Summary:
Calling WriteConsoleW is the most reliable way to print Unicode
characters to a Windows console.
If binary data gets printed to the console, attempting to re-encode it
shouldn't be a problem, since garbage in can produce garbage out.
This breaks printing strings in the local codepage, which WriteConsoleA
knows how to handle. For example, this can happen when user source code
is encoded with the local codepage, and an LLVM tool quotes it while
emitting a caret diagnostic. This is unfortunate, but well-behaved tools
should validate that their input is UTF-8 and escape non-UTF-8
characters before sending them to raw_fd_ostream. Clang already does
this, but not all LLVM tools do this.
One drawback to the current implementation is printing a string a byte
at a time doesn't work. Consider this LLVM code:
for (char C : MyStr) outs() << C;
Because outs() is now unbuffered, we wil try to convert each byte to
UTF-16, which will fail. However, this already didn't work, so I think
we may as well update callers that do that as we find them to print
complete portions of strings. You can see a real example of this in my
patch to SourceMgr.cpp
Fixes PR38669 and PR36267.
Reviewers: zturner, efriedma
Subscribers: llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D51558
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341433 91177308-0d34-0410-b5e6-96231b3b80d8
I'm probably missing some way to use m_Deferred to remove the code
duplication, but that can be a follow-up.
The improvement in demand_shrink_nsw.ll is an example of missing
the fold because the pattern matching was deficient. I didn't try
to follow the bits in that test, but Alive says it's correct:
https://rise4fun.com/Alive/ugc
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341426 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Issue occurs when doing ThinLTO with CodeGenOnly flag.
TMBuilder.TheTriple is assigned to by multiple threads in an unsafe way resulting in double-free of std::string memory.
Pseudocode:
if (CodeGenOnly) {
// Perform only parallel codegen and return.
ThreadPool Pool;
int count = 0;
for (auto &ModuleBuffer : Modules) {
Pool.async([&](int count) {
...
/// Now call OutputBuffer = codegen(*TheModule);
/// Which turns into initTMBuilder(moduleTMBuilder, Triple(TheModule.getTargetTriple()));
/// Which turns into
TMBuilder.TheTriple = std::move(TheTriple); // std::string = "....."
/// So, basically std::string assignment to same string on multiple threads = memory corruption
}
return;
}
Patch by Alex Borcan
Reviewers: llvm-commits, steven_wu
Reviewed By: steven_wu
Subscribers: mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, llvm-commits
Differential Revision: https://reviews.llvm.org/D51651
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341422 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Fixes the error "Link field value 0 in section .rela.plt is invalid" when copying/stripping certain binaries. Minimal repro:
```
$ cat /tmp/a.c
int main() { return 0; }
$ clang -static /tmp/a.c -o /tmp/a
$ llvm-strip /tmp/a -o /tmp/b
llvm-strip: error: Link field value 0 in section .rela.plt is invalid.
```
Reviewers: jakehehrlich, alexshap
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51493
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341419 91177308-0d34-0410-b5e6-96231b3b80d8
Reland r341269. Use std::stable_sort when sorting constant condidates.
Reverting commit, r341365:
Revert r341269: [Constant Hoisting] Hoisting Constant GEP Expressions
One of the tests is failing 50% of the time when expensive checks are
enabled. Not sure how deep the problem is so just reverting while the
author can investigate so that the bots stop repeatedly failing and
blaming things incorrectly. Will respond with details on the original
commit.
Original commit, r341269:
[Constant Hoisting] Hoisting Constant GEP Expressions
Leverage existing logic in constant hoisting pass to transform constant GEP
expressions sharing the same base global variable. Multi-dimensional GEPs are
rewritten into single-dimensional GEPs.
https://reviews.llvm.org/D51396
Differential Revision: https://reviews.llvm.org/D51654
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341417 91177308-0d34-0410-b5e6-96231b3b80d8
This is fix for PR38786.
First order recurrence phis were incorrectly treated as uniform,
which caused them to be vectorized as uniform instructions.
Patch by Ayal Zaks and Orivej Desh!
Reviewed by: Anna
Differential Revision: https://reviews.llvm.org/D51639
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341416 91177308-0d34-0410-b5e6-96231b3b80d8
There are 2 bugs shown here that were untested before:
1. We fail to perform the fold in 1/2 the possible commuted variants.
2. When the fold is done, it disregards extra uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341415 91177308-0d34-0410-b5e6-96231b3b80d8
Add a "CouldOnlyImpactOneFunction" bool that's true when we pass in a function.
