History log of /dalvik/vm/mterp/armv5te/alt_stub.S
Revision Date Author Comments
9a3147c7412f4794434b4c2604aa2ba784867774 03-Mar-2011 buzbee <buzbee@google.com> Interpreter restructuring

This is a restructuring of the Dalvik ARM and x86 interpreters:

o Combine the old portstd and portdbg interpreters into a single
portable interpreter.
o Add debug/profiling support to the fast (mterp) interpreters.
o Delete old mechansim of switching between interpreters. Now, once
you choose an interpreter at startup, you stick with it.
o Allow JIT to co-exist with profiling & debugging (necessary for
first-class support of debugging with the JIT active).
o Adds single-step capability to the fast assembly interpreters without
slowing them down (and, in fact, measurably improves their performance).
o Remove old "polling for safe point" mechanism. Breakouts now achieved
via modifying base of interpreter handler table.
o Simplify interpeter control mechanism.
o Allow thread-granularity control for profiling & debugging

The primary motivation behind this change was to improve the responsiveness
of debugging and profiling and to make it easier to add new debugging and
profiling capabilities in the future. Instead of always bailing out to the
slow debug portable interpreter, we can now stay in the fast interpreter.

A nice side effect of the change is that the fast interpreters
got a healthy speed boost because we were able to replace the
polling safepoint check that involved a dozen or so instructions
with a single table-base reload. When combined with the two earlier CLs
related to this restructuring, we show a 5.6% performance improvement
using libdvm_interp.so on the Checkers benchmark relative to Honeycomb.

Change-Id: I8d37e866b3618def4e582fc73f1cf69ffe428f3c
3d054be0780e2bee9553711d409608495cc2c19e 02-Mar-2011 buzbee <buzbee@google.com> mterp generation cleanup

Change I3a22048a introduced a new interpreter breakout mechanism, and
with it a bit of hackish ugliness in the mechanism to automatically
generate interpreter source files.

This CL applies some Lipo and Botox:
o New alt-op-start, alt-op-end commands removed - will just use
existing op-start & op-end.
o New command "handler-style" to explicitly declare interpreter
style (computed-goto, jump-table or all-c). Previous trigger
on "handler-size==0" removed.
o Alternate handler stub no longer using fixed file name, but
intead is named by command asm-alt-stub (which is modelled on
existing alt-stub command).
o Previous CL stated requirement for explicitly called-out handler
for the Dalvik dispatch opcode. Turns out this was not necessary.
Requirement removed.

Change-Id: I20f7411820715476533c2073d28f357e28c1ae52