If we have:
bb5:
br i1 %arg3, label %bb6, label %bb7
bb6:
%tmp = getelementptr inbounds i32, i32* %arg1, i64 2
store i32 3, i32* %tmp, align 4
br label %bb9
bb7:
%tmp8 = getelementptr inbounds i32, i32* %arg1, i64 2
store i32 3, i32* %tmp8, align 4
br label %bb9
bb9: ; preds = %bb4, %bb6, %bb7
...
We can't sink stores directly into bb9.
This patch creates new BB that is successor of %bb6 and %bb7
and sinks stores into that block.
SplitFooterBB is the parameter to the pass that controls
that behavior.
Change-Id: I7fdf50a772b84633e4b1b860e905bf7e3e29940f
Differential: https://reviews.llvm.org/D66234
llvm-svn: 371089
Summary:
Avoid visiting an instruction more than once by using a map.
This is similar to https://reviews.llvm.org/rL361416.
Reviewers: davidxl
Reviewed By: davidxl
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67198
llvm-svn: 371086
Summary:
Instead of building attributes for internal functions which we do not
update as long as we assume they are dead, we now do not create
attributes until we assume the internal function to be live. This
improves the number of required iterations, as well as the number of
required updates, in real code. On our tests, the results are mixed.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66914
llvm-svn: 370924
Summary:
We create attributes on-demand so we need to check the white list
on-demand. This also unifies the location at which we create,
initialize, and eventually invalidate new abstract attributes.
The tests show mixed results, a few more call site attributes are
determined which can cause more iterations.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66913
llvm-svn: 370922
Summary:
Before we tried to rule out non-exact definitions early but that lead to
on-demand attributes created for them anyway. As a consequence we needed
to look at the definition in the initialize of each attribute again.
This patch centralized this lookup and tightens the condition under
which we give up on non-exact definitions.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67115
llvm-svn: 370917
SROA pass processes debug info incorrecly if applied twice.
Specifically, after SROA works first time, instcombine converts dbg.declare
intrinsics into dbg.value. Inlining creates new opportunities for SROA,
so it is called again. This time it does not handle correctly previously
inserted dbg.value intrinsics.
Differential Revision: https://reviews.llvm.org/D64595
llvm-svn: 370906
Add the no-capture argument attribute deduction to the Attributor
fixpoint framework.
The new string attributed "no-capture-maybe-returned" is introduced to
allow deduction of no-capture through functions that "capture" an
argument but only by "returning" it. It is only used by the Attributor
for testing.
Differential Revision: https://reviews.llvm.org/D59922
llvm-svn: 370817
This extends the existing logic for propagating constant expressions in an analogous manner for what we do across basic blocks. The core point is that we chose some order of operands, and canonicalize uses towards that one.
The heuristic used is inspired by the one used across blocks; in a follow up change, I'd plan to common them so that the cross block version uses the slightly stronger ordering herein.
As noted by the TODOs in the code, there's a good amount of room for improving the existing code and making it more powerful. Some follow up work planned.
Differential Revision: https://reviews.llvm.org/D66977
llvm-svn: 370791
Summary:
Fold-tail currently supports reduction last-vector-value live-out's,
but has yet to support last-scalar-value live-outs, including
non-header phi's. As it relies on AllowedExit in order to detect
them and bail out we need to add the non-header PHI nodes to
AllowedExit, otherwise we end up with miscompiles.
Solves https://bugs.llvm.org/show_bug.cgi?id=43166
Reviewers: fhahn, Ayal
Reviewed By: fhahn, Ayal
Subscribers: anna, hiraditya, rkruppe, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67074
llvm-svn: 370721
bitcast <N x i8> (shuf X, undef, <N, N-1,...0>) to i{N*8} --> bswap (bitcast X to i{N*8})
In PR43146:
https://bugs.llvm.org/show_bug.cgi?id=43146
...we have a more complicated case where SLP is making a mess of bswap. This patch won't
do anything for that currently, but we need to improve bswap recognition in instcombine,
SLP, and/or a standalone pass to avoid that problem.
This is limited using the data-layout so we don't try to do this transform with actual
vector types. The backend does not appear to have folds to convert in either direction,
so we don't want to mess up something that is actually better lowered as a shuffle.
On x86, we're trading something like this:
vmovd %edi, %xmm0
vpshufb LCPI0_0(%rip), %xmm0, %xmm0 ## xmm0 = xmm0[3,2,1,0,u,u,u,u,u,u,u,u,u,u,u,u]
vmovd %xmm0, %eax
For:
movl %edi, %eax
bswapl %eax
Differential Revision: https://reviews.llvm.org/D66965
llvm-svn: 370659
Summary:
Back-end currently expands mempcpy, but middle-end should work with memcpy instead of mempcpy to enable more memcpy-optimization.
GCC backend emits mempcpy, so LLVM backend could form it too, if we know mempcpy libcall is better than memcpy + n.
https://godbolt.org/z/dOCG96
Reviewers: efriedma, spatel, craig.topper, RKSimon, jdoerfert
Reviewed By: efriedma
Subscribers: hjl.tools, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65737
llvm-svn: 370593
Use a { iN undef, i1 false } struct as the base, and only insert
the first operand, instead of using { iN undef, i1 undef } as the
base and inserting both. This is the same as what we do in InstCombine.
Differential Revision: https://reviews.llvm.org/D67034
llvm-svn: 370573
cold versus function being newly added.
This is the second half of https://reviews.llvm.org/D66374.
Profile symbol list is the collection of function symbols showing up in
the binary which generates the current profile. It is used to discriminate
function being cold versus function being newly added. Profile symbol list
is only added for profile with ExtBinary format.
During profile use compilation, when profile-sample-accurate is enabled,
a function without profile will be regarded as cold only when it is
contained in that list.
Differential Revision: https://reviews.llvm.org/D66766
llvm-svn: 370563
This is an updated version of https://reviews.llvm.org/D66909 to fix PR42605.
Basically, current phi translatation translates an old value number to an new
value number for a call instruction based on the literal equality of call
expression, without verifying there is no clobber in between. This is incorrect.
To get a finegrain check, use MachineDependence analysis to do the job. However,
this is still not ideal. Although given a call instruction,
`MemoryDependenceResults::getCallDependencyFrom` returns identical call
instructions without clobber in between using MemDepResult with its DepType to
be `Def`. However, identical is too strict here and we want it to be relaxed a
little to consider phi-translation -- callee is the same, param operands can be
different. That means changing the semantic of `MemDepResult::Def` and I don't
know the potential impact.
So currently the patch is still conservative to only handle
MemDepResult::NonFuncLocal, which means the current call has no function local
clobber. If there is clobber, even if the clobber doesn't stand in between the
current call and the call with the new value, we won't do phi-translate.
Differential Revision: https://reviews.llvm.org/D67013
llvm-svn: 370547
Summary:
Instead of recomputing information for call sites we now use the
function information directly. This is always valid and once we have
call site specific information we can improve here.
This patch also bootstraps attributes that are created on-demand through
an initial update call. Information that is known will then directly be
available in the new attribute without causing an iteration delay.
