By loading from indexed offsets into a byte array and applying a mask, a
program can test bits from the bit set with a relatively short instruction
sequence. For example, suppose we have 15 bit sets to lay out:
A (16 bits), B (15 bits), C (14 bits), D (13 bits), E (12 bits),
F (11 bits), G (10 bits), H (9 bits), I (7 bits), J (6 bits), K (5 bits),
L (4 bits), M (3 bits), N (2 bits), O (1 bit)
These bits can be laid out in a 16-byte array like this:
Byte Offset
0123456789ABCDEF
Bit
7 HHHHHHHHHIIIIIII
6 GGGGGGGGGGJJJJJJ
5 FFFFFFFFFFFKKKKK
4 EEEEEEEEEEEELLLL
3 DDDDDDDDDDDDDMMM
2 CCCCCCCCCCCCCCNN
1 BBBBBBBBBBBBBBBO
0 AAAAAAAAAAAAAAAA
For example, to test bit X of A, we evaluate ((bits[X] & 1) != 0), or to
test bit X of I, we evaluate ((bits[9 + X] & 0x80) != 0). This can be done
in 1-2 machine instructions on x86, or 4-6 instructions on ARM.
This uses the LPT multiprocessor scheduling algorithm to lay out the bits
efficiently.
Saves ~450KB of instructions in a recent build of Chromium.
Differential Revision: http://reviews.llvm.org/D7954
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231043 91177308-0d34-0410-b5e6-96231b3b80d8
There's really no reason to have them have entries in the symbol table
anymore. Old versions of ld64 had some bugs in this area but those have
been fixed long ago.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231041 91177308-0d34-0410-b5e6-96231b3b80d8
In the future, we should run the output of clang through instnamer to
make it easier to manually edit test cases.
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231037 91177308-0d34-0410-b5e6-96231b3b80d8
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.
Ought to be NFC, but it does slightly alter the output format of the
textual assembly.
This reapplies 230930 without the assertion in DebugLocEntry::finalize()
because not all Machine registers can be lowered into DWARF register
numbers and floating point constants cannot be expressed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231023 91177308-0d34-0410-b5e6-96231b3b80d8
This re-lands change r230921. r230921 was reverted because it broke a
clang test; a checkin fixing the clang test will be commited shortly.
Summary:
As far as I can tell, the real bug causing the issue was fixed in
r230533. SCEVExpander should mark an increment operation as nuw or nsw
only if it can *prove* that the operation does not overflow. There
shouldn't be any situation where we have to do something different
because of no-wrap flags generated by SCEVExpander.
Revert "IndVarSimplify: Allow LFTR to fire more often"
This reverts commit 1ade0f0faa (SVN: 222213).
Revert "IndVarSimplify: Don't let LFTR compare against a poison value"
This reverts commit c0f2b8b528 (SVN: 217102).
Reviewers: majnemer, atrick, spatel
Differential Revision: http://reviews.llvm.org/D7979
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231018 91177308-0d34-0410-b5e6-96231b3b80d8
The internal shell was already threading around a 'cwd' parameter. We
just have to make it mutable so that we can update it as the test script
executes.
If the shell ever grows support for environment variable substitution,
we could also implement support for export.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231017 91177308-0d34-0410-b5e6-96231b3b80d8
The issue is that now we have a diag handler during optimizations
and get forward every optimization remark, flooding stdout.
The same filtering should probably be done with or without a
custom handler, but for now just ignore remarks.
Original message:
gold-plugin: "Upgrade" debug info and handle its warnings.
The gold plugin never calls MaterializeModule, so any old debug info
was not deleted and could cause crashes.
Now that it is being "upgraded", the plugin also has to handle warnings
and create Modules with a nice id (it shows in the warning).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230991 91177308-0d34-0410-b5e6-96231b3b80d8
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.
Ought to be NFC, but it does slightly alter the output format of the
textual assembly.
