A bug was uncovered where if you have a StreamRef whose ViewOffset
is > 0, then when you call readLongestContiguousChunk it will
succeed even when it shouldn't, and it always return you a
buffer that was taken as if the ViewOffset was 0.
Fixed this bug and added a test for it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296556 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Currently, our post-dom tree tries to ignore and remove the effects of
infinite loops. It fails miserably at this, because it tries to do it
ahead of time, and thus can only detect self-loops, and any other type
of infinite loop, it pretends doesn't exist at all.
This can, in a bunch of cases, lead to wrong answers and a completely
empty post-dom tree.
Wrong answer:
```
declare void foo()
define internal void @f() {
entry:
br i1 undef, label %bb35, label %bb3.i
bb3.i:
call void @foo()
br label %bb3.i
bb35.loopexit3:
br label %bb35
bb35:
ret void
}
```
We get:
```
Inorder PostDominator Tree:
[1] <<exit node>> {0,7}
[2] %bb35 {1,6}
[3] %bb35.loopexit3 {2,3}
[3] %entry {4,5}
```
This is a trivial modification of the testcase for PR 6047
Note that we pretend bb3.i doesn't exist.
We also pretend that bb35 post-dominates entry.
While it's true that it does not exit in a theoretical sense, it's not
really helpful to try to ignore the effect and pretend that bb35
post-dominates entry. Worse, we pretend the infinite loop does
nothing (it's usually considered a side-effect), and doesn't even
exist, even when it calls a function. Sadly, this makes it impossible
to use when you are trying to move code safely. All compilers also
create virtual or real single exit nodes (including us), and connect
infinite loops there (which this patch does). In fact, others have
worked around our behavior here, to the point of building their own
post-dom trees:
https://zneak.github.io/fcd/2016/02/17/structuring.html and pointing
out the region infrastructure is near-useless for them with postdom in
this state :(
Completely empty post-dom tree:
```
define void @spam() #0 {
bb:
br label %bb1
bb1: ; preds = %bb1, %bb
br label %bb1
bb2: ; No predecessors!
ret void
}
```
Printing analysis 'Post-Dominator Tree Construction' for function 'foo':
=============================--------------------------------
Inorder PostDominator Tree:
[1] <<exit node>> {0,1}
:(
(note that even if you ignore the effects of infinite loops, bb2
should be present as an exit node that post-dominates nothing).
This patch changes post-dom to properly handle infinite loops and does
root finding during calculation to prevent empty tress in such cases.
We match gcc's (and the canonical theoretical) behavior for infinite
loops (find the backedge, connect it to the exit block).
Testcases coming as soon as i finish running this on a ton of random graphs :)
Reviewers: chandlerc, davide
Subscribers: bryant, llvm-commits
Differential Revision: https://reviews.llvm.org/D29705
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296535 91177308-0d34-0410-b5e6-96231b3b80d8
other tables. Providing a helpful error message to what the error is and
where the error occurred based on which opcode it was associated with.
There have been handful of bug fixes dealing with bad bind info in
object files, r294021 and r249845, which only put a band aid on the
problem after a bad bind table was created after unpacking from
its compact info. In these cases a bind table should have never been
created and an error should have simply been generated.
This change puts in place the plumbing to allow checking and returning
of an error when the compact info is unpacked. This follows the model
of iterators that can fail that Lang Hanes designed when fixing the problem
for bad archives r275316 (or r275361).
This change uses one of the existing test cases that now causes an
error instead of printing <<bad library ordinal>> after a bad bind table
is created. The error uses the offset into the opcode table as shown with
the macOS dyldinfo(1) tool to indicate where the error is and which
opcode and which parameter is in error.
