Summary:
This is patch 1 of the new DivergenceAnalysis (https://reviews.llvm.org/D50433).
The purpose of this patch is to free up the name DivergenceAnalysis for the new generic
implementation. The generic implementation class will be shared by specialized
divergence analysis classes.
Patch by: Simon Moll
Reviewed By: nhaehnle
Subscribers: jvesely, jholewinski, arsenm, nhaehnle, mgorny, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D50434
Change-Id: Ie8146b11be2c50d5312f30e11c7a3036a15b48cb
llvm-svn: 341071
Summary:
In the case of (and reg, constant) or (or reg, constant), it can be
beneficial to use a ANDNrr/ORNrr instruction instead of ANDrr/ORrr,
if the complement of the constant can be encoded using a single SETHI
instruction instead of a SETHI/ORri pair.
If the constant has more than one use, it is probably better to keep it
in its original form.
Reviewers: jyknight, venkatra
Reviewed By: jyknight
Subscribers: fedor.sergeev, jrtc27, llvm-commits
Differential Revision: https://reviews.llvm.org/D50964
llvm-svn: 341069
FileError is meant to encapsulate both an Error and a file name/path. It should be used in cases where an Error occurs deep down the call chain, and we want to return it to the caller along with the file name.
StringError was updated to display the error messages in different ways. These can be:
1. display the error_code message, and convert to the same error_code (ECError behavior)
2. display an arbitrary string, and convert to a provided error_code (current StringError behavior)
3. display both an error_code message and a string, in this order; and convert to the same error_code
These behaviors can be triggered depending on the constructor. The goal is to use StringError as a base class, when a library needs to provide a explicit Error type.
Differential Revision: https://reviews.llvm.org/D50807
llvm-svn: 341064
Summary:
This is a continuation of https://reviews.llvm.org/D49727
Below the original text, current changes in the comments:
Currently, in line with GCC, when specifying reserved registers like sp or pc on an inline asm() clobber list, we don't always preserve the original value across the statement. And in general, overwriting reserved registers can have surprising results.
For example:
extern int bar(int[]);
int foo(int i) {
int a[i]; // VLA
asm volatile(
"mov r7, #1"
:
:
: "r7"
);
return 1 + bar(a);
}
Compiled for thumb, this gives:
$ clang --target=arm-arm-none-eabi -march=armv7a -c test.c -o - -S -O1 -mthumb
...
foo:
.fnstart
@ %bb.0: @ %entry
.save {r4, r5, r6, r7, lr}
push {r4, r5, r6, r7, lr}
.setfp r7, sp, #12
add r7, sp, #12
.pad #4
sub sp, #4
movs r1, #7
add.w r0, r1, r0, lsl #2
bic r0, r0, #7
sub.w r0, sp, r0
mov sp, r0
@APP
mov.w r7, #1
@NO_APP
bl bar
adds r0, #1
sub.w r4, r7, #12
mov sp, r4
pop {r4, r5, r6, r7, pc}
...
r7 is used as the frame pointer for thumb targets, and this function needs to restore the SP from the FP because of the variable-length stack allocation a. r7 is clobbered by the inline assembly (and r7 is included in the clobber list), but LLVM does not preserve the value of the frame pointer across the assembly block.
This type of behavior is similar to GCC's and has been discussed on the bugtracker: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11807 . No consensus seemed to have been reached on the way forward. Clang behavior has briefly been discussed on the CFE mailing (starting here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058392.html). I've opted for following Eli Friedman's advice to print warnings when there are reserved registers on the clobber list so as not to diverge from GCC behavior for now.
The patch uses MachineRegisterInfo's target-specific knowledge of reserved registers, just before we convert the inline asm string in the AsmPrinter.
If we find a reserved register, we print a warning:
repro.c:6:7: warning: inline asm clobber list contains reserved registers: R7 [-Winline-asm]
"mov r7, #1"
^
Reviewers: efriedma, olista01, javed.absar
Reviewed By: efriedma
Subscribers: eraman, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D51165
llvm-svn: 341062
Providing that the load is known to be 4 byte aligned, we can optimise a
ldr(adr address) to just ldr address.
Differential Revision: https://reviews.llvm.org/D51030
llvm-svn: 341058
This reverts commit r340997.
This change turned out not to be NFC after all, but e.g. causes
clang to crash when building the linux kernel for aarch64.
llvm-svn: 341031
Summary:
This is the first step in the larger refactoring and reduction of
D50441.
