This reland includes a fix for the LowerTypeTests pass so that it
looks past aliases when determining which type identifiers are live.
Differential Revision: https://reviews.llvm.org/D37842
llvm-svn: 313229
This broke Chromium's CFI build; see crbug.com/765004.
> We were previously handling aliases during dead stripping by adding
> the aliased global's "original name" GUID to the worklist. This will
> lead to incorrect behaviour if the global has local linkage because
> the original name GUID will not correspond to the global's GUID in
> the summary.
>
> Because an alias is just another name for the global that it
> references, there is no need to mark the referenced global as used,
> or to follow references from any other copies of the global. So all
> we need to do is to follow references from the aliasee's summary
> instead of the alias.
>
> Differential Revision: https://reviews.llvm.org/D37789
llvm-svn: 313222
We were previously handling aliases during dead stripping by adding
the aliased global's "original name" GUID to the worklist. This will
lead to incorrect behaviour if the global has local linkage because
the original name GUID will not correspond to the global's GUID in
the summary.
Because an alias is just another name for the global that it
references, there is no need to mark the referenced global as used,
or to follow references from any other copies of the global. So all
we need to do is to follow references from the aliasee's summary
instead of the alias.
Differential Revision: https://reviews.llvm.org/D37789
llvm-svn: 313157
This change simplifies code that has to deal with
DIGlobalVariableExpression and mirrors how we treat DIExpressions in
debug info intrinsics. Before this change there were two ways of
representing empty expressions on globals, a nullptr and an empty
!DIExpression().
If someone needs to upgrade out-of-tree testcases:
perl -pi -e 's/(!DIGlobalVariableExpression\(var: ![0-9]*)\)/\1, expr: !DIExpression())/g' <MYTEST.ll>
will catch 95%.
llvm-svn: 312144
Summary:
This updates the Inliner to only add a single Optimization
Remark when Inlining, rather than an Analysis Remark and an
Optimization Remark.
Fixes https://bugs.llvm.org/show_bug.cgi?id=33786
Reviewers: anemet, davidxl, chandlerc
Reviewed By: anemet
Subscribers: haicheng, fhahn, mehdi_amini, dblaikie, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D36054
llvm-svn: 311349
Summary:
This updates the Inliner to only add a single Optimization
Remark when Inlining, rather than an Analysis Remark and an
Optimization Remark.
Fixes https://bugs.llvm.org/show_bug.cgi?id=33786
Reviewers: anemet, davidxl, chandlerc
Reviewed By: anemet
Subscribers: haicheng, fhahn, mehdi_amini, dblaikie, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D36054
llvm-svn: 311273
The %T lit expansion expands to a common directory shared between all the tests in the same directory, which is unexpected and unintuitive, and more importantly, it's been a source of subtle race conditions and flaky tests. In https://reviews.llvm.org/D35396, it was agreed that it would be best to simply ban %T and only keep %t, which is unique to each test. When a test needs a temporary directory, it can just create one using mkdir %t.
This patch removes %T in llvm.
Differential Revision: https://reviews.llvm.org/D36495
llvm-svn: 310953
We were previously creating a global variable of function type,
which is invalid IR. This issue was exposed by r304690, in which we
started asserting that global variables were of a valid type.
Fixes PR33462.
Differential Revision: https://reviews.llvm.org/D36438
llvm-svn: 310543
Summary: In ThinLTO backend compile, OPTOptions are not set so that the ICP in ThinLTO backend does not know if it is a SamplePGO build, in which profile count needs to be annotated directly on call instructions. This patch cleaned up the PGOOptions handling logic and passes down PGOOptions to ThinLTO backend.
Reviewers: chandlerc, tejohnson, davidxl
Reviewed By: chandlerc
Subscribers: sanjoy, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D36052
llvm-svn: 309780
Summary:
This exposes LTO's Conf.SampleProfile as a command line option
(-lto-sample-profile-file) for testing via the llvm-lto2 utility.
Reviewers: pcc, danielcdh
Subscribers: mehdi_amini, inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D36030
llvm-svn: 309456
If the LowerTypeTests pass decides to add a function to a jump
table for CFI, it will add its name to the set cfiFunctionDefs,
which among other things will cause the function to be renamed in
the ThinLTO backend.
One other thing that we must do with such functions is to not
internalize them, because the jump table in the full LTO object will
contain a reference to the actual function body in the ThinLTO object.
This patch handles that by ensuring that we export any functions
whose names appear in the cfiFunctionDefs set.
Fixes PR33831.
Differential Revision: https://reviews.llvm.org/D35605
llvm-svn: 308504
This is the same as r304719 but for ThinLTO.
The substantial difference is that in this case we don't have
whole visibility, just the summary.
In the LTO case, when we got the resolution for the input file we
could just see if the linker told us whether a symbol was linker
redefined (using --wrap or --defsym) and switch the linkage directly
for the GV.
Here, we have the summary. So, we record that the linkage changed
from <whatever it was> to $weakany to prevent IPOs across this symbol
boundaries and actually just switch the linkage at FunctionImport time.
This patch should also fixes the lld bits (as all the scaffolding for
communicating if a symbol is linker redefined should be there & should
be the same), but I'll make sure to add some tests there as well.
Fixes PR33192.