For example the exiting test case has this lazy binding opcode table:
% dyldinfo -opcodes test/tools/llvm-objdump/Inputs/bad-ordinal.macho-x86_64
…
lazy binding opcodes:
0x0000 BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB(0x02, 0x00000010)
0x0002 BIND_OPCODE_SET_DYLIB_ORDINAL_IMM(2)
In the test case the binary only has one library so setting the library
ordinal to the value of 2 in the BIND_OPCODE_SET_DYLIB_ORDINAL_IMM
opcode at 0x0002 above is an error. This now produces this error message:
% llvm-objdump -lazy-bind bad-ordinal.macho-x86_64
…
llvm-objdump: 'bad-ordinal.macho-x86_64': truncated or malformed object (for BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB bad library ordinal: 2 (max 1) for opcode at: 0x2)
This change provides the plumbing for the error handling and one example
of an error message. Other error checks and test cases will be added in follow
on commits.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296527 91177308-0d34-0410-b5e6-96231b3b80d8
Summary: For SamplePGO, the profile may contain cross-module inline stacks. As we need to make sure the profile annotation happens when all the hot inline stacks are expanded, we need to pass this info to the module importer so that it can import proper functions if necessary. This patch implemented this feature by emitting cross-module targets as part of function entry metadata. In the module-summary phase, the metadata is used to build call edges that points to functions need to be imported.
Reviewers: mehdi_amini, tejohnson
Reviewed By: tejohnson
Subscribers: davidxl, llvm-commits
Differential Revision: https://reviews.llvm.org/D30053
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296498 91177308-0d34-0410-b5e6-96231b3b80d8
Stack Smash Protection is not completely free, so in hot code, the overhead it causes can cause performance issues. By adding diagnostic information for which functions have SSP and why, a user can quickly determine what they can do to stop SSP being applied to a specific hot function.
This change adds a remark that is reported by the stack protection code when an instruction or attribute is encountered that causes SSP to be applied.
Patch by: James Henderson
Differential Revision: https://reviews.llvm.org/D29023
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296483 91177308-0d34-0410-b5e6-96231b3b80d8
Recommiting after fixup of 32-bit aliasing sign offset bug in DAGCombiner.
* Simplify Consecutive Merge Store Candidate Search
Now that address aliasing is much less conservative, push through
simplified store merging search and chain alias analysis which only
checks for parallel stores through the chain subgraph. This is cleaner
as the separation of non-interfering loads/stores from the
store-merging logic.
When merging stores search up the chain through a single load, and
finds all possible stores by looking down from through a load and a
TokenFactor to all stores visited.
This improves the quality of the output SelectionDAG and the output
Codegen (save perhaps for some ARM cases where we correctly constructs
wider loads, but then promotes them to float operations which appear
but requires more expensive constant generation).
Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)
Additional Minor Changes:
1. Finishes removing unused AliasLoad code
2. Unifies the chain aggregation in the merged stores across code
paths
3. Re-add the Store node to the worklist after calling
SimplifyDemandedBits.
4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
arbitrary, but seems sufficient to not cause regressions in
tests.
5. Remove Chain dependencies of Memory operations on CopyfromReg
nodes as these are captured by data dependence
6. Forward loads-store values through tokenfactors containing
{CopyToReg,CopyFromReg} Values.
7. Peephole to convert buildvector of extract_vector_elt to
extract_subvector if possible (see
CodeGen/AArch64/store-merge.ll)
8. Store merging for the ARM target is restricted to 32-bit as
some in some contexts invalid 64-bit operations are being
generated. This can be removed once appropriate checks are
added.
This finishes the change Matt Arsenault started in r246307 and
jyknight's original patch.
Many tests required some changes as memory operations are now
reorderable, improving load-store forwarding. One test in
particular is worth noting:
CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
forwarding converts a load-store pair into a parallel store and
a memory-realized bitcast of the same value. However, because we
lose the sharing of the explicit and implicit store values we
must create another local store. A similar transformation
happens before SelectionDAG as well.
Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296476 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This will allow future patches to inspect the details of the LLT. The implementation is now split between
the Support and CodeGen libraries to allow TableGen to use this class without introducing layering concerns.
Thanks to Ahmed Bougacha for finding a reasonable way to avoid the layering issue and providing the version of this patch without that problem.
Reviewers: t.p.northover, qcolombet, rovka, aditya_nandakumar, ab, javed.absar
Subscribers: arsenm, nhaehnle, mgorny, dberris, llvm-commits, kristof.beyls
Differential Revision: https://reviews.llvm.org/D30046
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296474 91177308-0d34-0410-b5e6-96231b3b80d8
These were noticed as missing in a code review. Add them and the boring
unit test to make sure they compile and DTRT.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296444 91177308-0d34-0410-b5e6-96231b3b80d8
This is also useful in cases when llvm is in a shared library. First we dlopen
the llvm shared library and then we register it as a permanent library in order
to keep the JIT and other services working.
