/* * Copyright (C) 2011 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. */ /* This file contains codegen for the Thumb2 ISA. */ #include "arm_lir.h" #include "codegen_arm.h" #include "dex/quick/mir_to_lir-inl.h" #include "entrypoints/quick/quick_entrypoints.h" namespace art { /* Return the position of an ssa name within the argument list */ int ArmMir2Lir::InPosition(int s_reg) { int v_reg = mir_graph_->SRegToVReg(s_reg); return v_reg - cu_->num_regs; } /* * Describe an argument. If it's already in an arg register, just leave it * there. NOTE: all live arg registers must be locked prior to this call * to avoid having them allocated as a temp by downstream utilities. */ RegLocation ArmMir2Lir::ArgLoc(RegLocation loc) { int arg_num = InPosition(loc.s_reg_low); if (loc.wide) { if (arg_num == 2) { // Bad case - half in register, half in frame. Just punt loc.location = kLocInvalid; } else if (arg_num < 2) { loc.low_reg = rARM_ARG1 + arg_num; loc.high_reg = loc.low_reg + 1; loc.location = kLocPhysReg; } else { loc.location = kLocDalvikFrame; } } else { if (arg_num < 3) { loc.low_reg = rARM_ARG1 + arg_num; loc.location = kLocPhysReg; } else { loc.location = kLocDalvikFrame; } } return loc; } /* * Load an argument. If already in a register, just return. If in * the frame, we can't use the normal LoadValue() because it assumed * a proper frame - and we're frameless. */ RegLocation ArmMir2Lir::LoadArg(RegLocation loc) { if (loc.location == kLocDalvikFrame) { int start = (InPosition(loc.s_reg_low) + 1) * sizeof(uint32_t); loc.low_reg = AllocTemp(); LoadWordDisp(rARM_SP, start, loc.low_reg); if (loc.wide) { loc.high_reg = AllocTemp(); LoadWordDisp(rARM_SP, start + sizeof(uint32_t), loc.high_reg); } loc.location = kLocPhysReg; } return loc; } /* Lock any referenced arguments that arrive in registers */ void ArmMir2Lir::LockLiveArgs(MIR* mir) { int first_in = cu_->num_regs; const int num_arg_regs = 3; // TODO: generalize & move to RegUtil.cc for (int i = 0; i < mir->ssa_rep->num_uses; i++) { int v_reg = mir_graph_->SRegToVReg(mir->ssa_rep->uses[i]); int InPosition = v_reg - first_in; if (InPosition < num_arg_regs) { LockTemp(rARM_ARG1 + InPosition); } } } /* Find the next MIR, which may be in a following basic block */ // TODO: should this be a utility in mir_graph? MIR* ArmMir2Lir::GetNextMir(BasicBlock** p_bb, MIR* mir) { BasicBlock* bb = *p_bb; MIR* orig_mir = mir; while (bb != NULL) { if (mir != NULL) { mir = mir->next; } if (mir != NULL) { return mir; } else { bb = bb->fall_through; *p_bb = bb; if (bb) { mir = bb->first_mir_insn; if (mir != NULL) { return mir; } } } } return orig_mir; } /* Used for the "verbose" listing */ // TODO: move to common code void ArmMir2Lir::GenPrintLabel(MIR* mir) { /* Mark the beginning of a Dalvik instruction for line tracking */ char* inst_str = cu_->verbose ? mir_graph_->GetDalvikDisassembly(mir) : NULL; MarkBoundary(mir->offset, inst_str); } MIR* ArmMir2Lir::SpecialIGet(BasicBlock** bb, MIR* mir, OpSize size, bool long_or_double, bool is_object) { int field_offset; bool is_volatile; uint32_t field_idx = mir->dalvikInsn.vC; bool fast_path = FastInstance(field_idx, field_offset, is_volatile, false); if (!fast_path || !