Just cleaning up a little bit, since I'm going to add in the per-function
remarks soon from D51467.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341407 91177308-0d34-0410-b5e6-96231b3b80d8
I'm looking at some codegen optimization in this area and want to make sure I understand the current codegen and don't regress it. This patch simply expands the two existing tests to capture more of the current code generation when it comes to heap-based and stack-based small memset on arm64. The tested code is already pretty good, notably when it comes to using STP, FP stores, FP immediate generation, and folding one of the stores into a stack spill when possible. The uses of STUR could be improved, and some more pairing could occur. Straying from bzero patterns currently yield suboptimal code, and I expect a variety of small changes could make things way better.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341406 91177308-0d34-0410-b5e6-96231b3b80d8
This is just a cleanup step. The TODO comments show
what is wrong with the 'and' version of the fold.
Fixing this should be part of recommitting:
rL300977
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341405 91177308-0d34-0410-b5e6-96231b3b80d8
On Windows, if shouldAssumeDSOLocal returns false, it's either a
dllimport reference, or a reference that we should treat as non-local
and create a stub for.
Clean up AArch64Subtarget::ClassifyGlobalReference a little while
touching the flag handling relating to dllimport.
Differential Revision: https://reviews.llvm.org/D51590
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341402 91177308-0d34-0410-b5e6-96231b3b80d8
The runtime pseudo relocations can't handle the AArch64 format PC
relative addressing in adrp+add/ldr pairs. By using stubs, the potentially
dllimported addresses can be touched up by the runtime pseudo relocation
framework.
Differential Revision: https://reviews.llvm.org/D51452
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341401 91177308-0d34-0410-b5e6-96231b3b80d8
Recent change to deleteDeadBlocksFromLoop was not enough to
fix all the problems related to dead blocks after nontrivial
unswitching of switches.
We need to delete all the dead blocks that were created during
unswitching, otherwise we will keep having problems with phi's
or dead blocks.
This change removes all the dead blocks that are reachable from the loop,
not trying to track whether these blocks are newly created by unswitching
or not. While not completely correct, we are unlikely to get loose but
reachable dead blocks that do not belong to our loop nest.
It does fix all the failures currently known, in particular PR38778.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D51519
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341398 91177308-0d34-0410-b5e6-96231b3b80d8
The tests attempted to check for commuted variants
of these folds, but complexity-based canonicalization
meant we had no coverage for at least 1/2 of the cases.
Also, the folds correctly check hasOneUse(), but there
was no coverage for that.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341394 91177308-0d34-0410-b5e6-96231b3b80d8
Use MachineOperand::ChangeToImmediate rather than reassigning
MachineOperands to new values created from MachineOperand::CreateImm,
so that their parent pointers are preserved.
This fixes "Instruction has operand with wrong parent set" errors
reported by the MachineVerifier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341389 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Control height reduction merges conditional blocks of code and reduces the
number of conditional branches in the hot path based on profiles.
if (hot_cond1) { // Likely true.
do_stg_hot1();
}
if (hot_cond2) { // Likely true.
do_stg_hot2();
}
->
if (hot_cond1 && hot_cond2) { // Hot path.
do_stg_hot1();
do_stg_hot2();
} else { // Cold path.
if (hot_cond1) {
do_stg_hot1();
}
if (hot_cond2) {
do_stg_hot2();
}
}
This speeds up some internal benchmarks up to ~30%.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: xbolva00, dmgreen, mehdi_amini, llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D50591
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341386 91177308-0d34-0410-b5e6-96231b3b80d8
One of the tests is failing 50% of the time when expensive checks are
enabled. Not sure how deep the problem is so just reverting while the
author can investigate so that the bots stop repeatedly failing and
blaming things incorrectly. Will respond with details on the original
commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341365 91177308-0d34-0410-b5e6-96231b3b80d8
Check for definedness of the __cpp_sized_deallocation and
__cpp_aligned_new feature test macros. These will not be defined
when the feature is not available, and that prevents any code that
includes this header from compiling with -Wundef -Werror.
Differential Revision: https://reviews.llvm.org/D51171
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341364 91177308-0d34-0410-b5e6-96231b3b80d8
Load Hardening.
Wires up the existing pass to work with a proper IR attribute rather
than just a hidden/internal flag. The internal flag continues to work
for now, but I'll likely remove it soon.
Most of the churn here is adding the IR attribute. I talked about this
Kristof Beyls and he seemed at least initially OK with this direction.
The idea of using a full attribute here is that we *do* expect at least
some forms of this for other architectures. There isn't anything
*inherently* x86-specific about this technique, just that we only have
an implementation for x86 at the moment.
