|  | /* | 
|  | * Copyright (C) 2014 The Android Open Source Project | 
|  | * | 
|  | * Licensed under the Apache License, Version 2.0 (the "License"); | 
|  | * you may not use this file except in compliance with the License. | 
|  | * You may obtain a copy of the License at | 
|  | * | 
|  | *      http://www.apache.org/licenses/LICENSE-2.0 | 
|  | * | 
|  | * Unless required by applicable law or agreed to in writing, software | 
|  | * distributed under the License is distributed on an "AS IS" BASIS, | 
|  | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
|  | * See the License for the specific language governing permissions and | 
|  | * limitations under the License. | 
|  | */ | 
|  |  | 
|  | #include <iomanip> | 
|  |  | 
|  | #include "resource_mask.h" | 
|  |  | 
|  | #include "utils/arena_allocator.h" | 
|  |  | 
|  | namespace art { | 
|  |  | 
|  | namespace {  // anonymous namespace | 
|  |  | 
|  | constexpr ResourceMask kNoRegMasks[] = { | 
|  | kEncodeNone, | 
|  | kEncodeHeapRef, | 
|  | kEncodeLiteral, | 
|  | kEncodeDalvikReg, | 
|  | ResourceMask::Bit(ResourceMask::kFPStatus), | 
|  | ResourceMask::Bit(ResourceMask::kCCode), | 
|  | }; | 
|  | // The 127-bit is the same as CLZ(masks_[1]) for a ResourceMask with only that bit set. | 
|  | COMPILE_ASSERT(kNoRegMasks[127-ResourceMask::kHeapRef].Equals( | 
|  | kEncodeHeapRef), check_kNoRegMasks_heap_ref_index); | 
|  | COMPILE_ASSERT(kNoRegMasks[127-ResourceMask::kLiteral].Equals( | 
|  | kEncodeLiteral), check_kNoRegMasks_literal_index); | 
|  | COMPILE_ASSERT(kNoRegMasks[127-ResourceMask::kDalvikReg].Equals( | 
|  | kEncodeDalvikReg), check_kNoRegMasks_dalvik_reg_index); | 
|  | COMPILE_ASSERT(kNoRegMasks[127-ResourceMask::kFPStatus].Equals( | 
|  | ResourceMask::Bit(ResourceMask::kFPStatus)), check_kNoRegMasks_fp_status_index); | 
|  | COMPILE_ASSERT(kNoRegMasks[127-ResourceMask::kCCode].Equals( | 
|  | ResourceMask::Bit(ResourceMask::kCCode)), check_kNoRegMasks_ccode_index); | 
|  |  | 
|  | template <size_t special_bit> | 
|  | constexpr ResourceMask OneRegOneSpecial(size_t reg) { | 
|  | return ResourceMask::Bit(reg).Union(ResourceMask::Bit(special_bit)); | 
|  | } | 
|  |  | 
|  | // NOTE: Working around gcc bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61484 . | 
|  | // This should be a two-dimensions array, kSingleRegMasks[][32] and each line should be | 
|  | // enclosed in an extra { }. However, gcc issues a bogus "error: array must be initialized | 
|  | // with a brace-enclosed initializer" for that, so we flatten this to a one-dimensional array. | 
|  | constexpr ResourceMask kSingleRegMasks[] = { | 
|  | #define DEFINE_LIST_32(fn) \ | 
|  | fn(0), fn(1), fn(2), fn(3), fn(4), fn(5), fn(6), fn(7),           \ | 
|  | fn(8), fn(9), fn(10), fn(11), fn(12), fn(13), fn(14), fn(15),     \ | 
|  | fn(16), fn(17), fn(18), fn(19), fn(20), fn(21), fn(22), fn(23),   \ | 
|  | fn(24), fn(25), fn(26), fn(27), fn(28), fn(29), fn(30), fn(31) | 
|  | // NOTE: Each line is 512B of constant data, 3KiB in total. | 
|  | DEFINE_LIST_32(ResourceMask::Bit), | 
|  | DEFINE_LIST_32(OneRegOneSpecial<ResourceMask::kHeapRef>), | 
|  | DEFINE_LIST_32(OneRegOneSpecial<ResourceMask::kLiteral>), | 
|  | DEFINE_LIST_32(OneRegOneSpecial<ResourceMask::kDalvikReg>), | 
|  | DEFINE_LIST_32(OneRegOneSpecial<ResourceMask::kFPStatus>), | 