This step in the process does the following:
- Introduces more granular types of `Record`s representing the many
kinds of records written/read by the Flight Data Recorder (FDR) mode
`Trace` loading function(s).
- Introduces an abstract `RecordVisitor` type meant to handle the
processing of the various `Record` derived types. This `RecordVisitor`
has two implementations in this patch: `RecordInitializer` and
`FDRTraceWriter`.
- We also introduce a convenience interface for building a collection of
`Record` instances called a `LogBuilder`. This allows us to generate
sequences of `Record` instances manually (used in unit tests but
useful otherwise).
- The`FDRTraceWriter` class implements the `RecordVisitor` interface and
handles the writing of metadata records to a `raw_ostream`. We
demonstrate that in the unit test, we can generate in-memory FDR mode
traces using the specific `Record` derived types, which we load
through the `loadTrace(...)` function yielding valid `Trace` objects.
This patch introduces the required types and concepts for us to start
replacing the logic implemented in the `loadFDRLog` function to use the
more granular types. In subsequent patches, we will introduce more
visitor implementations which isolate the verification, printing,
indexing, production/consumption, and finally the conversion of the FDR
mode logs.
The overarching goal of these changes is to make handling FDR mode logs
better tested, more understandable, more extensible, and more
systematic. This will also allow us to better represent the execution
trace, as we improve the fidelity of the events we represent in an XRay
`Trace` object, which we intend to do after FDR mode log processing is
in better shape.
Reviewers: eizan
Reviewed By: eizan
Subscribers: mgorny, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D51210
llvm-svn: 341029
In computeRegisterLiveness, the max instructions to search
was counting dbg_value instructions, which could potentially
cause an observable codegen change from the presence of debug
info.
llvm-svn: 341028
If there is an unused def, this would previously
report that the register was live. Check for uses
first so that it is reported as dead if never used.
llvm-svn: 341027
If the end of the block is reached during the scan, check
the live ins of the successors. This was already done in the
other direction if the block entry was reached.
llvm-svn: 341026
Check that Machine CSE correctly handles during the transformation, the
debug location information for local variables.
Differential Revision: https://reviews.llvm.org/D50887
llvm-svn: 341025
We now only add +64bit to the CPU string for "generic" CPU. All other CPU names are assumed to have the feature flag already set if they support 64-bit. I've remove the implies from CMPXCHG8 so that Feature64Bit only comes in via CPUs or user passing -mattr=+64bit.
I've changed the assert to a report_fatal_error so it's not lost in Release builds.
The test updates are to fix things that tripped the new error.
Differential Revision: https://reviews.llvm.org/D51231
llvm-svn: 341022
If an ABI-like value is used in a different block,
the type split used is not necessarily the same as
the call's ABI. The value is used through an intermediate
copy virtual registers from the other block. This
resulted in copies with inconsistent sizes later.
Fixes regressions since r338197 when AMDGPU started
splitting vector types for calls.
llvm-svn: 341018
These classes don't make any changes to IR and have no reason to be in
Transform/Utils. This patch moves them to Analysis folder. This will allow
us reusing these classes in some analyzes, like MustExecute.
llvm-svn: 341015
rL340921 has been reverted by rL340923 due to linkage dependency
from Transform/Utils to Analysis which is not allowed. In this patch
this has been fixed, a new utility function moved to Analysis.
Differential Revision: https://reviews.llvm.org/D51152
llvm-svn: 341014
Summary:
This change implements the profile loading functionality in LLVM to
support XRay's profiling mode in compiler-rt.
We introduce a type named `llvm::xray::Profile` which allows building a
profile representation. We can load an XRay profile from a file to build
Profile instances, or do it manually through the Profile type's API.
The intent is to get the `llvm-xray` tool to generate `Profile`
instances and use that as the common abstraction through which all
conversion and analysis can be done. In the future we can generate
`Profile` instances from `Trace` instances as well, through conversion
functions.
Some of the key operations supported by the `Profile` API are:
- Path interning (`Profile::internPath(...)`) which returns a unique path
identifier.
- Block appending (`Profile::addBlock(...)`) to add thread-associated
profile information.
- Path ID to Path lookup (`Profile::expandPath(...)`) to look up a
PathID and return the original interned path.
- Block iteration.
A 'Path' in this context represents the function call stack in
leaf-to-root order. This is represented as a path in an internally
managed prefix tree in the `Profile` instance. Having a handle (PathID)
to identify the unique Paths we encounter for a particular Profile
allows us to reduce the amount of memory required to associate profile
data to a particular Path.