The tests show how this improves the iteration count.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66781
llvm-svn: 370480
Summary:
Any pointer could have load/store users not only floating ones so we
move the manifest logic for alignment into the AAAlignImpl class.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66922
llvm-svn: 370479
Summary:
@mclow.lists brought up this issue up in IRC.
It is a reasonably common problem to compare some two values for equality.
Those may be just some integers, strings or arrays of integers.
In C, there is `memcmp()`, `bcmp()` functions.
In C++, there exists `std::equal()` algorithm.
One can also write that function manually.
libstdc++'s `std::equal()` is specialized to directly call `memcmp()` for
various types, but not `std::byte` from C++2a. https://godbolt.org/z/mx2ejJ
libc++ does not do anything like that, it simply relies on simple C++'s
`operator==()`. https://godbolt.org/z/er0Zwf (GOOD!)
So likely, there exists a certain performance opportunities.
Let's compare performance of naive `std::equal()` (no `memcmp()`) with one that
is using `memcmp()` (in this case, compiled with modified compiler). {F8768213}
```
#include <algorithm>
#include <cmath>
#include <cstdint>
#include <iterator>
#include <limits>
#include <random>
#include <type_traits>
#include <utility>
#include <vector>
#include "benchmark/benchmark.h"
template <class T>
bool equal(T* a, T* a_end, T* b) noexcept {
for (; a != a_end; ++a, ++b) {
if (*a != *b) return false;
}
return true;
}
template <typename T>
std::vector<T> getVectorOfRandomNumbers(size_t count) {
std::random_device rd;
std::mt19937 gen(rd());
std::uniform_int_distribution<T> dis(std::numeric_limits<T>::min(),
std::numeric_limits<T>::max());
std::vector<T> v;
v.reserve(count);
std::generate_n(std::back_inserter(v), count,
[&dis, &gen]() { return dis(gen); });
assert(v.size() == count);
return v;
}
struct Identical {
template <typename T>
static std::pair<std::vector<T>, std::vector<T>> Gen(size_t count) {
auto Tmp = getVectorOfRandomNumbers<T>(count);
return std::make_pair(Tmp, std::move(Tmp));
}
};
struct InequalHalfway {
template <typename T>
static std::pair<std::vector<T>, std::vector<T>> Gen(size_t count) {
auto V0 = getVectorOfRandomNumbers<T>(count);
auto V1 = V0;
V1[V1.size() / size_t(2)]++; // just change the value.
return std::make_pair(std::move(V0), std::move(V1));
}
};
template <class T, class Gen>
void BM_bcmp(benchmark::State& state) {
const size_t Length = state.range(0);
const std::pair<std::vector<T>, std::vector<T>> Data =
Gen::template Gen<T>(Length);
const std::vector<T>& a = Data.first;
const std::vector<T>& b = Data.second;
assert(a.size() == Length && b.size() == a.size());
benchmark::ClobberMemory();
benchmark::DoNotOptimize(a);
benchmark::DoNotOptimize(a.data());
benchmark::DoNotOptimize(b);
benchmark::DoNotOptimize(b.data());
for (auto _ : state) {
const bool is_equal = equal(a.data(), a.data() + a.size(), b.data());
benchmark::DoNotOptimize(is_equal);
}
state.SetComplexityN(Length);
state.counters["eltcnt"] =
benchmark::Counter(Length, benchmark::Counter::kIsIterationInvariant);
state.counters["eltcnt/sec"] =
benchmark::Counter(Length, benchmark::Counter::kIsIterationInvariantRate);
const size_t BytesRead = 2 * sizeof(T) * Length;
state.counters["bytes_read/iteration"] =
benchmark::Counter(BytesRead, benchmark::Counter::kDefaults,
benchmark::Counter::OneK::kIs1024);
state.counters["bytes_read/sec"] = benchmark::Counter(
BytesRead, benchmark::Counter::kIsIterationInvariantRate,
benchmark::Counter::OneK::kIs1024);
}
template <typename T>
static void CustomArguments(benchmark::internal::Benchmark* b) {
const size_t L2SizeBytes = []() {
for (const benchmark::CPUInfo::CacheInfo& I :
benchmark::CPUInfo::Get().caches) {
if (I.level == 2) return I.size;
}
return 0;
}();
// What is the largest range we can check to always fit within given L2 cache?
const size_t MaxLen = L2SizeBytes / /*total bufs*/ 2 /
/*maximal elt size*/ sizeof(T) / /*safety margin*/ 2;
b->RangeMultiplier(2)->Range(1, MaxLen)->Complexity(benchmark::oN);
}
BENCHMARK_TEMPLATE(BM_bcmp, uint8_t, Identical)
->Apply(CustomArguments<uint8_t>);
BENCHMARK_TEMPLATE(BM_bcmp, uint16_t, Identical)
->Apply(CustomArguments<uint16_t>);
BENCHMARK_TEMPLATE(BM_bcmp, uint32_t, Identical)
->Apply(CustomArguments<uint32_t>);
BENCHMARK_TEMPLATE(BM_bcmp, uint64_t, Identical)
->Apply(CustomArguments<uint64_t>);
BENCHMARK_TEMPLATE(BM_bcmp, uint8_t, InequalHalfway)
->Apply(CustomArguments<uint8_t>);
BENCHMARK_TEMPLATE(BM_bcmp, uint16_t, InequalHalfway)
->Apply(CustomArguments<uint16_t>);
BENCHMARK_TEMPLATE(BM_bcmp, uint32_t, InequalHalfway)
->Apply(CustomArguments<uint32_t>);
BENCHMARK_TEMPLATE(BM_bcmp, uint64_t, InequalHalfway)
->Apply(CustomArguments<uint64_t>);
```
{F8768210}
```
$ ~/src/googlebenchmark/tools/compare.py --no-utest benchmarks build-{old,new}/test/llvm-bcmp-bench
RUNNING: build-old/test/llvm-bcmp-bench --benchmark_out=/tmp/tmpb6PEUx
2019-04-25 21:17:11
Running build-old/test/llvm-bcmp-bench
Run on (8 X 4000 MHz CPU s)
CPU Caches:
L1 Data 16K (x8)
L1 Instruction 64K (x4)
L2 Unified 2048K (x4)
L3 Unified 8192K (x1)
Load Average: 0.65, 3.90, 4.14
---------------------------------------------------------------------------------------------------
Benchmark Time CPU Iterations UserCounters...
