LuaJIT Change History

-This is a list of changes between the released versions of LuaJIT.
-The current stable version is LuaJIT 2.0.5.
-

-Please check the -» Online Change History -to see whether newer versions are available. -

- -

LuaJIT 2.1.0-beta3 — 2017-05-01

Rewrite memory block allocator.
Add various extension from Lua 5.2/5.3.
Remove old Lua 5.0 compatibility defines.
Set arg table before evaluating LUA_INIT and -e chunks.
Fix FOLD rules for math.abs() and FP negation.
Fix soft-float math.abs() and negation.
Fix formatting of some small denormals at low precision.
LJ_GC64: Add JIT compiler support.
x64/LJ_GC64: Add JIT compiler backend.
x86/x64: Generate BMI2 shifts and rotates, if available.
Windows/x86: Add full exception interoperability.
ARM64: Add big-endian support.
ARM64: Add JIT compiler backend.
MIPS: Fix TSETR barrier.
MIPS: Support MIPS16 interlinking.
MIPS soft-float: Fix code generation for HREF.
MIPS64: Add MIPS64 hard-float JIT compiler backend.
MIPS64: Add MIPS64 hard-float/soft-float support to interpreter.
FFI: Compile bitfield loads/stores.
Various fixes common with the 2.0 branch.

- -

LuaJIT 2.1.0-beta2 — 2016-03-03

Enable trace stitching.
Use internal implementation for converting FP numbers to strings.
Parse Unicode escape '\u{XX...}' in string literals.
Add MIPS soft-float support.
Switch MIPS port to dual-number mode.
x86/x64: Add support for AES-NI, AVX and AVX2 to DynASM.
FFI: Add ssize_t declaration.
FFI: Parse #line NN and #NN.
Various minor fixes.

- -

LuaJIT 2.1.0-beta1 — 2015-08-25

-This is a brief summary of the major changes in LuaJIT 2.1 compared to 2.0. -Please take a look at the commit history for more details. -

Changes to the VM core: -
- Add low-overhead profiler (-jp).
- Add LJ_GC64 mode: 64 bit GC object references (really: 47 bit). Interpreter-only for now.
- Add LJ_FR2 mode: Two-slot frame info. Required by LJ_GC64 mode.
- Add table.new() and table.clear().
- Parse binary number literals (0bxxx).
Improvements to the JIT compiler: -
- Add trace stitching (disabled for now).
- Compile various builtins: string.char(), string.reverse(), string.lower(), string.upper(), string.rep(), string.format(), table.concat(), bit.tohex(), getfenv(0), debug.getmetatable().
- Compile string.find() for fixed string searches (no patterns).
- Compile BC_TSETM, e.g. {1,2,3,f()}.
- Compile string concatenations (BC_CAT).
- Compile __concat metamethod.
- Various minor optimizations.
Internal Changes: -
- Add support for embedding LuaJIT bytecode for builtins.
- Replace various builtins with embedded bytecode.
- Refactor string buffers and string formatting.
- Remove obsolete non-truncating number to integer conversions.
Ports: -
- Add Xbox One port (LJ_GC64 mode).
- ARM64: Add port of the interpreter (LJ_GC64 mode).
- x64: Add separate port of the interpreter to LJ_GC64 mode.
- x86/x64: Drop internal x87 math functions. Use libm functions.
- x86: Remove x87 support from interpreter. SSE2 is mandatory now.
- PPC/e500: Drop support for this architecture.
FFI library: -
- FFI: Add 64 bit bitwise operations.
- FFI: Compile VLA/VLS and large cdata allocations with default initialization.
- FFI: Compile conversions from functions to function pointers.
- FFI: Compile lightuserdata to void * conversion.
- FFI: Compile ffi.gc(cdata, nil), too.
- FFI: Add ffi.typeinfo().

