path: root/ChangeLog

This document describes changes between tagged Emscripten SDK versions.

Note that in the compiler, version numbering is used as the mechanism to invalidate internal compiler caches,
so version numbers do not necessarily reflect the amount of changes between versions.

To browse or download snapshots of old tagged versions, visit https://github.com/kripken/emscripten/releases .

Not all changes are documented here. In particular, new features, user-oriented fixes, options, command-line parameters, usage changes, deprecations, significant internal modifications and optimizations etc. generally deserve a mention. To examine the full set of changes between versions, visit the link to full changeset diff at the end of each section.

Current trunk code
------------------
 - To see a list of commits in the active development branch 'incoming', which have not yet been packaged in a release, see
    - Emscripten: https://github.com/kripken/emscripten/compare/1.21.1...incoming
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.21.1...incoming
    - Emscripten-Clang: https://github.com/kripken/emscripten-fastcomp-clang/compare/1.21.1...incoming

v1.21.1: 7/3/2014
------------------
 - Fixed an issue where wrong python interpreter could get invoked on Windows when both native and cygwin python were installed.
 - Updated musl from version 0.9.13 to version 1.0.3.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.21.0...1.21.1
    - Emscripten-LLVM: no changes.
    - Emscripten-Clang: no changes.

v1.21.0: 7/2/2014
------------------
 - Enable memory init files (.mem) by default in optimized builds (-O2+), as if  --memory-init-file 1  is specified. This makes the default behavior on optimized builds emit smaller and faster-to-load code, but does require that you ship both a .js and a .mem file (if you prefer not to, can use  --memory-init-file 1  ).
 - Implemented new SDL 1.2 functions SDL_GetRGB, SDL_GetRGBA and SDL_putenv.
 - Added support for /dev/random, /dev/urandom and C++11 std::random_device, which will use cryptographically secure random api if available. (#2447)
 - Added support for CMake find_path() directive.
 - Added support for std::unique_ptr in embind.
 - Improved Windows support for ffdb.py.
 - Implemented the clip_rect structure for created SDL surfaces.
 - Fixed a regression with SDL touch events (#2466)
 - Added support for C++11 std::thread::hardware_concurrency which backs to navigator.hardwareConcurrency. See http://wiki.whatwg.org/wiki/Navigator_HW_Concurrency (#2456)
 - Optimized embind code generation with constexprs.
 - Enabled the use of Runtime.add&removeFunction when closure minification is active (#2446)
 - Implemented support for accessing WebGL when building via the proxy to worker architecture.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.20.0...1.21.0
    - Emscripten-LLVM: no changes.
    - Emscripten-Clang: no changes.

v1.20.0: 6/13/2014
------------------
 - Optimize in-memory virtual filesystem performance when serialized to an IndexedDB.
 - Fixed memcpy regression with ta0 and ta1 modes.
 - Fixed an issue with line numbers being messed up when generating source maps (#2410)
 - Fixed an ffdb logging bug that could cause it to drop messages if they were being received too fast. Added support getting memory and system descriptions with ffdb.
 - Added a new extension to SDL "emscripten_SDL_SetEventHandler()" which enabled application to perform SDL event handling inside a JS event handler to overcome browser security restrictions. (#2417)
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.19.2...1.20.0
    - Emscripten-LLVM: no changes.
    - Emscripten-Clang: no changes.

v1.19.2: 6/9/2014
------------------
 - Updated CMake support for response file handling.
 - Fixed issues with glfwGetProcAddress and glfwSetWindowSizeCallback.
 - Fixed an issue with regexes that caused issues on IE11 runtime (#2400)
 - Added a new functions emscripten_get_preloaded_image_data() and emscripten_get_preloaded_image_data_from_FILE() to obtain pixel data of preloaded images.
 - Greatly improved ffdb capabilities to operate a FFOS device.
 - Fixed a Windows-specific bug where the user temp directory was littered with temporary .rsp files that did not get cleaned up.
 - Improved SIMD support.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.19.1...1.19.2
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.19.1...1.19.2
    - Emscripten-Clang: no changes.

v1.19.1: 6/3/2014
------------------
 - Migrate to using musl sscanf and sprintf and the family that writes to memory, and not directly to the filesystem.
 - Improve the error messages from -s SAFE_HEAP_ACCESS=1 runtime checks.
 - Added new linker flag -s NO_DYNAMIC_EXECUTION=1 which removes the use of eval() and new Function() in the generated output. For more information, see "Eval and related functions are disabled" in https://developer.chrome.com/extensions/contentSecurityPolicy .
 - Fixed a compiler issue when very large double constants are present. (#2392)
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.19.0...1.19.1
    - Emscripten-LLVM: no changes.
    - Emscripten-Clang: no changes.