---------------------------------------------------------------------------------------------------
<...>
BM_bcmp<uint8_t, Identical>/512000 432131 ns 432101 ns 1613 bytes_read/iteration=1000k bytes_read/sec=2.20706G/s eltcnt=825.856M eltcnt/sec=1.18491G/s
BM_bcmp<uint8_t, Identical>_BigO 0.86 N 0.86 N
BM_bcmp<uint8_t, Identical>_RMS 8 % 8 %
<...>
BM_bcmp<uint16_t, Identical>/256000 161408 ns 161409 ns 4027 bytes_read/iteration=1000k bytes_read/sec=5.90843G/s eltcnt=1030.91M eltcnt/sec=1.58603G/s
BM_bcmp<uint16_t, Identical>_BigO 0.67 N 0.67 N
BM_bcmp<uint16_t, Identical>_RMS 25 % 25 %
<...>
BM_bcmp<uint32_t, Identical>/128000 81497 ns 81488 ns 8415 bytes_read/iteration=1000k bytes_read/sec=11.7032G/s eltcnt=1077.12M eltcnt/sec=1.57078G/s
BM_bcmp<uint32_t, Identical>_BigO 0.71 N 0.71 N
BM_bcmp<uint32_t, Identical>_RMS 42 % 42 %
<...>
BM_bcmp<uint64_t, Identical>/64000 50138 ns 50138 ns 10909 bytes_read/iteration=1000k bytes_read/sec=19.0209G/s eltcnt=698.176M eltcnt/sec=1.27647G/s
BM_bcmp<uint64_t, Identical>_BigO 0.84 N 0.84 N
BM_bcmp<uint64_t, Identical>_RMS 27 % 27 %
<...>
BM_bcmp<uint8_t, InequalHalfway>/512000 192405 ns 192392 ns 3638 bytes_read/iteration=1000k bytes_read/sec=4.95694G/s eltcnt=1.86266G eltcnt/sec=2.66124G/s
BM_bcmp<uint8_t, InequalHalfway>_BigO 0.38 N 0.38 N
BM_bcmp<uint8_t, InequalHalfway>_RMS 3 % 3 %
<...>
BM_bcmp<uint16_t, InequalHalfway>/256000 127858 ns 127860 ns 5477 bytes_read/iteration=1000k bytes_read/sec=7.45873G/s eltcnt=1.40211G eltcnt/sec=2.00219G/s
BM_bcmp<uint16_t, InequalHalfway>_BigO 0.50 N 0.50 N
BM_bcmp<uint16_t, InequalHalfway>_RMS 0 % 0 %
<...>
BM_bcmp<uint32_t, InequalHalfway>/128000 49140 ns 49140 ns 14281 bytes_read/iteration=1000k bytes_read/sec=19.4072G/s eltcnt=1.82797G eltcnt/sec=2.60478G/s
BM_bcmp<uint32_t, InequalHalfway>_BigO 0.40 N 0.40 N
BM_bcmp<uint32_t, InequalHalfway>_RMS 18 % 18 %
<...>
BM_bcmp<uint64_t, InequalHalfway>/64000 32101 ns 32099 ns 21786 bytes_read/iteration=1000k bytes_read/sec=29.7101G/s eltcnt=1.3943G eltcnt/sec=1.99381G/s
BM_bcmp<uint64_t, InequalHalfway>_BigO 0.50 N 0.50 N
BM_bcmp<uint64_t, InequalHalfway>_RMS 1 % 1 %
RUNNING: build-new/test/llvm-bcmp-bench --benchmark_out=/tmp/tmpQ46PP0
2019-04-25 21:19:29
Running build-new/test/llvm-bcmp-bench
Run on (8 X 4000 MHz CPU s)
CPU Caches:
L1 Data 16K (x8)
L1 Instruction 64K (x4)
L2 Unified 2048K (x4)
L3 Unified 8192K (x1)
Load Average: 1.01, 2.85, 3.71
---------------------------------------------------------------------------------------------------
Benchmark Time CPU Iterations UserCounters...
---------------------------------------------------------------------------------------------------
<...>
BM_bcmp<uint8_t, Identical>/512000 18593 ns 18590 ns 37565 bytes_read/iteration=1000k bytes_read/sec=51.2991G/s eltcnt=19.2333G eltcnt/sec=27.541G/s
BM_bcmp<uint8_t, Identical>_BigO 0.04 N 0.04 N
BM_bcmp<uint8_t, Identical>_RMS 37 % 37 %
<...>
BM_bcmp<uint16_t, Identical>/256000 18950 ns 18948 ns 37223 bytes_read/iteration=1000k bytes_read/sec=50.3324G/s eltcnt=9.52909G eltcnt/sec=13.511G/s
BM_bcmp<uint16_t, Identical>_BigO 0.08 N 0.08 N
BM_bcmp<uint16_t, Identical>_RMS 34 % 34 %
<...>
BM_bcmp<uint32_t, Identical>/128000 18627 ns 18627 ns 37895 bytes_read/iteration=1000k bytes_read/sec=51.198G/s eltcnt=4.85056G eltcnt/sec=6.87168G/s
BM_bcmp<uint32_t, Identical>_BigO 0.16 N 0.16 N
BM_bcmp<uint32_t, Identical>_RMS 35 % 35 %
<...>
BM_bcmp<uint64_t, Identical>/64000 18855 ns 18855 ns 37458 bytes_read/iteration=1000k bytes_read/sec=50.5791G/s eltcnt=2.39731G eltcnt/sec=3.3943G/s
BM_bcmp<uint64_t, Identical>_BigO 0.32 N 0.32 N
BM_bcmp<uint64_t, Identical>_RMS 33 % 33 %
<...>
BM_bcmp<uint8_t, InequalHalfway>/512000 9570 ns 9569 ns 73500 bytes_read/iteration=1000k bytes_read/sec=99.6601G/s eltcnt=37.632G eltcnt/sec=53.5046G/s
BM_bcmp<uint8_t, InequalHalfway>_BigO 0.02 N 0.02 N
BM_bcmp<uint8_t, InequalHalfway>_RMS 29 % 29 %
<...>
BM_bcmp<uint16_t, InequalHalfway>/256000 9547 ns 9547 ns 74343 bytes_read/iteration=1000k bytes_read/sec=99.8971G/s eltcnt=19.0318G eltcnt/sec=26.8159G/s
BM_bcmp<uint16_t, InequalHalfway>_BigO 0.04 N 0.04 N
BM_bcmp<uint16_t, InequalHalfway>_RMS 29 % 29 %
<...>
BM_bcmp<uint32_t, InequalHalfway>/128000 9396 ns 9394 ns 73521 bytes_read/iteration=1000k bytes_read/sec=101.518G/s eltcnt=9.41069G eltcnt/sec=13.6255G/s
BM_bcmp<uint32_t, InequalHalfway>_BigO 0.08 N 0.08 N
BM_bcmp<uint32_t, InequalHalfway>_RMS 30 % 30 %
<...>
BM_bcmp<uint64_t, InequalHalfway>/64000 9499 ns 9498 ns 73802 bytes_read/iteration=1000k bytes_read/sec=100.405G/s eltcnt=4.72333G eltcnt/sec=6.73808G/s
BM_bcmp<uint64_t, InequalHalfway>_BigO 0.16 N 0.16 N
BM_bcmp<uint64_t, InequalHalfway>_RMS 28 % 28 %
Comparing build-old/test/llvm-bcmp-bench to build-new/test/llvm-bcmp-bench
Benchmark Time CPU Time Old Time New CPU Old CPU New
---------------------------------------------------------------------------------------------------------------------------------------
<...>
BM_bcmp<uint8_t, Identical>/512000 -0.9570 -0.9570 432131 18593 432101 18590
<...>
BM_bcmp<uint16_t, Identical>/256000 -0.8826 -0.8826 161408 18950 161409 18948
<...>
BM_bcmp<uint32_t, Identical>/128000 -0.7714 -0.7714 81497 18627 81488 18627
<...>
BM_bcmp<uint64_t, Identical>/64000 -0.6239 -0.6239 50138 18855 50138 18855
<...>
BM_bcmp<uint8_t, InequalHalfway>/512000 -0.9503 -0.9503 192405 9570 192392 9569
<...>
BM_bcmp<uint16_t, InequalHalfway>/256000 -0.9253 -0.9253 127858 9547 127860 9547
<...>
BM_bcmp<uint32_t, InequalHalfway>/128000 -0.8088 -0.8088 49140 9396 49140 9394
<...>
BM_bcmp<uint64_t, InequalHalfway>/64000 -0.7041 -0.7041 32101 9499 32099 9498
```
What can we tell from the benchmark?