Differential Revision: https://reviews.llvm.org/D35064
llvm-svn: 307303
Summary:
When linking a regular LTO module, if it has any non-prevailing values
(dropped to available_externally) in comdats, we need to do more than
just remove those values from their comdat. We also remove all values
from that comdat, so as to avoid leaving an incomplete comdat.
This is necessary in case we are compiling in mixed regular and ThinLTO
mode, since the resulting regularLTO native object is always linked into
the final binary first. We need to prevent the linker from selecting an
incomplete comdat that was not the prevailing copy.
Fixes PR32980.
Reviewers: pcc, rafael
Subscribers: mehdi_amini, david2050, llvm-commits, inglorion
Differential Revision: https://reviews.llvm.org/D34803
llvm-svn: 306826
If a regular LTO module has a summary index, then instead of linking
it into the combined regular LTO module right away, add it to the
combined summary index and associate it with a special module that
represents the combined regular LTO module.
Any such modules are linked during LTO::run(), at which time we use
the results of summary-based dead stripping to control whether to
link prevailing symbols.
Differential Revision: https://reviews.llvm.org/D33922
llvm-svn: 305482
Summary:
This patch updates Triple::isCompatibleWith to make armxx and thumbxx
triples compatible, as long as the subarch, vendor, os, envorionment and
object format match. Thumb/ARM code generation should be controlled
using the thumb-mode per-function target feature rather than by the
triple to allow mixing Thumb and ARM functions.
D33448 updates Clang's codegen to add thumb-mode for all functions with
armxx or thumbxx triples.
Reviewers: echristo, t.p.northover, rafael, kristof.beyls, rengolin, tejohnson
Reviewed By: tejohnson
Subscribers: rinon, eugenis, pcc, srhines, aemerson, mehdi_amini, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D33287
llvm-svn: 304884
procedural optimizations to prevent dropping symbols and allow the linker
to process re-directs.
PR33145: --wrap doesn't work with lto.
Differential Revision: https://reviews.llvm.org/D33621
llvm-svn: 304719
The whole-program-devirt pass needs to run at -O0 because only it
knows about the llvm.type.checked.load intrinsic: it needs to both
lower the intrinsic itself and handle it in the summary.
Differential Revision: https://reviews.llvm.org/D33571
llvm-svn: 304019
Prevailing symbol resolution is necessary for correctness. Without
this we can end up dropping a referenced linkonce symbol from the link.
Differential Revision: https://reviews.llvm.org/D33570
llvm-svn: 303939
This reapplies commit r303438 modified to not verify cross-imported
bitcode in FunctionImporter.
rdar://problem/31233625
Differential Revision: https://reviews.llvm.org/D33370
llvm-svn: 303470
Summary:
All GlobalIndirectSymbol types (not just GlobalAlias) should return
their base object.
Without this patch LTO would warn "Unable to determine comdat of
alias!" for an ifunc.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D33202
llvm-svn: 303096
Marking them as used causes them to be considered visible outside of LTO. This
prevents the symbols from being internalized or discarded, either by GlobalDCE
or by summary-based dead stripping in ThinLTO.
This change makes it unnecessary to add these symbols to llvm.compiler.used
in the backend, as the symbols are kept alive by virtue of being external,
so remove the backend code that handles that.
Fixes PR32798.
Differential Revision: https://reviews.llvm.org/D32544
llvm-svn: 301438
Start using it in LLD to avoid needing to read bitcode again just to get the
target triple, and in llvm-lto2 to avoid printing symbol table information
that is inappropriate for the target.
Differential Revision: https://reviews.llvm.org/D32038
llvm-svn: 300300
Summary:
The linker needs to be able to determine whether a symbol is text or data to
handle the case of a common being overridden by a strong definition in an
archive. If the archive contains a text member of the same name as the common,
that function is discarded. However, if the archive contains a data member of
the same name, that strong definition overrides the common. This is a behavior
of ld.bfd, which the Qualcomm linker also supports in LTO.
Here's a test case to illustrate:
####
cat > 1.c << \!
int blah;
!
cat > 2.c << \!
int blah() {
return 0;
}
!
cat > 3.c << \!
int blah = 20;
!
clang -c 1.c
clang -c 2.c
clang -c 3.c
ar cr lib.a 2.o 3.o
ld 1.o lib.a -t
####
The correct output is:
1.o
(lib.a)3.o
Thanks to Shankar Easwaran and Hemant Kulkarni for the test case!
Reviewers: mehdi_amini, rafael, pcc, davide
Reviewed By: pcc
Subscribers: davide, llvm-commits, inglorion
Differential Revision: https://reviews.llvm.org/D31901
llvm-svn: 300205
Move LTO::run() to a "run" subcommand so that we can introduce new subcommands
for testing different parts of the LTO implementation.
This doesn't use llvm::cl subcommands because it doesn't appear to be currently
possible to pass an argument not associated with a subcommand to a subcommand
(e.g. -lto-use-new-pm, -mcpu=yonah).
Differential Revision: https://reviews.llvm.org/D31410
llvm-svn: 299967
Summary:
In a .symver assembler directive like:
.symver name, name2@@nodename
"name2@@nodename" should get the same symbol binding as "name".
While the ELF object writer is updating the symbol binding for .symver
aliases before emitting the object file, not doing so when the module
inline assembly is handled by the RecordStreamer is causing the wrong
behavior in *LTO mode.
