runtime/arch/arm/quick_entrypoints_arm.S

/*
 * Copyright (C) 2012 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 "asm_support_arm.S"

#include "arch/quick_alloc_entrypoints.S"

    /* Deliver the given exception */
    .extern artDeliverExceptionFromCode
    /* Deliver an exception pending on a thread */
    .extern artDeliverPendingException

    /*
     * Macro that sets up the callee save frame to conform with
     * Runtime::CreateCalleeSaveMethod(kSaveAll)
     */
.macro SETUP_SAVE_ALL_CALLEE_SAVE_FRAME
    push {r4-r11, lr} @ 9 words of callee saves
    .save {r4-r11, lr}
    .cfi_adjust_cfa_offset 36
    .cfi_rel_offset r4, 0
    .cfi_rel_offset r5, 4
    .cfi_rel_offset r6, 8
    .cfi_rel_offset r7, 12
    .cfi_rel_offset r8, 16
    .cfi_rel_offset r9, 20
    .cfi_rel_offset r10, 24
    .cfi_rel_offset r11, 28
    .cfi_rel_offset lr, 32
    vpush {s0-s31}
    .pad #128
    .cfi_adjust_cfa_offset 128
    sub sp, #12       @ 3 words of space, bottom word will hold Method*
    .pad #12
    .cfi_adjust_cfa_offset 12
.endm

    /*
     * Macro that sets up the callee save frame to conform with
     * Runtime::CreateCalleeSaveMethod(kRefsOnly).
     */
.macro SETUP_REF_ONLY_CALLEE_SAVE_FRAME
    push {r5-r8, r10-r11, lr} @ 7 words of callee saves
    .save {r5-r8, r10-r11, lr}
    .cfi_adjust_cfa_offset 28
    .cfi_rel_offset r5, 0
    .cfi_rel_offset r6, 4
    .cfi_rel_offset r7, 8
    .cfi_rel_offset r8, 12
    .cfi_rel_offset r10, 16
    .cfi_rel_offset r11, 20
    .cfi_rel_offset lr, 24
    sub sp, #4                @ bottom word will hold Method*
    .pad #4
    .cfi_adjust_cfa_offset 4
.endm

.macro RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    add sp, #4               @ bottom word holds Method*
    pop {r5-r8, r10-r11, lr} @ 7 words of callee saves
    .cfi_restore r5
    .cfi_restore r6
    .cfi_restore r7
    .cfi_restore r8
    .cfi_restore r10
    .cfi_restore r11
    .cfi_adjust_cfa_offset -32
.endm

.macro RESTORE_REF_ONLY_CALLEE_SAVE_FRAME_AND_RETURN
    add sp, #4               @ bottom word holds Method*
    pop {r5-r8, r10-r11, lr} @ 7 words of callee saves
    .cfi_restore r5
    .cfi_restore r6
    .cfi_restore r7
    .cfi_restore r8
    .cfi_restore r10
    .cfi_restore r11
    .cfi_adjust_cfa_offset -32
    bx  lr                   @ return
.endm

    /*
     * Macro that sets up the callee save frame to conform with
     * Runtime::CreateCalleeSaveMethod(kRefsAndArgs).
     */
.macro SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
    push {r1-r3, r5-r8, r10-r11, lr}  @ 10 words of callee saves
    .save {r1-r3, r5-r8, r10-r11, lr}
    .cfi_rel_offset r1, 0
    .cfi_rel_offset r2, 4
    .cfi_rel_offset r3, 8
    .cfi_rel_offset r5, 12
    .cfi_rel_offset r6, 16
    .cfi_rel_offset r7, 20
    .cfi_rel_offset r8, 24
    .cfi_rel_offset r10, 28
    .cfi_rel_offset r11, 32
    .cfi_rel_offset lr, 36
    .cfi_adjust_cfa_offset 40
    sub sp, #8                        @ 2 words of space, bottom word will hold Method*
    .pad #8
    .cfi_adjust_cfa_offset 8
.endm