v1.19.0: 5/29/2014
------------------
 - Added an error message to signal that linkable modules are not supported in fastcomp.
 - Fixed a miscompilation issue that resulted in an error "SyntaxError: invalid increment operand" and a statement +(+0) being generated (#2314)
 - Make optimized compiler output smaller by running the shell code through uglify when not using closure.
 - Fixed a crash in SDL audio loading code introduced in v1.18.3
 - Fixed an issue where glTex(Sub)Image2D might throw an exception on error, instead of setting glGetError().
 - Added new typedefs emscripten_align1_short, emscripten_align{1/2}_int, emscripten_align{1/2}_float and emscripten_align{1/2/4}_double to ease signaling the compiler that unaligned data is present. (#2378)
 - Fixed an embind issue with refcount tracking on smart pointers.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.18.4...1.19.0
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.18.4...1.19.0
    - Emscripten-Clang: no changes.

v1.18.4: 5/27/2014
------------------
 - Fixed error message on unsupported linking options (#2365)
 - Updated embind to latest version from IMVU upstream.
 - Fixed an issue where source maps did not load properly in Firefox.
 - Added a more descriptive error message to fastcomp when MAX_SETJMPS limit is violated. (#2379)
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.18.3...1.18.4
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.18.3...1.18.4
    - Emscripten-Clang: no changes.

v1.18.3: 5/21/2014
------------------
 - Added support to emcc command line for "archive groups": -Wl,--start-group and -Wl,--end-group
 - Greatly optimized ccall and cwrap implementations.
 - Added new support for SDL_Mix backend to use WebAudio to play back audio clips.
 - Fixed a registerizeHarder issue with elimination of conditional expressions.
 - Migrated single-character standard C functions (islower, tolower, and the family) to use musl implementations.
 - Updated relooper to not optimize out breaks if it causes excessive nesting.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.18.2...1.18.3
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.18.2...1.18.3
    - Emscripten-Clang: no changes.

v1.18.2: 5/19/2014
------------------
 - Fixed a problem which blocked user applications from handling WebGL context loss events themselves.
 - Added a new HTML5 api function emscripten_is_webgl_context_lost() which allows polling for context loss in addition to receiving events.
 - Improved async wget progress events to work better across browsers.
 - Improved WebIDL binder support.
 - Added new typeof() function to emscripten::val.
 - Added support for SDL window events SDL_WINDOWEVENT_FOCUS_GAINED, SDL_WINDOWEVENT_FOCUS_LOST, SDL_WINDOWEVENT_SHOWN, SDL_WINDOWEVENT_HIDDEN.
 - Fixed a compiler miscompilation on unsigned i1 bitcasts (#2350)
 - Fixed a compiler bug where doubles in varargs might not get 8-byte aligned (#2358)
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.18.1...1.18.2
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.18.1...1.18.2
    - Emscripten-Clang: no changes.

v1.18.1: 5/12/2014
------------------
 - Fixed an issue where the mouse wheel scroll did not work with SDL.
 - Fixed an issue with emscripten_async_wget, which undesirably expected that the string pointer passed to it stayed alive for the duration of the operation (#2349)
 - Emscripten now issues a warning message when the EXPORTED_FUNCTIONS list contains invalid symbol names (#2338)
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.18.0...1.18.1
    - Emscripten-LLVM: no changes.
    - Emscripten-Clang: no changes.

v1.18.0: 5/10/2014
------------------
 - Enable support for low-level C<->JS interop to marshall 64 bit integers from C to JS.
 - Fixed an issue that caused some programs to immediately run out of memory "(cannot enlarge memory arrays)" at startup. (#2334)
 - Fixed a crash issue with generated touch events that didn't correspond to a real touch.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.17.0...1.18.0
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.17.0...1.18.0
    - Emscripten-Clang: no changes.