Patch reviewed by Vedant Kumar (D29955)!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296442 91177308-0d34-0410-b5e6-96231b3b80d8
This is a patch for the outliner described in the RFC at:
http://lists.llvm.org/pipermail/llvm-dev/2016-August/104170.html
The outliner is a code-size reduction pass which works by finding
repeated sequences of instructions in a program, and replacing them with
calls to functions. This is useful to people working in low-memory
environments, where sacrificing performance for space is acceptable.
This adds an interprocedural outliner directly before printing assembly.
For reference on how this would work, this patch also includes X86
target hooks and an X86 test.
The outliner is run like so:
clang -mno-red-zone -mllvm -enable-machine-outliner file.c
Patch by Jessica Paquette<jpaquette@apple.com>!
rdar://29166825
Differential Revision: https://reviews.llvm.org/D26872
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296418 91177308-0d34-0410-b5e6-96231b3b80d8
Before the endianness was specified on each call to read
or write of the StreamReader / StreamWriter, but in practice
it's extremely rare for streams to have data encoded in
multiple different endiannesses, so we should optimize for the
99% use case.
This makes the code cleaner and more general, but otherwise
has NFC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296415 91177308-0d34-0410-b5e6-96231b3b80d8
Instead of requiring every non-COFF MCObjectStreamer to implement the
COFF hooks just to do an llvm_unreachable to say that they're not
supported, do the llvm_unreachable in the default implementation, as
suggested by rnk in https://reviews.llvm.org/D26722.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296403 91177308-0d34-0410-b5e6-96231b3b80d8
This was reverted because it was breaking some builds, and
because of incorrect error code usage. Since the CL was
large and contained many different things, I'm resubmitting
it in pieces.
This portion is NFC, and consists of:
1) Renaming classes to follow a consistent naming convention.
2) Fixing the const-ness of the interface methods.
3) Adding detailed doxygen comments.
4) Fixing a few instances of passing `const BinaryStream& X`. These
are now passed as `BinaryStreamRef X`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296394 91177308-0d34-0410-b5e6-96231b3b80d8
fallible functions.
Some fallible functions (those returning Error or Expected<T>) may only fail
for a subset of their inputs. For example, a "safe" square root function will
succeed for all finite positive inputs:
Expected<double> safeSqrt(double d) {
if (d < 0 && !isnan(d) && !isinf(d))
return make_error<...>("Cannot sqrt -ve values, nans or infs");
return sqrt(d);
}
At a safe callsite for such a function, checking the error return value is
redundant:
if (auto ValOrErr = safeSqrt(42.0)) {
// use *ValOrErr.
} else
llvm_unreachable("safeSqrt should always succeed for +ve values");
The cantFail function wraps this check and extracts the contained value,
simplifying control flow:
double Result = cantFail(safeSqrt(42.0));
This function should be used with care: it is a programmatic error to wrap a
call with cantFail if it can in fact fail. For debug builds this will
result in llvm_unreachable being called. For release builds the behavior is
undefined.
Use of this function is likely to be rare in library code, but more common
for tool and unit-test code where inputs and mock functions may be known to be
safe.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296384 91177308-0d34-0410-b5e6-96231b3b80d8
The current pattern for extract bits in range is typically:
Mask.lshr(BitOffset).trunc(SubSizeInBits);
Which can be particularly slow for large APInts (MaskSizeInBits > 64) as they require the allocation of memory for the temporary variable.
This is another of the compile time issues identified in PR32037 (see also D30265).
This patch adds the APInt::extractBits() helper method which avoids the temporary memory allocation.