* Performance of naive equality check somewhat improves with element size,
maxing out at eltcnt/sec=1.58603G/s for uint16_t, or bytes_read/sec=19.0209G/s
for uint64_t. I think, that instability implies performance problems.
* Performance of `memcmp()`-aware benchmark always maxes out at around
bytes_read/sec=51.2991G/s for every type. That is 2.6x the throughput of the
naive variant!
* eltcnt/sec metric for the `memcmp()`-aware benchmark maxes out at
eltcnt/sec=27.541G/s for uint8_t (was: eltcnt/sec=1.18491G/s, so 24x) and
linearly decreases with element size.
For uint64_t, it's ~4x+ the elements/second.
* The call obvious is more pricey than the loop, with small element count.
As it can be seen from the full output {F8768210}, the `memcmp()` is almost
universally worse, independent of the element size (and thus buffer size) when
element count is less than 8.
So all in all, bcmp idiom does indeed pose untapped performance headroom.
This diff does implement said idiom recognition. I think a reasonable test
coverage is present, but do tell if there is anything obvious missing.
Now, quality. This does succeed to build and pass the test-suite, at least
without any non-bundled elements. {F8768216} {F8768217}
This transform fires 91 times:
```
$ /build/test-suite/utils/compare.py -m loop-idiom.NumBCmp result-new.json
Tests: 1149
Metric: loop-idiom.NumBCmp
Program result-new
MultiSourc...Benchmarks/7zip/7zip-benchmark 79.00
MultiSource/Applications/d/make_dparser 3.00
SingleSource/UnitTests/vla 2.00
MultiSource/Applications/Burg/burg 1.00
MultiSourc.../Applications/JM/lencod/lencod 1.00
MultiSource/Applications/lemon/lemon 1.00
MultiSource/Benchmarks/Bullet/bullet 1.00
MultiSourc...e/Benchmarks/MallocBench/gs/gs 1.00
MultiSourc...gs-C/TimberWolfMC/timberwolfmc 1.00
MultiSourc...Prolangs-C/simulator/simulator 1.00
```
The size changes are:
I'm not sure what's going on with SingleSource/UnitTests/vla.test yet, did not look.
```
$ /build/test-suite/utils/compare.py -m size..text result-{old,new}.json --filter-hash
Tests: 1149
Same hash: 907 (filtered out)
Remaining: 242
Metric: size..text
Program result-old result-new diff
test-suite...ingleSource/UnitTests/vla.test 753.00 833.00 10.6%
test-suite...marks/7zip/7zip-benchmark.test 1001697.00 966657.00 -3.5%
test-suite...ngs-C/simulator/simulator.test 32369.00 32321.00 -0.1%
test-suite...plications/d/make_dparser.test 89585.00 89505.00 -0.1%
test-suite...ce/Applications/Burg/burg.test 40817.00 40785.00 -0.1%
test-suite.../Applications/lemon/lemon.test 47281.00 47249.00 -0.1%
test-suite...TimberWolfMC/timberwolfmc.test 250065.00 250113.00 0.0%
test-suite...chmarks/MallocBench/gs/gs.test 149889.00 149873.00 -0.0%
test-suite...ications/JM/lencod/lencod.test 769585.00 769569.00 -0.0%
test-suite.../Benchmarks/Bullet/bullet.test 770049.00 770049.00 0.0%
test-suite...HMARK_ANISTROPIC_DIFFUSION/128 NaN NaN nan%
test-suite...HMARK_ANISTROPIC_DIFFUSION/256 NaN NaN nan%
test-suite...CHMARK_ANISTROPIC_DIFFUSION/64 NaN NaN nan%
test-suite...CHMARK_ANISTROPIC_DIFFUSION/32 NaN NaN nan%
test-suite...ENCHMARK_BILATERAL_FILTER/64/4 NaN NaN nan%
Geomean difference nan%
result-old result-new diff
count 1.000000e+01 10.00000 10.000000
mean 3.152090e+05 311695.40000 0.006749
std 3.790398e+05 372091.42232 0.036605
min 7.530000e+02 833.00000 -0.034981
25% 4.243300e+04 42401.00000 -0.000866
50% 1.197370e+05 119689.00000 -0.000392
75% 6.397050e+05 639705.00000 -0.000005
max 1.001697e+06 966657.00000 0.106242
```
I don't have timings though.
And now to the code. The basic idea is to completely replace the whole loop.
If we can't fully kill it, don't transform.
I have left one or two comments in the code, so hopefully it can be understood.
Also, there is a few TODO's that i have left for follow-ups:
* widening of `memcmp()`/`bcmp()`
* step smaller than the comparison size
* Metadata propagation
* more than two blocks as long as there is still a single backedge?
* ???
Reviewers: reames, fhahn, mkazantsev, chandlerc, craig.topper, courbet
Reviewed By: courbet
Subscribers: hiraditya, xbolva00, nikic, jfb, gchatelet, courbet, llvm-commits, mclow.lists
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61144
llvm-svn: 370454
Summary:
- Similar to the workaround in fix of PR30188, skip sinking common
lifetime markers of `alloca`. They are mostly left there after
inlining functions in branches.
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66950
llvm-svn: 370376
This is the naive implementation of x86 BZHI/BEXTR instruction:
it takes input and bit count, and extracts low nbits up to bit width.
I.e. unlike shift it does not have any UB when nbits >= bitwidth.
Which means we don't need a while PHI here, simple select will do.
And if it's a select, it should then be trivial to fix codegen
to select it to BEXTR/BZHI.
See https://bugs.llvm.org/show_bug.cgi?id=34704
llvm-svn: 370369
Summary:
Now that with D65143/D65144 we've produce `@llvm.umul.with.overflow`,
and with D65147 we've flattened the CFG, we now can see that
the guard may have been there to prevent division by zero is redundant.
We can simply drop it:
```
----------------------------------------
Name: no overflow or zero
%iszero = icmp eq i4 %y, 0
%umul = smul_overflow i4 %x, %y
%umul.ov = extractvalue {i4, i1} %umul, 1
%umul.ov.not = xor %umul.ov, -1
%retval.0 = or i1 %iszero, %umul.ov.not
ret i1 %retval.0
=>
%iszero = icmp eq i4 %y, 0
%umul = smul_overflow i4 %x, %y
%umul.ov = extractvalue {i4, i1} %umul, 1
%umul.ov.not = xor %umul.ov, -1
%retval.0 = or i1 %iszero, %umul.ov.not
ret i1 %umul.ov.not
Done: 1
Optimization is correct!