(mir->optimization_flags & MIR_IGNORE_NULL_CHECK)) { return NULL; } RegLocation rl_obj = mir_graph_->GetSrc(mir, 0); LockLiveArgs(mir); rl_obj = ArmMir2Lir::ArgLoc(rl_obj); RegLocation rl_dest; if (long_or_double) { rl_dest = GetReturnWide(false); } else { rl_dest = GetReturn(false); } // Point of no return - no aborts after this ArmMir2Lir::GenPrintLabel(mir); rl_obj = LoadArg(rl_obj); GenIGet(field_idx, mir->optimization_flags, size, rl_dest, rl_obj, long_or_double, is_object); return GetNextMir(bb, mir); } MIR* ArmMir2Lir::SpecialIPut(BasicBlock** bb, MIR* mir, OpSize size, bool long_or_double, bool is_object) { int field_offset; bool is_volatile; uint32_t field_idx = mir->dalvikInsn.vC; bool fast_path = FastInstance(field_idx, field_offset, is_volatile, false); if (!fast_path || !(mir->optimization_flags & MIR_IGNORE_NULL_CHECK)) { return NULL; } RegLocation rl_src; RegLocation rl_obj; LockLiveArgs(mir); if (long_or_double) { rl_src = mir_graph_->GetSrcWide(mir, 0); rl_obj = mir_graph_->GetSrc(mir, 2); } else { rl_src = mir_graph_->GetSrc(mir, 0); rl_obj = mir_graph_->GetSrc(mir, 1); } rl_src = ArmMir2Lir::ArgLoc(rl_src); rl_obj = ArmMir2Lir::ArgLoc(rl_obj); // Reject if source is split across registers & frame if (rl_obj.location == kLocInvalid) { ResetRegPool(); return NULL; } // Point of no return - no aborts after this ArmMir2Lir::GenPrintLabel(mir); rl_obj = LoadArg(rl_obj); rl_src = LoadArg(rl_src); GenIPut(field_idx, mir->optimization_flags, size, rl_src, rl_obj, long_or_double, is_object); return GetNextMir(bb, mir); } MIR* ArmMir2Lir::SpecialIdentity(MIR* mir) { RegLocation rl_src; RegLocation rl_dest; bool wide = (mir->ssa_rep->num_uses == 2); if (wide) { rl_src = mir_graph_->GetSrcWide(mir, 0); rl_dest = GetReturnWide(false); } else { rl_src = mir_graph_->GetSrc(mir, 0); rl_dest = GetReturn(false); } LockLiveArgs(mir); rl_src = ArmMir2Lir::ArgLoc(rl_src); if (rl_src.location == kLocInvalid) { ResetRegPool(); return NULL; } // Point of no return - no aborts after this ArmMir2Lir::GenPrintLabel(mir); rl_src = LoadArg(rl_src); if (wide) { StoreValueWide(rl_dest, rl_src); } else { StoreValue(rl_dest, rl_src); } return mir; } /* * Special-case code genration for simple non-throwing leaf methods. */ void ArmMir2Lir::GenSpecialCase(BasicBlock* bb, MIR* mir, SpecialCaseHandler special_case) { current_dalvik_offset_ = mir->offset; MIR* next_mir = NULL; switch (special_case) { case kNullMethod: DCHECK(mir->dalvikInsn.opcode == Instruction::RETURN_VOID); next_mir = mir; break; case kConstFunction: ArmMir2Lir::GenPrintLabel(mir); LoadConstant(rARM_RET0, mir->dalvikInsn.vB); next_mir = GetNextMir(&bb, mir); break; case kIGet: next_mir = SpecialIGet(&bb, mir, kWord, false, false); break; case kIGetBoolean: case kIGetByte: next_mir = SpecialIGet(&bb, mir, kUnsignedByte, false, false); break; case kIGetObject: next_mir = SpecialIGet(&bb, mir, kWord, false, true); break; case kIGetChar: next_mir = SpecialIGet(&bb, mir, kUnsignedHalf, false, false); break; case kIGetShort: next_mir = SpecialIGet(&bb, mir, kSignedHalf, false, false); break; case kIGetWide: next_mir = SpecialIGet(&bb, mir, kLong, true, false); break; case kIPut: next_mir = SpecialIPut(&bb, mir, kWord, false, false); break; case kIPutBoolean: case kIPutByte: next_mir = SpecialIPut(&bb, mir, kUnsignedByte, false, false); break; case kIPutObject: next_mir = SpecialIPut(&bb, mir, kWord, false, true); break; case kIPutChar: next_mir = SpecialIPut(&bb, mir, kUnsignedHalf, false, false); break; case kIPutShort: next_mir = SpecialIPut(&bb, mir, kSignedHalf, false, false); break; case kIPutWide: next_mir = SpecialIPut(&bb, mir, kLong, true, false); break; case kIdentity: next_mir = SpecialIdentity(mir); break; default: return; } if (next_mir != NULL) { current_dalvik_offset_ = next_mir->offset; if (special_case != kIdentity) { ArmMir2Lir::GenPrintLabel(next_mir); } NewLIR1(kThumbBx, rARM_LR); core_spill_mask_ = 0; num_core_spills_ = 0; fp_spill_mask_ = 0; num_fp_spills_ = 0; frame_size_ = 0; core_vmap_table_.clear(); fp_vmap_table_.clear(); } } /* * The sparse table in the literal pool is an array of <key,displacement> * pairs. For each set, we'll load them as a pair using ldmia. * This means that the register number of the temp we use for the key * must be lower than the reg for the displacement. * * The test loop will look something like: * * adr rBase, <table> * ldr r_val, [rARM_SP, v_reg_off] * mov r_idx, #table_size * lp: * ldmia rBase!, {r_key, r_disp} * sub r_idx, #1 * cmp r_val, r_key * ifeq * add rARM_PC, r_disp ; This is the branch from which we compute displacement * cbnz r_idx, lp */ void ArmMir2Lir::GenSparseSwitch(MIR* mir, uint32_t table_offset, RegLocation rl_src) { const uint16_t* table = cu_->insns + current_dalvik_offset_ + table_offset; if (cu_->verbose) { DumpSparseSwitchTable(table); } // Add the table to the list - we'll process it later SwitchTable *tab_rec = static_cast<SwitchTable*>(arena_->Alloc(sizeof(SwitchTable), ArenaAllocator::kAllocData)); tab_rec->table = table; tab_rec->vaddr = current_dalvik_offset_; int size = table[1]; tab_rec->targets = static_cast<LIR**>(arena_->Alloc(size * sizeof(LIR*), ArenaAllocator::kAllocLIR)); switch_tables_.Insert(tab_rec); // Get the switch value rl_src = LoadValue(rl_src, kCoreReg); int rBase = AllocTemp(); /* Allocate key and disp temps */ int r_key = AllocTemp(); int r_disp = AllocTemp(); // Make sure r_key's register number is less than r_disp's number for ldmia if (r_key > r_disp) { int tmp = r_disp; r_disp = r_key; r_key = tmp; } // Materialize a pointer to the switch table NewLIR3(kThumb2Adr, rBase, 0, reinterpret_cast<uintptr_t>(tab_rec)); // Set up r_idx int r_idx = AllocTemp(); LoadConstant(r_idx, size); // Establish loop branch target LIR* target = NewLIR0(kPseudoTargetLabel); // Load next key/disp NewLIR2(kThumb2LdmiaWB, rBase, (1 << r_key) | (1 << r_disp)); OpRegReg(kOpCmp, r_key, rl_src.low_reg); // Go if match. NOTE: No instruction set switch here - must stay Thumb2 OpIT(kCondEq, ""); LIR* switch_branch = NewLIR1(kThumb2AddPCR, r_disp); tab_rec->anchor = switch_branch; // Needs to use setflags encoding here NewLIR3(kThumb2SubsRRI12, r_idx, r_idx, 1); OpCondBranch(kCondNe, target); } void ArmMir2Lir::GenPackedSwitch(MIR* mir, uint32_t table_offset, RegLocation rl_src) { const uint16_t* table = cu_->insns + current_dalvik_offset_ + table_offset; if (cu_->verbose) { DumpPackedSwitchTable(table); } // Add the table to the list - we'll process it later SwitchTable *tab_rec = static_cast<SwitchTable*>(arena_->Alloc(sizeof(SwitchTable), ArenaAllocator::kAllocData)); tab_rec->table = table; tab_rec->vaddr = current_dalvik_offset_; int size = table[1]; tab_rec->targets = static_cast<LIR**>(arena_->Alloc(size * sizeof(LIR*), ArenaAllocator::kAllocLIR)); switch_tables_.Insert(tab_rec); // Get the switch value rl_src = LoadValue(rl_src, kCoreReg); int table_base = AllocTemp(); // Materialize a pointer to the switch table NewLIR3(kThumb2Adr, table_base, 0, reinterpret_cast<uintptr_t>(tab_rec)); int low_key = s4FromSwitchData(&table[2]); int keyReg; // Remove the bias, if necessary if (low_key == 0) { keyReg = rl_src.low_reg; } else { keyReg = AllocTemp(); OpRegRegImm(kOpSub, keyReg, rl_src.low_reg, low_key); } // Bounds check - if < 0 or >= size continue following switch OpRegImm(kOpCmp, keyReg, size-1); LIR* branch_over = OpCondBranch(kCondHi, NULL); // Load the displacement from the switch table int disp_reg = AllocTemp(); LoadBaseIndexed(table_base, keyReg, disp_reg, 2, kWord); // ..and go! NOTE: No instruction set switch here - must stay Thumb2 LIR* switch_branch = NewLIR1(kThumb2AddPCR, disp_reg); tab_rec->anchor = switch_branch; /* branch_over target here */ LIR* target = NewLIR0(kPseudoTargetLabel); branch_over->target = target; } /* * Array data table format: * ushort ident = 0x0300 magic value * ushort width width of each element in the table * uint size number of elements in the table * ubyte data[size*width] table of data values (may contain a single-byte * padding at the end) * * Total size is 4+(width * size + 1)/2 16-bit code units. */ void ArmMir2Lir::GenFillArrayData(uint32_t table_offset, RegLocation rl_src) { const uint16_t* table = cu_->insns + current_dalvik_offset_ + table_offset; // Add the table to the list - we'll process it later FillArrayData *tab_rec = static_cast<FillArrayData*>(arena_->Alloc(sizeof(FillArrayData), ArenaAllocator::kAllocData)); tab_rec->table = table; tab_rec->vaddr = current_dalvik_offset_; uint16_t width = tab_rec->table[1]; uint32_t size = tab_rec->table[2] | ((static_cast<uint32_t>(tab_rec->table[3])) << 16); tab_rec->size = (size * width) + 8; fill_array_data_.Insert(tab_rec); // Making a call - use explicit registers FlushAllRegs(); /* Everything to home location */ LoadValueDirectFixed(rl_src, r0); LoadWordDisp(rARM_SELF, QUICK_ENTRYPOINT_OFFSET(pHandleFillArrayData).Int32Value(), rARM_LR); // Materialize a pointer to the fill data image NewLIR3(kThumb2Adr, r1, 0, reinterpret_cast<uintptr_t>(tab_rec)); ClobberCalleeSave(); LIR* call_inst = OpReg(kOpBlx, rARM_LR); MarkSafepointPC(call_inst); } /* * Handle simple case (thin lock) inline. If it's complicated, bail * out to the heavyweight lock/unlock routines. We'll use dedicated * registers here in order to be in the right position in case we * to bail to oat[Lock/Unlock]Object(self, object) * * r0 -> self pointer [arg0 for oat[Lock/Unlock]Object * r1 -> object [arg1 for oat[Lock/Unlock]Object * r2 -> intial contents of object->lock, later result of strex * r3 -> self->thread_id * r12 -> allow to be used by utilities as general temp * * The result of the strex is 0 if we acquire the lock. * * See comments in monitor.cc for the layout of the lock word. * Of particular interest to this code is the test for the * simple case - which we handle inline. For monitor enter, the * simple case is thin lock, held by no-one. For monitor exit, * the simple case is thin lock, held by the unlocking thread with * a recurse count of 0. * * A minor complication is that there is a field in the lock word * unrelated to locking: the hash state. This field must be ignored, but * preserved. * */ void ArmMir2Lir::GenMonitorEnter(int opt_flags, RegLocation rl_src) { FlushAllRegs(); DCHECK_EQ(LW_SHAPE_THIN, 0); LoadValueDirectFixed(rl_src, r0); // Get obj LockCallTemps(); // Prepare for explicit register usage GenNullCheck(rl_src.s_reg_low, r0, opt_flags); LoadWordDisp(rARM_SELF, Thread::ThinLockIdOffset().Int32Value(), r2); NewLIR3(kThumb2Ldrex, r1, r0, mirror::Object::MonitorOffset().Int32Value() >> 2); // Get object->lock // Align owner OpRegImm(kOpLsl, r2, LW_LOCK_OWNER_SHIFT); // Is lock unheld on lock or held by us (==thread_id) on unlock? NewLIR4(kThumb2Bfi, r2, r1, 0, LW_LOCK_OWNER_SHIFT - 1); NewLIR3(kThumb2Bfc, r1, LW_HASH_STATE_SHIFT, LW_LOCK_OWNER_SHIFT - 1); OpRegImm(kOpCmp, r1, 0); OpIT(kCondEq, ""); NewLIR4(kThumb2Strex, r1, r2, r0, mirror::Object::MonitorOffset().Int32Value() >> 2); OpRegImm(kOpCmp, r1, 0); OpIT(kCondNe, "T"); // Go expensive route - artLockObjectFromCode(self, obj); LoadWordDisp(rARM_SELF, QUICK_ENTRYPOINT_OFFSET(pLockObject).Int32Value(), rARM_LR); ClobberCalleeSave(); LIR* call_inst = OpReg(kOpBlx, rARM_LR); MarkSafepointPC(call_inst); GenMemBarrier(kLoadLoad); } /* * For monitor unlock, we don't have to use ldrex/strex. Once * we've determined that the lock is thin and that we own it with * a zero recursion count, it's safe to punch it back to the * initial, unlock thin state with a store word. */ void ArmMir2Lir::GenMonitorExit(int opt_flags, RegLocation rl_src) { DCHECK_EQ(LW_SHAPE_THIN, 0); FlushAllRegs(); LoadValueDirectFixed(rl_src, r0); // Get obj LockCallTemps(); // Prepare for explicit register usage GenNullCheck(rl_src.s_reg_low, r0, opt_flags); LoadWordDisp(r0, mirror::Object::MonitorOffset().Int32Value(), r1); // Get lock LoadWordDisp(rARM_SELF, Thread::ThinLockIdOffset().Int32Value(), r2); // Is lock unheld on lock or held by us (==thread_id) on unlock? OpRegRegImm(kOpAnd, r3, r1, (LW_HASH_STATE_MASK << LW_HASH_STATE_SHIFT)); // Align owner OpRegImm(kOpLsl, r2, LW_LOCK_OWNER_SHIFT); NewLIR3(kThumb2Bfc, r1, LW_HASH_STATE_SHIFT, LW_LOCK_OWNER_SHIFT - 1); OpRegReg(kOpSub, r1, r2); OpIT(kCondEq, "EE"); StoreWordDisp(r0, mirror::Object::MonitorOffset().Int32Value(), r3); // Go expensive route - UnlockObjectFromCode(obj); LoadWordDisp(rARM_SELF, QUICK_ENTRYPOINT_OFFSET(pUnlockObject).Int32Value(), rARM_LR); ClobberCalleeSave(); LIR* call_inst = OpReg(kOpBlx, rARM_LR); MarkSafepointPC(call_inst); GenMemBarrier(kStoreLoad); } void ArmMir2Lir::GenMoveException(RegLocation rl_dest) { int ex_offset = Thread::ExceptionOffset().Int32Value(); RegLocation rl_result = EvalLoc(rl_dest, kCoreReg, true); int