Summary:
The LLVM Bitcode File Format documentation states that all bitstreams
begin with the magic number 'BC', and that generic bitstream analyzer
tools may check for this number in order to determine whether the
stream is a bitstream.
However, in practice:
* Only LLVM IR bitcode begins with 'BC'. Other bitstreams -- Clang
AST files and precompiled headers, Clang serialized diagnostics,
Swift modules -- do not start with 'BC'. A tool that actually checked
for 'BC' would only be able to recognize LLVM IR.
* The `llvm-bcanalyzer`, arguably the most used generic bitstream
analyzer tool, does not check for a magic number 'BC' (except to
determine whether the file is LLVM IR).
Update the bitcode format documentation to make it clear that not all
bitstreams begin with 'BC', and that tools should not rely on that
particular magic number value.
Test Plan:
Build the `docs-llvm-html` target and confirm the changes render in
a Safari web browser.
Reviewers: harlanhaskins, eugenis, mehdi_amini, pcc, angerman
Reviewed By: angerman
Subscribers: angerman, llvm-commits
Differential Revision: https://reviews.llvm.org/D42002
llvm-svn: 322520
This adds some more detail about the PDB container format,
specifically surrounding the layout of the Free Page Map.
Patch by Colden Cullen
Differential Revision: https://reviews.llvm.org/D41825
llvm-svn: 322404
Summary:
In D41919, I missed that there was a *second* step when uploading
diffs via web where the repository should be specified.
Reviewers: asb, probinson
Reviewed By: asb
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41956
llvm-svn: 322375
Summary:
Docs are out of date now that we have separate repositories for LLVM,
Clang, etc.
Reviewers: asb
Reviewed By: asb
Differential Revision: https://reviews.llvm.org/D41919
llvm-svn: 322290
We are printing / parsing the `frame-setup` MachineInstr flag but not
the `frame-destroy` one.
Differential Revision: https://reviews.llvm.org/D41509
llvm-svn: 322071
Summary:
The documentation has fallen a bit behind, update it with the latest evolution
of the allocator:
- clarify a couple of expectations regarding what is meant to be achieved;
- update the header format;
- document `-fsanitize=scudo`.
Reviewers: alekseyshl, flowerhack
Reviewed By: alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41670
llvm-svn: 321811
This new page acts as an entry point for (new) contributors to LLVM and
provides information about
* What to contribute
* How to submit a patch
* Where to start to learn more about LLVM's architecture and internals.
This version of the page duplicates some information from the
DeveloperPolicy and Phabricator pages. Subsequent changes should work
towards moving information for new developers to this page, where it
makes sense.
Reviewers: reames, probinson, kristof.beyls, silvas, rengolin, asb
Reviewed By: silvas
Differential Revision: https://reviews.llvm.org/D41665
llvm-svn: 321804
The examples in llvm/Support/Debug.h use `DEBUG(dbgs() << ...)` instead
of `errs()`, so the examples in the Programmer's Manual should match
that.
Patch by: Moritz Sichert <moritz.sichert@googlemail.com>
Differential revision: https://reviews.llvm.org/D41170
llvm-svn: 321444
Work towards the unification of MIR and debug output by refactoring the
interfaces.
Also add support for printing with a null TargetIntrinsicInfo and no
MachineFunction.
llvm-svn: 321111
Work towards the unification of MIR and debug output by refactoring the
interfaces.
Before this patch we printed "<call frame instruction>" in the debug
output.
llvm-svn: 321084
LLVM IR function names which disable mangling start with '\01'
(https://www.llvm.org/docs/LangRef.html#identifiers).
When an identifier like "\01@abc@" gets dumped to MIR, it is quoted, but
only with single quotes.
http://www.yaml.org/spec/1.2/spec.html#id2770814:
"The allowed character range explicitly excludes the C0 control block
allowed), the surrogate block #xD800-#xDFFF, #xFFFE, and #xFFFF."
http://www.yaml.org/spec/1.2/spec.html#id2776092:
"All non-printable characters must be escaped.
[...]
Note that escape sequences are only interpreted in double-quoted scalars."