```
Note that this is inverted from what we have in a previous patch,
here we are looking for the inverted overflow bit.
And that inversion is kinda problematic - given this particular
pattern we neither hoist that `not` closer to `ret` (then the pattern
would have been identical to the one without inversion,
and would have been handled by the previous patch), neither
do the opposite transform. But regardless, we should handle this too.
I've filled [[ https://bugs.llvm.org/show_bug.cgi?id=42720 | PR42720 ]].
Reviewers: nikic, spatel, xbolva00, RKSimon
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65151
llvm-svn: 370351
Summary:
Now that with D65143/D65144 we've produce `@llvm.umul.with.overflow`,
and with D65147 we've flattened the CFG, we now can see that
the guard may have been there to prevent division by zero is redundant.
We can simply drop it:
```
----------------------------------------
Name: no overflow and not zero
%iszero = icmp ne i4 %y, 0
%umul = umul_overflow i4 %x, %y
%umul.ov = extractvalue {i4, i1} %umul, 1
%retval.0 = and i1 %iszero, %umul.ov
ret i1 %retval.0
=>
%iszero = icmp ne i4 %y, 0
%umul = umul_overflow i4 %x, %y
%umul.ov = extractvalue {i4, i1} %umul, 1
%retval.0 = and i1 %iszero, %umul.ov
ret %umul.ov
Done: 1
Optimization is correct!
```
Reviewers: nikic, spatel, xbolva00
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65150
llvm-svn: 370350
Summary:
As it can be seen in the tests in D65143/D65144, even though we have formed an '@llvm.umul.with.overflow'
and got rid of potential for division-by-zero, the control flow remains, we still have that branch.
We have this condition:
```
// Don't fold i1 branches on PHIs which contain binary operators
// These can often be turned into switches and other things.
if (PN->getType()->isIntegerTy(1) &&
(isa<BinaryOperator>(PN->getIncomingValue(0)) ||
isa<BinaryOperator>(PN->getIncomingValue(1)) ||
isa<BinaryOperator>(IfCond)))
return false;
```
which was added back in rL121764 to help with `select` formation i think?
That check prevents us to flatten the CFG here, even though we know
we no longer need that guard and will be able to drop everything
but the '@llvm.umul.with.overflow' + `not`.
As it can be seen from tests, we end here because the `not` is being
sinked into the PHI's incoming values by InstCombine,
so we can't workaround this by hoisting it to after PHI.
Thus i suggest that we relax that check to not bailout if we'd get to hoist the `not`.
Reviewers: craig.topper, spatel, fhahn, nikic
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65147
llvm-svn: 370349
Summary:
Finally, the fold i was looking forward to :)
The legality check is muddy, i doubt i've groked the full generalization,
but it handles all the cases i care about, and can come up with:
https://rise4fun.com/Alive/26j
I.e. we can perform the fold if **any** of the following is true:
* The shift amount is either zero or one less than widest bitwidth
* Either of the values being shifted has at most lowest bit set
* The value that is being shifted by `shl` (which is not truncated) should have no less leading zeros than the total shift amount;
* The value that is being shifted by `lshr` (which **is** truncated) should have no less leading zeros than the widest bit width minus total shift amount minus one
I strongly suspect there is some better generalization, but i'm not aware of it as of right now.
For now i also avoided using actual `computeKnownBits()`, but restricted it to constants.
Reviewers: spatel, nikic, xbolva00
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66383
llvm-svn: 370324
As dependences between abstract attributes can become stale, e.g., if
one was sufficient to imply another one at some point but it has since
been wakened to the point it is not usable for the formerly implied one.
To weed out spurious dependences, and thereby eliminate unneeded
updates, we introduce an option to determine how often the dependence
cache is cleared and recomputed during the fixpoint iteration.
Note that the initial value was determined such that we see a positive
result on our tests.
Differential Revision: https://reviews.llvm.org/D63315
llvm-svn: 370230
Summary:
Until we have proper call-site information we should not recompute
liveness and return information for each call site. This patch directly
uses the function versions and introduces TODOs at the usage sites.
The required iterations to get to the fixpoint are most of the time
reduced by this change and we always avoid work duplication.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66562
llvm-svn: 370208
Allow vectorizing loops that have reductions when tail is folded by masking.
A select is introduced in VPlan, choosing between the last value carried by the
loop-exit/live-out instruction of the reduction, and the penultimate value
carried by the reduction phi, according to the "i < n" mask of fold-tail.
This select replaces the last value as the live-out value of the loop.
Differential Revision: https://reviews.llvm.org/D66720
llvm-svn: 370173
The code we had isSafeToLoadUnconditionally was blatantly wrong. This function takes a "Size" argument which is supposed to describe the span loaded from. Instead, the code use the size of the pointer passed (which may be unrelated!) and only checks that span. For any Size > LoadSize, this can and does lead to miscompiles.
Worse, the generic code just a few lines above correctly handles the cases which *are* valid. So, let's delete said code.
Removing this code revealed two issues:
1) As noted by jdoerfert the removed code incorrectly handled external globals. The test update in SROA is to stop testing incorrect behavior.
2) SROA was confusing bytes and bits, but this wasn't obvious as the Size parameter was being essentially ignored anyway. Fixed.
Differential Revision: https://reviews.llvm.org/D66778
llvm-svn: 370102
Summary:
Try to verify how many iterations we need for a fixpoint in our tests.
This patch adjust the way we count to make it easier to follow. It also
adjusts the bounds to actually account for a fixpoint and not only the
minimum number to pass all checks.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66757
llvm-svn: 369945
By default, the Attributor tracks potential dependences between abstract
attributes based on the issued Attributor::getAAFor queries. This
simplifies the development of new abstract attributes but it can also
lead to spurious dependences that might increase compile time and make
internalization harder (D63312). With this patch, abstract attributes
can opt-out of implicit dependence tracking and instead register
dependences explicitly. It is up to the implementation to make sure all
existing dependences are registered.
Differential Revision: https://reviews.llvm.org/D63314
llvm-svn: 369935
Summary:
When reconstructing the CFG of the loop after unrolling,
LoopUnroll could in some cases remove the phi operands of
loop-carried values instead of preserving them, resulting
in undef phi values after loop unrolling.
When doing this reconstruction, avoid removing incoming
phi values for phis in the successor blocks if the successor
is the block we are jumping to anyway.
Patch-by: ebevhan
Reviewers: fhahn, efriedma
Reviewed By: fhahn
Subscribers: bjope, lebedev.ri, zzheng, dmgreen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66334
llvm-svn: 369886
Summary:
`matchThreeWayIntCompare()` looks for
```
select i1 (a == b),
i32 Equal,
i32 (select i1 (a < b), i32 Less, i32 Greater)
```
but both of these selects/compares can be in it's commuted form,
so out of 8 variants, only the two most basic ones is handled.
This fixes regression being introduced in D66232.
Reviewers: spatel, nikic, efriedma, xbolva00
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66607
llvm-svn: 369841
Summary:
If we have e.g.:
```
%t = icmp ult i32 %x, 65536
%r = select i1 %t, i32 %y, i32 65535
```
the constants `65535` and `65536` are suspiciously close.