This is the first of a series of patches to migrate the `llvm-stacks`
tool towards using a single profile representation.
Depends on D48653.
Reviewers: kpw, eizan
Reviewed By: kpw
Subscribers: kpw, thakis, mgorny, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D48370
llvm-svn: 341012
We don't have enough information to know if struct types being
bitcast will cause validation failures or not, so be conservative
and allow such cases to persist (fot now).
Fixes: https://bugs.llvm.org/show_bug.cgi?id=38711
Subscribers: dschuff, jgravelle-google, aheejin, sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D51460
llvm-svn: 341010
Summary:
Global variables that are external and zero initialized are
supposed to be merged with global variables in the bss section
rather than the data section.
Reviewers: efriedma, rengolin, t.p.northover, javed.absar, asl, john.brawn, pcc
Reviewed By: efriedma
Subscribers: dmgreen, llvm-commits
Differential Revision: https://reviews.llvm.org/D51379
llvm-svn: 341008
The cost modeling was not accounting for the fact we were duplicating the instruction once per predecessor. With a default threshold of 1, this meant we were actually creating #pred copies.
Adding to the fun, there is *absolutely no* test coverage for this. Simply bailing for more than one predecessor passes all checked in tests.
llvm-svn: 341001
These bugs were found by writing a Python script which spidered
the entire Chromium build directory tree demangling every symbol
in every object file. At the start, the tool printed:
Processed 27443 object files.
2926377/2936108 symbols successfully demangled (99.6686%)
9731 symbols could not be demangled (0.3314%)
14589 files crashed while demangling (53.1611%)
After this patch, it prints:
Processed 27443 object files.
41295518/41295617 symbols successfully demangled (99.9998%)
99 symbols could not be demangled (0.0002%)
0 files crashed while demangling (0.0000%)
The issues fixed in this patch are:
* Ignore empty parameter packs. Previously we would encounter
a mangling for an empty parameter pack and add a null node
to the AST. Since we don't print these anyway, we now just
don't add anything to the AST and ignore it entirely. This
fixes some of the crashes.
* Account for "incorrect" string literal demanglings. Apparently
an older version of clang would not truncate mangled string
literals to 32 bytes of encoded character data. The demangling
code however would allocate a 32 byte buffer thinking that it
would not encounter more than this, and overrun the buffer.
We now demangle up to 128 bytes of data, since the buggy
clang would encode up to 32 *characters* of data.
* Extended support for demangling init-fini stubs. If you had
something like
struct Foo {
static vector<string> S;
};
this would generate a dynamic atexit initializer *for the
variable*. We didn't handle this, but now we print something
nice. This is actually an improvement over undname, which will
fail to demangle this at all.
* Fixed one case of static this adjustment. We weren't handling
several thunk codes so we didn't recognize the mangling. These
are now handled.
* Fixed a back-referencing problem. Member pointer templates
should have their components considered for back-referencing
The remaining 99 symbols which can't be demangled are all symbols
which are compiler-generated and undname can't demangle either.
llvm-svn: 341000
This should more accurately reflect what the AsmPrinter will actually
do.
This is NFC, as far as I can tell; all the places that might be affected
already have an extra check to avoid using the result of
getPreferredAlignment in this situation.
Differential Revision: https://reviews.llvm.org/D51377
llvm-svn: 340999
On AMDGPU we have 70 register classes, so iterating over all 70
each time and exiting is costly on the CPU, this flips the loop
around so that it loops over the 70 register classes first,
and exits without doing the inner loop if needed.
On my test just starting radv this takes
RegUsageInfoCollector::runOnMachineFunction
from 6.0% of total time to 2.7% of total time,
and reduces the startup from 2.24s to 2.19s
Patch by David Airlie!
Differential Revision: https://reviews.llvm.org/D48582
llvm-svn: 340993
Teach LICM to hoist stores out of loops when the store writes to a location otherwise unused in the loop, writes a value which is invariant, and is guaranteed to execute if the loop is entered.
Worth noting is that this transformation is partially overlapping with the existing promotion transformation. Reasons this is worthwhile anyway include:
* For multi-exit loops, this doesn't require duplication of the store.
* It kicks in for case where we can't prove we exit through a normal exit (i.e. we may throw), but can prove the store executes before that possible side exit.
