Reapply r199191, reverted in r199197 because it carelessly broke
Other/link-opts.ll. The problem was that calling
createInternalizePass("main") would select
createInternalizePass(bool("main")) instead of
createInternalizePass(ArrayRef<const char *>("main")). This commit
fixes the bug.
The original commit message follows.
Add API to LTOCodeGenerator to specify a strategy for the -internalize
pass.
This is a new attempt at Bill's change in r185882, which he reverted in
r188029 due to problems with the gold linker. This puts the onus on the
linker to decide whether (and what) to internalize.
In particular, running internalize before outputting an object file may
change a 'weak' symbol into an internal one, even though that symbol
could be needed by an external object file --- e.g., with arclite.
This patch enables three strategies:
- LTO_INTERNALIZE_FULL: the default (and the old behaviour).
- LTO_INTERNALIZE_NONE: skip -internalize.
- LTO_INTERNALIZE_HIDDEN: only -internalize symbols with hidden
visibility.
LTO_INTERNALIZE_FULL should be used when linking an executable.
Outputting an object file (e.g., via ld -r) is more complicated, and
depends on whether hidden symbols should be internalized. E.g., for
ld -r, LTO_INTERNALIZE_NONE can be used when -keep_private_externs, and
LTO_INTERNALIZE_HIDDEN can be used otherwise. However,
LTO_INTERNALIZE_FULL is inappropriate, since the output object file will
eventually need to link with others.
lto_codegen_set_internalize_strategy() sets the strategy for subsequent
calls to lto_codegen_write_merged_modules() and lto_codegen_compile*().
<rdar://problem/14334895>
llvm-svn: 199244
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.
Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:
define available_externally dllimport void @f() {}
@Var = dllexport global i32 1, align 4
Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.
llvm-svn: 199218
Representing dllexport/dllimport as distinct linkage types prevents using
these attributes on templates and inline functions.
Instead of introducing further mixed linkage types to include linkonce and
weak ODR, the old import/export linkage types are replaced with a new
separate visibility-like specifier:
define available_externally dllimport void @f() {}
@Var = dllexport global i32 1, align 4
Linkage for dllexported globals and functions is now equal to their linkage
without dllexport. Imported globals and functions must be either
declarations with external linkage, or definitions with
AvailableExternallyLinkage.
llvm-svn: 199204
Add API to LTOCodeGenerator to specify a strategy for the -internalize
pass.
This is a new attempt at Bill's change in r185882, which he reverted in
r188029 due to problems with the gold linker. This puts the onus on the
linker to decide whether (and what) to internalize.
In particular, running internalize before outputting an object file may
change a 'weak' symbol into an internal one, even though that symbol
could be needed by an external object file --- e.g., with arclite.
This patch enables three strategies:
- LTO_INTERNALIZE_FULL: the default (and the old behaviour).
- LTO_INTERNALIZE_NONE: skip -internalize.
- LTO_INTERNALIZE_HIDDEN: only -internalize symbols with hidden
visibility.
LTO_INTERNALIZE_FULL should be used when linking an executable.
Outputting an object file (e.g., via ld -r) is more complicated, and
depends on whether hidden symbols should be internalized. E.g., for
ld -r, LTO_INTERNALIZE_NONE can be used when -keep_private_externs, and
LTO_INTERNALIZE_HIDDEN can be used otherwise. However,
LTO_INTERNALIZE_FULL is inappropriate, since the output object file will
eventually need to link with others.
lto_codegen_set_internalize_strategy() sets the strategy for subsequent
calls to lto_codegen_write_merged_modules() and lto_codegen_compile*().
<rdar://problem/14334895>
llvm-svn: 199191
SymbolLookUp() call back to return a demangled C++ name to
be used as a comment.
For example darwin's otool(1) program the uses the llvm
disassembler now can produce disassembly like:
callq __ZNK4llvm6Target20createMCDisassemblerERKNS_15MCSubtargetInfoE ## llvm::Target::createMCDisassembler(llvm::MCSubtargetInfo const&) const
Also fix a bug in LLVMDisasmInstruction() that was not flushing
the raw_svector_ostream for the disassembled instruction string
before copying it to the output buffer that was causing truncation
of the output.
rdar://10173828
llvm-svn: 198637
The inalloca attribute is designed to support passing C++ objects by
value in the Microsoft C++ ABI. It behaves the same as byval, except
that it always implies that the argument is in memory and that the bytes
are never copied. This attribute allows the caller to take the address
of an outgoing argument's memory and execute arbitrary code to store
into it.
This patch adds basic IR support, docs, and verification. It does not
attempt to implement any lowering or fix any possibly broken transforms.
When this patch lands, a complete description of this feature should
appear at http://llvm.org/docs/InAlloca.html .
Differential Revision: http://llvm-reviews.chandlerc.com/D2173
llvm-svn: 197645
This adds a loop rerolling pass: the opposite of (partial) loop unrolling. The
transformation aims to take loops like this:
for (int i = 0; i < 3200; i += 5) {
a[i] += alpha * b[i];
a[i + 1] += alpha * b[i + 1];
a[i + 2] += alpha * b[i + 2];
a[i + 3] += alpha * b[i + 3];
a[i + 4] += alpha * b[i + 4];
}
and turn them into this:
for (int i = 0; i < 3200; ++i) {
a[i] += alpha * b[i];
}
and loops like this:
for (int i = 0; i < 500; ++i) {
x[3*i] = foo(0);
x[3*i+1] = foo(0);
x[3*i+2] = foo(0);
}
and turn them into this:
for (int i = 0; i < 1500; ++i) {
x[i] = foo(0);
}
There are two motivations for this transformation:
1. Code-size reduction (especially relevant, obviously, when compiling for
code size).