We could perform a transformation to deduplicate them:
```
Name: ult
%t = icmp ult i32 %x, 65536
%r = select i1 %t, i32 %y, i32 65535
=>
%t.inv = icmp ugt i32 %x, 65535
%r = select i1 %t.inv, i32 65535, i32 %y
```
https://rise4fun.com/Alive/avb
While this may seem esoteric, this should certainly be good for vectors
(less constant pool usage) and for opt-for-size - need to have only one constant.
But the real fun part here is that it allows further transformation,
in particular it finishes cleaning up the `clamp` folding,
see e.g. `canonicalize-clamp-with-select-of-constant-threshold-pattern.ll`.
We start with e.g.
```
%dont_need_to_clamp_positive = icmp sle i32 %X, 32767
%dont_need_to_clamp_negative = icmp sge i32 %X, -32768
%clamp_limit = select i1 %dont_need_to_clamp_positive, i32 -32768, i32 32767
%dont_need_to_clamp = and i1 %dont_need_to_clamp_positive, %dont_need_to_clamp_negative
%R = select i1 %dont_need_to_clamp, i32 %X, i32 %clamp_limit
```
without this patch we currently produce
```
%1 = icmp slt i32 %X, 32768
%2 = icmp sgt i32 %X, -32768
%3 = select i1 %2, i32 %X, i32 -32768
%R = select i1 %1, i32 %3, i32 32767
```
which isn't really a `clamp` - both comparisons are performed on the original value,
this patch changes it into
```
%1.inv = icmp sgt i32 %X, 32767
%2 = icmp sgt i32 %X, -32768
%3 = select i1 %2, i32 %X, i32 -32768
%R = select i1 %1.inv, i32 32767, i32 %3
```
and then the magic happens! Some further transform finishes polishing it and we finally get:
```
%t1 = icmp sgt i32 %X, -32768
%t2 = select i1 %t1, i32 %X, i32 -32768
%t3 = icmp slt i32 %t2, 32767
%R = select i1 %t3, i32 %t2, i32 32767
```
which is beautiful and just what we want.
Proofs for `getFlippedStrictnessPredicateAndConstant()` for de-canonicalization:
https://rise4fun.com/Alive/THl
Proofs for the fold itself: https://rise4fun.com/Alive/THl
Reviewers: spatel, dmgreen, nikic, xbolva00
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66232
llvm-svn: 369840
Summary:
We can now manifest alignment information in load/store instructions if
the pointer is known to have a better alignment.
Reviewers: uenoku, sstefan1, lebedev.ri
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66567
llvm-svn: 369804
This is a patch split from https://reviews.llvm.org/D66374. It tries to add
a new format of profile called ExtBinary. The format adds a section header
table to the profile and organize the profile in sections, so the future
extension like adding a new section or extending an existing section will be
easier while keeping backward compatiblity feasible.
Differential Revision: https://reviews.llvm.org/D66513
llvm-svn: 369798
Started implementing the vector case and realized the scalar case hadn't handled the GEP producing a different type than the base correctly. It's entertaining seeing what slips through review when we're focused on the 'hard' parts. :(
Also adding an extra vector test as it happened to be in workspace and wasn't worth separating.
llvm-svn: 369795
This generalizes the isGEPKnownNonNull rule from ValueTracking to apply when we do not know if the base is non-null, and thus need to replace one condition with another.
The core notion is that since an inbounds GEP can only form null if the base pointer is null and the offset is zero. However, if the offset is non-zero, the the "inbounds" marker makes the result poison. Thus, we're free to ignore the case where the offset is non-zero. Similarly, there's no case under which a non-null base can result in a null result without generating poison.
Differential Revision: https://reviews.llvm.org/D66608
llvm-svn: 369789
Summary:
If the unique return value is a constant we now replace call uses with
that constant.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66551
llvm-svn: 369785
Summary:
If we have a loop in which the dereferenceability of a pointer decreases
we did slowly decrease it iteration by iteration, leading to a timeout.
With this patch we detect such circular reasoning and indicate a
fixpoint early.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66558
llvm-svn: 369784
Summary:
If we have a negative inbounds offset dereferenceabily "grows". However,
until we do not handle the overflow that can occur in the
dereferenceable bytes and the problem with loops, we simply do not grow
the state.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66557
llvm-svn: 369771
Summary:
When we have new attributes and we end the fixpoint iteration because
the iteration limit is reached, we need to treat the new ones as if they
changed in the last iteration, as they might have.
This adds a test for which we should not derive anything regardless of
the iteration limit, e.g., if we abort there should not be any
attributes manifested in the IR.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66549
llvm-svn: 369768
We were computing the loop exit value, but not ensuring the addrec belonged to the loop whose exit value we were computing. I couldn't actually trip this; the test case shows the basic setup which *might* trip this, but none of the variations I've tried actually do.
llvm-svn: 369730
The alignment is calculated incorrectly, thus sometimes it doesn't generate aligned mov instructions, as shown by the example below:
```
// b.cc
typedef long long index;
extern "C" index g_tid;
extern "C" index g_num;
void add3(float* __restrict__ a, float* __restrict__ b, float* __restrict__ c) {
index n = 64*1024;
index m = 16*1024;
index k = 4*1024;
index tid = g_tid;
index num = g_num;
__builtin_assume_aligned(a, 32);
__builtin_assume_aligned(b, 32);
__builtin_assume_aligned(c, 32);
for (index i0=tid*k; i0<m; i0+=num*k)
for (index i1=0; i1<n*m; i1+=m)
for (index i2=0; i2<k; i2++)
c[i1+i0+i2] = b[i0+i2] + a[i1+i0+i2];
}
```
Compile with `clang b.cc -Ofast -march=skylake -mavx2 -S`
```
vmovaps -224(%rdi,%rbx,4), %ymm0
vmovups -192(%rdi,%rbx,4), %ymm1 # should be movaps
vmovups -160(%rdi,%rbx,4), %ymm2 # should be movaps
vmovups -128(%rdi,%rbx,4), %ymm3 # should be movaps
vaddps -224(%rsi,%rbx,4), %ymm0, %ymm0
vaddps -192(%rsi,%rbx,4), %ymm1, %ymm1
vaddps -160(%rsi,%rbx,4), %ymm2, %ymm2
vaddps -128(%rsi,%rbx,4), %ymm3, %ymm3
vmovaps %ymm0, -224(%rdx,%rbx,4)
vmovups %ymm1, -192(%rdx,%rbx,4) # should be movaps
vmovups %ymm2, -160(%rdx,%rbx,4) # should be movaps
vmovups %ymm3, -128(%rdx,%rbx,4) # should be movaps
```
Differential Revision: https://reviews.llvm.org/D66575
Patch by Dun Liang
llvm-svn: 369723
I noticed another instance of the issue where references to aliases were
being replaced with aliasees, this time in InstCombine. In the instance that
I saw it turned out to be only a QoI issue (a symbol ended up being missing
from the symbol table due to the last reference to the alias being removed,
preventing HWASAN from symbolizing a global reference), but it could easily
have manifested as incorrect behaviour.