.macro RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
    add  sp, #8                      @ rewind sp
    pop {r1-r3, r5-r8, r10-r11, lr}  @ 10 words of callee saves
    .cfi_restore r1
    .cfi_restore r2
    .cfi_restore r3
    .cfi_restore r5
    .cfi_restore r6
    .cfi_restore r7
    .cfi_restore r8
    .cfi_restore r10
    .cfi_restore r11
    .cfi_adjust_cfa_offset -48
.endm

.macro RETURN_IF_RESULT_IS_ZERO
    cbnz   r0, 1f              @ result non-zero branch over
    bx     lr                  @ return
1:
.endm

.macro RETURN_IF_RESULT_IS_NON_ZERO
    cbz    r0, 1f              @ result zero branch over
    bx     lr                  @ return
1:
.endm

    /*
     * Macro that set calls through to artDeliverPendingExceptionFromCode, where the pending
     * exception is Thread::Current()->exception_
     */
.macro DELIVER_PENDING_EXCEPTION
    .fnend
    .fnstart
    SETUP_SAVE_ALL_CALLEE_SAVE_FRAME           @ save callee saves for throw
    mov    r0, r9                              @ pass Thread::Current
    mov    r1, sp                              @ pass SP
    b      artDeliverPendingExceptionFromCode  @ artDeliverPendingExceptionFromCode(Thread*, SP)
.endm

.macro NO_ARG_RUNTIME_EXCEPTION c_name, cxx_name
    .extern \cxx_name
ENTRY \c_name
    SETUP_SAVE_ALL_CALLEE_SAVE_FRAME  // save all registers as basis for long jump context
    mov r0, r9                      @ pass Thread::Current
    mov r1, sp                      @ pass SP
    b   \cxx_name                   @ \cxx_name(Thread*, SP)
END \c_name
.endm

.macro ONE_ARG_RUNTIME_EXCEPTION c_name, cxx_name
    .extern \cxx_name
ENTRY \c_name
    SETUP_SAVE_ALL_CALLEE_SAVE_FRAME  // save all registers as basis for long jump context
    mov r1, r9                      @ pass Thread::Current
    mov r2, sp                      @ pass SP
    b   \cxx_name                   @ \cxx_name(Thread*, SP)
    bkpt
END \c_name
.endm

.macro TWO_ARG_RUNTIME_EXCEPTION c_name, cxx_name
    .extern \cxx_name
ENTRY \c_name
    SETUP_SAVE_ALL_CALLEE_SAVE_FRAME  // save all registers as basis for long jump context
    mov r2, r9                      @ pass Thread::Current
    mov r3, sp                      @ pass SP
    b   \cxx_name                   @ \cxx_name(Thread*, SP)
    bkpt
END \c_name
.endm

    /*
     * Called by managed code, saves callee saves and then calls artThrowException
     * that will place a mock Method* at the bottom of the stack. Arg1 holds the exception.
     */
ONE_ARG_RUNTIME_EXCEPTION art_quick_deliver_exception, artDeliverExceptionFromCode

    /*
     * Called by managed code to create and deliver a NullPointerException.
     */
NO_ARG_RUNTIME_EXCEPTION art_quick_throw_null_pointer_exception, artThrowNullPointerExceptionFromCode

    /*
     * Called by managed code to create and deliver an ArithmeticException.
     */
NO_ARG_RUNTIME_EXCEPTION art_quick_throw_div_zero, artThrowDivZeroFromCode

    /*
     * Called by managed code to create and deliver an ArrayIndexOutOfBoundsException. Arg1 holds
     * index, arg2 holds limit.
     */
TWO_ARG_RUNTIME_EXCEPTION art_quick_throw_array_bounds, artThrowArrayBoundsFromCode

    /*
     * Called by managed code to create and deliver a StackOverflowError.
     */
NO_ARG_RUNTIME_EXCEPTION art_quick_throw_stack_overflow, artThrowStackOverflowFromCode

    /*
     * Called by managed code to create and deliver a NoSuchMethodError.
     */
ONE_ARG_RUNTIME_EXCEPTION art_quick_throw_no_such_method, artThrowNoSuchMethodFromCode