While we could potentially expose this as a Clang-level attribute as
well, that seems like a good question to defer for the moment as it
isn't 100% clear whether that or some other programmer interface (or
both?) would be best. We'll defer the programmer interface side of this
for now, but at least get to the point where the feature can be enabled
without relying on implementation details.
This also allows us to do something that was really hard before: we can
enable *just* the indirect call retpolines when using SLH. For x86, we
don't have any other way to mitigate indirect calls. Other architectures
may take a different approach of course, and none of this is surfaced to
user-level flags.
Differential Revision: https://reviews.llvm.org/D51157
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341363 91177308-0d34-0410-b5e6-96231b3b80d8
implementing the proposed mitigation technique described in the original
design document.
The idea is to check after calls that the return address used to arrive
at that location is in fact the correct address. In the event of
a mis-predicted return which reaches a *valid* return but not the
*correct* return, this will detect the mismatch much like it would
a mispredicted conditional branch.
This is the last published attack vector that I am aware of in the
Spectre v1 space which is not mitigated by SLH+retpolines. However,
don't read *too* much into that: this is an area of ongoing research
where we expect more issues to be discovered in the future, and it also
makes no attempt to mitigate Spectre v4. Still, this is an important
completeness bar for SLH.
The change here is of course delightfully simple. It was predicated on
cutting support for post-instruction symbols into LLVM which was not at
all simple. Many thanks to Hal Finkel, Reid Kleckner, and Justin Bogner
who helped me figure out how to do a bunch of the complex changes
involved there.
Differential Revision: https://reviews.llvm.org/D50837
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341358 91177308-0d34-0410-b5e6-96231b3b80d8
retpolines.
This implements the core design of tracing the intended target into the
target, checking it, and using that to update the predicate state. It
takes advantage of a few interesting aspects of SLH to make it a bit
easier to implement:
- We already split critical edges with conditional branches, so we can
assume those are gone.
- We already unfolded any memory access in the indirect branch
instruction itself.
I've left hard errors in place to catch if any of these somewhat subtle
invariants get violated.
There is some code that I can factor out and share with D50837 when it
lands, but I didn't want to couple landing the two patches, so I'll do
that in a follow-up cleanup commit if alright.
Factoring out the code to handle different scenarios of materializing an
address remains frustratingly hard. In a bunch of cases you want to fold
one of the cases into an immediate operand of some other instruction,
and you also have both symbols and basic blocks being used which require
different methods on the MI builder (and different operand kinds).
Still, I'll take a stab at sharing at least some of this code in
a follow-up if I can figure out how.
Differential Revision: https://reviews.llvm.org/D51083
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341356 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Refactoring done by rL340872 accidentally appeared to be non-NFC, changing the way how
multiple instances of the same pass are handled - aggregation of results by PassName
forced data for multiple instances to be merged together and reported as one line.
Getting back to creating/reporting timers per pass instance.
Reporting was a bit enhanced by counting pass instances and adding #<num> suffix
to the pass description. Note that it is instances that are being counted,
not invocations of them.
time-passes test updated to account for multiple passes being run.
Reviewers: paquette, jhenderson, MatzeB, skatkov
Reviewed By: skatkov
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D51535
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341346 91177308-0d34-0410-b5e6-96231b3b80d8
This patch removes the function `expandSCEVIfNeeded` which behaves not as
it was intended. This function tries to make a lookup for exact existing expansion
and only goes to normal expansion via `expandCodeFor` if this lookup hasn't found
anything. As a result of this, if some instruction above the loop has a `SCEVConstant`
SCEV, this logic will return this instruction when asked for this `SCEVConstant` rather
than return a constant value. This is both non-profitable and in some cases leads to
breach of LCSSA form (as in PR38674).
Whether or not it is possible to break LCSSA with this algorithm and with some
non-constant SCEVs is still in question, this is still being investigated. I wasn't
able to construct such a test so far, so maybe this situation is impossible. If it is,
it will go as a separate fix.
Rather than do it, it is always correct to just invoke `expandCodeFor` unconditionally:
it behaves smarter about insertion points, and as side effect of this it will choose a
constant value for SCEVConstants. For other SCEVs it may end up finding a better insertion
point. So it should not be worse in any case.
NOTE: So far the only known case for which this transform may break LCSSA is mapping
of SCEVConstant to an instruction. However there is a suspicion that the entire algorithm
can compromise LCSSA form for other cases as well (yet not proved).
Differential Revision: https://reviews.llvm.org/D51286
Reviewed By: etherzhhb
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341345 91177308-0d34-0410-b5e6-96231b3b80d8
Reid Kleckner