Since this is the third such issue encountered (previously: D65118, D65314)
it seems to be time to address this common error/QoI issue once and for all
and make the strip* family of functions not look through aliases.
Includes a test for the specific issue that I saw, but no doubt there are
other similar bugs fixed here.
As with D65118 this has been tested to make sure that the optimization isn't
load bearing. I built Clang, Chromium for Linux, Android and Windows as well
as the test-suite and there were no size regressions.
Differential Revision: https://reviews.llvm.org/D66606
llvm-svn: 369697
Locally the tight iterations bounds work fine but the bots seem unhappy.
Try to get green bots and some time to determine the underlying problem.
llvm-svn: 369592
Summary:
To be able to track how many iterations we need to manifest all
information we check for we now make the maximum iteration count
explicit. The count is set tightly now and should be kept that way.
Reviewers: uenoku, sstefan1
Subscribers: bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66554
llvm-svn: 369586
Currently we do not properly translate addresses with PHIs if LoadBB !=
LI->getParent(), because PHITranslateAddr expects a direct predecessor as argument,
because it considers all instructions outside of the current block to
not requiring translation.
The amount of cases that trigger this should be very low, as most single
predecessor blocks should be folded into their predecessor by GVN before
we actually start with value numbering. It is still not guaranteed to
happen, so we should do PHI translation along all edges between the
loads' block and the predecessor where we have to place a load.
There are a few test cases showing current limits of the PHI translation, which
could be improved later.
Reviewers: spatel, reames, efriedma, john.brawn
Reviewed By: efriedma
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65020
llvm-svn: 369570
Summary:
Add a flag to the FunctionToLoopAdaptor that allows enabling MemorySSA only for the loop pass managers that are known to preserve it.
If an LPM is known to have only loop transforms that *all* preserve MemorySSA, then use MemorySSA if `EnableMSSALoopDependency` is set.
If an LPM has loop passes that do not preserve MemorySSA, then the flag passed is `false`, regardless of the value of `EnableMSSALoopDependency`.
When using a custom loop pass pipeline via `passes=...`, use keyword `loop` vs `loop-mssa` to use MemorySSA in that LPM. If a loop that does not preserve MemorySSA is added while using the `loop-mssa` keyword, that's an error.
Add the new `loop-mssa` keyword to a few tests where a difference occurs when enabling MemorySSA.
Reviewers: chandlerc
Subscribers: mehdi_amini, Prazek, george.burgess.iv, sanjoy.google, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66376
llvm-svn: 369548
An intermediate extend is used to widen the narrow operand to the width of
the other (wider) operand. At that point, we have the same logic as the
existing transform that was restricted to folds of equal width zext/sext.
This mostly solves PR42700:
https://bugs.llvm.org/show_bug.cgi?id=42700
llvm-svn: 369519
For an internal function, if all its call sites are dead, the body of the function is considered dead.
Reviewers: jdoerfert, uenoku
Subscribers: hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D66155
llvm-svn: 369470
Summary:
When the line format is wrong, we may end up accessing out of bound
memory. eg: the test with invalide line will cause assert.
Assertion `idx < size()' failed
The fix is to report fatal when we found mismatched line format.
Reviewers: qcolombet, volkan
Reviewed By: qcolombet
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66444
llvm-svn: 369389
Before, we create the set of abstract attributes initially and then
dealt with the fact hat a lookup could fail, e.g., return a nullptr.
This patch will ensure we always return a valid object from a lookup,
allowing us not only to remove the nullptr checks but also to grow the
set of abstract attributes "in-flight" on-demand.
One can now start from those that have the best chance of improving
performance without the need to specify all they might depend on.
While this introduces some boilerplate, the usage of attributes is much
easier and cleaner now.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66276
llvm-svn: 369331
Summary:
This is analogous to D66128 but for AADereferenceable. We have the logic
concentrated in the floating value updateImpl and we use the combiner
helper classes for arguments and return values.
The regressions will go away with "on-demand" attribute creation.
Improvements are already visible in the existing tests.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66272
llvm-svn: 369329
Summary:
What D66126 did for AAAlign, this patch does for AANonNull. Agian, the
logic becomes more concise and localized. Again, returned poiners are
not annotated properly but that will not be an issue if this lands with
the "on-demand" generation of attributes. First improvements due to the
genericValueTraversal are already visible.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66128
llvm-svn: 369328
This reverts commit 5dbb90bfe1.
As noted in the post-commit thread for r367891, this can create
a multiply that is lowered to a libcall that may not exist.
We need to improve the backend decomposition for integer multiply
before trying to re-land this (if it's still worthwhile after
doing the backend work).
llvm-svn: 369174
If OptimizeExtractBits() encountered a shift instruction with no operands at all,
it would erase the instruction, but still return false.
This previously didn’t matter because its caller would always return after
processing the instruction, but https://reviews.llvm.org/D63233 changed the
function’s caller to fall through if it returned false, which would then cause
a use-after-free detectable by ASAN.
This change makes OptimizeExtractBits return true if it removes a shift
instruction with no users, terminating processing of the instruction.
Patch by: @brentdax (Brent Royal-Gordon)
Differential Revision: https://reviews.llvm.org/D66330
llvm-svn: 369168
Summary:
Before we required the comparison against null to be "canonical", hence
null to be operand #1. This patch allows null to be in either operand,
similar to the handling of loaded globals that follows.
Reviewers: sanjoy, hfinkel, aykevl, sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66321
llvm-svn: 369158
Summary:
This is the first commit aiming to structure the attribute deduction.
The base idea is that we have default propagation patterns as listed
below on top of which we can add specific, e.g., context sensitive,
logic.
Deduction patterns used in this patch:
- argument states are determined from call site argument states,
see AAAlignArgument and AAArgumentFromCallSiteArguments.
- call site argument states are determined as if they were floating
values, see AAAlignCallSiteArgument and AAAlignFloating.
- floating value states are determined by traversing the def-use chain
and combining the states determined for the leaves, see
AAAlignFloating and genericValueTraversal.
- call site return states are determined from function return states,
see AAAlignCallSiteReturned and AACallSiteReturnedFromReturned.
- function return states are determined from returned value states,
see AAAlignReturned and AAReturnedFromReturnedValues.
Through this strategy all logic for alignment is concentrated in the
AAAlignFloating::updateImpl method.
Note: This commit works on its own but is part of a larger change that
involves "on-demand" creation of abstract attributes that will
participate in the fixpoint iteration. Without this part, we sometimes
do not have an AAAlign abstract attribute to query, loosing information
we determined before. All tests have appropriate FIXMEs and the
information will be recovered once we added all parts.
Reviewers: sstefan1, uenoku
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66126
llvm-svn: 369144
This pattern may arise more frequently with an enhancement to SLP vectorization suggested in PR42755:
https://bugs.llvm.org/show_bug.cgi?id=42755
...but we should handle this pattern to make things easier for the backend either way.
For all in-tree targets that I looked at, codegen for typical vector sizes looks better when we change
to a vector select, so this is safe to do without a cost model (in other words, as a target-independent
canonicalization).
