Lit as it exists today has three hacks that allow users to run tests earlier:
1) An entire test suite can set the `is_early` boolean.
2) A very recently introduced "early_tests" feature.
3) The `--incremental` flag forces failing tests to run first.
All of these approaches have problems.
1) The `is_early` feature was until very recently undocumented. Nevertheless it still lacks testing and is a imprecise way of optimizing test starting times.
2) The `early_tests` feature requires manual updates and doesn't scale.
3) `--incremental` is undocumented, untested, and it requires modifying the *source* file system by "touching" the file. This "touch" based approach is arguably a hack because it confuses editors (because it looks like the test was modified behind the back of the editor) and "touching" the test source file doesn't work if the test suite is read only from the perspective of `lit` (via advanced filesystem/build tricks).
This patch attempts to simplify and address all of the above problems.
This patch formalizes, documents, tests, and defaults lit to recording the execution time of tests and then reordering all tests during the next execution. By reordering the tests, high core count machines run faster, sometimes significantly so.
This patch also always runs failing tests first, which is a positive user experience win for those that didn't know about the hidden `--incremental` flag.
Finally, if users want, they can _optionally_ commit the test timing data (or a subset thereof) back to the repository to accelerate bots and first-time runs of the test suite.
Reviewed By: jhenderson, yln
Differential Revision: https://reviews.llvm.org/D98179
Add printf-style alternate form flag to prefix hex number with 0x when
present. This works on both empty numeric expression (e.g. variable
definition from input) and when matching a numeric expression. The
syntax is as follows:
[[#%#<precision specifier><format specifier>, ...]
where <precision specifier> and <format specifier> are optional and ...
can be a variable definition or not with an empty expression or not.
This feature was requested in https://reviews.llvm.org/D81144#2075532
for llvm/test/MC/ELF/gen-dwarf64.s
Reviewed By: jdenny
Differential Revision: https://reviews.llvm.org/D97845
Recently we improved the lowering of low overhead loops and tail
predicated loops, but concentrated first on the DLS do style loops. This
extends those improvements over to the WLS while loops, improving the
chance of lowering them successfully. To do this the lowering has to
change a little as the instructions are terminators that produce a value
- something that needs to be treated carefully.
Lowering starts at the Hardware Loop pass, inserting a new
llvm.test.start.loop.iterations that produces both an i1 to control the
loop entry and an i32 similar to the llvm.start.loop.iterations
intrinsic added for do loops. This feeds into the loop phi, properly
gluing the values together:
%wls = call { i32, i1 } @llvm.test.start.loop.iterations.i32(i32 %div)
%wls0 = extractvalue { i32, i1 } %wls, 0
%wls1 = extractvalue { i32, i1 } %wls, 1
br i1 %wls1, label %loop.ph, label %loop.exit
...
loop:
%lsr.iv = phi i32 [ %wls0, %loop.ph ], [ %iv.next, %loop ]
..
%iv.next = call i32 @llvm.loop.decrement.reg.i32(i32 %lsr.iv, i32 1)
%cmp = icmp ne i32 %iv.next, 0
br i1 %cmp, label %loop, label %loop.exit
The llvm.test.start.loop.iterations need to be lowered through ISel
lowering as a pair of WLS and WLSSETUP nodes, which each get converted
to t2WhileLoopSetup and t2WhileLoopStart Pseudos. This helps prevent
t2WhileLoopStart from being a terminator that produces a value,
something difficult to control at that stage in the pipeline. Instead
the t2WhileLoopSetup produces the value of LR (essentially acting as a
lr = subs rn, 0), t2WhileLoopStart consumes that lr value (the Bcc).
These are then converted into a single t2WhileLoopStartLR at the same
point as t2DoLoopStartTP and t2LoopEndDec. Otherwise we revert the loop
to prevent them from progressing further in the pipeline. The
t2WhileLoopStartLR is a single instruction that takes a GPR and produces
LR, similar to the WLS instruction.
%1:gprlr = t2WhileLoopStartLR %0:rgpr, %bb.3
t2B %bb.1
...
bb.2.loop:
%2:gprlr = PHI %1:gprlr, %bb.1, %3:gprlr, %bb.2
...
%3:gprlr = t2LoopEndDec %2:gprlr, %bb.2
t2B %bb.3
The t2WhileLoopStartLR can then be treated similar to the other low
overhead loop pseudos, eventually being lowered to a WLS providing the
branches are within range.
Differential Revision: https://reviews.llvm.org/D97729
Demonstrate how to generate vadd/vfadd intrinsic functions
1. add -gen-riscv-vector-builtins for clang builtins.
2. add -gen-riscv-vector-builtin-codegen for clang codegen.
3. add -gen-riscv-vector-header for riscv_vector.h. It also generates
ifdef directives with extension checking, base on D94403.