This patch adds support for printing escaped non-printable characters
between double quotes if needed.
Should also fix PR31743.
Differential Revision: https://reviews.llvm.org/D41290
llvm-svn: 320996
Work towards the unification of MIR and debug output by printing
`<mcsymbol sym>` instead of `<MCSym=sym>`.
Only debug syntax is affected.
llvm-svn: 320685
Work towards the unification of MIR and debug output by printing `target-index(target-specific) + 8` instead of `<ti#0+8>` and `target-index(target-specific) + 8` instead of `<ti#0-8>`.
Only debug syntax is affected.
llvm-svn: 320565
Work towards the unification of MIR and debug output by printing
`%const.0 + 8` instead of `<cp#0+8>` and `%const.0 - 8` instead of
`<cp#0-8>`.
Only debug syntax is affected.
Differential Revision: https://reviews.llvm.org/D41116
llvm-svn: 320564
This change makes XRay print the log file output only when the verbosity
level is higher than 0. It reduces the log spam in the default case when
we want XRay running silently, except when there are actual
fatal/serious errors.
We also update the documentation to show how to get the information
after the change to the default behaviour.
llvm-svn: 320550
Summary:
Add isRenamable() predicate to MachineOperand. This predicate can be
used by machine passes after register allocation to determine whether it
is safe to rename a given register operand. Register operands that
aren't marked as renamable may be required to be assigned their current
register to satisfy constraints that are not captured by the machine
IR (e.g. ABI or ISA constraints).
Reviewers: qcolombet, MatzeB, hfinkel
Subscribers: nemanjai, mcrosier, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D39400
llvm-svn: 320503
Correct committed version to match intended accepted review D40051 id=123417
- Rename Bonaire target to be gfx704.
- Eliminate gfx800 and make Iceland and Tonga both use gfx802 as they use the same code.
- List target features supported by each processor in the processor table together with the default value.
- Add xnack flag to e_flags.
- Remove xnack from kernel metadata and kernel descriptor since it is now a whole code object property.
Differential Revision: https://reviews.llvm.org/D40051
llvm-svn: 320457
Summary:
That allows to get the same data as produced by "llvm-cov report",
but in JSON format, which is better for further processing by end users.
Reviewers: vsk
Reviewed By: vsk
Differential Revision: https://reviews.llvm.org/D41085
llvm-svn: 320435
- Rename Bonaire target to be gfx704.
- Eliminate gfx800 and make Iceland and Tonga both use gfx802 as they use the same code.
- List target features supported by each processor in the processor table together with the default value.
- Add xnack flag to e_flags.
- Remove xnack from kernel metadata and kernel descriptor since it is now a whole code object property.
Differential Revision: https://reviews.llvm.org/D40051
llvm-svn: 320378
Summary:
This is LLVM instrumentation for the new HWASan tool. It is basically
a stripped down copy of ASan at this point, w/o stack or global
support. Instrumenation adds a global constructor + runtime callbacks
for every load and store.
HWASan comes with its own IR attribute.
A brief design document can be found in
clang/docs/HardwareAssistedAddressSanitizerDesign.rst (submitted earlier).
Reviewers: kcc, pcc, alekseyshl
Subscribers: srhines, mehdi_amini, mgorny, javed.absar, eraman, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D40932
llvm-svn: 320217
Work towards the unification of MIR and debug output by refactoring the
interfaces.
Add support for operand subreg index as an immediate to debug printing
and use ::print in the MIRPrinter.
Differential Review: https://reviews.llvm.org/D40965
llvm-svn: 320209
The Debugify pass synthesizes debug info for IR. It's paired with a
CheckDebugify pass which determines how much of the original debug info
is preserved. These passes make it easier to create targeted tests for
debug info preservation.
Here is the Debugify algorithm:
NextLine = 1
for (Instruction &I : M)
attach DebugLoc(NextLine++) to I
NextVar = 1
for (Instruction &I : M)
if (canAttachDebugValue(I))
attach dbg.value(NextVar++) to I
The CheckDebugify pass expects contiguous ranges of DILocations and
DILocalVariables. If it fails to find all of the expected debug info, it
prints a specific error to stderr which can be FileChecked.