- -

LuaJIT 2.0.5 — 2017-05-01

Add workaround for MSVC 2015 stdio changes.
Limit mcode alloc probing, depending on the available pool size.
Fix overly restrictive range calculation in mcode allocation.
Fix out-of-scope goto handling in parser.
Remove internal __mode = "K" and replace with safe check.
Add "proto" field to jit.util.funcinfo().
Fix GC step size calculation.
Initialize uv->immutable for upvalues of loaded chunks.
Fix for cdata vs. non-cdata arithmetics/comparisons.
Drop leftover regs in 'for' iterator assignment, too.
Fix PHI remarking in SINK pass.
Don't try to record outermost pcall() return to lower frame.
Add guard for obscure aliasing between open upvalues and SSA slots.
Remove assumption that lj_math_random_step() doesn't clobber FPRs.
Fix handling of non-numeric strings in arithmetic coercions.
Fix recording of select(n, ...) with off-trace varargs
Fix install for cross-builds.
Don't allocate unused 2nd result register in JIT compiler backend.
Drop marks from replayed instructions when sinking.
Fix unsinking check.
Properly handle OOM in trace_save().
Limit number of arguments given to io.lines() and fp:lines().
Fix narrowing of TOBIT.
OSX: Fix build with recent XCode.
x86/x64: Don't spill an explicit REF_BASE in the IR.
x86/x64: Fix instruction length decoder.
x86/x64: Search for exit jumps with instruction length decoder.
ARM: Fix BLX encoding for Thumb interworking calls.
MIPS: Don't use RID_GP as a scratch register.
MIPS: Fix emitted code for U32 to float conversion.
MIPS: Backport workaround for compact unwind tables.
MIPS: Fix cross-endian jit.bcsave.
MIPS: Fix BC_ISNEXT fallback path.
MIPS: Fix use of ffgccheck delay slots in interpreter.
FFI: Fix FOLD rules for int64_t comparisons.
FFI: Fix SPLIT pass for CONV i64.u64.
FFI: Fix ipairs() recording.
FFI: Don't propagate qualifiers into subtypes of complex.

- -

LuaJIT 2.0.4 — 2015-05-14

Fix stack check in narrowing optimization.
Fix Lua/C API typecheck error for special indexes.
Fix string to number conversion.
Fix lexer error for chunks without tokens.
Don't compile IR_RETF after CALLT to ff with-side effects.
Fix BC_UCLO/BC_JMP join optimization in Lua parser.
Fix corner case in string to number conversion.
Gracefully handle lua_error() for a suspended coroutine.
Avoid error messages when building with Clang.
Fix snapshot #0 handling for traces with a stack check on entry.
Fix fused constant loads under high register pressure.
Invalidate backpropagation cache after DCE.
Fix ABC elimination.
Fix debug info for main chunk of stripped bytecode.
Fix FOLD rule for string.sub(s, ...) == k.
Fix FOLD rule for STRREF of SNEW.
Fix frame traversal while searching for error function.
Prevent GC estimate miscalculation due to buffer growth.
Prevent adding side traces for stack checks.
Fix top slot calculation for snapshots with continuations.
Fix check for reuse of SCEV results in FORL.
Add PS Vita port.
Fix compatibility issues with Illumos.
Fix DragonFly build (unsupported).
OpenBSD/x86: Better executable memory allocation for W^X mode.
x86: Fix argument checks for ipairs() iterator.
x86: lj_math_random_step() clobbers XMM regs on OSX Clang.
x86: Fix code generation for unused result of math.random().
x64: Allow building with LUAJIT_USE_SYSMALLOC and LUAJIT_USE_VALGRIND.
x86/x64: Fix argument check for bit shifts.
x86/x64: Fix code generation for fused test/arith ops.
ARM: Fix write barrier check in BC_USETS.
PPC: Fix red zone overflow in machine code generation.
PPC: Don't use mcrxr on PPE.
Various archs: Fix excess stack growth in interpreter.
FFI: Fix FOLD rule for TOBIT + CONV num.u32.
FFI: Prevent DSE across ffi.string().
FFI: No meta fallback when indexing pointer to incomplete struct.
FFI: Fix initialization of unions of subtypes.
FFI: Fix cdata vs. non-cdata arithmetic and comparisons.
FFI: Fix __index/__newindex metamethod resolution for ctypes.
FFI: Fix compilation of reference field access.
FFI: Fix frame traversal for backtraces with FFI callbacks.
FFI: Fix recording of indexing a struct pointer ctype object itself.
FFI: Allow non-scalar cdata to be compared for equality by address.
FFI: Fix pseudo type conversions for type punning.