E.g. when "name" is global, "name2@@nodename" must also be marked as
global. Otherwise, the symbol is skipped when iterating over the LTO
InputFile symbols (InputFile::Symbol::shouldSkip). So, for example,
when performing any *LTO via the gold-plugin, the versioned symbol
definition is not recorded by the plugin and passed back to the
linker. If the object was in an archive, and there were no other symbols
needed from that object, the object would not be included in the final
link and references to the versioned symbol are undefined.
The llvm-lto2 tests added will give an error about an unused symbol
resolution without the fix.
Reviewers: rafael, pcc
Reviewed By: pcc
Subscribers: mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D30485
llvm-svn: 297332
Fixes PR 31921
Summary:
Predicateinfo requires an ugly workaround to try to avoid literal
struct types due to the intrinsic mangling not being implemented.
This workaround actually does not work in all cases (you can hit the
assert by bootstrapping with -print-predicateinfo), and can't be made
to work without DFS'ing the type (IE copying getMangledStr and using a
version that detects if it would crash).
Rather than do that, i just implemented the mangling. It seems
simple, since they are unified structurally.
Looking at the overloaded-mangling testcase we have, it actually turns
out the gc intrinsics will *also* crash if you try to use a literal
struct. Thus, the testcase added fails before this patch, and works
after, without needing to resort to predicateinfo.
Reviewers: chandlerc, davide
Subscribers: llvm-commits, sanjoy
Differential Revision: https://reviews.llvm.org/D29925
llvm-svn: 295253
Summary:
Add a field to LTO::Config, CGFileType, to select the file type to emit (object
or assembly). This is useful for testing and to implement -save-temps.
Reviewers: tejohnson, mehdi_amini, pcc
Reviewed By: mehdi_amini
Subscribers: davide, llvm-commits
Differential Revision: https://reviews.llvm.org/D29475
llvm-svn: 295226
until we can get better TargetMachine::isCompatibleDataLayout to compare - otherwise
we can't code generate existing bitcode without a string equality data layout.
This reverts commit r294702.
llvm-svn: 294709
For other platforms we should find out what they need and likely
make the same change, however, a smaller additional change is easier
for platforms we know have it specified in the ABI. As part of this
rewrite some of the handling in the backends for data layout and update
a bunch of testcases.
Based on a patch by Simonas Kazlauskas!
llvm-svn: 294702
These linkages mean that the ultimately prevailing symbol will have the same
semantics as any non-prevailing copy of the symbol, so we are free to ignore
the linker's resolution.
Differential Revision: https://reviews.llvm.org/D29367
llvm-svn: 293865
This patch renumbers the metadata nodes in debug info testcases after
https://reviews.llvm.org/D26769. This is a separate patch because it
causes so much churn. This was implemented with a python script that
pipes the testcases through llvm-as - | llvm-dis - and then goes
through the original and new output side-by side to insert all
comments at a close-enough location.
Differential Revision: https://reviews.llvm.org/D27765
llvm-svn: 290292
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 290153
This reverts commit 289920 (again).
I forgot to implement a Bitcode upgrade for the case where a DIGlobalVariable
has not DIExpression. Unfortunately it is not possible to safely upgrade
these variables without adding a flag to the bitcode record indicating which
version they are.
My plan of record is to roll the planned follow-up patch that adds a
unit: field to DIGlobalVariable into this patch before recomitting.
This way we only need one Bitcode upgrade for both changes (with a
version flag in the bitcode record to safely distinguish the record
formats).
Sorry for the churn!
llvm-svn: 289982
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 289920
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 289902
Also, udpate the ~60 failing tests in the tree which did
not contain a valid datalayout.
This fixes PR31123. lld will be updated in a following patch,
immediately after this is committed.
Differential Revision: https://reviews.llvm.org/D27082
llvm-svn: 289719
It is used to drive this from the clang driver via -mllvm.
Same option name is used as in opt.
Differential Revision: https://reviews.llvm.org/D26832
llvm-svn: 287356
During Module linking, it's possible for SrcM->getIdentifiedStructTypes();
to return types that are actually defined in the destination module
(DstM). Depending on how the bitcode file was read,
getIdentifiedStructTypes() might do a walk over all values, including
metadata nodes, looking for types. In my case, a debug info metadata
node was shared between the two modules, and it referred to a type
defined in the destination module (see test case).
Differential Revision: https://reviews.llvm.org/D26212
llvm-svn: 287353
This restores the rest of r286297 (part was restored in r286475).
Specifically, it restores the part requiring adding a dependency from
the Analysis to Object library (downstream use changed to correctly
model split BitReader vs BitWriter libraries).
Original description of this part of patch follows:
Module level asm may also contain defs of values. We need to prevent
export of any refs to local values defined in module level asm (e.g. a
ref in normal IR), since that also requires renaming/promotion of the
local. To do that, the summary index builder looks at all values in the
module level asm string that are not marked Weak or Global, which is
exactly the set of locals that are defined. A summary is created for
each of these local defs and flagged as NoRename.
This required adding handling to the BitcodeWriter to look at GV
declarations to see if they have a summary (rather than skipping them
all).
Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to
ensure that an MCAsmParser is available, otherwise the module asm parse
would silently fail. Initialized the asm parser in the opt tool for use
in testing this fix.