This was discussed on llvm-dev in the thread:
"Passes to add/validate synthetic debug info"
Differential Revision: https://reviews.llvm.org/D40512
llvm-svn: 320202
This marks certain flags in XRay as deprecated (in particular,
`xray_naive_log=` and `xray_fdr_log=`), and recommends the use of the
`xray_mode=` flag.
llvm-svn: 319763
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.
The MIR printer prints the IR name of a MBB only for block definitions.
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix
Differential Revision: https://reviews.llvm.org/D40422
llvm-svn: 319665
As noted in D40594, the frem instruction corresponds to fmod() except that it can't set errno.
I modified the text that we currently use for intrinsics that map to libm functions and applied
it to frem.
Differential Revision: https://reviews.llvm.org/D40629
llvm-svn: 319437
Re applying after fixing issues in the diff, sorry for any painful conflicts/merges!
Original RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-August/117028.html
This change adds a '.stack-size' section containing metadata on function stack sizes to output ELF files behind the new -stack-size-section flag. The section contains pairs of function symbol references (8 byte) and stack sizes (unsigned LEB128).
The contents of this section can be used to measure changes to stack sizes between different versions of the compiler or a source base. The advantage of having a section is that we can extract this information when examining binaries that we didn't build, and it allows users and tools easy access to that information just by referencing the binary.
There is a follow up change to add an option to clang.
Thanks.
Reviewers: hfinkel, MatzeB
Reviewed By: MatzeB
Subscribers: thegameg, asb, llvm-commits
Differential Revision: https://reviews.llvm.org/D39788
llvm-svn: 319430
Summary:
Original RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-August/117028.html
I wasn't sure who to put as reviewers, so please add/remove people as appropriate.
This change adds a '.stack-size' section containing metadata on function stack sizes to output ELF files behind the new -stack-size-section flag. The section contains pairs of function symbol references (8 byte) and stack sizes (unsigned LEB128).
The contents of this section can be used to measure changes to stack sizes between different versions of the compiler or a source base. The advantage of having a section is that we can extract this information when examining binaries that we didn't build, and it allows users and tools easy access to that information just by referencing the binary.
There is a follow up change to add an option to clang.
Thanks.
Reviewers: hfinkel, MatzeB
Reviewed By: MatzeB
Subscribers: thegameg, asb, llvm-commits
Differential Revision: https://reviews.llvm.org/D39788
llvm-svn: 319423
We've recently changed the default for `xray_naive_log=` to be `false`
instead of `true` to make it more consistent with the FDR mode logging
implementation. This means we will now ask users to explicitly choose
which version of the XRay logging is being used.
llvm-svn: 319400
This patch adds a new abstraction layer to VPlan and leverages it to model the planned
instructions that manipulate masks (AND, OR, NOT), introduced during predication.
The new VPValue and VPUser classes model how data flows into, through and out
of a VPlan, forming the vertices of a planned Def-Use graph. The new
VPInstruction class is a generic single-instruction Recipe that models a
planned instruction along with its opcode, operands and users. See
VectorizationPlan.rst for more details.
Differential Revision: https://reviews.llvm.org/D38676
llvm-svn: 318645
Differential Revision: https://reviews.llvm.org/D39737
This is the second attempt to commit this. The test was broken on Linux in the first attempt.
llvm-svn: 318560
llvm.invariant.group.barrier may accept pointers to arbitrary address space.
This patch let it accept pointers to i8 in any address space and returns
pointer to i8 in the same address space.
Differential Revision: https://reviews.llvm.org/D39973
llvm-svn: 318413
This change adds generic fuzzing tools capable of running libFuzzer tests on
any optimization pass or combination of them.
Differential Revision: https://reviews.llvm.org/D39555
llvm-svn: 317883
- Use ELF header flags to identify processor.
- Remove isa note record.
- Add target feature section.
- Make metadata for NumVGPRs, NumSGPRs and MaxFlatWorkGroupSize required.
- Add FixedWorkGroupSize to CodeProps metadata.
- Add ReqdWorkGroupSize* to kernel descriptor and move MaxFlatWorkGroupSize to be adjacent.