- -

LuaJIT 2.0.3 — 2014-03-12

Add PS4 port.
Add support for multilib distro builds.
Fix OSX build.
Fix MinGW build.
Fix Xbox 360 build.
Improve ULOAD forwarding for open upvalues.
Fix GC steps threshold handling when called by JIT-compiled code.
Fix argument checks for math.deg() and math.rad().
Fix jit.flush(func|true).
Respect jit.off(func) when returning to a function, too.
Fix compilation of string.byte(s, nil, n).
Fix line number for relocated bytecode after closure fixup
Fix frame traversal for backtraces.
Fix ABC elimination.
Fix handling of redundant PHIs.
Fix snapshot restore for exit to function header.
Fix type punning alias analysis for constified pointers
Fix call unroll checks in the presence of metamethod frames.
Fix initial maxslot for down-recursive traces.
Prevent BASE register coalescing if parent uses IR_RETF.
Don't purge modified function from stack slots in BC_RET.
Fix recording of BC_VARG.
Don't access dangling reference to reallocated IR.
Fix frame depth display for bytecode dump in -jdump.
ARM: Fix register allocation when rematerializing FPRs.
x64: Fix store to upvalue for lightuserdata values.
FFI: Add missing GC steps for callback argument conversions.
FFI: Properly unload loaded DLLs.
FFI: Fix argument checks for ffi.string().
FFI/x64: Fix passing of vector arguments to calls.
FFI: Rehash finalizer table after GC cycle, if needed.
FFI: Fix cts->L for cdata unsinking in snapshot restore.

- -

LuaJIT 2.0.2 — 2013-06-03

Fix memory access check for fast string interning.
Fix MSVC intrinsics for older versions.
Add missing GC steps for io.* functions.
Fix spurious red zone overflows in machine code generation.
Fix jump-range constrained mcode allocation.
Inhibit DSE for implicit loads via calls.
Fix builtin string to number conversion for overflow digits.
Fix optional argument handling while recording builtins.
Fix optional argument handling in table.concat().
Add partial support for building with MingW64 GCC 4.8-SEH.
Add missing PHI barrier to string.sub(str, a, b) == kstr FOLD rule.
Fix compatibility issues with Illumos.
ARM: Fix cache flush/sync for exit stubs of JIT-compiled code.
MIPS: Fix cache flush/sync for JIT-compiled code jump area.
PPC: Add plt suffix for external calls from assembler code.
FFI: Fix snapshot substitution in SPLIT pass.
FFI/x86: Fix register allocation for 64 bit comparisons.
FFI: Fix tailcall in lowest frame to C function with bool result.
FFI: Ignore long type specifier in ffi.istype().
FFI: Fix calling conventions for 32 bit OSX and iOS simulator (struct returns).
FFI: Fix calling conventions for ARM hard-float EABI (nested structs).
FFI: Improve error messages for arithmetic and comparison operators.
FFI: Insert no-op type conversion for pointer to integer cast.
FFI: Fix unroll limit for ffi.fill().
FFI: Must sink XBAR together with XSTOREs.
FFI: Preserve intermediate string for const char * conversion.

- -

LuaJIT 2.0.1 — 2013-02-19

Don't clear frame for out-of-memory error.
Leave hook when resume catches error thrown from hook.
Add missing GC steps for template table creation.
Fix discharge order of comparisons in Lua parser.
Improve buffer handling for io.read().
OSX: Add support for Mach-O object files to -b option.
Fix PS3 port.
Fix/enable Xbox 360 port.
x86/x64: Always mark ref for shift count as non-weak.
x64: Don't fuse implicitly 32-to-64 extended operands.
ARM: Fix armhf call argument handling.
ARM: Fix code generation for integer math.min/math.max.
PPC/e500: Fix lj_vm_floor() for Inf/NaN.
FFI: Change priority of table initializer variants for structs.
FFI: Fix code generation for bool call result check on x86/x64.
FFI: Load FFI library on-demand for bytecode with cdata literals.
FFI: Fix handling of qualified transparent structs/unions.

