When plugins are used the Multiplex(AST)Consumer is employed to dispatch
to both the plugin ASTConsumers and the IRGen ASTConsumer. It wasn't
dispatching a critical call for debug info, resulting in plugin users
having a negative debugging experience.
While I'm here, forward a bunch of other missing calls through the
consumer that seem like they should be there.
To test this, use the example plugin (requires plugins and examples) and
split the test case up so that the plugin testing can be done under that
requirement while the non-plugin testing will execute even in builds
that don't include plugin support or examples.
llvm-svn: 213213
These tests are logically related, but they're spread about several
different CodeGen directories. Consolidate them in one place to make
them easier to manage.
llvm-svn: 203541
These tests were added before we had settled on using a .profdata extension
for the profile data files. Renaming them now for consistency.
llvm-svn: 203166
Previously, we made one traversal of the AST prior to codegen to assign
counters to the ASTs and then propagated the count values during codegen. This
patch now adds a separate AST traversal prior to codegen for the
-fprofile-instr-use option to propagate the count values. The counts are then
saved in a map from which they can be retrieved during codegen.
This new approach has several advantages:
1. It gets rid of a lot of extra PGO-related code that had previously been
added to codegen.
2. It fixes a serious bug. My original implementation (which was mailed to the
list but never committed) used 3 counters for every loop. Justin improved it to
move 2 of those counters into the less-frequently executed breaks and continues,
but that turned out to produce wrong count values in some cases. The solution
requires visiting a loop body before the condition so that the count for the
condition properly includes the break and continue counts. Changing codegen to
visit a loop body first would be a fairly invasive change, but with a separate
AST traversal, it is easy to control the order of traversal. I've added a
testcase (provided by Justin) to make sure this works correctly.
3. It improves the instrumentation overhead, reducing the number of counters for
a loop from 3 to 1. We no longer need dedicated counters for breaks and
continues, since we can just use the propagated count values when visiting
breaks and continues.
To make this work, I needed to make a change to the way we count case
statements, going back to my original approach of not including the fall-through
in the counter values. This was necessary because there isn't always an AST node
that can be used to record the fall-through count. Now case statements are
handled the same as default statements, with the fall-through paths branching
over the counter increments. While I was at it, I also went back to using this
approach for do-loops -- omitting the fall-through count into the loop body
simplifies some of the calculations and make them behave the same as other
loops. Whenever we start using this instrumentation for coverage, we'll need
to add the fall-through counts into the counter values.
llvm-svn: 201528
This test requires asserts for now, and exception handling has an
awkward structure that leads to extra run lines. Because of this, the
test file's not a great place for other C++ PGO tests, but
instr-profile.cpp is obviously the better name for them.
llvm-svn: 199863