Summary:
Whole Wavefront Wode (WWM) is similar to WQM, except that all of the
lanes are always enabled, regardless of control flow. This is required
for implementing wavefront reductions in non-uniform control flow, where
we need to use the inactive lanes to propagate intermediate results, so
they need to be enabled. We need to propagate WWM to uses (unless
they're explicitly marked as exact) so that they also propagate
intermediate results correctly. We do the analysis and exec mask munging
during the WQM pass, since there are interactions with WQM for things
that require both WQM and WWM. For simplicity, WWM is entirely
block-local -- blocks are never WWM on entry or exit of a block, and WWM
is not propagated to the block level. This means that computations
involving WWM cannot involve control flow, but we only ever plan to use
WWM for a few limited purposes (none of which involve control flow)
anyways.
Shaders can ask for WWM using the @llvm.amdgcn.wwm intrinsic. There
isn't yet a way to turn WWM off -- that will be added in a future
change.
Finally, it turns out that turning on inactive lanes causes a number of
problems with register allocation. While the best long-term solution
seems like teaching LLVM's register allocator about predication, for now
we need to add some hacks to prevent ourselves from getting into trouble
due to constraints that aren't currently expressed in LLVM. For the gory
details, see the comments at the top of SIFixWWMLiveness.cpp.
Reviewers: arsenm, nhaehnle, tpr
Subscribers: kzhuravl, wdng, mgorny, yaxunl, dstuttard, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D35524
llvm-svn: 310087
Summary:
Right now, the WQM pass conflates two different things when tracking the
Needs of an instruction:
1. Needs can be StateWQM, which is propagated to other instructions, and
means that this instruction (and everything it depends on) must be
calculated in WQM.
2. Needs can be StateExact, which is not propagated to other
instructions, and means that this instruction must not be calculated in
WQM and WQM-ness must not be propagated past this instruction.
This works now because there are only two different states, but in the
future we want to be able to express things like "calculate this in WQM,
but please disable WWM and don't propagate it" (to implement
@llvm.amdgcn.set.inactive). In order to do this, we need to split the
per-instruction Needs field in two: a new Needs field, which can only
contain StateWQM (and in the future, StateWWM) and is propagated to
sources, and a Disables field, which can also contain just StateWQM or
nothing for now.
We keep the per-block tracking the same for now, by translating
Needs/Disables to the old representation with only StateWQM or
StateExact. The other place that needs special handling is when we
emit the state transitions. We could just translate back to the old
representation there as well, which we almost do, but instead of 0 as a
placeholder value for "any state," we explicitly or together all the
states an instruction is allowed to be in. This lets us refactor the
code in preparation for WWM, where we'll need to be able to handle
things like "this instruction must be in Exact or WQM, but not WWM."
Reviewers: arsenm, nhaehnle, tpr
Subscribers: kzhuravl, wdng, yaxunl, dstuttard, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D35523
llvm-svn: 310086
Summary:
Previously, we assumed that certain types of instructions needed WQM in
pixel shaders, particularly DS instructions and image sampling
instructions. This was ok because with OpenGL, the assumption was
correct. But we want to start using DPP instructions for derivatives as
well as other things, so the assumption that we can infer whether to use
WQM based on the instruction won't continue to hold. This intrinsic lets
frontends like Mesa indicate what things need WQM based on their
knowledge of the API, rather than second-guessing them in the backend.
We need to keep around the old method of enabling WQM, but eventually we
should remove it once Mesa catches up. For now, this will let us use DPP
instructions for computing derivatives correctly.
Reviewers: arsenm, tpr, nhaehnle
Subscribers: kzhuravl, wdng, yaxunl, dstuttard, llvm-commits, t-tye
Differential Revision: https://reviews.llvm.org/D35167
llvm-svn: 310085
Summary:
It was added to support clang warnings about includes with case
mismatches, but it ended up not being necessary.
Reviewers: twoh, rafael
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D36328
llvm-svn: 310078
This revision ports all libFuzzer tests apart from the unittest to LIT.
The advantages of doing so include:
- Tests being self-contained
- Much easier debugging of a single test
- No need for using a two-stage compilation
The unit-test is still compiled using CMake, but it does not need a
freshly built compiler.
NOTE: The previous two-stage bot configuration will NOT work, as in the
second stage build LLVM_USE_SANITIZER is set, which disables ASAN from
being built.