This reapplies 230930 with a relaxed assertion in DebugLocEntry::finalize()
that allows for empty DWARF expressions for constant FP values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230975 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When the RHS of a conditional move node is zero, we can utilize the $zero
register by inverting the conditional move instruction and by swapping the
order of its True/False operands.
Reviewers: dsanders
Differential Revision: http://reviews.llvm.org/D7945
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230956 91177308-0d34-0410-b5e6-96231b3b80d8
This manifested as assertions and/or crashes in later phases of optimization,
depending on the build configuration.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230939 91177308-0d34-0410-b5e6-96231b3b80d8
Previously this resulted in asserts and/or crashes (depending on build configuration) at various phases in the optimizer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230938 91177308-0d34-0410-b5e6-96231b3b80d8
Previously this would result in assertion failures or simply crashes
at various points in the optimizer when trying to create types of zero
bit width.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230936 91177308-0d34-0410-b5e6-96231b3b80d8
This manifested as an assertion failure in +Asserts builds, and a hard crash in -Asserts builds. Found by fuzzing the LL parser.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230934 91177308-0d34-0410-b5e6-96231b3b80d8
A short list of some of the improvements:
1) Now supports -all command line argument, which implies many
other command line arguments to simplify usage.
2) Now supports -no-compiler-generated command line argument to
exclude compiler generated types.
3) Prints base class list.
4) -class-definitions implies -types.
5) Proper display of bitfields.
6) Can now distinguish between struct/class/interface/union.
And a few other minor tweaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230933 91177308-0d34-0410-b5e6-96231b3b80d8
TargetRegisterInfo. DebugLocEntry now holds a buffer with the raw bytes
of the pre-calculated DWARF expression.
Ought to be NFC, but it does slightly alter the output format of the
textual assembly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230930 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
As far as I can tell, the real bug causing the issue was fixed in
r230533. SCEVExpander should mark an increment operation as nuw or nsw
only if it can *prove* that the operation does not overflow. There
shouldn't be any situation where we have to do something different
because of no-wrap flags generated by SCEVExpander.
Revert "IndVarSimplify: Allow LFTR to fire more often"
This reverts commit 1ade0f0faa (SVN: 222213).
Revert "IndVarSimplify: Don't let LFTR compare against a poison value"
This reverts commit c0f2b8b528 (SVN: 217102).
Reviewers: majnemer, atrick, spatel
Differential Revision: http://reviews.llvm.org/D7979
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230921 91177308-0d34-0410-b5e6-96231b3b80d8
It emits *millions of warnings* during selfhosting LTO build, to choke the buildbot with gigbytes of log.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230885 91177308-0d34-0410-b5e6-96231b3b80d8
r228631 stopped using `DW_OP_piece` inside `DIExpression`s in the IR,
but it apparently missed updating these testcases. Caught by verifier
checks for `MDExpression` while working on moving the new hierarchy into
place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230882 91177308-0d34-0410-b5e6-96231b3b80d8
There are two types of files in the old (current) debug info schema.
!0 = !{!"some/filename", !"/path/to/dir"}
!1 = !{!"0x29", !0} ; [ DW_TAG_file_type ]
!1 has a wrapper class called `DIFile` which inherits from `DIScope` and
is referenced in 'scope' fields.
!0 is called a "file node", and debug info nodes with a 'file' field
point at one of these directly -- although they're built in `DIBuilder`
by sending in a `DIFile` and reaching into it.
In the new hierarchy, I unified these nodes as `MDFile` (which `DIFile`
is a lightweight wrapper for) in r230057. Moving the new hierarchy into
place (and upgrading testcases) caused CodeGen/X86/unknown-location.ll
to start failing -- apparently "0x29" was previously showing up in the
linetable as a filename, causing:
.loc 2 4 3
(where 2 points at filename "0x29") instead of:
.loc 1 4 3
(where 1 points at the actual filename).