v1.17.0: 5/6/2014
------------------
 - Enabled asm.js compilation and -s PRECISE_F32 support when using embind.
 - Improved relooper to emit switches in many-entried blocks.
 - Fixed a GLFW bug where mouse wheel direction was reversed.
 - Fixed glfwGetKey to work even when no callback is registered with glfwGetKeyCallback (#1320)
 - Added a new tool 'webidl_binder' that generates C <-> JS interop code from WebIDL descriptions.
 - Fix emscripten compilation to work on pages that don't contain a HTML canvas.
 - Added a new error message to default shell when an uncaught exception is thrown.
 - Improved error diagnostics reported by -s SAFE_HEAP=1.
 - Added support for registering callbacks hook to VFS file open, write, move, close and delete.
 - Added embind support to std::basic_string<unsigned char>
 - By default, the C runtime will no longer exit after returning from main() when safeSetTimeout() or safeSetInterval() is used.
 - Fixed an issue with sscanf formatting (#2322)
 - Fixed an issue where precompiled headers were given a wrong output filename (#2320)
 - Enabled registerizeHarder optimization pass to work when outlining is enabled.
 - Fixed an issue with strptime month handling (#2324)
 - Added an initial implementation of a new tool 'ffdb' which can be used to operate a Firefox OS phone from the command line.
 - Fixed a compiler crash on assertion failure '!contains(BranchesOut, Target)' (emscripten-fastcomp #32)
 - Added a new ABI to Clang that targets Emscripten specifically. Stop aligning member functions to save some space in the function table array.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.16.0...1.17.0
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.16.0...1.17.0
    - Emscripten-Clang: https://github.com/kripken/emscripten-fastcomp-clang/compare/1.16.0...1.17.0

v1.16.0: 4/16/2014
------------------
 - Removed browser warnings message in VFS library about replacing __proto__ performance issue. 
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.15.1...1.16.0
    - Emscripten-LLVM: no changes.
    - Emscripten-Clang: https://github.com/kripken/emscripten-fastcomp-clang/compare/1.15.1...1.16.0

v1.15.1: 4/15/2014
------------------
 - Added support for SDL2 touch api.
 - Added new user-controllable emdind-related define #define EMSCRIPTEN_HAS_UNBOUND_TYPE_NAMES, which allows optimizing embind for minimal size when std::type_info is not needed. 
 - Fixed issues with CMake support where CMAKE_AR and CMAKE_RANLIB were not accessible from CMakeLists.txt files.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.15.0...1.15.1
    - Emscripten-LLVM: no changes.
    - Emscripten-Clang: no changes.

v1.15.0: 4/11/2014
------------------
 - Fix outlining feature for functions that return a double (#2278)
 - Added support for C++11 atomic constructs (#2273)
 - Adjusted stdout and stderr stream behavior in the default shell.html to always print out to both web page text log box, and the browser console.
 - Fixed an issue with loop variable optimization.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.14.1...1.15.0
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.14.1...1.15.0
    - Emscripten-Clang: https://github.com/kripken/emscripten-fastcomp-clang/compare/1.14.1...1.15.0

v1.14.1: 4/8/2014
------------------
 - Added new command line utility 'emcmake', which can be used to call emconfigure for cmake.
 - Added a new emcc command line parameter '--valid-abspath', which allows selectively suppressing warning messages that occur when using absolute path names in include and link directories.
 - Added a new emcc linker command line parameter '--emit-symbol-map', which will save a map file between minified global names and the original function names.
 - Fixed an issue with --default-object-ext not always working properly.
 - Added optimizations to eliminate redundant loop variables and redundant self-assignments.
 - Migrated several libc functions to use compiled code from musl instead of handwritten JS implementations.
 - Improved embind support.
 - Renamed the EM_ASM_() macro to the form EM_ASM_ARGS().
 - Fixed mouse button ordering issue in glfw.
 - Fixed an issue when creating a path name that ends in a slash (#2258, #2263)
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.14.0...1.14.1
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.14.0...1.14.1
    - Emscripten-Clang: no changes.

v1.14.0: 3/25/2014
------------------
 - Added new emcc linker command line option '-profiling', which defaults JS code generation options suited for benchmarking and profiling purposes.
 - Implemented the EGL function eglWaitGL().
 - Fixed an issue with the HTML5 API that caused the HTML5 event listener unregistration to fail.
 - Fixed issues with numpad keys in SDL support library.
 - Added a new JS optimizer pass 'simplifyIfs', which is run when -s SIMPLIFY_IFS=1 link flag is set and -g is not specified. This pass merges multiple nested if()s together into single comparisons, where possible.
 - Removed false positive messages on missing internal "emscripten_xxx" symbols at link stage.
 - Updated to latest relooper version.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.13.2...1.14.0
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.13.2...1.14.0
    - Emscripten-Clang: no changes.