Thus bots will be reconfigured in the next few commits.
Differential Revision: https://reviews.llvm.org/D36295
llvm-svn: 310075
This is a continuation of https://reviews.llvm.org/D36219
This patch uses reverse mapping (encoding->name) in
ARMInstPrinter::printBankedRegOperand to get rid of
hard-coded values (as pointed out by @olista01).
Reviewed by: @fhahn, @rovka, @olista01
Differential Revision: https://reviews.llvm.org/D36260
llvm-svn: 310072
The frontend may have requested a higher alignment for any reason, and
downstream optimizations may already have taken advantage of it. We
should keep the same alignment when moving the allocation from the
parameter area to the local variable area.
Fixes PR34038
llvm-svn: 310071
Summary: We originally set the hotness threshold as 99.9% to be consistent with gcc FDO. But because the inline heuristic is different between 2 compilers: llvm uses bottom-up algorithm while gcc uses priority based. The LLVM algorithm tends to inline too much early that prevents hot callsites from further inlined into its caller. Due to this restriction, we think it is reasonable to lower the hotness threshold to give priority to those that are really hot. Our experiments show that this change would improve performance on large applications. Note that the inline heuristic has great room for further tuning. Once the inline heuristics are refined, we could adjust this threshold to allow inlining for less hot callsites.
Reviewers: davidxl, tejohnson, eraman
Reviewed By: tejohnson
Subscribers: sanjoy, llvm-commits
Differential Revision: https://reviews.llvm.org/D36317
llvm-svn: 310065
Summary:
The (not (sext)) case is really (xor (sext), -1) which should have been simplified to (sext (xor, 1)) before we got here. So we shouldn't need to handle it.
With that taken care of we only need to two cases so don't need the swap anymore. This makes us in sync with the equivalent code in visitOr so inline this to match.
Reviewers: spatel, eli.friedman, majnemer
Reviewed By: spatel
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D36240
llvm-svn: 310063
Adds function attributes to index: ReadNone, ReadOnly, NoRecurse, NoAlias. This attributes will be used for future ThinLTO optimizations that will propagate function attributes across modules.
llvm-svn: 310061
Name: narrow_shift
Pre: C1 < 8
%zx = zext i8 %x to i32
%l = lshr i32 %zx, C1
=>
%narrowC = trunc i32 C1 to i8
%ns = lshr i8 %x, %narrowC
%l = zext i8 %ns to i32
http://rise4fun.com/Alive/jIV
This isn't directly applicable to PR34046 as written, but we
need to have more narrowing folds like this to be sure that
rotate patterns are recognized.
llvm-svn: 310060
If all the operands of a BUILD_VECTOR extract elements from same vector then split the vector efficiently based on the maximum vector access index.
Committed on behalf of @jbhateja (Jatin Bhateja)
Differential Revision: https://reviews.llvm.org/D35788
llvm-svn: 310058
Summary:
This fixes PR31777.
If both stores' values are ConstantInt, we merge the two stores
(shifting the smaller store appropriately) and replace the earlier (and
larger) store with an updated constant.
In the future we should also support vectors of integers. And maybe
float/double if we can.
Reviewers: hfinkel, junbuml, jfb, RKSimon, bkramer
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30703
llvm-svn: 310055
Summary:
This commit allows matchSelectPattern to recognize clamp of float
arguments in the presence of FMF the same way as already done for
integers.
This case is a little different though. With integers, given the
min/max pattern is recognized, DAGBuilder starts selecting MIN/MAX
"automatically". That is not the case for float, because for them only
full FMINNAN/FMINNUM/FMAXNAN/FMAXNUM ISD nodes exist and they do care
about NaNs. On the other hand, some backends (e.g. X86) have only
FMIN/FMAX nodes that do not care about NaNS and the former NAN/NUM
nodes are illegal thus selection is not happening. So I decided to do
such kind of transformation in IR (InstCombiner) instead of
complicating the logic in the backend.