- Move IsXNACKEnabled in the kernel descriptor to be at the end of the unused flags.
- Remove IsDynamicCallStack from the metadata and kernel descriptor.
- Remove legacy debugger metadata.
- Remove old XNACK enabled processor names.
Differential Revision: https://reviews.llvm.org/D39828
llvm-svn: 317855
This patch implements Chandler's idea [0] for supporting languages that
require support for infinite loops with side effects, such as Rust, providing
part of a solution to bug 965 [1].
Specifically, it adds an `llvm.sideeffect()` intrinsic, which has no actual
effect, but which appears to optimization passes to have obscure side effects,
such that they don't optimize away loops containing it. It also teaches
several optimization passes to ignore this intrinsic, so that it doesn't
significantly impact optimization in most cases.
As discussed on llvm-dev [2], this patch is the first of two major parts.
The second part, to change LLVM's semantics to have defined behavior
on infinite loops by default, with a function attribute for opting into
potential-undefined-behavior, will be implemented and posted for review in
a separate patch.
[0] http://lists.llvm.org/pipermail/llvm-dev/2015-July/088103.html
[1] https://bugs.llvm.org/show_bug.cgi?id=965
[2] http://lists.llvm.org/pipermail/llvm-dev/2017-October/118632.html
Differential Revision: https://reviews.llvm.org/D38336
llvm-svn: 317729
Summary:
This makes it very easy to test files that only differ in a constant
value somewhere in the test case.
Reviewers: jlebar, hfinkel, chandlerc, probinson
Reviewed By: probinson
Subscribers: probinson, llvm-commits
Differential Revision: https://reviews.llvm.org/D39629
llvm-svn: 317572
This document contains information on how to cross-compile the compiler-rt
builtins library for several flavours of Arm target and how to test the
libraries using qemu.
Differential Revision: https://reviews.llvm.org/D39600
llvm-svn: 317554
As discussed on llvm-dev:
http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html
and again more recently:
http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html
...this is a step in cleaning up our fast-math-flags implementation in IR to better match
the capabilities of both clang's user-visible flags and the backend's flags for SDNode.
As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the
'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic
reassociation - 'AllowReassoc'.
We're also adding a bit to allow approximations for library functions called 'ApproxFunc'
(this was initially proposed as 'libm' or similar).
...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did
look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits),
but that's apparently already used for other purposes. Also, I don't think we can just
add a field to FPMathOperator because Operator is not intended to be instantiated.
We'll defer movement of FMF to another day.
We keep the 'fast' keyword. I thought about removing that, but seeing IR like this:
%f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2
...made me think we want to keep the shortcut synonym.
Finally, this change is binary incompatible with existing IR as seen in the
compatibility tests. This statement:
"Newer releases can ignore features from older releases, but they cannot miscompile
them. For example, if nsw is ever replaced with something else, dropping it would be
a valid way to upgrade the IR."
( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility )
...provides the flexibility we want to make this change without requiring a new IR
version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will
fail to optimize some previously 'fast' code because it's no longer recognized as
'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'.
Note: an inter-dependent clang commit to use the new API name should closely follow
commit.
Differential Revision: https://reviews.llvm.org/D39304
llvm-svn: 317488
It is currently not possible to build the documentation with cmake and
the same version of Sphinx (1.5.1) used to generate the public facing
documentation on llvm.org. When code blocks cannot be parsed by
Pygments, it generates a warning which is treated as an error.
In addition to being annoying and confusing for developers, this
needlessly increases the bar for newcomers that want to get involved.
This patch removes the language specifier from the affected block. The
result is the same as when parsing fails: the block are not highlighted.
llvm-svn: 317472
Summary:
Currently the block frequency analysis is an approximation for irreducible
loops.
The new irreducible loop metadata is used to annotate the irreducible loop
headers with their header weights based on the PGO profile (currently this is
approximated to be evenly weighted) and to help improve the accuracy of the
block frequency analysis for irreducible loops.