v1.13.2: 3/15/2014
------------------
 - Fixed issues with SDL audio on Safari.
 - Fixed issues with HTML5 API mouse scroll events on Safari.
 - Fixed issues with HTML5 fullscreen requests in IE11.
 - Enabled support for emscripten_get_callstack on IE10+.
 - Fixed issues with Closure symbol minification.
 - Further improved em_asm()-related error messages.
 - Updated to latest relooper version.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.13.1...1.13.2
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.13.1...1.13.2
    - Emscripten-Clang: no changes.

v1.13.1: 3/10/2014
------------------
 - Disallow C implicit function declarations by making it an error instead of a warning by default. These will not work with Emscripten, due to strict Emscripten signature requirements when calling function pointers (#2175).
 - Allow transitioning to full screen from SDL as a response to mouse press events.
 - Fixed a bug in previous 1.13.0 release that broke fullscreen transitioning from working.
 - Fixed emscripten/html5.h to be used in C source files.
 - Fix an issue where extraneous system libraries would get included in the generated output (#2191).
 - Added a new function emscripten_async_wget2_data() that allows reading from an XMLHTTPRequest directly into memory while supporting advanced features.
 - Fixed esc key code in GLFW.
 - Added new emscripten_debugger() intrinsic function, which calls into JS "debugger;" statement to break into a JS debugger.
 - Fixed varargs function call alignment of doubles to 8 bytes.
 - Switched to using default function local stack alignment to 16 bytes to be SIMD-friendly.
 - Improved error messages when user code has a syntax error in em_asm() statements.
 - Switched to using a new custom LLVM datalayout format for Emscripten. See https://github.com/kripken/emscripten-fastcomp/commit/65405351ba0b32a8658c65940e0b65ceb2601ad4
 - Optimized function local stack space to use fewer temporary JS variables.
 - Full list of changes:
    - Emscripten: https://github.com/kripken/emscripten/compare/1.13.0...1.13.1
    - Emscripten-LLVM: https://github.com/kripken/emscripten-fastcomp/compare/1.13.0...1.13.1
    - Emscripten-Clang: https://github.com/kripken/emscripten-fastcomp-clang/compare/1.13.0...1.13.1

v1.13.0: 3/3/2014
------------------
 - Fixed the deprecated source mapping syntax warning.
 - Fixed a buffer overflow issue in emscripten_get_callstack (#2171).
 - Added support for -Os (optimize for size) and -Oz (aggressively optimize for size) arguments to emcc.
 - Fixed a typo that broko the call signature of glCompressedTexSubImage2D() function (#2173).
 - Added new browser fullscreen resize logic that always retains aspect ratio and adds support for IE11.
 - Improve debug messaging with bad function pointer calls when -s ASSERTIONS=2 is set.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.12.3...1.13.0

v1.12.3: 2/27/2014
------------------
 - Fixed alcOpenDevice on Safari.
 - Improved the warning message on missing symbols to not show false positives (#2154).
 - Improved EmscriptenFullscreenChangeEvent HTML5 API structure to return information about HTML element and screen sizes for convenience.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.12.2...1.12.3

v1.12.2: 2/25/2014
------------------
 - Added better warning message if Emscripten, LLVM and Clang versions don't match.
 - Introduced the asmjs-unknown-emscripten target triple that allows specializing LLVM codegen for Emscripten purposes.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.12.1...1.12.2

v1.12.1: 2/25/2014
------------------
 - TURNED ON FASTCOMP BY DEFAULT. This means that you will need to migrate to fastcomp-clang build. Either use an Emscripten SDK distribution, or to build manually, see https://github.com/kripken/emscripten/wiki/LLVM-Backend for info.
 - Migrate to requiring Clang 3.3 instead of Clang 3.2. The fastcomp-clang repository by Emscripten is based on Clang 3.3.
 - Deprecated old Emscripten libgc implementation.
 - asm.js will now be always enabled, even in -O0 builds in fastcomp.
 - Remove support for -s RUNTIME_TYPE_INFO, which is unsupported in fastcomp.
 - Added a new "powered by Emscripten" logo.
 - Updated default shell.html graphical layout.
 - Added new macro EM_ASM_, which allows sending values to JS without returning anything.
 - Deprecated the jcache compiler option. It should not be needed anymore.
 - Added support for fetching callstack column information in Firefox 30 in emscripten_get_callstack.
 - Fix issues with missing exceptions-related symbols in fastcomp.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.12.0...1.12.1