4. add -gen-riscv-vector-generic-header for riscv_vector_generic.h.
Generate overloading version Header for generic api.
https://github.com/riscv/rvv-intrinsic-doc/blob/master/rvv-intrinsic-rfc.md#c11-generic-interface
5. update tblgen doc for riscv related options.
riscv_vector.td also defines some unused type transformers for vadd,
because I think it could demonstrate how tranfer type work and we need
them for the whole intrinsic functions implementation in the future.
Authored-by: Roger Ferrer Ibanez <rofirrim@gmail.com>
Co-Authored-by: Zakk Chen <zakk.chen@sifive.com>
Reviewed By: jrtc27, craig.topper, HsiangKai, Jim, Paul-C-Anagnostopoulos
Differential Revision: https://reviews.llvm.org/D95016
It is good to have a combined `divrem` instruction when the
`div` and `rem` are computed from identical input operands.
Some targets can lower them through a single expansion that
computes both division and remainder. It effectively reduces
the number of instructions than individually expanding them.
Reviewed By: arsenm, paquette
Differential Revision: https://reviews.llvm.org/D96013
This patch introduces a new intrinsic @llvm.experimental.vector.splice
that constructs a vector of the same type as the two input vectors,
based on a immediate where the sign of the immediate distinguishes two
variants. A positive immediate specifies an index into the first vector
and a negative immediate specifies the number of trailing elements to
extract from the first vector.
For example:
@llvm.experimental.vector.splice(<A,B,C,D>, <E,F,G,H>, 1) ==> <B, C, D, E> ; index
@llvm.experimental.vector.splice(<A,B,C,D>, <E,F,G,H>, -3) ==> <B, C, D, E> ; trailing element count
These intrinsics support both fixed and scalable vectors, where the
former is lowered to a shufflevector to maintain existing behaviour,
although while marked as experimental the recommended way to express
this operation for fixed-width vectors is to use shufflevector. For
scalable vectors where it is not possible to express a shufflevector
mask for this operation, a new ISD node has been implemented.
This is one of the named shufflevector intrinsics proposed on the
mailing-list in the RFC at [1].
Patch by Paul Walker and Cullen Rhodes.
[1] https://lists.llvm.org/pipermail/llvm-dev/2020-November/146864.html
Reviewed By: sdesmalen
Differential Revision: https://reviews.llvm.org/D94708
This diff introduces --keep-undefined in llvm-objcopy/llvm-strip for Mach-O
which makes the tools preserve undefined symbols.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D97040
This is a minor patch that addresses concerns about lifetime in D94002.
We need to mention that what's written in LangRef isn't everything about lifetime.start/end
and its semantics depends on the stack coloring algorithm's pattern matching of a stack pointer.
If the stack coloring algorithm cannot conclude that a pointer is a stack-allocated object, the pointer is conservatively
considered as a non-stack one because stack coloring won't take this lifetime into account while assigning addresses.
A reference from alloca to lifetime.start/end is added as well.
Differential Revision: https://reviews.llvm.org/D98112
This is a basic How-To that describes:
- What Windows Itanium is.
- How to assemble a build environment.
Differential Revision: https://reviews.llvm.org/D89518
This is a basic How-To that describes:
- What Windows Itanium is.
- How to assemble a build environment.
Differential Revision: https://reviews.llvm.org/D89518
Clarify that the base type endianity is used when creating implicit
location storage.
Remove duplicate definition of the generic type.
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D98137
In "DWARF Extensions For Heterogeneous Debugging" document that the
DWARF generic type has a target architecture defined endianity.
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D98126
This patch adds a new metadata node, DIArgList, which contains a list of SSA
values. This node is in many ways similar in function to the existing
ValueAsMetadata node, with the difference being that it tracks a list instead of
a single value. Internally, it uses ValueAsMetadata to track the individual
values, but there is also a reasonable amount of DIArgList-specific
value-tracking logic on top of that. Similar to ValueAsMetadata, it is a special
case in parsing and printing due to the fact that it requires a function state
(as it may reference function-local values).
This patch should not result in any immediate functional change; it allows for
DIArgLists to be parsed and printed, but debug variable intrinsics do not yet
recognize them as a valid argument (outside of parsing).
Differential Revision: https://reviews.llvm.org/D88175
Rewrites test to use correct architecture triple; fixes incorrect
reference in SourceLevelDebugging doc; simplifies `spillReg` behaviour
so as to not be dependent on changes elsewhere in the patch stack.
This reverts commit d2000b45d0.
explicitly emitting retainRV or claimRV calls in the IR
This reapplies ed4718eccb, which was reverted
because it was causing a miscompile. The bug that was causing the miscompile
has been fixed in 75805dce5f.
