Subzero, WASM: stop writing uninitialized data to .o file. Add timers.

Subzero, WASM: stop writing uninitialized data to .o file. Add timers.

Previously we were writing large numbers of zeros to the output
file. This change only writes out the initialized portion and
allocates the full address space at runtime. This reduces compile time
by around 50%.

This change also adds a couple of WASM-specific timers.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
R=jpp@chromium.org, stichnot@chromium.org

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a=commit;h=179a55d73a968fc224726baa5df6165658e31ad7

[Eric Holk, 2016-04-29 22:37:41]

eholk@chromium.org changed reviewers:
+ jpp@chromium.org, kschimpf@google.com, stichnot@chromium.org

[Eric Holk, 2016-04-29 22:37:42]

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp
File src/WasmTranslator.cpp (left):

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp#...
src/WasmTranslator.cpp:1165: Operand *sanitizeAddress(Operand *Base, uint32_t
Offset) {
This function is just moved down lower to make it private.

[John, 2016-04-30 04:11:56]

lgtm

https://codereview.chromium.org/1938643002/diff/20001/runtime/wasm-runtime.cpp
File runtime/wasm-runtime.cpp (right):

https://codereview.chromium.org/1938643002/diff/20001/runtime/wasm-runtime.cp...
runtime/wasm-runtime.cpp:227: WASM_MEMORY = &WasmHeap[0];
WasmHeap->data()?

[Jim Stichnoth, 2016-05-02 16:04:08]

lgtm

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp
File src/WasmTranslator.cpp (right):

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp#...
src/WasmTranslator.cpp:284: assert(!WasmMemory);
assert(WasmMemory == nullptr);

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp#...
src/WasmTranslator.cpp:1329: assert(WasmMemory);
assert(WasmMemory != nullptr);

I think we're pretty consistent in the code base these days about explicitly
comparing pointers against nullptr.

[Eric Holk, 2016-05-02 17:42:30]

Description was changed from

==========
Subzero, WASM: stop writing uninitialized data to .o file. Add timers.

Previously we were writing large numbers of zeros to the output
file. This change only writes out the initialized portion and
allocates the full address space at runtime. This reduces compile time
by around 50%.

This change also adds a couple of WASM-specific timers.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
==========

to

==========
Subzero, WASM: stop writing uninitialized data to .o file. Add timers.

Previously we were writing large numbers of zeros to the output
file. This change only writes out the initialized portion and
allocates the full address space at runtime. This reduces compile time
by around 50%.

This change also adds a couple of WASM-specific timers.

BUG= https://bugs.chromium.org/p/nativeclient/issues/detail?id=4369
R=jpp@chromium.org, stichnot@chromium.org

Committed:
https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a...
==========

[Eric Holk, 2016-05-02 17:42:31]

Committed patchset #2 (id:20001) manually as
179a55d73a968fc224726baa5df6165658e31ad7 (presubmit successful).

[Eric Holk, 2016-05-02 17:42:38]

https://codereview.chromium.org/1938643002/diff/20001/runtime/wasm-runtime.cpp
File runtime/wasm-runtime.cpp (right):

https://codereview.chromium.org/1938643002/diff/20001/runtime/wasm-runtime.cp...
runtime/wasm-runtime.cpp:227: WASM_MEMORY = &WasmHeap[0];
On 2016/04/30 04:11:55, John wrote:
> WasmHeap->data()?

Done.

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp
File src/WasmTranslator.cpp (right):

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp#...
src/WasmTranslator.cpp:284: assert(!WasmMemory);
On 2016/05/02 16:04:07, stichnot wrote:
> assert(WasmMemory == nullptr);

Done.

https://codereview.chromium.org/1938643002/diff/20001/src/WasmTranslator.cpp#...
src/WasmTranslator.cpp:1329: assert(WasmMemory);
On 2016/05/02 16:04:07, stichnot wrote:
> assert(WasmMemory != nullptr);
> 
> I think we're pretty consistent in the code base these days about explicitly
> comparing pointers against nullptr.

Done.