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8178495: Bug in the align_size_up_ macro

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Reviewed-by: kbarrett, tschatzl, rehn
This commit is contained in:
Stefan Karlsson 2017-04-12 13:05:59 +02:00
parent 1854382c4d
commit 229f386a8f
2 changed files with 157 additions and 3 deletions
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15
hotspot/src/share/vm/utilities/globalDefinitions.hpp
View File

@ -505,7 +505,18 @@ const bool support_IRIW_for_not_multiple_copy_atomic_cpu = false;
// for use in places like enum definitions that require compile-time constant
// expressions and a function for all other places so as to get type checking.
#define align_size_up_(size, alignment) (((size) + ((alignment) - 1)) & ~((alignment) - 1))
// Using '(what) & ~align_mask(alignment)' to align 'what' down is broken when
// 'alignment' is an unsigned int and 'what' is a wider type. The & operation
// will widen the inverted mask, and not sign extend it, leading to a mask with
// zeros in the most significant bits. The use of align_mask_widened() solves
// this problem.
#define align_mask(alignment) ((alignment) - 1)
#define widen_to_type_of(what, type_carrier) (true ? (what) : (type_carrier))
#define align_mask_widened(alignment, type_carrier) widen_to_type_of(align_mask(alignment), (type_carrier))
#define align_size_down_(size, alignment) ((size) & ~align_mask_widened((alignment), (size)))
#define align_size_up_(size, alignment) (align_size_down_((size) + align_mask(alignment), (alignment)))
inline bool is_size_aligned(size_t size, size_t alignment) {
return align_size_up_(size, alignment) == size;
@ -519,8 +530,6 @@ inline intptr_t align_size_up(intptr_t size, intptr_t alignment) {
return align_size_up_(size, alignment);
}
#define align_size_down_(size, alignment) ((size) & ~((alignment) - 1))
inline intptr_t align_size_down(intptr_t size, intptr_t alignment) {
return align_size_down_(size, alignment);
}

145
hotspot/test/native/utilities/test_align.cpp Normal file
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@ -0,0 +1,145 @@
/*
* Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include "precompiled.hpp"
#include "utilities/formatBuffer.hpp"
#include "utilities/globalDefinitions.hpp"
#include "unittest.hpp"
#include <limits>
// A few arbitrarily chosen values to test the align functions on.
static uint64_t values[] = {1, 3, 10, 345, 1023, 1024, 1025, 23909034, INT_MAX, uint64_t(-1) / 2, uint64_t(-1) / 2 + 100, -1 };
template <typename T>
static T max_alignment() {
T max = std::numeric_limits<T>::max();
return max ^ (max >> 1);
}
#define log(...) SCOPED_TRACE(err_msg(__VA_ARGS__).buffer())
template <typename T, typename A>
static void test_alignments() {
log("### Test: %c" SIZE_FORMAT " " UINT64_FORMAT " : %c" SIZE_FORMAT " " UINT64_FORMAT " ###\n",
std::numeric_limits<T>::is_signed ? 's' : 'u', sizeof(T), (uint64_t)std::numeric_limits<T>::max(),
std::numeric_limits<A>::is_signed ? 's' : 'u', sizeof(A), (uint64_t)std::numeric_limits<A>::max());
ASSERT_LE((uint64_t)std::numeric_limits<T>::max(), (uint64_t)std::numeric_limits<intptr_t>::max()) << "The test assumes that casting to intptr_t will not truncate bits";
// Test all possible alignment values that fit in type A.
for (A alignment = max_alignment<A>(); alignment > 0; alignment >>= 1) {
log("=== Alignment: " UINT64_FORMAT " ===\n", (uint64_t)alignment);
for (size_t i = 0; i < ARRAY_SIZE(values); i++) {
log("--- Value: " UINT64_FORMAT "\n", values[i]);
// Test align up
const uint64_t up = align_size_up_(values[i], (uint64_t)alignment);
if (0 < up && up <= (uint64_t)std::numeric_limits<T>::max()) {
log("Testing align_up: alignment: 0x" UINT64_FORMAT_X " value: 0x" UINT64_FORMAT_X " expected: 0x" UINT64_FORMAT_X "\n", (uint64_t)alignment, values[i], up);
T value = T(values[i]);
// Check against uint64_t version
ASSERT_EQ(align_size_up(value, alignment), (intptr_t)up);
// Check inline function vs macro
ASSERT_EQ(align_size_up(value, alignment), (intptr_t)align_size_up_(value, alignment));
// Sanity check
ASSERT_GE(align_size_up(value, alignment), (intptr_t)value);
}
// Test align down
const uint64_t down = align_size_down_(values[i], (uint64_t)alignment);
if (down <= (uint64_t)std::numeric_limits<T>::max()) {
log("Testing align_size_down: alignment: 0x" UINT64_FORMAT_X " value: 0x" UINT64_FORMAT_X " expected: 0x" UINT64_FORMAT_X "\n", (uint64_t)alignment, values[i], down);
T value = T(values[i]);
// Check against uint64_t version
ASSERT_EQ(align_size_down(value, alignment), (intptr_t)down);
// Check inline function vs macro
ASSERT_EQ(align_size_down(value, alignment), (intptr_t)align_size_down_(value, alignment));
// Sanity check
ASSERT_LE(align_size_down(value, alignment), (intptr_t)value);
}
// Test is aligned
const bool is = is_size_aligned_(values[i], (uint64_t)alignment);
if (values[i] <= (uint64_t)std::numeric_limits<T>::max()) {
log("Testing is_aligned: alignment: 0x" UINT64_FORMAT_X " value: 0x" UINT64_FORMAT_X " expected: %s\n", (uint64_t)alignment, values[i], is ? "true" : "false");
T value = T(values[i]);
// Check against uint64_t version
ASSERT_EQ(is_size_aligned(value, alignment), is);
// Check inline function vs macro
ASSERT_EQ(is_size_aligned(value, alignment), is_size_aligned_(value, alignment));
}
}
}
}
TEST(Align, functions_and_macros) {
// Test the alignment functions with different type combinations.
// The current implementation of the alignment functions use intptr_t
// as return and input parameter type. Therefore, we restrict the tested
// types on 32-bit platforms.
#ifdef _LP64
test_alignments<int64_t, uint8_t>();
test_alignments<int64_t, uint16_t>();
test_alignments<int64_t, uint32_t>();
test_alignments<int64_t, int8_t>();
test_alignments<int64_t, int16_t>();
test_alignments<int64_t, int32_t>();
test_alignments<int64_t, int64_t>();
test_alignments<uint32_t, uint8_t>();
test_alignments<uint32_t, uint16_t>();
test_alignments<uint32_t, uint32_t>();
test_alignments<uint32_t, int8_t>();
test_alignments<uint32_t, int16_t>();
test_alignments<uint32_t, int32_t>();
#endif
test_alignments<int32_t, uint8_t>();
test_alignments<int32_t, uint16_t>();
test_alignments<int32_t, int8_t>();
test_alignments<int32_t, int16_t>();
test_alignments<int32_t, int32_t>();
test_alignments<uint16_t, uint8_t>();
test_alignments<uint16_t, uint16_t>();
test_alignments<uint16_t, int8_t>();
test_alignments<uint16_t, int16_t>();
test_alignments<int16_t, uint8_t>();
test_alignments<int16_t, int8_t>();
test_alignments<int16_t, int16_t>();
test_alignments<uint8_t, int8_t>();
test_alignments<uint8_t, uint8_t>();
test_alignments<int8_t, int8_t>();
}