This patch is a basic support for this.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: mehdi_amini, llvm-commits, eraman
Differential Revision: https://reviews.llvm.org/D39028
llvm-svn: 317278
The LLVM tools can be used as a replacement for binutils, in which case
it's convenient to create symlinks with the binutils names. Add support
for these symlinks in the build system. As with any other llvm tool
symlinks, the user can limit the installed symlinks by only adding the
desired ones to `LLVM_TOOLCHAIN_TOOLS`.
Differential Revision: https://reviews.llvm.org/D39530
llvm-svn: 317272
Identifies kernels which performs device side kernel enqueues and emit
metadata for the associated hidden kernel arguments. Such kernels are
marked with calls-enqueue-kernel function attribute by
AMDGPUOpenCLEnqueueKernelLowering pass and later on
hidden kernel arguments metadata HiddenDefaultQueue and
HiddenCompletionAction are emitted for them.
Differential Revision: https://reviews.llvm.org/D39255
llvm-svn: 316907
Currently we do not represent runtime preemption in the IR, which has several
drawbacks:
1) The semantics of GlobalValues differ depending on the object file format
you are targeting (as well as the relocation-model and -fPIE value).
2) We have no way of disabling inlining of run time interposable functions,
since in the IR we only know if a function is link-time interposable.
Because of this llvm cannot support elf-interposition semantics.
3) In LTO builds of executables we will have extra knowledge that a symbol
resolved to a local definition and can't be preemptable, but have no way to
propagate that knowledge through the compiler.
This patch adds preemptability specifiers to the IR with the following meaning:
dso_local --> means the compiler may assume the symbol will resolve to a
definition within the current linkage unit and the symbol may be accessed
directly even if the definition is not within this compilation unit.
dso_preemptable --> means that the compiler must assume the GlobalValue may be
replaced with a definition from outside the current linkage unit at runtime.
To ease transitioning dso_preemptable is treated as a 'default' in that
low-level codegen will still do the same checks it did previously to see if a
symbol should be accessed indirectly. Eventually when IR producers emit the
specifiers on all Globalvalues we can change dso_preemptable to mean 'always
access indirectly', and remove the current logic.
Differential Revision: https://reviews.llvm.org/D20217
llvm-svn: 316668
Summary:
When describing trunc/zext/sext/ptrtoint/inttoptr in the chapter
about Constant Expressions we now simply refer to the Instruction
Reference. As far as I know there are no difference when it comes
to the semantics and the argument constraints. The only difference
is that the syntax is slighly different for the constant expressions,
regarding the use of parenthesis in constant expressions.
Referring to the Instruction Reference is the same solution as
already used for several other operations, such as bitcast.
The main goal was to add information that vector types are allowed
also in trunc/zext/sext/ptrtoint/inttoptr constant expressions.
That was not explicitly mentioned earlier, and resulted in some
questions in the review of https://reviews.llvm.org/D38546
Reviewers: efriedma, majnemer
Reviewed By: efriedma
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39165
llvm-svn: 316429
Summary:
Updated the XRayExample docs with instructions for using the llvm-xray stacks
command.
Reviewers: dberris
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D39106
llvm-svn: 316192
This patch adds a new kind of metadata that indicates the possible callees of
indirect calls.
Differential Revision: https://reviews.llvm.org/D37354
llvm-svn: 315944
static __global int Var = 0;
__global int* Ptr[] = {&Var};
...
In this case Var is a non premptable symbol and so its address can be used as the value of Ptr, with a base relative relocation that will add the delta between the ELF address and the actual load address. Such relocations do not require a symbol.
Differential Revision: https://reviews.llvm.org/D38909
llvm-svn: 315935
- Update docs to match llvm coding style
- Add missing FP16_OVFL bit for gfx9
- Fix the size of the kernel descriptor in the docs
Differential Revision: https://reviews.llvm.org/D38902
llvm-svn: 315822
This refers to a temporary path that can be shared across all tests,
identified by a particular label. This can be used for things like
caches.
At the moment, the character set for the LABEL is limited to C
identifier characters, plus '-', '+', '=', and '.'. This is the same
set of characters currently allowed in REQUIRES clause identifiers.
llvm-svn: 315697
Brian Gesiak