Differential Revision: https://reviews.llvm.org/D50925
llvm-svn: 340974
Summary:
Assert from PR38737 happens on the dead block inside the parent loop
after unswitching nontrivial switch in the inner loop.
deleteDeadBlocksFromLoop now takes extra care to detect/remove dead
blocks in all the parent loops in addition to the blocks from original
loop being unswitched.
Reviewers: asbirlea, chandlerc
Reviewed By: asbirlea
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51415
llvm-svn: 340955
This is a follow-up to rL339604 which did the same transform
for a sin libcall. The handling of intrinsics vs. libcalls
is unfortunately scattered, so I'm just adding this next to
the existing transform for llvm.cos for now.
This should resolve PR38458:
https://bugs.llvm.org/show_bug.cgi?id=38458
If the call was already negated, the negates will cancel
each other out.
llvm-svn: 340952
Summary:
Port libFuzzer to windows-msvc.
This patch allows libFuzzer targets to be built and run on Windows, using -fsanitize=fuzzer and/or fsanitize=fuzzer-no-link. It allows these forms of coverage instrumentation to work on Windows as well.
It does not fix all issues, such as those with -fsanitize-coverage=stack-depth, which is not usable on Windows as of this patch.
It also does not fix any libFuzzer integration tests. Nearly all of them fail to compile, fixing them will come in a later patch, so libFuzzer tests are disabled on Windows until them.
Reviewers: morehouse, rnk
Reviewed By: morehouse, rnk
Subscribers: #sanitizers, delcypher, morehouse, kcc, eraman
Differential Revision: https://reviews.llvm.org/D51022
llvm-svn: 340949
Expand the simplification of `pow(exp{,2}(x), y)` to all FP types.
This improvement helps some benchmarks in SPEC CPU2000 and CPU2006, such as
252.eon, 447.dealII, 453.povray. Otherwise, no significant regressions on
x86-64 or A64.
Differential revision: https://reviews.llvm.org/D51195
llvm-svn: 340948
Generalize the simplification of `pow(2.0, y)` to `pow(2.0 ** n, y)` for all
scalar and vector types.
This improvement helps some benchmarks in SPEC CPU2000 and CPU2006, such as
252.eon, 447.dealII, 453.povray. Otherwise, no significant regressions on
x86-64 or A64.
Differential revision: https://reviews.llvm.org/D49273
llvm-svn: 340947
Variables declared with the dllimport attribute are accessed via a
stub variable named __imp_<var>. In MinGW configurations, variables that
aren't declared with a dllimport attribute might still end up imported
from another DLL with runtime pseudo relocs.
For x86_64, this avoids the risk that the target is out of range
for a 32 bit PC relative reference, in case the target DLL is loaded
further than 4 GB from the reference. It also avoids having to make the
text section writable at runtime when doing the runtime fixups, which
makes it worthwhile to do for i386 as well.
Add stub variables for all dso local data references where a definition
of the variable isn't visible within the module, since the DLL data
autoimporting might make them imported even though they are marked as
dso local within LLVM.
Don't do this for variables that actually are defined within the same
module, since we then know for sure that it actually is dso local.
Don't do this for references to functions, since there's no need for
runtime pseudo relocations for autoimporting them; if a function from
a different DLL is called without the appropriate dllimport attribute,
the call just gets routed via a thunk instead.
GCC does something similar since 4.9 (when compiling with -mcmodel=medium
or large; from that version, medium is the default code model for x86_64
mingw), but only for x86_64.
Differential Revision: https://reviews.llvm.org/D51288
llvm-svn: 340942
We were calling getNumUses to check for 1 or 2 uses. But getNumUses is linear in the number of uses. We can instead use !hasNUsesOrMore(3) which will stop the linear scan as soon as it determines there are at least 3 uses even if there are more.
llvm-svn: 340939
MipsSEInstrInfo class defines for internal purpose unconditional
branches as Mips::B nad Mips:J even in case of microMIPS code
generation. Under some conditions that leads to the bug - for rather long
branch which fits to Mips jump instruction offset size, but does not fit
to microMIPS jump offset size, we generate 'short' branch and later show
an error 'out of range PC16 fixup' after check in the isBranchOffsetInRange
routine.
Differential revision: https://reviews.llvm.org/D50615
llvm-svn: 340932
Involves microMIPS's jump in the analyzable branch set to reduce some
code patterns.
Differential revision: https://reviews.llvm.org/D50613
llvm-svn: 340931