Attributes are now also permitted on declarations and specs.

• futhark repl now has a :nanbreak command (#839).

Removed

• The C# backend has been removed (#984).

• The unsafe keyword has been removed. Use #[unsafe] instead.

Changed

• Out-of-bounds literals are now an error rather than a warning.

• Type ascriptions on entry points now always result in opaque types
  when the underlying concrete type is a tuple (#1048).

Fixed

• Fix bug in slice simplification (#992).

• Fixed a typer checker bug for tracking the aliases of closures
  (#995).

• Fixed handling of dumb terminals in futhark test (#1000).

• Fixed exotic monomorphisation case involving lifted type
  parameters instantiated with functions that take named parameters
  (#1026).

• Further tightening of the causality restriction (#1042).

• Fixed alias tracking for right-operand operator sections (#1043).

0.15.8

Added

• Warnings for overflowing literals, such as 1000 : u8.

• Futhark now supports an attribute system, whereby expressions can
  be tagged with attributes that provide hints or directions to the
  compiler. This is an expert-level feature, but it is sometimes
  useful.

0.15.7

Added

• Faster index calculations for very tight GPU kernels (such as the
  ones corresponding to 2D tiling).

• scan with vectorised operators (e.g. map2 (+)) is now faster
  in some cases.

• The C API has now been documented and stabilized, including
  obtaining profiling information (although this is still
  unstructured).

Fixed

• Fixed some cases of missing fusion (#953).

• Context deinitialisation is now more complete, and should not leak
  memory (or at least not nearly as much, if any). This makes it
  viable to repeatedly create and free Futhark contexts in the same
  process (although this can still be quite slow).

0.15.6

Added

• Binary operators now act as left-to-right sequence points with
  respect to size types.

• futhark bench now has more colourful and hopefully readable
  output.

• The compiler is now about 30% faster for most nontrivial programs.
  This is due to parallelising the inlining stage, and tweaking the
  default configuration of the Haskell RTS.

• futhark dataset is now about 8-10x faster.

Fixed

• Fixed some errors regarding constants (#941).

• Fixed a few missing type checker cases for sum types (#938).

• Fix OOB write in CUDA backend runtime code (#950).