Fixes PR30610.
llvm-svn: 286844
Summary:
This patch uses the same approach added for inline asm in r285513 to
similarly prevent promotion/renaming of locals used or defined in module
level asm.
All static global values defined in normal IR and used in module level asm
should be included on either the llvm.used or llvm.compiler.used global.
The former were already being flagged as NoRename in the summary, and
I've simply added llvm.compiler.used values to this handling.
Module level asm may also contain defs of values. We need to prevent
export of any refs to local values defined in module level asm (e.g. a
ref in normal IR), since that also requires renaming/promotion of the
local. To do that, the summary index builder looks at all values in the
module level asm string that are not marked Weak or Global, which is
exactly the set of locals that are defined. A summary is created for
each of these local defs and flagged as NoRename.
This required adding handling to the BitcodeWriter to look at GV
declarations to see if they have a summary (rather than skipping them
all).
Finally, added an assert to IRObjectFile::CollectAsmUndefinedRefs to
ensure that an MCAsmParser is available, otherwise the module asm parse
would silently fail. Initialized the asm parser in the opt tool for use
in testing this fix.
Fixes PR30610.
Reviewers: mehdi_amini
Subscribers: johanengelen, krasin, llvm-commits
Differential Revision: https://reviews.llvm.org/D26146
llvm-svn: 286297
We need to use the overload of Mangler::getNameWithPrefix that takes a
GlobalValue in order to mangle in the stdcall stack byte count for Windows
targets.
Differential Revision: https://reviews.llvm.org/D25529
llvm-svn: 284040
If the llvm. prefix is dropped other parts of llvm don't see this as
an intrinsic. This means that the number of regular symbols depends
on the context the module is loaded into, which causes LTO to abort.
Fixes PR30509.
llvm-svn: 283117
Summary:
In runThinLTO we start the task numbering for ThinLTO backend
tasks depending on whether there was also a regular LTO object
(CombinedModule). However, the CombinedModule is moved at
the end of runRegularLTO, so we need to save this information and
pass it into runThinLTO. Otherwise the AddOutput callback to the client
will use the same task number for both the regular LTO object
and the first ThinLTO object, which in gold-plugin caused only
one to be end up in the output filename array and therefore passed
back to gold for the final native link.
Reviewers: pcc, mehdi_amini
Subscribers: mehdi_amini, kromanova
Differential Revision: https://reviews.llvm.org/D24643
llvm-svn: 281725
If TBAA is on an intrinsic and it gets upgraded, it'll delete the call
instruction that we collected in a vector. Even if we were to use
WeakVH, it'll drop the TBAA and we'll hit the assert on the upgrade
path.
r263673 gave a shot to make sure the TBAA upgrade happens before
intrinsics upgrade, but failed to account for all cases.
Instead of collecting instructions in a vector, this patch makes it
just upgrade the TBAA on the fly, because metadata are always
already loaded at this point.
Differential Revision: https://reviews.llvm.org/D24533
llvm-svn: 281549
Previously the prevailing information was not honored, and commons
symbols could override a strong definition. This patch fixes it and
propose the following semantic for commons: the client should mark
as prevailing the commons that it expects the LTO implementation to
merge (i.e. take the maximum size and alignment).
It implies that commons are allowed to have multiple prevailing
definitions.
Differential Revision: https://reviews.llvm.org/D24545
llvm-svn: 281538
Summary:
It does not play well with directories (end up with a bunch of hidden
files).
Also, do not strip the 0 suffix for the first task, especially since
0 can be used by ThinLTO as well now.
Reviewers: tejohnson
Subscribers: mehdi_amini, pcc, llvm-commits
Differential Revision: https://reviews.llvm.org/D23612
llvm-svn: 279014
This restores commit r278330, with fixes for a few bot failures:
- Fix a late change I had made to the save temps output file that I
missed due to existing files sitting on my disk
- Fix a bunch of Windows bot failures with "ambiguous call to overloaded
function" due to confusion between llvm::make_unique vs
std::make_unique (preface the new make_unique calls with "llvm::")
- Attempt to fix a modules bot failure by adding a missing include
to LTO/Config.h.
Original change:
Resolution-based LTO API.
Summary:
This introduces a resolution-based LTO API. The main advantage of this API over
existing APIs is that it allows the linker to supply a resolution for each
symbol in each object, rather than the combined object as a whole. This will
become increasingly important for use cases such as ThinLTO which require us
to process symbol resolutions in a more complicated way than just adjusting
linkage.
Patch by Peter Collingbourne.
Reviewers: rafael, tejohnson, mehdi_amini
Subscribers: lhames, tejohnson, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D20268
llvm-svn: 278338
This reverts commit r278330.
I made a change to the save temps output that is causing issues with the
bots. Didn't realize this because I had older output files sitting on
disk in my test output directory.
llvm-svn: 278331
Summary:
This introduces a resolution-based LTO API. The main advantage of this API over
existing APIs is that it allows the linker to supply a resolution for each
symbol in each object, rather than the combined object as a whole. This will
become increasingly important for use cases such as ThinLTO which require us
to process symbol resolutions in a more complicated way than just adjusting
linkage.
Patch by Peter Collingbourne.
