From b45e3246cee8c92b72622808f03b5cb7d539e244 Mon Sep 17 00:00:00 2001 From: Mike Pall Date: Tue, 9 Nov 2010 18:11:35 +0100 Subject: Split up extension/API docs into sub-pages. --- doc/ext_jit.html | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) create mode 100644 doc/ext_jit.html (limited to 'doc/ext_jit.html') diff --git a/doc/ext_jit.html b/doc/ext_jit.html new file mode 100644 index 00000000..d621476b --- /dev/null +++ b/doc/ext_jit.html @@ -0,0 +1,177 @@ + + + +jit.* Library + + + + + + + + +
+Lua +
+ + +
+

+The functions in this built-in module control the behavior +of the JIT compiler engine. +

+ +

jit.on()
+jit.off()

+

+Turns the whole JIT compiler on (default) or off. +

+

+These functions are typically used with the command line options +-j on or -j off. +

+ +

jit.flush()

+

+Flushes the whole cache of compiled code. +

+ +

jit.on(func|true [,true|false])
+jit.off(func|true [,true|false])
+jit.flush(func|true [,true|false])

+

+jit.on enables JIT compilation for a Lua function (this is +the default). +

+

+jit.off disables JIT compilation for a Lua function and +flushes any already compiled code from the code cache. +

+

+jit.flush flushes the code, but doesn't affect the +enable/disable status. +

+

+The current function, i.e. the Lua function calling this library +function, can also be specified by passing true as the first +argument. +

+

+If the second argument is true, JIT compilation is also +enabled, disabled or flushed recursively for all sub-functions of a +function. With false only the sub-functions are affected. +

+

+The jit.on and jit.off functions only set a flag +which is checked when the function is about to be compiled. They do +not trigger immediate compilation. +

+

+Typical usage is jit.off(true, true) in the main chunk +of a module to turn off JIT compilation for the whole module for +debugging purposes. +

+ +

jit.flush(tr)

+

+Flushes the specified root trace and all of its side traces from the cache. +The code for the trace will be retained as long as there are any other +traces which link to it. +

+ +

status, ... = jit.status()

+

+Returns the current status of the JIT compiler. The first result is +either true or false if the JIT compiler is turned +on or off. The remaining results are strings for CPU-specific features +and enabled optimizations. +

+ +

jit.version

+

+Contains the LuaJIT version string. +

+ +

jit.version_num

+

+Contains the version number of the LuaJIT core. Version xx.yy.zz +is represented by the decimal number xxyyzz. +

+ +

jit.arch

+

+Contains the target architecture name (CPU and optional ABI). +

+ +

jit.opt.* — JIT compiler optimization control

+

+This sub-module provides the backend for the -O command line +option. +

+

+You can also use it programmatically, e.g.: +

+
+jit.opt.start(2) -- same as -O2
+jit.opt.start("-dce")
+jit.opt.start("hotloop=10", "hotexit=2")
+
+

+Unlike in LuaJIT 1.x, the module is built-in and +optimization is turned on by default! +It's no longer necessary to run require("jit.opt").start(), +which was one of the ways to enable optimization. +

+ +

jit.util.* — JIT compiler introspection

+

+This sub-module holds functions to introspect the bytecode, generated +traces, the IR and the generated machine code. The functionality +provided by this module is still in flux and therefore undocumented. +

+

+The debug modules -jbc, -jv and -jdump make +extensive use of these functions. Please check out their source code, +if you want to know more. +

+
+
+ + + -- cgit v1.2.3-55-g6feb