reset_reg = AllocTemp(); LoadWordDisp(rARM_SELF, ex_offset, rl_result.low_reg); LoadConstant(reset_reg, 0); StoreWordDisp(rARM_SELF, ex_offset, reset_reg); FreeTemp(reset_reg); StoreValue(rl_dest, rl_result); } /* * Mark garbage collection card. Skip if the value we're storing is null. */ void ArmMir2Lir::MarkGCCard(int val_reg, int tgt_addr_reg) { int reg_card_base = AllocTemp(); int reg_card_no = AllocTemp(); LIR* branch_over = OpCmpImmBranch(kCondEq, val_reg, 0, NULL); LoadWordDisp(rARM_SELF, Thread::CardTableOffset().Int32Value(), reg_card_base); OpRegRegImm(kOpLsr, reg_card_no, tgt_addr_reg, gc::accounting::CardTable::kCardShift); StoreBaseIndexed(reg_card_base, reg_card_no, reg_card_base, 0, kUnsignedByte); LIR* target = NewLIR0(kPseudoTargetLabel); branch_over->target = target; FreeTemp(reg_card_base); FreeTemp(reg_card_no); } void ArmMir2Lir::GenEntrySequence(RegLocation* ArgLocs, RegLocation rl_method) { int spill_count = num_core_spills_ + num_fp_spills_; /* * On entry, r0, r1, r2 & r3 are live. Let the register allocation * mechanism know so it doesn't try to use any of them when * expanding the frame or flushing. This leaves the utility * code with a single temp: r12. This should be enough. */ LockTemp(r0); LockTemp(r1); LockTemp(r2); LockTemp(r3); /* * We can safely skip the stack overflow check if we're * a leaf *and* our frame size < fudge factor. */ bool skip_overflow_check = (mir_graph_->MethodIsLeaf() && (static_cast<size_t>(frame_size_) < Thread::kStackOverflowReservedBytes)); NewLIR0(kPseudoMethodEntry); if (!skip_overflow_check) { /* Load stack limit */ LoadWordDisp(rARM_SELF, Thread::StackEndOffset().Int32Value(), r12); } /* Spill core callee saves */ NewLIR1(kThumb2Push, core_spill_mask_); /* Need to spill any FP regs? */ if (num_fp_spills_) { /* * NOTE: fp spills are a little different from core spills in that * they are pushed as a contiguous block. When promoting from * the fp set, we must allocate all singles from s16..highest-promoted */ NewLIR1(kThumb2VPushCS, num_fp_spills_); } if (!skip_overflow_check) { OpRegRegImm(kOpSub, rARM_LR, rARM_SP, frame_size_ - (spill_count * 4)); GenRegRegCheck(kCondCc, rARM_LR, r12, kThrowStackOverflow); OpRegCopy(rARM_SP, rARM_LR); // Establish stack } else { OpRegImm(kOpSub, rARM_SP, frame_size_ - (spill_count * 4)); } FlushIns(ArgLocs, rl_method); FreeTemp(r0); FreeTemp(r1); FreeTemp(r2); FreeTemp(r3); } void ArmMir2Lir::GenExitSequence() { int spill_count = num_core_spills_ + num_fp_spills_; /* * In the exit path, r0/r1 are live - make sure they aren't * allocated by the register utilities as temps. */ LockTemp(r0); LockTemp(r1); NewLIR0(kPseudoMethodExit); OpRegImm(kOpAdd, rARM_SP, frame_size_ - (spill_count * 4)); /* Need to restore any FP callee saves? */ if (num_fp_spills_) { NewLIR1(kThumb2VPopCS, num_fp_spills_); } if (core_spill_mask_ & (1 << rARM_LR)) { /* Unspill rARM_LR to rARM_PC */ core_spill_mask_ &= ~(1 << rARM_LR); core_spill_mask_ |= (1 << rARM_PC); } NewLIR1(kThumb2Pop, core_spill_mask_); if (!(core_spill_mask_ & (1 << rARM_PC))) { /* We didn't pop to rARM_PC, so must do a bv rARM_LR */ NewLIR1(kThumbBx, rARM_LR); } } } // namespace art