Reviewers: rafael, tejohnson, mehdi_amini
Subscribers: lhames, tejohnson, mehdi_amini, llvm-commits
Differential Revision: https://reviews.llvm.org/D20268
Address review comments
llvm-svn: 278330
The linker supports a feature to force load an object from a static
archive if it defines an Objective-C category.
This API supports this feature by looking at every section in the
module to find if a category is defined in the module.
llvm-svn: 275125
Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.
Also start using the attribute for memset, memcpy, and memmove intrinsics,
and remove their special-casing in BasicAliasAnalysis.
Reviewers: reames, joker.eph
Subscribers: joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D18714
llvm-svn: 274485
If a local_unnamed_addr attribute is attached to a global, the address
is known to be insignificant within the module. It is distinct from the
existing unnamed_addr attribute in that it only describes a local property
of the module rather than a global property of the symbol.
This attribute is intended to be used by the code generator and LTO to allow
the linker to decide whether the global needs to be in the symbol table. It is
possible to exclude a global from the symbol table if three things are true:
- This attribute is present on every instance of the global (which means that
the normal rule that the global must have a unique address can be broken without
being observable by the program by performing comparisons against the global's
address)
- The global has linkonce_odr linkage (which means that each linkage unit must have
its own copy of the global if it requires one, and the copy in each linkage unit
must be the same)
- It is a constant or a function (which means that the program cannot observe that
the unique-address rule has been broken by writing to the global)
Although this attribute could in principle be computed from the module
contents, LTO clients (i.e. linkers) will normally need to be able to compute
this property as part of symbol resolution, and it would be inefficient to
materialize every module just to compute it.
See:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160509/356401.htmlhttp://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20160516/356738.html
for earlier discussion.
Part of the fix for PR27553.
Differential Revision: http://reviews.llvm.org/D20348
llvm-svn: 272709
This patch introduces a new option -lto-strip-invalid-debug-info, which
drops malformed debug info from the input.
The problem I'm trying to solve with this sequence of patches is that
historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about
breaking bitcode compatibility with existing producers. For example, we
don't necessarily want IR produced by an older version of clang to be
rejected by an LTO link just because of malformed debug info, and rather
provide an option to strip it. Note that merely outdated (but well-formed)
debug info would continue to be auto-upgraded in this scenario.
rdar://problem/25818489
http://reviews.llvm.org/D19987
This reapplies 268936 with a test case fix for Linux (-exported-symbol foo)
llvm-svn: 268965
This patch introduces a new option -lto-strip-invalid-debug-info, which
drops malformed debug info from the input.
The problem I'm trying to solve with this sequence of patches is that
historically we've done a really bad job at verifying debug info. We want
to be able to make the verifier stricter without having to worry about
breaking bitcode compatibility with existing producers. For example, we
don't necessarily want IR produced by an older version of clang to be
rejected by an LTO link just because of malformed debug info, and rather
provide an option to strip it. Note that merely outdated (but well-formed)
debug info would continue to be auto-upgraded in this scenario.
rdar://problem/25818489
http://reviews.llvm.org/D19987
llvm-svn: 268936
This reverts commit r267657, r267656, and r267655.
The test does not pass on multiple bots, I'm unsure why yet but let's unbreak them.
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 267664
This is intended to be shared by the ThinLTOCodeGenerator.
Note that there is a change in the way the verifier is run, previously
it was ran as a Pass on the merged module during internalization.
While now the verifier is called explicitely on the merged module
outside of the internalize "pass pipeline".
What remains strange in the API is the fact that `DisableVerify` in
the API does not disable this initial verifier.
Differential Revision: http://reviews.llvm.org/D19000
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266047
when compiling with LTO.
r244523 a new class DiagnosticInfoOptimizationRemarkAnalysisAliasing for
optimization analysis remarks related to pointer aliasing without
guarding it in isDiagnosticEnabled in LLVMContext.cpp. This caused the
diagnostic message to be printed unconditionally when compiling with
LTO.
This commit cleans up isDiagnosticEnabled and makes sure all the
vectorization optimization remarks are guarded.
rdar://problem/25382153
llvm-svn: 265084
Summary:
Rename the section embeds bitcode from ".llvmbc,.llvmbc" to "__LLVM,__bitcode".
The new name matches MachO section naming convention.
Reviewers: rafael, pcc
Subscribers: davide, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D17388
llvm-svn: 262245
Summary:
This is a companion patch for http://reviews.llvm.org/D16124.
Internalized symbols increase the size of strongly-connected components in
SCC-based module splitting and thus reduce the amount of parallelism. This
patch records the original linkage of non-local symbols prior to
internalization and then restores it just before splitting/CodeGen. This is
also useful for cases where the linker requires symbols to remain external, for
instance, so they can be placed according to linker script rules.
It's currently under its own flag (-restore-globals) but should eventually
share a common flag with D16124.
Reviewers: joker.eph, pcc
Subscribers: slarin, llvm-commits, joker.eph
Differential Revision: http://reviews.llvm.org/D16229
llvm-svn: 258100
This means that LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN will not be set
in a few cases.
This should have no impact in ld64 since it doesn't use lazy loading
when merging modules and that is when it checks
LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN.
llvm-svn: 257915
Summary:
This patch introduces two new function attributes
InaccessibleMemOnly: This attribute indicates that the function may only access memory that is not accessible by the program/IR being compiled. This is a weaker form of ReadNone.
inaccessibleMemOrArgMemOnly: This attribute indicates that the function may only access memory that is either not accessible by the program/IR being compiled, or is pointed to by its pointer arguments. This is a weaker form of ArgMemOnly
Test cases have been updated. This revision uses this (d001932f3a) as reference.