For example, if the condition of the select is a scalar, we end up with something like this on x86:
vpcmpgtd %xmm0, %xmm1, %xmm0
vpextrb $12, %xmm0, %eax
testb $1, %al
jne LBB0_2
## %bb.1:
vmovaps %xmm3, %xmm2
LBB0_2:
vmovaps %xmm2, %xmm0
Rather than the splat-condition variant:
vpcmpgtd %xmm0, %xmm1, %xmm0
vpshufd $255, %xmm0, %xmm0 ## xmm0 = xmm0[3,3,3,3]
vblendvps %xmm0, %xmm2, %xmm3, %xmm0
Differential Revision: https://reviews.llvm.org/D66095
llvm-svn: 369140
Summary:
This is continuation of D63829 / https://bugs.llvm.org/show_bug.cgi?id=42399
I thought naive pattern would solve my issue, but nope, it involved truncation,
thus more folds needed.. This isn't really the fold i'm interested in,
i need trunc-of-lshr, but i'we decided to start with `shl` because it's simpler.
In this case, no extra legality checks are needed:
https://rise4fun.com/Alive/CAb
We should be careful about not increasing instruction count,
since we need to produce `zext` because `and` is done in wider type.
Reviewers: spatel, nikic, xbolva00
Reviewed By: spatel
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66057
llvm-svn: 369117
We don't yet know how to generate these instructions for MVE. And in the case
of VLD3, we don't even have the instruction. For the moment don't tell the
vectoriser that we have VLD4, just to end up serialising the results.
Differential Revision: https://reviews.llvm.org/D66009
llvm-svn: 369101
Summary:
Currently we fail to compute known bits for recurrences where the
first incoming value is the start value of the recurrence.
Instead of exiting the loop when the first incoming value is not
the step of the recurrence, continue to check the second incoming
value.
The original code uses a loop to handle both cases, but incorrectly
exits instead of continuing.
Reviewers: lebedev.ri, spatel, nikic
Reviewed By: lebedev.ri
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66216
llvm-svn: 369088
assume_safety implies that loads under "if's" can be safely executed
speculatively (unguarded, unmasked). However this assumption holds only for the
original user "if's", not those introduced by the compiler, such as the
fold-tail "if" that guards us from loading beyond the original loop trip-count.
Currently the combination of fold-tail and assume-safety pragmas results in
ignoring the fold-tail predicate that guards the loads, generating unmasked
loads. This patch fixes this behavior.
Differential Revision: https://reviews.llvm.org/D66106
Reviewers: Ayal, hsaito, fhahn
llvm-svn: 368973
Summary:
Fixes https://bugs.llvm.org/show_bug.cgi?id=36578 and https://bugs.llvm.org/show_bug.cgi?id=36296.
Supersedes: https://reviews.llvm.org/D55966
One of the fundamental transformation that CoroSplit pass performs before splitting the coroutine is to find which values need to survive between suspend and resume and provide a slot for them in the coroutine frame to spill and restore the value as needed.
Coroutine frame becomes available once the storage for it was allocated and that point is marked in the pre-split coroutine with a llvm.coro.begin intrinsic.
FE normally puts all of the user-authored code that would be accessing those values after llvm.coro.begin, however, sometimes instructions accessing those values would end up prior to coro.begin. For example, writing out a value of the parameter into the alloca done by the FE or instructions that are added by the optimization passes such as SROA when it rewrites allocas.
Prior to this change, CoroSplit pass would try to move instructions that may end up accessing the values in the coroutine frame after CoroBegin. However it would run into problems (report_fatal_error) if some of the values would be used both in the allocation function (for example allocator is passed as a parameter to a coroutine) and in the use-authored body of the coroutine.
To handle this case and to simplify the instruction moving logic, this change removes all of the instruction moving. Instead, we only change the uses of the spilled values that are dominated by coro.begin and leave other instructions intact.
Before:
```
%var = alloca i32
%1 = getelementptr .. %var; ; will move this one after coro.begin
%f = call i8* @llvm.coro.begin(
```
After:
```
%var = alloca i32
%1 = getelementptr .. %var; stays put
%f = call i8* @llvm.coro.begin(
```
If we discover that there is a potential write into an alloca, prior to coro.begin we would copy its value from the alloca into the spill slot in the coroutine frame.
Before:
```
%var = alloca i32
store .. %var ; will move this one after coro.begin
%f = call i8* @llvm.coro.begin(
```
After:
```
%var = alloca i32
store .. %var ;stays put
%f = call i8* @llvm.coro.begin(
%tmp = load %var
store %tmp, %spill.slot.for.var
```
Note: This change does not handle array allocas as that is something that C++ FE does not produce, but, it can be added in the future if need arises
Reviewers: llvm-commits, modocache, ben-clayton, tks2103, rjmccall
Reviewed By: modocache
Subscribers: bartdesmet
Differential Revision: https://reviews.llvm.org/D66230
llvm-svn: 368949
Summary:
As one of the first attributes, and one of the complex ones,
AAReturnedValues was not using liveness but we filtered the result after
the fact. This change adds liveness usage during the creation. The
algorithm is also improved and shorter.
The new algorithm will collect returned values over time using the
generic facilities that work with liveness already, e.g.,
genericValueTraversal which does not look at dead PHI node predecessors.
A test to show how this leads to better results is included.
Note: Unresolved calls and resolved calls are now tracked explicitly.
Reviewers: uenoku, sstefan1
Subscribers: hiraditya, bollu, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66120
llvm-svn: 368922
We already supported rewriting loop exit values for multiple exit loops, but if any of the loop exits were not computable, we gave up on all loop exit values. This patch generalizes the existing code to handle individual computable loop exits where possible.
As discussed in the review, this is a starting point for figuring out a better API. The code is a bit ugly, but getting it in lets us test as we go.
Differential Revision: https://reviews.llvm.org/D65544
llvm-svn: 368898
Summary:
We can't speculate around indirect branches: indirectbr and invoke. The
callbr instruction needs to be included here.
Reviewers: nickdesaulniers, manojgupta, chandlerc
Reviewed By: chandlerc
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66200
llvm-svn: 368873
Now that we legalize by widening, the element types here won't change. Previously these were modeled as the elements being widened and then the instruction might become an AND or SHL/ASHR pair. But now they'll become something like a ZERO_EXTEND_VECTOR_INREG/SIGN_EXTEND_VECTOR_INREG.
For AVX2, when the destination type is legal its clear the cost should be 1 since we have extend instructions that can produce 256 bit vectors from less than 128 bit vectors. I'm a little less sure about AVX1 costs, but I think the ones I changed were definitely too high, but they might still be too high.
Differential Revision: https://reviews.llvm.org/D66169
llvm-svn: 368858
This is the compiler-flag equivalent of the Predicate pragma
(https://reviews.llvm.org/D65197), to direct the vectorizer to fold the
remainder-loop into the main-loop using predication.
Differential Revision: https://reviews.llvm.org/D66108
Reviewers: Ayal, hsaito, fhahn, SjoerdMeije
llvm-svn: 368801
The support for swifterror allocas should work in all lowerings.
The support for swifterror arguments only really works in a lowering
with prototypes where you can ensure that the prototype also has a
swifterror argument; I'm not really sure how it could possibly be
made to work in the switch lowering.
llvm-svn: 368795
Roman Lebedev