|  | DEFINE_LIST_32(OneRegOneSpecial<ResourceMask::kCCode>), | 
|  | #undef DEFINE_LIST_32 | 
|  | }; | 
|  |  | 
|  | constexpr size_t SingleRegMaskIndex(size_t main_index, size_t sub_index) { | 
|  | return main_index * 32u + sub_index; | 
|  | } | 
|  |  | 
|  | // The 127-bit is the same as CLZ(masks_[1]) for a ResourceMask with only that bit set. | 
|  | COMPILE_ASSERT(kSingleRegMasks[SingleRegMaskIndex(127-ResourceMask::kHeapRef, 0)].Equals( | 
|  | OneRegOneSpecial<ResourceMask::kHeapRef>(0)), check_kSingleRegMasks_heap_ref_index); | 
|  | COMPILE_ASSERT(kSingleRegMasks[SingleRegMaskIndex(127-ResourceMask::kLiteral, 0)].Equals( | 
|  | OneRegOneSpecial<ResourceMask::kLiteral>(0)), check_kSingleRegMasks_literal_index); | 
|  | COMPILE_ASSERT(kSingleRegMasks[SingleRegMaskIndex(127-ResourceMask::kDalvikReg, 0)].Equals( | 
|  | OneRegOneSpecial<ResourceMask::kDalvikReg>(0)), check_kSingleRegMasks_dalvik_reg_index); | 
|  | COMPILE_ASSERT(kSingleRegMasks[SingleRegMaskIndex(127-ResourceMask::kFPStatus, 0)].Equals( | 
|  | OneRegOneSpecial<ResourceMask::kFPStatus>(0)), check_kSingleRegMasks_fp_status_index); | 
|  | COMPILE_ASSERT(kSingleRegMasks[SingleRegMaskIndex(127-ResourceMask::kCCode, 0)].Equals( | 
|  | OneRegOneSpecial<ResourceMask::kCCode>(0)), check_kSingleRegMasks_ccode_index); | 
|  |  | 
|  | // NOTE: arraysize(kNoRegMasks) multiplied by 32 due to the gcc bug workaround, see above. | 
|  | COMPILE_ASSERT(arraysize(kSingleRegMasks) == arraysize(kNoRegMasks) * 32, check_arraysizes); | 
|  |  | 
|  | constexpr ResourceMask kTwoRegsMasks[] = { | 
|  | #define TWO(a, b) ResourceMask::Bit(a).Union(ResourceMask::Bit(b)) | 
|  | // NOTE: 16 * 15 / 2 = 120 entries, 16 bytes each, 1920B in total. | 
|  | TWO(0, 1), | 
|  | TWO(0, 2), TWO(1, 2), | 
|  | TWO(0, 3), TWO(1, 3), TWO(2, 3), | 
|  | TWO(0, 4), TWO(1, 4), TWO(2, 4), TWO(3, 4), | 
|  | TWO(0, 5), TWO(1, 5), TWO(2, 5), TWO(3, 5), TWO(4, 5), | 
|  | TWO(0, 6), TWO(1, 6), TWO(2, 6), TWO(3, 6), TWO(4, 6), TWO(5, 6), | 
|  | TWO(0, 7), TWO(1, 7), TWO(2, 7), TWO(3, 7), TWO(4, 7), TWO(5, 7), TWO(6, 7), | 
|  | TWO(0, 8), TWO(1, 8), TWO(2, 8), TWO(3, 8), TWO(4, 8), TWO(5, 8), TWO(6, 8), TWO(7, 8), | 
|  | TWO(0, 9), TWO(1, 9), TWO(2, 9), TWO(3, 9), TWO(4, 9), TWO(5, 9), TWO(6, 9), TWO(7, 9), | 
|  | TWO(8, 9), | 
|  | TWO(0, 10), TWO(1, 10), TWO(2, 10), TWO(3, 10), TWO(4, 10), TWO(5, 10), TWO(6, 10), TWO(7, 10), | 
|  | TWO(8, 10), TWO(9, 10), | 
|  | TWO(0, 11), TWO(1, 11), TWO(2, 11), TWO(3, 11), TWO(4, 11), TWO(5, 11), TWO(6, 11), TWO(7, 11), | 
|  | TWO(8, 11), TWO(9, 11), TWO(10, 11), | 
|  | TWO(0, 12), TWO(1, 12), TWO(2, 12), TWO(3, 12), TWO(4, 12), TWO(5, 12), TWO(6, 12), TWO(7, 12), | 
|  | TWO(8, 12), TWO(9, 12), TWO(10, 12), TWO(11, 12), | 
|  | TWO(0, 13), TWO(1, 13), TWO(2, 13), TWO(3, 13), TWO(4, 13), TWO(5, 13), TWO(6, 13), TWO(7, 13), | 
|  | TWO(8, 13), TWO(9, 13), TWO(10, 13), TWO(11, 13), TWO(12, 13), | 
|  | TWO(0, 14), TWO(1, 14), TWO(2, 14), TWO(3, 14), TWO(4, 14), TWO(5, 14), TWO(6, 14), TWO(7, 14), | 
|  | TWO(8, 14), TWO(9, 14), TWO(10, 14), TWO(11, 14), TWO(12, 14), TWO(13, 14), | 
|  | TWO(0, 15), TWO(1, 15), TWO(2, 15), TWO(3, 15), TWO(4, 15), TWO(5, 15), TWO(6, 15), TWO(7, 15), | 
|  | TWO(8, 15), TWO(9, 15), TWO(10, 15), TWO(11, 15), TWO(12, 15), TWO(13, 15), TWO(14, 15), | 