Original commit message:
Background:
This fixes a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.
https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue
What this patch does to fix the problem:
- The front-end adds operand bundle "clang.arc.attachedcall" to calls,
which indicates the call is implicitly followed by a marker
instruction and an implicit retainRV/claimRV call that consumes the
call result. In addition, it emits a call to
@llvm.objc.clang.arc.noop.use, which consumes the call result, to
prevent the middle-end passes from changing the return type of the
called function. This is currently done only when the target is arm64
and the optimization level is higher than -O0.
- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
with the operand bundle in the IR and removes the inserted calls after
processing the function.
- ARC contract pass emits retainRV/claimRV calls after the call with the
operand bundle. It doesn't remove the operand bundle on the call since
the backend needs it to emit the marker instruction. The retainRV and
claimRV calls are emitted late in the pipeline to prevent optimization
passes from transforming the IR in a way that makes it harder for the
ARC middle-end passes to figure out the def-use relationship between
the call and the retainRV/claimRV calls (which is the cause of
PR31925).
- The function inliner removes an autoreleaseRV call in the callee if
nothing in the callee prevents it from being paired up with the
retainRV/claimRV call in the caller. It then inserts a release call if
claimRV is attached to the call since autoreleaseRV+claimRV is
equivalent to a release. If it cannot find an autoreleaseRV call, it
tries to transfer the operand bundle to a function call in the callee.
This is important since the ARC optimizer can remove the autoreleaseRV
returning the callee result, which makes it impossible to pair it up
with the retainRV/claimRV call in the caller. If that fails, it simply
emits a retain call in the IR if retainRV is attached to the call and
does nothing if claimRV is attached to it.
- SCCP refrains from replacing the return value of a call with a
constant value if the call has the operand bundle. This ensures the
call always has at least one user (the call to
@llvm.objc.clang.arc.noop.use).
- This patch also fixes a bug in replaceUsesOfNonProtoConstant where
multiple operand bundles of the same kind were being added to a call.
Future work:
- Use the operand bundle on x86-64.
- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
calls with the operand bundles.
rdar://71443534
Differential Revision: https://reviews.llvm.org/D92808
This patch adds a new instruction that can represent variadic debug values,
DBG_VALUE_VAR. This patch alone covers the addition of the instruction and a set
of basic code changes in MachineInstr and a few adjacent areas, but does not
correctly handle variadic debug values outside of these areas, nor does it
generate them at any point.
The new instruction is similar to the existing DBG_VALUE instruction, with the
following differences: the operands are in a different order, any number of
values may be used in the instruction following the Variable and Expression
operands (these are referred to in code as “debug operands”) and are indexed
from 0 so that getDebugOperand(X) == getOperand(X+2), and the Expression in a
DBG_VALUE_VAR must use the DW_OP_LLVM_arg operator to pass arguments into the
expression.
The new DW_OP_LLVM_arg operator is only valid in expressions appearing in a
DBG_VALUE_VAR; it takes a single argument and pushes the debug operand at the
index given by the argument onto the Expression stack. For example the
sub-expression `DW_OP_LLVM_arg, 0` has the meaning “Push the debug operand at
index 0 onto the expression stack.”
Differential Revision: https://reviews.llvm.org/D82363
This patch adds a pipeline to support in-order CPUs such as ARM
Cortex-A55.
In-order pipeline implements a simplified version of Dispatch,
Scheduler and Execute stages as a single stage. Entry and Retire
stages are common for both in-order and out-of-order pipelines.
Differential Revision: https://reviews.llvm.org/D94928
The help text and documentation for the --discard-all option failed to
mention that the option also causes the removal of debug sections. This
change fixes both for both llvm-objcopy and llvm-strip.
Reviewed by: MaskRay
Differential Revision: https://reviews.llvm.org/D97662
This patch is an update to LangRef by describing lifetime intrinsics' behavior
by following the description of MIR's LIFETIME_START/LIFETIME_END markers
at StackColoring.cpp (eb44682d67/llvm/lib/CodeGen/StackColoring.cpp (L163)) and the discussion in llvm-dev.
In order to explicitly define the meaning of an object lifetime, I added 'Object Lifetime' subsection.
Reviewed By: nlopes
Differential Revision: https://reviews.llvm.org/D94002
See pr46990(https://bugs.llvm.org/show_bug.cgi?id=46990). LICM should not sink store instructions to loop exit blocks which cross coro.suspend intrinsics. This breaks semantic of coro.suspend intrinsic which return to caller directly. Also this leads to use-after-free if the coroutine is freed before control returns to the caller in multithread environment.
This patch disable promotion by check whether loop contains coro.suspend intrinsics.
This is a resubmit of D86190.
Disabling LICM for loops with coroutine suspension is a better option not only for correctness purpose but also for performance purpose.