- -

LuaJIT 2.0.0 — 2012-11-08

Correctness and completeness: -
- Fix Android/x86 build.
- Fix recording of equality comparisons with __eq metamethods.
- Fix detection of immutable upvalues.
- Replace error with PANIC for callbacks from JIT-compiled code.
- Fix builtin string to number conversion for INT_MIN.
- Don't create unneeded array part for template tables.
- Fix CONV.num.int sinking.
- Don't propagate implicitly widened number to index metamethods.
- ARM: Fix ordered comparisons of number vs. non-number.
- FFI: Fix code generation for replay of sunk float fields.
- FFI: Fix signedness of bool.
- FFI: Fix recording of bool call result check on x86/x64.
- FFI: Fix stack-adjustment for __thiscall callbacks.

- -

LuaJIT 2.0.0-beta11 — 2012-10-16

New features: -
- Use ARM VFP instructions, if available (build-time detection).
- Add support for ARM hard-float EABI (armhf).
- Add PS3 port.
- Add many features from Lua 5.2, e.g. goto/labels. - Refer to this list.
- FFI: Add parameterized C types.
- FFI: Add support for copy constructors.
- FFI: Equality comparisons never raise an error (treat as unequal instead).
- FFI: Box all accessed or returned enums.
- FFI: Check for __new metamethod when calling a constructor.
- FFI: Handle __pairs/__ipairs metamethods for cdata objects.
- FFI: Convert io.* file handle to FILE * pointer (but as a void *).
- FFI: Detect and support type punning through unions.
- FFI: Improve various error messages.
Build-system reorganization: -
- Reorganize directory layout:
  - lib/* → src/jit/*
  - src/buildvm_*.dasc → src/vm_*.dasc
  - src/buildvm_*.h → removed
  - src/buildvm* → src/host/*
- Add minified Lua interpreter plus Lua BitOp (minilua) to run DynASM.
- Change DynASM bit operations to use Lua BitOp
- Translate only vm_*.dasc for detected target architecture.
- Improve target detection for msvcbuild.bat.
- Fix build issues on Cygwin and MinGW with optional MSys.
- Handle cross-compiles with FPU/no-FPU or hard-fp/soft-fp ABI mismatch.
- Remove some library functions for no-JIT/no-FFI builds.
- Add uninstall target to top-level Makefile.
Correctness and completeness: -
- Preserve snapshot #0 PC for all traces.
- Fix argument checks for coroutine.create().
- Command line prints version and JIT status to stdout, not stderr.
- Fix userdata __gc separations at Lua state close.
- Fix TDUP to HLOAD forwarding for LJ_DUALNUM builds.
- Fix buffer check in bytecode writer.
- Make os.date() thread-safe.
- Add missing declarations for MSVC intrinsics.
- Fix dispatch table modifications for return hooks.
- Workaround for MSVC conversion bug (double → uint32_t → int32_t).
- Fix FOLD rule (i-j)-i => 0-j.
- Never use DWARF unwinder on Windows.
- Fix shrinking of direct mapped blocks in builtin allocator.
- Limit recursion depth in string.match() et al.
- Fix late despecialization of ITERN after loop has been entered.
- Fix 'f' and 'L' options for debug.getinfo() and lua_getinfo().
- Fix package.searchpath().
- OSX: Change dylib names to be consistent with other platforms.
- Android: Workaround for broken sprintf("%g", -0.0).
- x86: Remove support for ancient CPUs without CMOV (before Pentium Pro).
- x86: Fix register allocation for calls returning register pair.
- x86/x64: Fix fusion of unsigned byte comparisons with swapped operands.
- ARM: Fix tonumber() argument check.
- ARM: Fix modulo operator and math.floor()/math.ceil() for inf/nan.
- ARM: Invoke SPLIT pass for leftover IR_TOBIT.
- ARM: Fix BASE register coalescing.
- PPC: Fix interpreter state setup in callbacks.
- PPC: Fix string.sub() range check.
- MIPS: Support generation of MIPS/MIPSEL bytecode object files.
- MIPS: Fix calls to floor()/ceil()/trunc().
- ARM/PPC: Detect more target architecture variants.
- ARM/PPC/e500/MIPS: Fix tailcalls from fast functions, esp. tostring().
- ARM/PPC/MIPS: Fix rematerialization of FP constants.
- FFI: Don't call FreeLibrary() on our own EXE/DLL.
- FFI: Resolve metamethods for constructors, too.
- FFI: Properly disable callbacks on iOS (would require executable memory).
- FFI: Fix cdecl string parsing during recording.
- FFI: Show address pointed to for tostring(ref), too.
- FFI: Fix alignment of C call argument/return structure.
- FFI: Initialize all fields of standard types.
- FFI: Fix callback handling when new C types are declared in callback.
- FFI: Fix recording of constructors for pointers.
- FFI: Always resolve metamethods for pointers to structs.
- FFI: Correctly propagate alignment when interning nested types.
Structural and performance enhancements: -
- Add allocation sinking and store sinking optimization.
- Constify immutable upvalues.
- Add builtin string to integer or FP number conversion. Improves cross-platform consistency and correctness.
- Create string hash slots in template tables for non-const values, too. Avoids later table resizes.
- Eliminate HREFK guard for template table references.
- Add various new FOLD rules.
- Don't use stack unwinding for lua_yield() (slow on x64).
- ARM, PPC, MIPS: Improve XLOAD operand fusion and register hinting.
- PPC, MIPS: Compile math.sqrt() to sqrt instruction, if available.
- FFI: Fold KPTR + constant offset in SPLIT pass.
- FFI: Optimize/inline ffi.copy() and ffi.fill().
- FFI: Compile and optimize array/struct copies.
- FFI: Compile ffi.typeof(cdata|ctype), ffi.sizeof(), ffi.alignof(), ffi.offsetof() and ffi.gc().