Differential Revision: https://reviews.llvm.org/D30336
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296272 91177308-0d34-0410-b5e6-96231b3b80d8
r296215, "[PDB] General improvements to Stream library."
r296217, "Disable BinaryStreamTest.StreamReaderObject temporarily."
r296220, "Re-enable BinaryStreamTest.StreamReaderObject."
r296244, "[PDB] Disable some tests that are breaking bots."
r296249, "Add static_cast to silence -Wc++11-narrowing."
std::errc::no_buffer_space should be used for OS-oriented errors for socket transmission.
(Seek discussions around llvm/xray.)
I could substitute s/no_buffer_space/others/g, but I revert whole them ATM.
Could we define and use LLVM errors there?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296258 91177308-0d34-0410-b5e6-96231b3b80d8
Recommiting after fixup of 32-bit aliasing sign offset bug in DAGCombiner.
* Simplify Consecutive Merge Store Candidate Search
Now that address aliasing is much less conservative, push through
simplified store merging search and chain alias analysis which only
checks for parallel stores through the chain subgraph. This is cleaner
as the separation of non-interfering loads/stores from the
store-merging logic.
When merging stores search up the chain through a single load, and
finds all possible stores by looking down from through a load and a
TokenFactor to all stores visited.
This improves the quality of the output SelectionDAG and the output
Codegen (save perhaps for some ARM cases where we correctly constructs
wider loads, but then promotes them to float operations which appear
but requires more expensive constant generation).
Some minor peephole optimizations to deal with improved SubDAG shapes (listed below)
Additional Minor Changes:
1. Finishes removing unused AliasLoad code
2. Unifies the chain aggregation in the merged stores across code
paths
3. Re-add the Store node to the worklist after calling
SimplifyDemandedBits.
4. Increase GatherAllAliasesMaxDepth from 6 to 18. That number is
arbitrary, but seems sufficient to not cause regressions in
tests.
5. Remove Chain dependencies of Memory operations on CopyfromReg
nodes as these are captured by data dependence
6. Forward loads-store values through tokenfactors containing
{CopyToReg,CopyFromReg} Values.
7. Peephole to convert buildvector of extract_vector_elt to
extract_subvector if possible (see
CodeGen/AArch64/store-merge.ll)
8. Store merging for the ARM target is restricted to 32-bit as
some in some contexts invalid 64-bit operations are being
generated. This can be removed once appropriate checks are
added.
This finishes the change Matt Arsenault started in r246307 and
jyknight's original patch.
Many tests required some changes as memory operations are now
reorderable, improving load-store forwarding. One test in
particular is worth noting:
CodeGen/PowerPC/ppc64-align-long-double.ll - Improved load-store
forwarding converts a load-store pair into a parallel store and
a memory-realized bitcast of the same value. However, because we
lose the sharing of the explicit and implicit store values we
must create another local store. A similar transformation
happens before SelectionDAG as well.
Reviewers: arsenm, hfinkel, tstellarAMD, jyknight, nhaehnle
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296252 91177308-0d34-0410-b5e6-96231b3b80d8
This adds various new functionality and cleanup surrounding the
use of the Stream library. Major changes include:
* Renaming of all classes for more consistency / meaningfulness
* Addition of some new methods for reading multiple values at once.
* Full suite of unit tests for reader / writer functionality.
* Full set of doxygen comments for all classes.
* Streams now store their own endianness.
* Fixed some bugs in a few of the classes that were discovered
by the unit tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296215 91177308-0d34-0410-b5e6-96231b3b80d8
This is part of a larger effort to get the Stream code moved
up to Support. I don't want to do it in one large patch, in
part because the changes are so big that it will treat everything
as file deletions and add, losing history in the process.
Aside from that though, it's just a good idea in general to
make small changes.
So this change only changes the names of the Stream related
source files, and applies necessary source fix ups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296211 91177308-0d34-0410-b5e6-96231b3b80d8
With the "wasm32-unknown-unknown-wasm" triple, this allows writing out
simple wasm object files, and is another step in a larger series toward
migrating from ELF to general wasm object support. Note that this code
and the binary format itself is still experimental.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296190 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r296009. It broke one out of tree target and also
does not account for all partial lines added or removed when calculating
PressureDiff.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296182 91177308-0d34-0410-b5e6-96231b3b80d8
The current pattern for extract bits in range is typically:
Mask.lshr(BitOffset).trunc(SubSizeInBits);
Which can be particularly slow for large APInts (MaskSizeInBits > 64) as they require the allocation of memory for the temporary variable.