In most cases LICM sinks memory operations. In the case of coroutine, sinking memory operation out of the loop does not improve performance since coroutien needs to get data from the frame anyway. In fact LICM would hurt coroutine performance since it adds more entries to the frame.
Differential Revision: https://reviews.llvm.org/D96928
This caused miscompiles of Chromium tests for iOS due clobbering of live
registers. See discussion on the code review for details.
> Background:
>
> This fixes a longstanding problem where llvm breaks ARC's autorelease
> optimization (see the link below) by separating calls from the marker
> instructions or retainRV/claimRV calls. The backend changes are in
> https://reviews.llvm.org/D92569.
>
> https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue
>
> What this patch does to fix the problem:
>
> - The front-end adds operand bundle "clang.arc.attachedcall" to calls,
> which indicates the call is implicitly followed by a marker
> instruction and an implicit retainRV/claimRV call that consumes the
> call result. In addition, it emits a call to
> @llvm.objc.clang.arc.noop.use, which consumes the call result, to
> prevent the middle-end passes from changing the return type of the
> called function. This is currently done only when the target is arm64
> and the optimization level is higher than -O0.
>
> - ARC optimizer temporarily emits retainRV/claimRV calls after the calls
> with the operand bundle in the IR and removes the inserted calls after
> processing the function.
>
> - ARC contract pass emits retainRV/claimRV calls after the call with the
> operand bundle. It doesn't remove the operand bundle on the call since
> the backend needs it to emit the marker instruction. The retainRV and
> claimRV calls are emitted late in the pipeline to prevent optimization
> passes from transforming the IR in a way that makes it harder for the
> ARC middle-end passes to figure out the def-use relationship between
> the call and the retainRV/claimRV calls (which is the cause of
> PR31925).
>
> - The function inliner removes an autoreleaseRV call in the callee if
> nothing in the callee prevents it from being paired up with the
> retainRV/claimRV call in the caller. It then inserts a release call if
> claimRV is attached to the call since autoreleaseRV+claimRV is
> equivalent to a release. If it cannot find an autoreleaseRV call, it
> tries to transfer the operand bundle to a function call in the callee.
> This is important since the ARC optimizer can remove the autoreleaseRV
> returning the callee result, which makes it impossible to pair it up
> with the retainRV/claimRV call in the caller. If that fails, it simply
> emits a retain call in the IR if retainRV is attached to the call and
> does nothing if claimRV is attached to it.
>
> - SCCP refrains from replacing the return value of a call with a
> constant value if the call has the operand bundle. This ensures the
> call always has at least one user (the call to
> @llvm.objc.clang.arc.noop.use).
>
> - This patch also fixes a bug in replaceUsesOfNonProtoConstant where
> multiple operand bundles of the same kind were being added to a call.
>
> Future work:
>
> - Use the operand bundle on x86-64.
>
> - Fix the auto upgrader to convert call+retainRV/claimRV pairs into
> calls with the operand bundles.
>
> rdar://71443534
>
> Differential Revision: https://reviews.llvm.org/D92808
This reverts commit ed4718eccb.
Document the default for the XNACK and SRAMECC target features for code object V2-V3 and V4.
Reviewed By: kzhuravl
Differential Revision: https://reviews.llvm.org/D97598
And clarify in the "writing a pass" docs that both the legacy and new
PMs are being used for the codegen/optimization pipelines.
Reviewed By: ychen, asbirlea
Differential Revision: https://reviews.llvm.org/D97515
This document was originally introduced in ab4648504b, and was reverted in
912bc4980e while I investigated a number of shpinx bot errors. This commit
reintroduces the document with fixes for those errors, as well as some
improvements to the wording and formatting.
For some build configurations, `check-all` calls lit multiple times to
run multiple lit test suites. Most recently, I've found this to be
true when configuring openmp as part of `LLVM_ENABLE_RUNTIMES`, but
this is not the first time.
If one test suite fails, none of the remaining test suites run, so you
cannot determine if your patch has broken them. It can then be
frustrating to try to determine which `check-` targets will run the
remaining tests without getting stuck on the failing tests.
When such cases arise, it is probably best to adjust the cmake
configuration for `check-all` to run all test suites as part of one
lit invocation. Because that fix will likely not be implemented and
land immediately, this patch introduces `--ignore-fail` to serve as a
workaround for developers trying to see test results until it does
land:
```
$ LIT_OPTS=--ignore-fail ninja check-all
```
One problem with `--ignore-fail` is that it makes it challenging to
detect test failures in a script, perhaps in CI. This problem should
serve as motivation to actually fix the cmake configuration instead of
continuing to use `--ignore-fail` indefinitely.
Reviewed By: jhenderson, thopre
Differential Revision: https://reviews.llvm.org/D96371
Vaivaswatha Nagaraj