2. Providing greater choice to the loop vectorizer (and generic unroller) to
choose the unrolling factor (and a better ability to vectorize). The loop
vectorizer can take vector lengths and register pressure into account when
choosing an unrolling factor, for example, and a pre-unrolled loop limits that
choice. This is especially problematic if the manual unrolling was optimized
for a machine different from the current target.
The current implementation is limited to single basic-block loops only. The
rerolling recognition should work regardless of how the loop iterations are
intermixed within the loop body (subject to dependency and side-effect
constraints), but the significant restriction is that the order of the
instructions in each iteration must be identical. This seems sufficient to
capture all current use cases.
This pass is not currently enabled by default at any optimization level.
llvm-svn: 194939
stack traces by default if you use PrettyStackTraceProgram, so that existing LLVM-based
tools will continue to get it without any changes.
llvm-svn: 193971
linkonce_odr_auto_hide was in incomplete attempt to implement a way
for the linker to hide symbols that are known to be available in every
TU and whose addresses are not relevant for a particular DSO.
It was redundant in that it all its uses are equivalent to
linkonce_odr+unnamed_addr. Unlike those, it has never been connected
to clang or llvm's optimizers, so it was effectively dead.
Given that nothing produces it, this patch just nukes it
(other than the llvm-c enum value).
llvm-svn: 193865
Objective-C data structures.
This is allows tools such as darwin's otool(1) that uses the
LLVM disassembler take a pointer value being loaded by
an instruction and add a comment to what it is being referenced
to make following disassembly of Objective-C programs
more readable.
For example disassembling the Mac OS X TextEdit app one
will see comments like the following:
movq 0x20684(%rip), %rsi ## Objc selector ref: standardUserDefaults
movq 0x21985(%rip), %rdi ## Objc class ref: _OBJC_CLASS_$_NSUserDefaults
movq 0x1d156(%rip), %r14 ## Objc message: +[NSUserDefaults standardUserDefaults]
leaq 0x23615(%rip), %rdx ## Objc cfstring ref: @"SelectLinePanel"
callq 0x10001386c ## Objc message: -[[%rdi super] initWithWindowNibName:]
These diffs also include putting quotes around C strings
in literal pools and uses "symbol address" in the comment
when adding a symbol name to the comment to tell these
types of references apart:
leaq 0x4f(%rip), %rax ## literal pool for: "Hello world"
movq 0x1c3ea(%rip), %rax ## literal pool symbol address: ___stack_chk_guard
Of course the easy changes are in the LLVM disassembler and
the hard work is up to the implementer of the SymbolLookUp()
call back.
rdar://10602439
llvm-svn: 193833
There are two ways one could implement hiding of linkonce_odr symbols in LTO:
* LLVM tells the linker which symbols can be hidden if not used from native
files.
* The linker tells LLVM which symbols are not used from other object files,
but will be put in the dso symbol table if present.
GOLD's API is the second option. It was implemented almost 1:1 in llvm by
passing the list down to internalize.
LLVM already had partial support for the first option. It is also very similar
to how ld64 handles hiding these symbols when *not* doing LTO.
This patch then
* removes the APIs for the DSO list.
* marks LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN all linkonce_odr unnamed_addr
global values and other linkonce_odr whose address is not used.
* makes the gold plugin responsible for handling the API mismatch.
llvm-svn: 193800
This reverts commit r193255 and instead creates an lto_bool_t typedef
that points to bool, _Bool, or unsigned char depending on what is
available. Only recent versions of MSVC provide a stdbool.h header.
Reviewers: rafael.espindola
Differential Revision: http://llvm-reviews.chandlerc.com/D2019
llvm-svn: 193377
All of the Core API functions have versions which accept explicit context, in
addition to ones which work on global context. This commit adds functions
which accept explicit context to the Target API for consistency.
Patch by Peter Zotov
Differential Revision: http://llvm-reviews.chandlerc.com/D1912
llvm-svn: 192913
I expose the API with some caveats:
- The C++ API involves a traditional void* opaque pointer for the fatal
error callback. The C API doesn’t do this. I don’t think that the void*
opaque pointer makes any sense since this is a global callback - there will
only be one of them. So if you need to pass some data to your callback,
just put it in a global variable.
- The bindings will ignore the gen_crash_diag boolean. I ignore it because
(1) I don’t know what it does, (2) it’s not documented AFAIK, and (3) I
couldn’t imagine any use for it. I made the gut call that it probably
wasn’t important enough to expose through the C API.
llvm-svn: 192864
The C API currently allows to dump values (LLVMDumpValue), but a similar method for types was not exported.
Patch by Peter Zotov
Differential Revision: http://llvm-reviews.chandlerc.com/D1911
llvm-svn: 192852
Like LLVMDumpModule but returns the string (that needs to be freed
with LLVMDisposeMessage) instead of printing it to stderr.
Differential Revision: http://llvm-reviews.chandlerc.com/D1941
llvm-svn: 192821
This new library will be linked in when using the "all-targets"
component and contains the LLVMInitializeAll* functions.
This means that those functions will exist as real symbols in
the shared library, and can therefore can be called from
bindings that are using ffi the shared library.
llvm-svn: 192690
This reverts commit r192316. The original change introduced circular
dependencies between libTarget and backends. That would broke a build unless
link everything into one big binary.
llvm-svn: 192329
Making them proper functions defined in the (shared)lib instead of
static inlines defined in the header files makes it possible to
actually distribute a binary compiled against the shared library
without having to worry about getting undefined symbol errors when
calling e.g LLVMInitializeAllTargetInfos because the shared library on
the other system was compiled with different targets.
Differential Revision: http://llvm-reviews.chandlerc.com/D1714
llvm-svn: 192316
Duncan P. N. Exon Smith