- -

LuaJIT 2.0.0-beta10 — 2012-05-09

New features: -
- The MIPS of LuaJIT is complete. It requires a CPU conforming to the -MIPS32 R1 architecture with hardware FPU. O32 hard-fp ABI, -little-endian or big-endian.
- Auto-detect target arch via cross-compiler. No need for -TARGET=arch anymore.
- Make DynASM compatible with Lua 5.2.
- From Lua 5.2: Try __tostring metamethod on non-string error -messages..
Correctness and completeness: -
- Fix parsing of hex literals with exponents.
- Fix bytecode dump for certain number constants.
- Fix argument type in error message for relative arguments.
- Fix argument error handling on Lua stacks without a frame.
- Add missing mcode limit check in assembler backend.
- Fix compilation on OpenBSD.
- Avoid recursive GC steps after GC-triggered trace exit.
- Replace <unwind.h> definitions with our own.
- Fix OSX build issues. Bump minimum required OSX version to 10.4.
- Fix discharge order of comparisons in Lua parser.
- Ensure running __gc of userdata created in __gc -at state close.
- Limit number of userdata __gc separations at state close.
- Fix bytecode JMP slot range when optimizing -and/or with constant LHS.
- Fix DSE of USTORE.
- Make lua_concat() work from C hook with partial frame.
- Add required PHIs for implicit conversions, e.g. via XREF -forwarding.
- Add more comparison variants to Valgrind suppressions file.
- Disable loading bytecode with an extra header (BOM or #!).
- Fix PHI stack slot syncing.
- ARM: Reorder type/value tests to silence Valgrind.
- ARM: Fix register allocation for ldrd-optimized -HREFK.
- ARM: Fix conditional branch fixup for OBAR.
- ARM: Invoke SPLIT pass for double args in FFI call.
- ARM: Handle all CALL* ops with double results in -SPLIT pass.
- ARM: Fix rejoin of POW in SPLIT pass.
- ARM: Fix compilation of math.sinh, math.cosh, -math.tanh.
- ARM, PPC: Avoid pointless arg clearing in BC_IFUNCF.
- PPC: Fix resume after yield from hook.
- PPC: Fix argument checking for rawget().
- PPC: Fix fusion of floating-point XLOAD/XSTORE.
- PPC: Fix HREFK code generation for huge tables.
- PPC: Use builtin D-Cache/I-Cache sync code.
FFI library: -
- Ignore empty statements in ffi.cdef().
- Ignore number parsing errors while skipping definitions.
- Don't touch frame in callbacks with tailcalls to fast functions.
- Fix library unloading on POSIX systems.
- Finalize cdata before userdata when closing the state.
- Change ffi.load() library name resolution for Cygwin.
- Fix resolving of function name redirects on Windows/x86.
- Fix symbol resolving error messages on Windows.
- Fix blacklisting of C functions calling callbacks.
- Fix result type of pointer difference.
- Use correct PC in FFI metamethod error message.
- Allow 'typedef _Bool int BOOL;' for the Windows API.
- Don't record test for bool result of call, if ignored.