Reviewers: jmolloy, hfinkel
Subscribers: reames, joker.eph, llvm-commits
Differential Revision: http://reviews.llvm.org/D15499
llvm-svn: 255778
This introduces two new options:
- "llvm-lto -save-merged-module -o outfile" dumps the LTO Module to
outfile.merged.bc prior to CodeGen and after LTO optimizations have been run.
- "llvm-lto -filetype=asm -o outfile" makes llvm-lto emit assembly instead of
object code in outfile.
Both are intended for use in lit tests.
llvm-svn: 253624
This is a follow-up from the previous discussion on the thread:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151019/307763.html
The LibLTO lto_get_error_message() API reads error messages from a std::string
sLastErrorString. Instead of passing this string around as an argument, this
patch creates a diagnostic handler and then sends this handler to the
constructor of LTOCodeGenerator.
Differential Revision: http://reviews.llvm.org/D14313
llvm-svn: 252791
This attribute allows the compiler to assume that the function never recurses into itself, either directly or indirectly (transitively). This can be used among other things to demote global variables to locals.
llvm-svn: 252282
When building LLVM as a (potentially dynamic) library that can be linked against
by multiple compilers, the default triple is not really meaningful.
We allow to explicitely set it to an empty string when configuring LLVM.
In this case, said "target independent" tests in the test suite that are using
the default triple are disabled by matching the newly available feature
"default_triple".
Reviewers: probinson, echristo
Differential Revision: http://reviews.llvm.org/D12660
From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 247775
The verifier currently runs three times in LTO: (1) after parsing, (2)
at the beginning of the optimization pipeline, and (3) at the end of it.
The first run is important, since we're not sure where the bitcode comes
from and it's nice to validate it, but in release builds the extra runs
aren't appropriate.
This commit:
- Allows these runs to be disabled in LTOCodeGenerator.
- Adds command-line options to llvm-lto.
- Adds command-line options to libLTO.dylib, and disables the verifier
by default in release builds (based on NDEBUG).
This shaves about 3.5% off the runtime of ld64 when linking
verify-uselistorder with -flto -g.
rdar://22509081
llvm-svn: 247729
llvm::splitCodeGen is a function that implements the core of parallel LTO
code generation. It uses llvm::SplitModule to split the module into linkable
partitions and spawning one code generation thread per partition. The function
produces multiple object files which can be linked in the usual way.
This has been threaded through to LTOCodeGenerator (and llvm-lto for testing
purposes). Separate patches will add parallel LTO support to the gold plugin
and lld.
Differential Revision: http://reviews.llvm.org/D12260
llvm-svn: 246236
The personality routine currently lives in the LandingPadInst.
This isn't desirable because:
- All LandingPadInsts in the same function must have the same
personality routine. This means that each LandingPadInst beyond the
first has an operand which produces no additional information.
- There is ongoing work to introduce EH IR constructs other than
LandingPadInst. Moving the personality routine off of any one
particular Instruction and onto the parent function seems a lot better
than have N different places a personality function can sneak onto an
exceptional function.
Differential Revision: http://reviews.llvm.org/D10429
llvm-svn: 239940
See r230786 and r230794 for similar changes to gep and load
respectively.
Call is a bit different because it often doesn't have a single explicit
type - usually the type is deduced from the arguments, and just the
return type is explicit. In those cases there's no need to change the
IR.
When that's not the case, the IR usually contains the pointer type of
the first operand - but since typed pointers are going away, that
representation is insufficient so I'm just stripping the "pointerness"
of the explicit type away.
This does make the IR a bit weird - it /sort of/ reads like the type of
the first operand: "call void () %x(" but %x is actually of type "void
()*" and will eventually be just of type "ptr". But this seems not too
bad and I don't think it would benefit from repeating the type
("void (), void () * %x(" and then eventually "void (), ptr %x(") as has
been done with gep and load.
This also has a side benefit: since the explicit type is no longer a
pointer, there's no ambiguity between an explicit type and a function
that returns a function pointer. Previously this case needed an explicit
type (eg: a function returning a void() function was written as
"call void () () * @x(" rather than "call void () * @x(" because of the
ambiguity between a function returning a pointer to a void() function
and a function returning void).
No ambiguity means even function pointer return types can just be
written alone, without writing the whole function's type.
This leaves /only/ the varargs case where the explicit type is required.
Given the special type syntax in call instructions, the regex-fu used
for migration was a bit more involved in its own unique way (as every
one of these is) so here it is. Use it in conjunction with the apply.sh
script and associated find/xargs commands I've provided in rr230786 to
migrate your out of tree tests. Do let me know if any of this doesn't
cover your cases & we can iterate on a more general script/regexes to
help others with out of tree tests.
