COFF doesn't have mergeable sections so LLVM/clang's normal tactics for
string deduplication will not have any effect.
To remedy this we place each string inside it's own section and mark
the section as IMAGE_COMDAT_SELECT_ANY. However, we can only do this if the
string has an external name that we can generate from it's contents.
To be compatible with MSVC, we must use their scheme. Otherwise identical
strings in translation units from clang may not be deduplicated with
translation units in MSVC.
This fixes PR18248.
N.B. We will not attempt to do anything with a string literal which is not of
type 'char' or 'wchar_t' because their compiler does not support unicode
string literals as of this date.
llvm-svn: 204562
location that the next call emitLocation() would default to. Otherwise
setLocation() may wrongly believe that the current source file didn't
change, when in fact it did.
llvm-svn: 204517
Variables with available_externally linkage can be dropped at will.
This causes link errors, since there are still references to the
instrumentation! linkonce_odr is almost equivalent, so use that
instead.
As a drive-by fix (I don't have an Elf system, so I'm not sure how to
write a testcase), use linkonce linkage for the instrumentation of
extern_weak functions.
<rdar://problem/15943240>
llvm-svn: 204408
The variable is used to set the linkage for variables, and will become
different from function linkage in a follow-up commit.
<rdar://problem/15943240>
llvm-svn: 204407
These functions are in the profile runtime. PGO comes later.
Unfortunately, there's only room for 16 characters in a Darwin section,
so use __llvm_prf_ instead of __llvm_profile_ for section names.
<rdar://problem/15943240>
llvm-svn: 204390
Remove the remaining explicit static initialization from translation
units, at least on Darwin. Instead, create a use of __llvm_pgo_runtime,
which will pull in required code from compiler-rt.
After this commit (and its pair in compiler-rt), a user can define their
own __llvm_pgo_runtime to satisfy this undefined symbol and call the
functions in compiler-rt directly.
<rdar://problem/15943240>
llvm-svn: 204379
The hash itself is still the number of counters, which isn't all that
useful, but this separates the API changes from the actual
implementation of the hash and will make it easier to transition to
the ProfileData library once it's implemented.
llvm-svn: 204186
In instrumentation-based profiling, we need a set of data structures to
represent the counters. Previously, these were built up during static
initialization. Now, they're shoved into a specially-named section so
that they show up as an array.
As a consequence of the reorganizing symbols, instrumentation data
structures for linkonce functions are now correctly coalesced.
This is the first step in a larger project to minimize runtime overhead
and dependencies in instrumentation-based profilng. The larger picture
includes removing all initialization overhead and making the dependency
on libc optional.
<rdar://problem/15943240>
llvm-svn: 204080
data members by addition of CXXDefaultInitExpr node to the initializer expression,
it has broken treatment of arc code for such initializations. Reviewed by John McCall.
// rdar://16299964
llvm-svn: 203935
Drive-by fixing some incorrect types where a for loop would be improperly using ObjCInterfaceDecl::protocol_iterator. No functional changes in these cases.
llvm-svn: 203842
This makes Clang take advantage of the recent IR addition of a
"failure" memory ordering requirement. As with the "success" ordering,
we try to emit just a single version if the expression is constant,
but fall back to runtime detection (to allow optimisation across
function-call boundaries).
rdar://problem/15996804
llvm-svn: 203837
This updates CodeGenPGO to use the ProfileDataReader introduced to
llvm in r203703 and the new API for writing out the profile introduced
to compiler-rt in r203710.
llvm-svn: 203711
When a struct has bitfields overlapping with other members
(as required by the AAPCS), clang uses a packed struct to
represent this. If such a struct is large enough for clang to
pass it as a byval pointer (>64 bytes), we need to set the
alignment of the argument to match the original type.
llvm-svn: 203660
PGO counters are 64-bit and branch weights are 32-bit. Scale them down
when necessary, instead of just taking the lower 32 bits.
<rdar://problem/16276448>
llvm-svn: 203592
This is a conservative check, because it's valid for the expression to be
non-constant, and in cases like that we just don't know whether it's valid.
rdar://problem/16242991
llvm-svn: 203561
Previously, we would always emit them with internal linkage,
but with hidden visibility when the function was hidden, which
is an illegal combination, which could lead LLVM to actually
emit them as strong hidden symbols with hilarious results.
rdar://16265084
llvm-svn: 203503
David Majnemer