Change the testcase to use the old schema correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230880 91177308-0d34-0410-b5e6-96231b3b80d8
While gaining practical experience hand-updating CHECK lines (for moving
the new debug info hierarchy into place), I learnt a few things about
CHECK-ability of the specialized node assembly output.
- The first part of a `CHECK:` is to identify the "right" node (this
is especially true if you intend to use the new `CHECK-SAME`
feature, since the first CHECK needs to identify the node correctly
before you can split the line).
- If there's a `tag:`, it should go first.
- If there's a `name:`, it should go next (followed by the
`linkageName:`, if any).
- If there's a `scope:`, it should follow after that.
- When a node type supports multiple DW_TAGs, but one is implied by
its name and is overwhelmingly more common, the `tag:` field is
terribly uninteresting unless it's different.
- `MDBasicType` is almost always `DW_TAG_base_type`.
- `MDTemplateValueParameter` is almost always
`DW_TAG_template_value_parameter`.
- Printing `name: ""` doesn't improve CHECK-ability, and there are far
more nodes than I realized that are commonly nameless.
- There are a few other fields that similarly aren't very interesting
when they're empty.
This commit updates the `AsmWriter` as suggested above (and makes
necessary changes in `LLParser` for round-tripping).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230877 91177308-0d34-0410-b5e6-96231b3b80d8
Properly escape string fields in metadata. I've added a spot-check with
direct coverage for `MDFile::getFilename()`, but we'll get more coverage
once the hierarchy is moved into place (since this comes up in various
checked-in testcases).
I've replicated the `if` logic using the `ShouldSkipEmpty` flag
(although a follow-up commit is going to change how often this flag is
specified); no NFCI other than escaping the string fields.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230875 91177308-0d34-0410-b5e6-96231b3b80d8
Leaving empty blocks around just opens up a can of bugs like PR22704. Deleting
them early also slightly simplifies code.
Thanks to Sanjay for the IR test case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230856 91177308-0d34-0410-b5e6-96231b3b80d8
It turns out the naming of inserted phis and selects is sensative to the order in which two sets are iterated. We need to nail this down to avoid non-deterministic output and possible test failures.
The modified test is the one I first noticed something odd in. The change is making it more strict to report the error. With the test change, but without the code change, the test fails roughly 1 in 5. With the code change, I've run ~30 runs without error.
Long term, the right fix here is to adjust the naming scheme. I'm checking in this hack to avoid any possible non-determinism in the tests over the weekend. HJust because I only noticed one case doesn't mean it's actually the only case. I hope to get to the right change Monday.
std->llvm data structure changes bugfix change #3
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230835 91177308-0d34-0410-b5e6-96231b3b80d8
This class is responsible for getting the linked data to the
disk in the appropriate form. Today it it an empty shell that
just instantiates an MC layer.
As we do not put anything in the resulting file yet, we just
check it has the right architecture (and check that -o does
the right thing).
To be able to create all the components, this commit adds a
few dependencies to llvm-dsymutil, namely all-targets, MC and
AsmPrinter.
Also add a -no-output option, so that tests that do not need
the binary result can continue to run even if they do not have
the required target linked in.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230824 91177308-0d34-0410-b5e6-96231b3b80d8
These tests cover the 'base object' identification and rewritting portion of RewriteStatepointsForGC. These aren't completely exhaustive, but they've proven to be reasonable effective over time at finding regressions.
In the process of porting these tests over, I found my first "cleanup per llvm code style standards" bug. We were relying on the order of iteration when testing the base pointers found for a derived pointer. When we switched from std::set to DenseSet, this stopped being a safe assumption. I'm suspecting I'm going to find more of those. In particular, I'm now really wondering about the main iteration loop for this algorithm. I need to go take a closer look at the assumptions there.
I'm not really happy with the fact these are testing what is essentially debug output (i.e. enabled via command line flags). Suggestions for how to structure this better are very welcome.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230818 91177308-0d34-0410-b5e6-96231b3b80d8