About 9 test cases couldn't be automatically migrated - half of those
were functions returning function pointers, where I just had to manually
delete the function argument types now that we didn't need an explicit
function type there. The other half were typedefs of function types used
in calls - just had to manually drop the * from those.
import fileinput
import sys
import re
pat = re.compile(r'((?:=|:|^|\s)call\s(?:[^@]*?))(\s*$|\s*(?:(?:\[\[[a-zA-Z0-9_]+\]\]|[@%](?:(")?[\\\?@a-zA-Z0-9_.]*?(?(3)"|)|{{.*}}))(?:\(|$)|undef|inttoptr|bitcast|null|asm).*$)')
addrspace_end = re.compile(r"addrspace\(\d+\)\s*\*$")
func_end = re.compile("(?:void.*|\)\s*)\*$")
def conv(match, line):
if not match or re.search(addrspace_end, match.group(1)) or not re.search(func_end, match.group(1)):
return line
return line[:match.start()] + match.group(1)[:match.group(1).rfind('*')].rstrip() + match.group(2) + line[match.end():]
for line in sys.stdin:
sys.stdout.write(conv(re.search(pat, line), line))
llvm-svn: 235145
This change also introduces a link-time optimization level of 1. This
optimization level runs only the globaldce pass as well as cleanup passes for
passes that run at -O0, specifically simplifycfg which cleans up lowerbitsets.
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20150316/266951.html
llvm-svn: 232769
Essentially the same as the GEP change in r230786.
A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)
import fileinput
import sys
import re
pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")
for line in sys.stdin:
sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))
Reviewers: rafael, dexonsmith, grosser
Differential Revision: http://reviews.llvm.org/D7649
llvm-svn: 230794
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.
This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.
* This doesn't modify gep operators, only instructions (operators will be
handled separately)
* Textual IR changes only. Bitcode (including upgrade) and changing the
in-memory representation will be in separate changes.
* geps of vectors are transformed as:
getelementptr <4 x float*> %x, ...
->getelementptr float, <4 x float*> %x, ...
Then, once the opaque pointer type is introduced, this will ultimately look
like:
getelementptr float, <4 x ptr> %x
with the unambiguous interpretation that it is a vector of pointers to float.
* address spaces remain on the pointer, not the type:
getelementptr float addrspace(1)* %x
->getelementptr float, float addrspace(1)* %x
Then, eventually:
getelementptr float, ptr addrspace(1) %x
Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.
update.py:
import fileinput
import sys
import re
ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile( r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
def conv(match, line):
if not match:
return line
line = match.groups()[0]
if len(match.groups()[5]) == 0:
line += match.groups()[2]
line += match.groups()[3]
line += ", "
line += match.groups()[1]
line += "\n"
return line
for line in sys.stdin:
if line.find("getelementptr ") == line.find("getelementptr inbounds"):
if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
line = conv(re.match(ibrep, line), line)
elif line.find("getelementptr ") != line.find("getelementptr ("):
line = conv(re.match(normrep, line), line)
sys.stdout.write(line)
apply.sh:
for name in "$@"
do
python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
rm -f "$name.tmp"
done
The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh
After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).
The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.
Reviewers: rafael, dexonsmith, grosser
Differential Revision: http://reviews.llvm.org/D7636
llvm-svn: 230786
This work is currently being rethought along different lines and
if this work is needed it can be resurrected out of svn. Remove it
for now as no current work in ongoing on it and it's unused. Verified
with the authors before removal.
llvm-svn: 230780
When debugging LTO issues with ld64, we use -save-temps to save the merged
optimized bitcode file, then invoke ld64 again on the single bitcode file to
speed up debugging code generation passes and ld64 stuff after code generation.
llvm linking a single bitcode file via lto_codegen_add_module will generate a
different bitcode file from the single input. With the newly-added
lto_codegen_set_module, we can make sure the destination module is the same as
the input.
lto_codegen_set_module will transfer the ownship of the module to code
generator.
rdar://19024554
llvm-svn: 230290
A null MCTargetStreamer allows IRObjectFile to ignore target-specific
directives. Previously we were crashing.
Differential Revision: http://reviews.llvm.org/D7711
llvm-svn: 229797
accumulateAndSortLibcalls in LTOCodeGenerator.cpp collects names of runtime
library functions which are used to identify user-defined functions that should
be protected. Previously, this function would only scan the TargetLowering
object belonging to the "main" subtarget for the library function names. This
commit changes it to scan all per-function subtargets.
Differential Revision: http://reviews.llvm.org/D7275
llvm-svn: 227533
The bitcode reading interface used std::error_code to report an error to the
callers and it is the callers job to print diagnostics.
This is not ideal for error handling or diagnostic reporting:
* For error handling, all that the callers care about is 3 possibilities:
* It worked
* The bitcode file is corrupted/invalid.
* The file is not bitcode at all.
* For diagnostic, it is user friendly to include far more information
about the invalid case so the user can find out what is wrong with the
bitcode file. This comes up, for example, when a developer introduces a
bug while extending the format.
The compromise we had was to have a lot of error codes.
With this patch we use the DiagnosticHandler to communicate with the
human and std::error_code to communicate with the caller.
This allows us to have far fewer error codes and adds the infrastructure to
print better diagnostics. This is so because the diagnostics are printed when
he issue is found. The code that detected the problem in alive in the stack and
can pass down as much context as needed. As an example the patch updates
test/Bitcode/invalid.ll.
