1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17
18 /*! \file LowerReturn.cpp
19 \brief This file lowers the following bytecodes: RETURN
20
21 */
22 #include "libdex/DexOpcodes.h"
23 #include "libdex/DexFile.h"
24 #include "mterp/Mterp.h"
25 #include "Lower.h"
26 #include "enc_wrapper.h"
27 #include "NcgHelper.h"
28
29 //4 GPRs and scratch registers used in get_self_pointer, set_glue_method and set_glue_dvmdex
30 //will jump to "gotoBail" if caller method is NULL or if debugger is active
31 //what is %edx for each case? for the latter case, it is 1
32 #define P_GPR_1 PhysicalReg_ECX //must be ecx
33 #define P_GPR_2 PhysicalReg_EBX
34 #define P_SCRATCH_1 PhysicalReg_EDX
35 #define P_OLD_FP PhysicalReg_EAX
36 /*!
37 \brief common section to return from a method
38
39 If the helper switch is on, this will generate a helper function
40 */
common_returnFromMethod()41 int common_returnFromMethod() {
42 #if defined(ENABLE_TRACING) && !defined(TRACING_OPTION2)
43 insertMapWorklist(offsetPC, mapFromBCtoNCG[offsetPC], 1); //check when helper switch is on
44 #endif
45
46 scratchRegs[0] = PhysicalReg_SCRATCH_7;
47 get_self_pointer(2, false);
48
49 //update rFP to caller stack frame
50 move_reg_to_reg(OpndSize_32, PhysicalReg_FP, true, 10, false);
51 move_mem_to_reg(OpndSize_32, -sizeofStackSaveArea+offStackSaveArea_prevFrame, PhysicalReg_FP, true, PhysicalReg_FP, true); //update rFP
52 //get caller method by accessing the stack save area
53 move_mem_to_reg(OpndSize_32, -sizeofStackSaveArea+offStackSaveArea_method, PhysicalReg_FP, true, 6, false);
54 compare_imm_reg(OpndSize_32, 0, 6, false);
55 conditional_jump(Condition_E, "common_gotoBail_0", false);
56 get_self_pointer(3, false);
57 //update glue->method
58 move_reg_to_mem(OpndSize_32, 6, false, offsetof(Thread, interpSave.method), 2, false);
59 //get clazz of caller method
60 move_mem_to_reg(OpndSize_32, offMethod_clazz, 6, false, 14, false);
61 //update self->frame
62 move_reg_to_mem(OpndSize_32, PhysicalReg_FP, true, offThread_curFrame, 3, false);
63 //get method->clazz->pDvmDex
64 move_mem_to_reg(OpndSize_32, offClassObject_pDvmDex, 14, false, 7, false);
65 move_reg_to_mem(OpndSize_32, 7, false, offsetof(Thread, interpSave.methodClassDex), 2, false);
66
67 compare_imm_mem(OpndSize_32, 0, offsetof(Thread, suspendCount), 2, false); /* suspendCount */
68 move_mem_to_reg(OpndSize_32, -sizeofStackSaveArea+offStackSaveArea_returnAddr, 10, false, PhysicalReg_EBX, true);
69 move_imm_to_reg(OpndSize_32, 0, 17, false);
70 /* if suspendCount is not zero, clear the chaining cell address */
71 conditional_move_reg_to_reg(OpndSize_32, Condition_NZ, 17, false/*src*/, PhysicalReg_EBX, true/*dst*/);
72 move_mem_to_reg(OpndSize_32, -sizeofStackSaveArea+offStackSaveArea_savedPc, 10, false, PhysicalReg_EAX, true);
73 //if returnAddr is not NULL, the thread is still in code cache
74 move_reg_to_mem(OpndSize_32, PhysicalReg_EBX, true, offThread_inJitCodeCache, 3, false);
75
76 insertLabel(".LreturnToInterp", true); //local label
77 //move rPC by 6 (3 bytecode units for INVOKE)
78 alu_binary_imm_reg(OpndSize_32, add_opc, 6, PhysicalReg_EAX, true);
79
80 //returnAddr in %ebx, if not zero, jump to returnAddr
81 compare_imm_reg(OpndSize_32, 0, PhysicalReg_EBX, true);
82 conditional_jump(Condition_E, ".LcontinueToInterp", true);
83 #ifdef DEBUG_CALL_STACK3
84 move_reg_to_reg(OpndSize_32, PhysicalReg_EBX, true, PhysicalReg_ESI, true);
85 move_imm_to_reg(OpndSize_32, 0xaabb, PhysicalReg_EBX, true);
86 scratchRegs[0] = PhysicalReg_EAX;
87 call_debug_dumpSwitch(); //%ebx, %eax, %edx
88 move_reg_to_reg(OpndSize_32, PhysicalReg_ESI, true, PhysicalReg_EBX, true);
89 call_debug_dumpSwitch();
90 move_reg_to_reg(OpndSize_32, PhysicalReg_ESI, true, PhysicalReg_EBX, true);
91 #endif
92 unconditional_jump_reg(PhysicalReg_EBX, true);
93 insertLabel(".LcontinueToInterp", true);
94 scratchRegs[0] = PhysicalReg_SCRATCH_4;
95 typedef void (*vmHelper)(int);
96 vmHelper funcPtr = dvmJitToInterpNoChainNoProfile; //%eax is the input
97 move_imm_to_reg(OpndSize_32, (int)funcPtr, C_SCRATCH_1, isScratchPhysical);
98 #if defined(WITH_JIT_TUNING)
99 /* Return address not in code cache. Indicate that continuing with interpreter.
100 */
101 move_imm_to_mem(OpndSize_32, kCallsiteInterpreted, 0, PhysicalReg_ESP, true);
102 #endif
103 unconditional_jump_reg(C_SCRATCH_1, isScratchPhysical);
104 touchEax();
105 return 0;
106 }
107 #undef P_GPR_1
108 #undef P_GPR_2
109 #undef P_SCRATCH_1
110
111 //! lower bytecode RETURN_VOID
112
113 //! It seems that shared code cache does not support helper switch
op_return_void()114 int op_return_void() {
115 int retval;
116 retval = common_returnFromMethod();
117 rPC += 1;
118 return retval;
119 }
120
121 //! lower bytecode RETURN
122
123 //! It seems that shared code cache does not support helper switch
124 //! The return value is stored to glue->retval first
op_return()125 int op_return() {
126 u2 vA = INST_AA(inst);
127
128 get_virtual_reg(vA, OpndSize_32, 22, false);
129 scratchRegs[0] = PhysicalReg_SCRATCH_1;
130 set_return_value(OpndSize_32, 22, false);
131
132 common_returnFromMethod();
133 rPC += 1;
134 return 0;
135 }
136
137 //! lower bytecode RETURN_WIDE
138
139 //! It seems that shared code cache does not support helper switch
140 //! The return value is stored to glue->retval first
op_return_wide()141 int op_return_wide() {
142 u2 vA = INST_AA(inst);
143 get_virtual_reg(vA, OpndSize_64, 1, false);
144 scratchRegs[0] = PhysicalReg_SCRATCH_10; scratchRegs[1] = PhysicalReg_Null;
145 scratchRegs[2] = PhysicalReg_Null; scratchRegs[3] = PhysicalReg_Null;
146 set_return_value(OpndSize_64, 1, false);
147
148 common_returnFromMethod();
149 rPC += 1;
150 return 0;
151 }
152