v1.12.0: 2/22/2014
------------------
 - Improved the runtime abort error message when calling an invalid function pointer if compiled with -s ASSERTIONS=1 and 2. This allows the developer to better deduce errors with bad function pointers or function pointers casted and invoked via a wrong signature.
 - Added a new api function emscripten_set_main_loop_arg, which allows passing a userData pointer that will be carried via the function call, useful for object-oriented encapsulation purposes (#2114).
 - Fixed CMake MinSizeRel configuration type to actually optimize for minimal size with -Os.
 - Added support for GLES2 VAO extension OES_vertex_array_object for browsers that support it.
 - Fix issues with emscripten/html5.f when compiled with the SAFE_HEAP option.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.11.1...1.12.0

v1.11.1: 2/19/2014
------------------
 - Improved eglSwapBuffers to be spec-conformant.
 - Fixed an issue with asm.js validation and va_args (#2120).
 - Fixed asm.js validation issues found with fuzzing.
 - Added new link-time compiler flag -s RETAIN_COMPILER_SETTINGS=1, which enables a runtime API for querying which Emscripten settings were used to compile the file.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.11.0...1.11.1

v1.11.0: 2/14/2014
------------------
 - Implemented some new SDL library functions.
 - Renamed standard file descriptors to have handles 0, 1 and 2 rather than 1, 2 and 3 to coincide with unix numbering.
 - Improved embind support with smart pointers and mixins.
 - Improved the registerization -O3 optimization pass around switch-case constructs.
 - Upper-case files with suffix .C are now also recognized (#2109).
 - Fixed an issue with glGetTexParameter (#2112).
 - Improved exceptions support in fastcomp.
 - Added new linker option -s NO_EXIT_RUNTIME=1, which can be used to set a default value for the Module["noExitRuntime"] parameter at compile-time.
 - Improved SDL audio buffer queueing when the sample rate matches the native web audio graph sample rate.
 - Added an optimization that removes redundant Math.frounds in -O3.
 - Improved the default shell.html file.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.10.4...1.11.0

v1.10.4: 2/10/2014
------------------
 - Added support for legacy GL emulation in fastcomp.
 - Deprecated the --split-js compiler option. This is not supported in fastcomp. 
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.10.3...1.10.4

v1.10.3: 2/9/2014
------------------
 - Work on supporting GL/EGL GetProcAddress.
 - Fixed issues with shared lib linking support.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.10.2...1.10.3

v1.10.2: 2/7/2014
------------------
 - Added basic FS unmount support.
 - Improved screen orientation lock API to return a success code.
 - Added PRECISE_F32 support to fastcomp.
 - Fixed issues in fastcomp related to special floating point literal serialization.
 - Improved SDL audio buffer queueing.
 - Added new link-time option -s WARN_UNALIGNED=1 to fastcomp to report compiler warnings about generated unaligned memory accesses, which can hurt performance.
 - Optimized libc strcmp and memcmp with the implementations from musl libc.
 - Optimized libc memcpy and memset to back to native code for large buffer sizes.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.10.1...1.10.2

v1.10.1: 1/31/2014
------------------
 - Improve srand() and rand() to be seedable and use a Linear Congruential Generator (LCG) for the rng generation for performance.
 - Improved OpenAL library support.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.10.0...1.10.1

v1.10.0: 1/29/2014
------------------
 - Improved C++ exception handling.
 - Improved OpenAL library support.
 - Fixed an issue where loading side modules could try to allocate from sealed heap (#2060).
 - Fixed safe heap issues (2068).
 - Added new EM_ASM variants that return a value but do not receive any inputs (#2070).
 - Add support for simultaneously using setjmp and C++ exceptions in fastcomp.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.9.5...1.10.0

v1.9.5: 1/25/2014
------------------
 - Added a spinner logo to default html shell.
 - Full list of changes: https://github.com/kripken/emscripten/compare/1.9.4...1.9.5

v1.9.4: 1/24/2014
------------------
 - Add support for Ninja and Eclipse+Ninja builds with Emscripten+CMake.
 - Fixed regressions with GL emulation.
 - Added support for #if !X in .js library preprocessor.
 - Make the syntax EM_ASM("code"); not silently fail. Note that the proper form is EM_ASM(code); without double-quotes.
 - Optimize generated code size by minifying loop labels as well.
 - Revised the -O3 optimization level to mean "safe, but very slow optimizations on top