- -

LuaJIT 2.0.0-beta9 — 2011-12-14

New features: -
- PPC port of LuaJIT is complete. Default is the dual-number port -(usually faster). Single-number port selectable via src/Makefile -at build time.
- Add FFI callback support.
- Extend -b to generate .c, .h or .obj/.o -files with embedded bytecode.
- Allow loading embedded bytecode with require().
- From Lua 5.2: Change to '\z' escape. Reject undefined escape -sequences.
Correctness and completeness: -
- Fix OSX 10.7 build. Fix install_name and versioning on OSX.
- Fix iOS build.
- Install dis_arm.lua, too.
- Mark installed shared library as executable.
- Add debug option to msvcbuild.bat and improve error handling.
- Fix data-flow analysis for iterators.
- Fix forced unwinding triggered by external unwinder.
- Record missing for loop slot loads (return to lower frame).
- Always use ANSI variants of Windows system functions.
- Fix GC barrier for multi-result table constructor (TSETM).
- Fix/add various FOLD rules.
- Add potential PHI for number conversions due to type instability.
- Do not eliminate PHIs only referenced from other PHIs.
- Correctly anchor implicit number to string conversions in Lua/C API.
- Fix various stack limit checks.
- x64: Use thread-safe exceptions for external unwinding (GCC platforms).
- x64: Fix result type of cdata index conversions.
- x64: Fix math.random() and bit.bswap() code generation.
- x64: Fix lightuserdata comparisons.
- x64: Always extend stack-passed arguments to pointer size.
- ARM: Many fixes to code generation backend.
- PPC/e500: Fix dispatch for binop metamethods.
- PPC/e500: Save/restore condition registers when entering/leaving the VM.
- PPC/e500: Fix write barrier in stores of strings to upvalues.
FFI library: -
- Fix C comment parsing.
- Fix snapshot optimization for cdata comparisons.
- Fix recording of const/enum lookups in namespaces.
- Fix call argument and return handling for I8/U8/I16/U16 types.
- Fix unfused loads of float fields.
- Fix ffi.string() recording.
- Save GetLastError() around ffi.load() and symbol -resolving, too.
- Improve ld script detection in ffi.load().
- Record loads/stores to external variables in namespaces.
- Compile calls to stdcall, fastcall and vararg functions.
- Treat function ctypes like pointers in comparisons.
- Resolve __call metamethod for pointers, too.
- Record C function calls with bool return values.
- Record ffi.errno().
- x86: Fix number to uint32_t conversion rounding.
- x86: Fix 64 bit arithmetic in assembler backend.
- x64: Fix struct-by-value calling conventions.
- ARM: Ensure invocation of SPLIT pass for float conversions.
Structural and performance enhancements: -
- Display trace types with -jv and -jdump.
- Record isolated calls. But prefer recording loops over calls.
- Specialize to prototype for non-monomorphic functions. Solves the -trace-explosion problem for closure-heavy programming styles.
- Always generate a portable vmdef.lua. Easier for distros.

- -

LuaJIT 2.0.0-beta8 — 2011-06-23

New features: -
- Soft-float ARM port of LuaJIT is complete.
- Add support for bytecode loading/saving and -b command line -option.
- From Lua 5.2: __len metamethod for tables -(disabled by default).
Correctness and completeness: -
- ARM: Misc. fixes for interpreter.
- x86/x64: Fix bit.* argument checking in interpreter.
- Catch early out-of-memory in memory allocator initialization.
- Fix data-flow analysis for paths leading to an upvalue close.
- Fix check for missing arguments in string.format().
- Fix Solaris/x86 build (note: not a supported target).
- Fix recording of loops with instable directions in side traces.
- x86/x64: Fix fusion of comparisons with u8/u16 -XLOAD.
- x86/x64: Fix register allocation for variable shifts.
FFI library: -
- Add ffi.errno(). Save errno/GetLastError() -around allocations etc.
- Fix __gc for VLA/VLS cdata objects.
- Fix recording of casts from 32 bit cdata pointers to integers.
- tonumber(cdata) returns nil for non-numbers.
- Show address pointed to for tostring(pointer).
- Print NULL pointers as "cdata<... *>: NULL".
- Support __tostring metamethod for pointers to structs, too.
Structural and performance enhancements: -
- More tuning for loop unrolling heuristics.
- Flatten and compress in-memory debug info (saves ~70%).