Reviewers: spatel, jmolloy, majnemer, efriedma, craig.topper
Reviewed By: efriedma
Subscribers: hiraditya, javed.absar, n.bozhenov, llvm-commits
Patch by Andrei Elovikov <andrei.elovikov@intel.com>
Differential Revision: https://reviews.llvm.org/D33186
llvm-svn: 310054
Summary:
- add more tests
- pr27236.ll: rename %tmpN -> %N because otherwise a FileCheck
variable for newly appeared unnamed value would use the same name as
tmpN (as generated by update_test_checks.py)
- run update_test_checks.py
Reviewers: efriedma
Reviewed By: efriedma
Subscribers: n.bozhenov, llvm-commits
Patch by Andrei Elovikov <andrei.elovikov@intel.com>
Differential Revision: https://reviews.llvm.org/D35002
llvm-svn: 310053
Error was:
field of type 'llvm::ArgDescriptor' has private default constructor
const AMDGPUFunctionArgInfo AMDGPUArgumentUsageInfo::ExternFunctionInfo{};
^
llvm-svn: 310048
Author: milena.vujosevic.janicic
The patch extends size reduction pass for MicroMIPS.
The following instructions are examined and transformed, if possible:
ADDIU instruction is transformed into 16-bit instruction ADDIUSP
ADDIU instruction is transformed into 16-bit instruction ADDIUR1SP
Usage of u_int64_t replaced by uint64_t to avoid issues because of which previous patch version was reverted:
Differential Revision: https://reviews.llvm.org/D34511
llvm-svn: 310044
Summary: When polly is linked into the tools because of the LLVM_POLLY_LINK_INTO_TOOLS option being set, we need to register its passes with the PassBuilder. Because polly is linked in, we can directly call its callback registration method, which registers the appropriate callbacks with the new PM's PassBuilder. This essentially follows exactly the way it worked with the legacy PM.
Reviewers: grosser, chandlerc, bollu
Reviewed By: grosser
Subscribers: pollydev, llvm-commits
Differential Revision: https://reviews.llvm.org/D36273
llvm-svn: 310043
In case if SI_KILL is in between of the SI_IF and SI_END_CF we need
to preserve the bits actually flipped by if rather then restoring
the original mask.
Differential Revision: https://reviews.llvm.org/D36299
llvm-svn: 310031
This change adds the "-O binary" flag which directs llvm-objcopy to
output the object file to the same format as GNU objcopy does when given
the flag "-O binary". This was done by splitting the Object class into
two subclasses ObjectELF and ObjectBianry which each output a different
format but relay on the same code to read in the Object in Object.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D34480
llvm-svn: 310018
The full story is in the comments:
// Do not attempt to close stdout or stderr. We used to try to maintain the
// property that tools that support writing file to stdout should not also
// write informational output to stdout, but in practice we were never able to
// maintain this invariant. Many features have been added to LLVM and clang
// (-fdump-record-layouts, optimization remarks, etc) that print to stdout, so
// users must simply be aware that mixed output and remarks is a possibility.
NFC, I am just updating comments to reflect reality.
llvm-svn: 310016
This is similar to what we are doing in "regular" SROA and creates
DW_OP_LLVM_fragment operations to describe the resulting variables.
rdar://problem/33654891
llvm-svn: 310014
Summary:
Following the docs, we need at least 5 wait states between an EXEC write
and an instruction that uses DPP.
Reviewers: tstellar, arsenm
Subscribers: kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, llvm-commits
Differential Revision: https://reviews.llvm.org/D34849
llvm-svn: 310013
This patch makes a slight change to the way llvm-cov determines line
execution counts. If there are multiple line segments on a line, the
line count is the max count among the regions which start *and* end on
the line. This avoids an issue posed by deferred regions which start on
the same line as a terminated region, e.g:
if (false)
return; //< The line count should be 0, even though a new region
//< starts at the semi-colon.
foo();
Another change is that counts from line segments which don't correspond
to region entries are considered. This enables the first change, and
corrects an outstanding issue (see the showLineExecutionCounts.cpp test
change).
This is related to D35925.
Testing: check-profile, llvm-cov lit tests
Differential Revision: https://reviews.llvm.org/D36014
llvm-svn: 310012
Summary:
Detect when the working set size of a profiled application is huge,
by comparing the number of counts required to reach the hot percentile
in the profile summary to a large threshold*.
When the working set size is determined to be huge, disable peeling
to avoid bloating the working set further.
*Note that the selected threshold (15K) is significantly larger than the
largest working set value in SPEC cpu2006 (which is gcc at around 11K).
Reviewers: davidxl
Subscribers: mehdi_amini, mzolotukhin, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D36288
llvm-svn: 310005
Connor Abbott