|  | #undef TWO | 
|  | }; | 
|  | COMPILE_ASSERT(arraysize(kTwoRegsMasks) ==  16 * 15 / 2, check_arraysize_kTwoRegsMasks); | 
|  |  | 
|  | constexpr size_t TwoRegsIndex(size_t higher, size_t lower) { | 
|  | return (higher * (higher - 1)) / 2u + lower; | 
|  | } | 
|  |  | 
|  | constexpr bool CheckTwoRegsMask(size_t higher, size_t lower) { | 
|  | return ResourceMask::Bit(lower).Union(ResourceMask::Bit(higher)).Equals( | 
|  | kTwoRegsMasks[TwoRegsIndex(higher, lower)]); | 
|  | } | 
|  |  | 
|  | constexpr bool CheckTwoRegsMaskLine(size_t line, size_t lower = 0u) { | 
|  | return (lower == line) || | 
|  | (CheckTwoRegsMask(line, lower) && CheckTwoRegsMaskLine(line, lower + 1u)); | 
|  | } | 
|  |  | 
|  | constexpr bool CheckTwoRegsMaskTable(size_t lines) { | 
|  | return lines == 0 || | 
|  | (CheckTwoRegsMaskLine(lines - 1) && CheckTwoRegsMaskTable(lines - 1u)); | 
|  | } | 
|  |  | 
|  | COMPILE_ASSERT(CheckTwoRegsMaskTable(16), check_two_regs_masks_table); | 
|  |  | 
|  | }  // anonymous namespace | 
|  |  | 
|  | const ResourceMask* ResourceMaskCache::GetMask(const ResourceMask& mask) { | 
|  | // Instead of having a deduplication map, we shall just use pre-defined constexpr | 
|  | // masks for the common cases. At most one of the these special bits is allowed: | 
|  | constexpr ResourceMask kAllowedSpecialBits = ResourceMask::Bit(ResourceMask::kFPStatus) | 
|  | .Union(ResourceMask::Bit(ResourceMask::kCCode)) | 
|  | .Union(kEncodeHeapRef).Union(kEncodeLiteral).Union(kEncodeDalvikReg); | 
|  | const ResourceMask* res = nullptr; | 
|  | // Limit to low 32 regs and the kAllowedSpecialBits. | 
|  | if ((mask.masks_[0] >> 32) == 0u && (mask.masks_[1] & ~kAllowedSpecialBits.masks_[1]) == 0u) { | 
|  | // Check if it's only up to two registers. | 
|  | uint32_t low_regs = static_cast<uint32_t>(mask.masks_[0]); | 
|  | uint32_t low_regs_without_lowest = low_regs & (low_regs - 1u); | 
|  | if (low_regs_without_lowest == 0u && IsPowerOfTwo(mask.masks_[1])) { | 
|  | // 0 or 1 register, 0 or 1 bit from kAllowedBits. Use a pre-defined mask. | 
|  | size_t index = (mask.masks_[1] != 0u) ? CLZ(mask.masks_[1]) : 0u; | 
|  | DCHECK_LT(index, arraysize(kNoRegMasks)); | 
|  | res = (low_regs != 0) ? &kSingleRegMasks[SingleRegMaskIndex(index, CTZ(low_regs))] | 
|  | : &kNoRegMasks[index]; | 
|  | } else if (IsPowerOfTwo(low_regs_without_lowest) && mask.masks_[1] == 0u) { | 
|  | // 2 registers and no other flags. Use predefined mask if higher reg is < 16. | 
|  | if (low_regs_without_lowest < (1u << 16)) { | 
|  | res = &kTwoRegsMasks[TwoRegsIndex(CTZ(low_regs_without_lowest), CTZ(low_regs))]; | 
|  | } | 
|  | } | 
|  | } else if (mask.Equals(kEncodeAll)) { | 
|  | res = &kEncodeAll; | 
|  | } | 
|  | if (res != nullptr) { | 
|  | DCHECK(res->Equals(mask)) | 
|  | << "(" << std::hex << std::setw(16) << mask.masks_[0] | 
|  | << ", "<< std::hex << std::setw(16) << mask.masks_[1] | 
|  | << ") != (" << std::hex << std::setw(16) << res->masks_[0] | 
|  | << ", "<< std::hex << std::setw(16) << res->masks_[1] << ")"; | 
|  | return res; | 
|  | } | 
|  |  | 
|  | // TODO: Deduplicate. (At least the most common masks.) | 
|  | void* mem = allocator_->Alloc(sizeof(ResourceMask), kArenaAllocLIRResourceMask); | 
|  | return new (mem) ResourceMask(mask); | 
|  | } | 
|  |  | 
|  | }  // namespace art |