1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
//===-- Benchmark memory specific tools -----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "LibcMemoryBenchmark.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include <algorithm>
namespace llvm {
namespace libc_benchmarks {
// Returns a distribution that samples the buffer to satisfy the required
// alignment.
// When alignment is set, the distribution is scaled down by `Factor` and scaled
// up again by the same amount during sampling.
static std::uniform_int_distribution<uint32_t>
getOffsetDistribution(size_t BufferSize, size_t MaxSizeValue,
MaybeAlign AccessAlignment) {
if (AccessAlignment && *AccessAlignment > AlignedBuffer::Alignment)
report_fatal_error(
"AccessAlignment must be less or equal to AlignedBuffer::Alignment");
if (!AccessAlignment)
return std::uniform_int_distribution<uint32_t>(0, 0); // Always 0.
// If we test up to Size bytes, the returned offset must stay under
// BuffersSize - Size.
int64_t MaxOffset = BufferSize;
MaxOffset -= MaxSizeValue;
MaxOffset -= 1;
if (MaxOffset < 0)
report_fatal_error(
"BufferSize too small to exercise specified Size configuration");
MaxOffset /= AccessAlignment->value();
return std::uniform_int_distribution<uint32_t>(0, MaxOffset);
}
OffsetDistribution::OffsetDistribution(size_t BufferSize, size_t MaxSizeValue,
MaybeAlign AccessAlignment)
: Distribution(
getOffsetDistribution(BufferSize, MaxSizeValue, AccessAlignment)),
Factor(AccessAlignment.valueOrOne().value()) {}
// Precomputes offset where to insert mismatches between the two buffers.
MismatchOffsetDistribution::MismatchOffsetDistribution(size_t BufferSize,
size_t MaxSizeValue,
size_t MismatchAt)
: MismatchAt(MismatchAt) {
if (MismatchAt <= 1)
return;
for (size_t I = MaxSizeValue + 1; I < BufferSize; I += MaxSizeValue)
MismatchIndices.push_back(I);
if (MismatchIndices.empty())
report_fatal_error("Unable to generate mismatch");
MismatchIndexSelector =
std::uniform_int_distribution<size_t>(0, MismatchIndices.size() - 1);
}
} // namespace libc_benchmarks
} // namespace llvm
|