- -

LuaJIT 2.0.0-beta7 — 2011-05-05

New features: -
- ARM port of the LuaJIT interpreter is complete.
- FFI library: Add ffi.gc(), ffi.metatype(), -ffi.istype().
- FFI library: Resolve ld script redirection in ffi.load().
- From Lua 5.2: package.searchpath(), fp:read("*L"), -load(string).
- From Lua 5.2, disabled by default: empty statement, -table.unpack(), modified coroutine.running().
Correctness and completeness: -
- FFI library: numerous fixes.
- Fix type mismatches in store-to-load forwarding.
- Fix error handling within metamethods.
- Fix table.maxn().
- Improve accuracy of x^-k on x64.
- Fix code generation for Intel Atom in x64 mode.
- Fix narrowing of POW.
- Fix recording of retried fast functions.
- Fix code generation for bit.bnot() and multiplies.
- Fix error location within cpcall frames.
- Add workaround for old libgcc unwind bug.
- Fix lua_yield() and getmetatable(lightuserdata) on x64.
- Misc. fixes for PPC/e500 interpreter.
- Fix stack slot updates for down-recursion.
Structural and performance enhancements: -
- Add dual-number mode (int/double) for the VM. Enabled for ARM.
- Improve narrowing of arithmetic operators and for loops.
- Tune loop unrolling heuristics and increase trace recorder limits.
- Eliminate dead slots in snapshots using bytecode data-flow analysis.
- Avoid phantom stores to proxy tables.
- Optimize lookups in empty proxy tables.
- Improve bytecode optimization of and/or operators.

- -

LuaJIT 2.0.0-beta6 — 2011-02-11

New features: -
- PowerPC/e500v2 port of the LuaJIT interpreter is complete.
- Various minor features from Lua 5.2: Hex escapes in literals, -'\*' escape, reversible string.format("%q",s), -"%g" pattern, table.sort checks callbacks, -os.exit(status|true|false[,close]).
- Lua 5.2 __pairs and __ipairs metamethods -(disabled by default).
- Initial release of the FFI library.
Correctness and completeness: -
- Fix string.format() for non-finite numbers.
- Fix memory leak when compiled to use the built-in allocator.
- x86/x64: Fix unnecessary resize in TSETM bytecode.
- Fix various GC issues with traces and jit.flush().
- x64: Fix fusion of indexes for array references.
- x86/x64: Fix stack overflow handling for coroutine results.
- Enable low-2GB memory allocation on FreeBSD/x64.
- Fix collectgarbage("count") result if more than 2GB is in use.
- Fix parsing of hex floats.
- x86/x64: Fix loop branch inversion with trailing -HREF+NE/EQ.
- Add jit.os string.
- coroutine.create() permits running C functions, too.
- Fix OSX build to work with newer ld64 versions.
- Fix bytecode optimization of and/or operators.
Structural and performance enhancements: -
- Emit specialized bytecode for pairs()/next().
- Improve bytecode coalescing of nil constants.
- Compile calls to vararg functions.
- Compile select().
- Improve alias analysis, esp. for loads from allocations.
- Tuning of various compiler heuristics.
- Refactor and extend IR conversion instructions.
- x86/x64: Various backend enhancements related to the FFI.
- Add SPLIT pass to split 64 bit IR instructions for 32 bit CPUs.

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LuaJIT 2.0.0-beta5 — 2010-08-24

Correctness and completeness: -
- Fix trace exit dispatch to function headers.
- Fix Windows and OSX builds with LUAJIT_DISABLE_JIT.
- Reorganize and fix placement of generated machine code on x64.
- Fix TNEW in x64 interpreter.
- Do not eliminate PHIs for values only referenced from side exits.
- OS-independent canonicalization of strings for non-finite numbers.
- Fix string.char() range check on x64.
- Fix tostring() resolving within print().
- Fix error handling for next().
- Fix passing of constant arguments to external calls on x64.
- Fix interpreter argument check for two-argument SSE math functions.
- Fix C frame chain corruption caused by lua_cpcall().
- Fix return from pcall() within active hook.
Structural and performance enhancements: -
- Replace on-trace GC frame syncing with interpreter exit.
- Improve hash lookup specialization by not removing dead keys during GC.
- Turn traces into true GC objects.
- Avoid starting a GC cycle immediately after library init.
- Add weak guards to improve dead-code elimination.
- Speed up string interning.