Using a DiagnosticHandler also moves the fatal/non-fatal error decision to the
caller. A simple one like llvm-dis can just use fatal errors. The gold plugin
needs a bit more complex treatment because of being passed non-bitcode files. An
hypothetical interactive tool would make all bitcode errors non-fatal.
llvm-svn: 225562
Add coverage in `llvm-lto` for the API exposed by libLTO to create
modules in local contexts.
The goal here isn't to test the symbol-related API extensively, just to
confirm that these modules work at all. (I'll be shifting code around
soon that should be NFC and I realized there was no test coverage.)
llvm-svn: 224408
We were already lazily linking functions, but all GlobalValues can be treated
uniformly for this.
The test updates are to ensure that a given GlobalValue is still linked in.
This fixes pr21494.
llvm-svn: 223681
This commit adds a new pass that can inject checks before indirect calls to
make sure that these calls target known locations. It supports three types of
checks and, at compile time, it can take the name of a custom function to call
when an indirect call check fails. The default failure function ignores the
error and continues.
This pass incidentally moves the function JumpInstrTables::transformType from
private to public and makes it static (with a new argument that specifies the
table type to use); this is so that the CFI code can transform function types
at call sites to determine which jump-instruction table to use for the check at
that site.
Also, this removes support for jumptables in ARM, pending further performance
analysis and discussion.
Review: http://reviews.llvm.org/D4167
llvm-svn: 221708
r206400 and r209442 added remarks that are disabled by default.
However, if a diagnostic handler is registered, the remarks are sent
unfiltered to the handler. This is the right behaviour for clang, since
it has its own filters.
However, the diagnostic handler exposed in the LTO API receives only the
severity and message. It doesn't have the information to filter by pass
name. For LTO, disabled remarks should be filtered by the producer.
I've changed `LLVMContext::setDiagnosticHandler()` to take a `bool`
argument indicating whether to respect the built-in filters. This
defaults to `false`, so other consumers don't have a behaviour change,
but `LTOCodeGenerator::setDiagnosticHandler()` sets it to `true`.
To make this behaviour testable, I added a `-use-diagnostic-handler`
command-line option to `llvm-lto`.
This fixes PR21108.
llvm-svn: 218784
This format is simply a regular object file with the bitcode stored in a
section named ".llvmbc", plus any number of other (non-allocated) sections.
One immediate use case for this is to accommodate compilation processes
which expect the object file to contain metadata in non-allocated sections,
such as the ".go_export" section used by some Go compilers [1], although I
imagine that in the future we could consider compiling parts of the module
(such as large non-inlinable functions) directly into the object file to
improve LTO efficiency.
[1] http://golang.org/doc/install/gccgo#Imports
Differential Revision: http://reviews.llvm.org/D4371
llvm-svn: 218078
to match llvm-size and other UNIX systems for their nm(1).
Tweak test cases that used llvm-nm with standard input to add a "-" to
indicate that and add a test case to check the default of a.out for llvm-nm.
llvm-svn: 211529
Visibilities of `hidden` and `protected` are meaningless for symbols
with local linkage.
- Change the assembler to reject non-default visibility on symbols
with local linkage.
- Change the bitcode reader to auto-upgrade `hidden` and `protected`
to `default` when the linkage is local.
- Update LangRef.
<rdar://problem/16141113>
llvm-svn: 208263
This adds support for an -mattr option to the gold plugin and to llvm-lto. This
allows the caller to specify details of the subtarget architecture, like +aes,
or +ssse3 on x86. Note that this requires a change to the include/llvm-c/lto.h
interface: it adds a function lto_codegen_set_attr and it increments the
version of the interface.
llvm-svn: 207279
part of an asm .symver directive as being used. This prevents referenced
functions from being internalized and deleted.
Without the patch to LTOModule.cpp, the test case will produce the error:
LLVM ERROR: A @@ version cannot be undefined.
llvm-svn: 205221
During LTO, user-supplied definitions of C library functions often
exist. -instcombine uses Module::getOrInsertFunction() to get a handle
on library functions (e.g., @puts, when optimizing @printf).
Previously, Module::getOrInsertFunction() would rename any matching
functions with local linkage, and create a new declaration. In LTO,
this is the opposite of desired behaviour, as it skips by the
user-supplied version of the library function and creates a new
undefined reference which the linker often cannot resolve.
After some discussing with Rafael on the list, it looks like it's
undesired behaviour. If a consumer actually *needs* this behaviour, we
should add new API with a more explicit name.
I added two testcases: one specifically for the -instcombine behaviour
and one for the LTO flow.
<rdar://problem/16165191>
llvm-svn: 203513
r201608 made llvm corretly handle private globals with MachO. r201622 fixed
a bug in it and r201624 and r201625 were changes for using private linkage,
assuming that llvm would do the right thing.
They all got reverted because r201608 introduced a crash in LTO. This patch
includes a fix for that. The issue was that TargetLoweringObjectFile now has
to be initialized before we can mangle names of private globals. This is
trivially true during the normal codegen pipeline (the asm printer does it),
but LTO has to do it manually.
llvm-svn: 201700
Add user-supplied C runtime and compiler-rt library functions to
llvm.compiler.used to protect them from premature optimization by
passes like -globalopt and -ipsccp. Calls to (seemingly unused)
runtime library functions can be added by -instcombine and instruction
lowering.
Patch by Duncan Exon Smith, thanks!
Fixes <rdar://problem/14740087>
llvm-svn: 194514
Peter Collingbourne