This is another of the compile time issues identified in PR32037 (see also D30265).
This patch adds the APInt::extractBits() helper method which avoids the temporary memory allocation.
Differential Revision: https://reviews.llvm.org/D30336
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296147 91177308-0d34-0410-b5e6-96231b3b80d8
The current pattern for extract bits in range is typically:
Mask.lshr(BitOffset).trunc(SubSizeInBits);
Which can be particularly slow for large APInts (MaskSizeInBits > 64) as they require the allocation of memory for the temporary variable.
This is another of the compile time issues identified in PR32037 (see also D30265).
This patch adds the APInt::extractBits() helper method which avoids the temporary memory allocation.
Differential Revision: https://reviews.llvm.org/D30336
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296141 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
This isn't testable for AArch64 by itself so this patch also adds
support for constant immediates in the pattern and physical
register uses in the result.
The new IntOperandMatcher matches the constant in patterns such as
'(set $rd:GPR32, (G_XOR $rs:GPR32, -1))'. It's always safe to fold
immediates into an instruction so this is the first rule that will match
across multiple BB's.
The Renderer hierarchy is responsible for adding operands to the result
instruction. Renderers can copy operands (CopyRenderer) or add physical
registers (in particular %wzr and %xzr) to the result instruction
in any order (OperandMatchers now import the operand names from
SelectionDAG to allow renderers to access any operand). This allows us to
emit the result instruction for:
%1 = G_XOR %0, -1 --> %1 = ORNWrr %wzr, %0
%1 = G_XOR -1, %0 --> %1 = ORNWrr %wzr, %0
although the latter is untested since the matcher/importer has not been
taught about commutativity yet.
Added BuildMIAction which can build new instructions and mutate them where
possible. W.r.t the mutation aspect, MatchActions are now told the name of
an instruction they can recycle and BuildMIAction will emit mutation code
when the renderers are appropriate. They are appropriate when all operands
are rendered using CopyRenderer and the indices are the same as the matcher.
This currently assumes that all operands have at least one matcher.
Finally, this change also fixes a crash in
AArch64InstructionSelector::select() caused by an immediate operand
passing isImm() rather than isCImm(). This was uncovered by the other
changes and was detected by existing tests.
Depends on D29711
Reviewers: t.p.northover, ab, qcolombet, rovka, aditya_nandakumar, javed.absar
Reviewed By: rovka
Subscribers: aemerson, dberris, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D29712
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296131 91177308-0d34-0410-b5e6-96231b3b80d8
The current pattern for setting bits in range is typically:
Mask |= APInt::getBitsSet(MaskSizeInBits, LoPos, HiPos);
Which can be particularly slow for large APInts (MaskSizeInBits > 64) as they require the allocation memory for the temporary variable.
This is one of the key compile time issues identified in PR32037.
This patch adds the APInt::setBits() helper method which avoids the temporary memory allocation completely, this first implementation uses setBit() internally instead but already significantly reduces the regression in PR32037 (~10% drop). Additional optimization may be possible.
I investigated whether there is need for APInt::clearBits() and APInt::flipBits() equivalents but haven't seen these patterns to be particularly common, but reusing the code would be trivial.
Differential Revision: https://reviews.llvm.org/D30265
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296102 91177308-0d34-0410-b5e6-96231b3b80d8
Add an optimization remark to asm-printer that summarizes the number
of instructions emitted per function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296053 91177308-0d34-0410-b5e6-96231b3b80d8
DiagnosticInfo switched from DebugLoc to DiagnosticLocation in
r295519, update these subclasses to match.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296052 91177308-0d34-0410-b5e6-96231b3b80d8
This allows the ability to call IPDBSession::getGlobalScope with a NativeSession and
to then query it for some basic fields from the PDB's InfoStream.
Note that the symbols now have non-const references back to the Session so that
NativeRawSymbol can access the PDBFile through the Session.
Differential Revision: https://reviews.llvm.org/D30314
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296049 91177308-0d34-0410-b5e6-96231b3b80d8