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LuaJIT 2.0.0-beta4 — 2010-03-28

Correctness and completeness: -
- Fix precondition for on-trace creation of table keys.
- Fix {f()} on x64 when table is resized.
- Fix folding of ordered comparisons with same references.
- Fix snapshot restores for multi-result bytecodes.
- Fix potential hang when recording bytecode with nested closures.
- Fix recording of getmetatable(), tonumber() and bad argument types.
- Fix SLOAD fusion across returns to lower frames.
Structural and performance enhancements: -
- Add array bounds check elimination. -Oabc is enabled by default.
- More tuning for x64, e.g. smaller table objects.

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LuaJIT 2.0.0-beta3 — 2010-03-07

LuaJIT x64 port: -
- Port integrated memory allocator to Linux/x64, Windows/x64 and OSX/x64.
- Port interpreter and JIT compiler to x64.
- Port DynASM to x64.
- Many 32/64 bit cleanups in the VM.
- Allow building the interpreter with either x87 or SSE2 arithmetics.
- Add external unwinding and C++ exception interop (default on x64).
Correctness and completeness: -
- Fix constructor bytecode generation for certain conditional values.
- Fix some cases of ordered string comparisons.
- Fix lua_tocfunction().
- Fix cutoff register in JMP bytecode for some conditional expressions.
- Fix PHI marking algorithm for references from variant slots.
- Fix package.cpath for non-default PREFIX.
- Fix DWARF2 frame unwind information for interpreter on OSX.
- Drive the GC forward on string allocations in the parser.
- Implement call/return hooks (zero-cost if disabled).
- Implement yield from C hooks.
- Disable JIT compiler on older non-SSE2 CPUs instead of aborting.
Structural and performance enhancements: -
- Compile recursive code (tail-, up- and down-recursion).
- Improve heuristics for bytecode penalties and blacklisting.
- Split CALL/FUNC recording and clean up fast function call semantics.
- Major redesign of internal function call handling.
- Improve FOR loop const specialization and integerness checks.
- Switch to pre-initialized stacks. Avoid frame-clearing.
- Colocation of prototypes and related data: bytecode, constants, debug info.
- Cleanup parser and streamline bytecode generation.
- Add support for weak IR references to register allocator.
- Switch to compressed, extensible snapshots.
- Compile returns to frames below the start frame.
- Improve alias analysis of upvalues using a disambiguation hash value.
- Compile floor/ceil/trunc to SSE2 helper calls or SSE4.1 instructions.
- Add generic C call handling to IR and backend.
- Improve KNUM fuse vs. load heuristics.
- Compile various io.*() functions.
- Compile math.sinh(), math.cosh(), math.tanh() -and math.random().

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LuaJIT 2.0.0-beta2 — 2009-11-09

Reorganize build system. Build static+shared library on POSIX.
Allow C++ exception conversion on all platforms -using a wrapper function.
Automatically catch C++ exceptions and rethrow Lua error -(DWARF2 only).
Check for the correct x87 FPU precision at strategic points.
Always use wrappers for libm functions.
Resurrect metamethod name strings before copying them.
Mark current trace, even if compiler is idle.
Ensure FILE metatable is created only once.
Fix type comparisons when different integer types are involved.
Fix getmetatable() recording.
Fix TDUP with dead keys in template table.
jit.flush(tr) returns status. -Prevent manual flush of a trace that's still linked.
Improve register allocation heuristics for invariant references.
Compile the push/pop variants of table.insert() and -table.remove().
Compatibility with MSVC link /debug.
Fix lua_iscfunction().
Fix math.random() when compiled with -fpic (OSX).
Fix table.maxn().
Bump MACOSX_DEPLOYMENT_TARGET to 10.4
luaL_check*() and luaL_opt*() now support -negative arguments, too.
-This matches the behavior of Lua 5.1, but not the specification.

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LuaJIT 2.0.0-beta1 — 2009-10-31

This is the first public release of LuaJIT 2.0.
The whole VM has been rewritten from the ground up, so there's -no point in listing differences over earlier versions.

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