Add branch instructions to Subzero bitcode reader.

Add branch instructions to Subzero bitcode reader.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=3894
R=stichnot@chromium.org

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a=commit;h=c836acb

[Karl, 2014-09-04 21:43:05]

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

[Jim Stichnoth, 2014-09-04 21:58:17]

LGTM, with a few nits.

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp
File src/PNaClTranslator.cpp (right):

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp#newc...
src/PNaClTranslator.cpp:875: // TODO(kschimpf) Remove error recovery once
implementation complete.
Maybe "return NULL;" here, to help propagate the error upward?

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp#newc...
src/PNaClTranslator.cpp:1322: if (Block == NULL) return;
return statement on separate line

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp#newc...
src/PNaClTranslator.cpp:1338: if (ThenBlock == 0 || ElseBlock == 0) return;
return on separate line.  Also, NULL instead of 0.

[Karl, 2014-09-05 15:32:55]

Committed patchset #2 (id:20001) manually as c836acb (presubmit successful).

[Karl, 2014-09-05 15:33:08]

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp
File src/PNaClTranslator.cpp (right):

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp#newc...
src/PNaClTranslator.cpp:875: // TODO(kschimpf) Remove error recovery once
implementation complete.
On 2014/09/04 21:58:17, stichnot wrote:
> Maybe "return NULL;" here, to help propagate the error upward?

The only block we always know we can recover to is block 0. If we return NULL,
we shouldn't be generating an error.

However, as discussed with Jim, I added code to check if errors occurred while
generating a function block. If so, it will not do any downstream translation.

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp#newc...
src/PNaClTranslator.cpp:1322: if (Block == NULL) return;
On 2014/09/04 21:58:17, stichnot wrote:
> return statement on separate line

Done.

https://codereview.chromium.org/545603003/diff/1/src/PNaClTranslator.cpp#newc...
src/PNaClTranslator.cpp:1338: if (ThenBlock == 0 || ElseBlock == 0) return;
On 2014/09/04 21:58:17, stichnot wrote:
> return on separate line.  Also, NULL instead of 0.

Done.