diff options
Diffstat (limited to 'deps/v8/src/wasm/jump-table-assembler.h')
| -rw-r--r-- | deps/v8/src/wasm/jump-table-assembler.h | 100 |
1 files changed, 68 insertions, 32 deletions
diff --git a/deps/v8/src/wasm/jump-table-assembler.h b/deps/v8/src/wasm/jump-table-assembler.h index eef9fea167..379a547b55 100644 --- a/deps/v8/src/wasm/jump-table-assembler.h +++ b/deps/v8/src/wasm/jump-table-assembler.h @@ -17,7 +17,16 @@ namespace wasm { // each slot containing a dispatch to the currently published {WasmCode} that // corresponds to the function. // -// Note that the table is split into lines of fixed size, with lines laid out +// Additionally to this main jump table, there exist special jump tables for +// other purposes: +// - the runtime stub table contains one entry per wasm runtime stub (see +// {WasmCode::RuntimeStubId}, which jumps to the corresponding embedded +// builtin. +// - the lazy compile table contains one entry per wasm function which jumps to +// the common {WasmCompileLazy} builtin and passes the function index that was +// invoked. +// +// The main jump table is split into lines of fixed size, with lines laid out // consecutively within the executable memory of the {NativeModule}. The slots // in turn are consecutive within a line, but do not cross line boundaries. // @@ -27,6 +36,7 @@ namespace wasm { // // The above illustrates jump table lines {Li} containing slots {Si} with each // line containing {n} slots and some padding {x} for alignment purposes. +// Other jump tables are just consecutive. class V8_EXPORT_PRIVATE JumpTableAssembler : public MacroAssembler { public: // Translate an offset into the continuous jump table to a jump table index. @@ -39,7 +49,7 @@ class V8_EXPORT_PRIVATE JumpTableAssembler : public MacroAssembler { } // Translate a jump table index to an offset into the continuous jump table. - static uint32_t SlotIndexToOffset(uint32_t slot_index) { + static uint32_t JumpSlotIndexToOffset(uint32_t slot_index) { uint32_t line_index = slot_index / kJumpTableSlotsPerLine; uint32_t line_offset = (slot_index % kJumpTableSlotsPerLine) * kJumpTableSlotSize; @@ -60,40 +70,56 @@ class V8_EXPORT_PRIVATE JumpTableAssembler : public MacroAssembler { return slot_index * kJumpTableStubSlotSize; } + // Translate a slot index to an offset into the lazy compile table. + static uint32_t LazyCompileSlotIndexToOffset(uint32_t slot_index) { + return slot_index * kLazyCompileTableSlotSize; + } + // Determine the size of a jump table containing only runtime stub slots. static constexpr uint32_t SizeForNumberOfStubSlots(uint32_t slot_count) { return slot_count * kJumpTableStubSlotSize; } - static void EmitLazyCompileJumpSlot(Address base, uint32_t slot_index, - uint32_t func_index, - Address lazy_compile_target, - WasmCode::FlushICache flush_i_cache) { - Address slot = base + SlotIndexToOffset(slot_index); - JumpTableAssembler jtasm(slot); - jtasm.EmitLazyCompileJumpSlot(func_index, lazy_compile_target); - jtasm.NopBytes(kJumpTableSlotSize - jtasm.pc_offset()); - if (flush_i_cache) { - FlushInstructionCache(slot, kJumpTableSlotSize); + // Determine the size of a lazy compile table. + static constexpr uint32_t SizeForNumberOfLazyFunctions(uint32_t slot_count) { + return slot_count * kLazyCompileTableSlotSize; + } + + static void GenerateLazyCompileTable(Address base, uint32_t num_slots, + uint32_t num_imported_functions, + Address wasm_compile_lazy_target) { + uint32_t lazy_compile_table_size = num_slots * kLazyCompileTableSlotSize; + // Assume enough space, so the Assembler does not try to grow the buffer. + JumpTableAssembler jtasm(base, lazy_compile_table_size + 256); + for (uint32_t slot_index = 0; slot_index < num_slots; ++slot_index) { + DCHECK_EQ(slot_index * kLazyCompileTableSlotSize, jtasm.pc_offset()); + jtasm.EmitLazyCompileJumpSlot(slot_index + num_imported_functions, + wasm_compile_lazy_target); } + DCHECK_EQ(lazy_compile_table_size, jtasm.pc_offset()); + FlushInstructionCache(base, lazy_compile_table_size); } - static void EmitRuntimeStubSlot(Address base, uint32_t slot_index, - Address builtin_target, - WasmCode::FlushICache flush_i_cache) { - Address slot = base + StubSlotIndexToOffset(slot_index); - JumpTableAssembler jtasm(slot); - jtasm.EmitRuntimeStubSlot(builtin_target); - jtasm.NopBytes(kJumpTableStubSlotSize - jtasm.pc_offset()); - if (flush_i_cache) { - FlushInstructionCache(slot, kJumpTableStubSlotSize); + static void GenerateRuntimeStubTable(Address base, Address* targets, + int num_stubs) { + uint32_t table_size = num_stubs * kJumpTableStubSlotSize; + // Assume enough space, so the Assembler does not try to grow the buffer. + JumpTableAssembler jtasm(base, table_size + 256); + int offset = 0; + for (int index = 0; index < num_stubs; ++index) { + DCHECK_EQ(offset, StubSlotIndexToOffset(index)); + DCHECK_EQ(offset, jtasm.pc_offset()); + jtasm.EmitRuntimeStubSlot(targets[index]); + offset += kJumpTableStubSlotSize; + jtasm.NopBytes(offset - jtasm.pc_offset()); } + FlushInstructionCache(base, table_size); } static void PatchJumpTableSlot(Address base, uint32_t slot_index, Address new_target, WasmCode::FlushICache flush_i_cache) { - Address slot = base + SlotIndexToOffset(slot_index); + Address slot = base + JumpSlotIndexToOffset(slot_index); JumpTableAssembler jtasm(slot); jtasm.EmitJumpSlot(new_target); jtasm.NopBytes(kJumpTableSlotSize - jtasm.pc_offset()); @@ -115,44 +141,54 @@ class V8_EXPORT_PRIVATE JumpTableAssembler : public MacroAssembler { // boundaries. The jump table line size has been chosen to satisfy this. #if V8_TARGET_ARCH_X64 static constexpr int kJumpTableLineSize = 64; - static constexpr int kJumpTableSlotSize = 10; + static constexpr int kJumpTableSlotSize = 5; + static constexpr int kLazyCompileTableSlotSize = 10; static constexpr int kJumpTableStubSlotSize = 18; #elif V8_TARGET_ARCH_IA32 static constexpr int kJumpTableLineSize = 64; - static constexpr int kJumpTableSlotSize = 10; + static constexpr int kJumpTableSlotSize = 5; + static constexpr int kLazyCompileTableSlotSize = 10; static constexpr int kJumpTableStubSlotSize = 10; #elif V8_TARGET_ARCH_ARM - static constexpr int kJumpTableLineSize = 5 * kInstrSize; - static constexpr int kJumpTableSlotSize = 5 * kInstrSize; - static constexpr int kJumpTableStubSlotSize = 5 * kInstrSize; -#elif V8_TARGET_ARCH_ARM64 static constexpr int kJumpTableLineSize = 3 * kInstrSize; static constexpr int kJumpTableSlotSize = 3 * kInstrSize; + static constexpr int kLazyCompileTableSlotSize = 5 * kInstrSize; + static constexpr int kJumpTableStubSlotSize = 5 * kInstrSize; +#elif V8_TARGET_ARCH_ARM64 + static constexpr int kJumpTableLineSize = 1 * kInstrSize; + static constexpr int kJumpTableSlotSize = 1 * kInstrSize; + static constexpr int kLazyCompileTableSlotSize = 3 * kInstrSize; static constexpr int kJumpTableStubSlotSize = 6 * kInstrSize; #elif V8_TARGET_ARCH_S390X static constexpr int kJumpTableLineSize = 128; - static constexpr int kJumpTableSlotSize = 20; + static constexpr int kJumpTableSlotSize = 14; + static constexpr int kLazyCompileTableSlotSize = 20; static constexpr int kJumpTableStubSlotSize = 14; #elif V8_TARGET_ARCH_PPC64 static constexpr int kJumpTableLineSize = 64; - static constexpr int kJumpTableSlotSize = 48; + static constexpr int kJumpTableSlotSize = 7 * kInstrSize; + static constexpr int kLazyCompileTableSlotSize = 12 * kInstrSize; static constexpr int kJumpTableStubSlotSize = 7 * kInstrSize; #elif V8_TARGET_ARCH_MIPS static constexpr int kJumpTableLineSize = 6 * kInstrSize; - static constexpr int kJumpTableSlotSize = 6 * kInstrSize; + static constexpr int kJumpTableSlotSize = 4 * kInstrSize; + static constexpr int kLazyCompileTableSlotSize = 6 * kInstrSize; static constexpr int kJumpTableStubSlotSize = 4 * kInstrSize; #elif V8_TARGET_ARCH_MIPS64 static constexpr int kJumpTableLineSize = 8 * kInstrSize; - static constexpr int kJumpTableSlotSize = 8 * kInstrSize; + static constexpr int kJumpTableSlotSize = 6 * kInstrSize; + static constexpr int kLazyCompileTableSlotSize = 8 * kInstrSize; static constexpr int kJumpTableStubSlotSize = 6 * kInstrSize; #else static constexpr int kJumpTableLineSize = 1; static constexpr int kJumpTableSlotSize = 1; + static constexpr int kLazyCompileTableSlotSize = 1; static constexpr int kJumpTableStubSlotSize = 1; #endif static constexpr int kJumpTableSlotsPerLine = kJumpTableLineSize / kJumpTableSlotSize; + STATIC_ASSERT(kJumpTableSlotsPerLine >= 1); // {JumpTableAssembler} is never used during snapshot generation, and its code // must be independent of the code range of any isolate anyway. Just ensure |