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
PNaCl and Emscripten can both handle va_arg IR instructions with
struct type.
Also add a test to cover generating a va_arg IR instruction from
va_arg in C on le32 (as already handled by VisitVAArgExpr() in
CGExprScalar.cpp), which was not covered by a test before.
(This fixes https://code.google.com/p/nativeclient/issues/detail?id=2381)
Differential Revision: http://llvm-reviews.chandlerc.com/D2539
llvm-svn: 199830
adjustFallThroughCount isn't a good name, and the documentation was
even worse. This commit attempts to clarify what it's for and when to
use it.
llvm-svn: 199139
With the introduction of explicit address space casts into LLVM, there's
a need to provide a new cast kind the front-end can create for C/OpenCL/CUDA
and code to produce address space casts from those kinds when appropriate.
Patch by Michele Scandale!
llvm-svn: 197036
This is the same way GenericSelectionExpr works, and it's generally a
more consistent approach.
A large part of this patch is devoted to caching the value of the condition
of a ChooseExpr; it's needed to avoid threading an ASTContext into
IgnoreParens().
Fixes <rdar://problem/14438917>.
llvm-svn: 186738
Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).
This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.
llvm-svn: 183872
Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.
There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.
llvm-svn: 179958
aggregate types in a profoundly wrong way that has to be
worked around in every call site, to getEvaluationKind,
which classifies and distinguishes between all of these
cases.
Also, normalize the API for loading and storing complexes.
I'm working on a larger patch and wanted to pull these
changes out, but it would have be annoying to detangle
them from each other.
llvm-svn: 176656
Title: [PR9027] volatile struct bug: member is not loaded at -O;
This is caused by last flag passed to @llvm.memcpy being false,
not honoring that aggregate has at least one 'volatile' data member
(even though aggregate itself has not been qualified as 'volatile'.
As a result, optimization optimizes away the memcpy altogether.
Patch review by John MaCall (I still need to fix up a test though).
llvm-svn: 173535
uncovered.
This required manually correcting all of the incorrect main-module
headers I could find, and running the new llvm/utils/sort_includes.py
script over the files.
I also manually added quite a few missing headers that were uncovered by
shuffling the order or moving headers up to be main-module-headers.
llvm-svn: 169237
Separate out the notions of 'has a trivial special member' and 'has a
non-trivial special member', and use them appropriately. These are not
opposites of one another (there might be no special member, or in C++11 there
might be a trivial one and a non-trivial one). The CXXRecordDecl predicates
continue to produce incorrect results, but do so in fewer cases now, and
they document the cases where they might be wrong.
No functionality changes are intended here (they will come when the predicates
start producing the right answers...).
llvm-svn: 168119
This fixes a regression from r162254, the optimizer has problems reasoning
about the smaller memcpy as it's often not safe to widen a store but making it
smaller is.
llvm-svn: 164917
the trap BB out of the individual checks and into a common function, to prepare
for making this code call into a runtime library. Rename the existing EmitCheck
to EmitTypeCheck to clarify it and to move it out of the way of the new
EmitCheck.
llvm-svn: 163451
(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call. Fixes PR13195.
llvm-svn: 162962
* when checking that a pointer or reference refers to appropriate storage for a type, also check the alignment and perform a null check
* check that references are bound to appropriate storage
* check that 'this' has appropriate storage in member accesses and member function calls
llvm-svn: 162523
to overwrite objects that might have been allocated into the type's
tail padding. This patch is missing some potential optimizations where
the destination is provably a complete object, but it's necessary for
correctness.
Patch by Jonathan Sauer.
llvm-svn: 162254
if we want to ignore a result, the Dest will be null. Otherwise,
we must copy into it. This means we need to ensure a slot when
loading from a volatile l-value.
With all that in place, fix a bug with chained assignments into
__block variables of aggregate type where we were losing insight into
the actual source of the value during the second assignment.
llvm-svn: 159630
In addition, I've made the pointer and reference typedef 'void' rather than T*
just so they can't get misused. I would've omitted them entirely but
std::distance likes them to be there even if it doesn't use them.
This rolls back r155808 and r155869.
Review by Doug Gregor incorporating feedback from Chandler Carruth.
llvm-svn: 158104
filter_decl_iterator had a weird mismatch where both op* and op-> returned T*
making it difficult to generalize this filtering behavior into a reusable
library of any kind.
This change errs on the side of value, making op-> return T* and op* return
T&.
(reviewed by Richard Smith)
llvm-svn: 155808
initialize an array of unsigned char. Outside C++11 mode, this bug was benign,
and just resulted in us emitting a constant which was double the required
length, padded with 0s. In C++11, it resulted in us generating an array whose
first element was something like i8 ptrtoint ([n x i8]* @str to i8).
llvm-svn: 154756
track whether the referenced declaration comes from an enclosing
local context. I'm amenable to suggestions about the exact meaning
of this bit.
llvm-svn: 152491
we correctly emit loads of BlockDeclRefExprs even when they
don't qualify as ODR-uses. I think I'm adequately convinced
that BlockDeclRefExpr can die.
llvm-svn: 152479
Richard Smith