    /*
     * All generated callsites for interface invokes and invocation slow paths will load arguments
     * as usual - except instead of loading arg0/r0 with the target Method*, arg0/r0 will contain
     * the method_idx.  This wrapper will save arg1-arg3, load the caller's Method*, align the
     * stack and call the appropriate C helper.
     * NOTE: "this" is first visible argument of the target, and so can be found in arg1/r1.
     *
     * The helper will attempt to locate the target and return a 64-bit result in r0/r1 consisting
     * of the target Method* in r0 and method->code_ in r1.
     *
     * If unsuccessful, the helper will return NULL/NULL. There will bea pending exception in the
     * thread and we branch to another stub to deliver it.
     *
     * On success this wrapper will restore arguments and *jump* to the target, leaving the lr
     * pointing back to the original caller.
     */
.macro INVOKE_TRAMPOLINE c_name, cxx_name
    .extern \cxx_name
ENTRY \c_name
    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME  @ save callee saves in case allocation triggers GC
    ldr    r2, [sp, #48]                  @ pass caller Method*
    mov    r3, r9                         @ pass Thread::Current
    mov    r12, sp
    str    r12, [sp, #-16]!               @ expand the frame and pass SP
    .pad #16
    .cfi_adjust_cfa_offset 16
    bl     \cxx_name                      @ (method_idx, this, caller, Thread*, SP)
    add    sp, #16                        @ strip the extra frame
    .cfi_adjust_cfa_offset -16
    mov    r12, r1                        @ save Method*->code_
    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
    cbz    r0, 1f                         @ did we find the target? if not go to exception delivery
    bx     r12                            @ tail call to target
1:
    DELIVER_PENDING_EXCEPTION
END \c_name
.endm

INVOKE_TRAMPOLINE art_quick_invoke_interface_trampoline, artInvokeInterfaceTrampoline
INVOKE_TRAMPOLINE art_quick_invoke_interface_trampoline_with_access_check, artInvokeInterfaceTrampolineWithAccessCheck

INVOKE_TRAMPOLINE art_quick_invoke_static_trampoline_with_access_check, artInvokeStaticTrampolineWithAccessCheck
INVOKE_TRAMPOLINE art_quick_invoke_direct_trampoline_with_access_check, artInvokeDirectTrampolineWithAccessCheck
INVOKE_TRAMPOLINE art_quick_invoke_super_trampoline_with_access_check, artInvokeSuperTrampolineWithAccessCheck
INVOKE_TRAMPOLINE art_quick_invoke_virtual_trampoline_with_access_check, artInvokeVirtualTrampolineWithAccessCheck

    /*
     * Quick invocation stub.
     * On entry:
     *   r0 = method pointer
     *   r1 = argument array or NULL for no argument methods
     *   r2 = size of argument array in bytes
     *   r3 = (managed) thread pointer
     *   [sp] = JValue* result
     *   [sp + 4] = shorty
     */
ENTRY art_quick_invoke_stub
    push   {r0, r4, r5, r9, r11, lr}       @ spill regs
    .save  {r0, r4, r5, r9, r11, lr}
    .pad #24
    .cfi_adjust_cfa_offset 24
    .cfi_rel_offset r0, 0
    .cfi_rel_offset r4, 4
    .cfi_rel_offset r5, 8
    .cfi_rel_offset r9, 12
    .cfi_rel_offset r11, 16
    .cfi_rel_offset lr, 20
    mov    r11, sp                         @ save the stack pointer
    .cfi_def_cfa_register r11
    mov    r9, r3                          @ move managed thread pointer into r9
    mov    r4, #SUSPEND_CHECK_INTERVAL     @ reset r4 to suspend check interval
    add    r5, r2, #16                     @ create space for method pointer in frame
    and    r5, #0xFFFFFFF0                 @ align frame size to 16 bytes
    sub    sp, r5                          @ reserve stack space for argument array
    add    r0, sp, #4                      @ pass stack pointer + method ptr as dest for memcpy
    bl     memcpy                          @ memcpy (dest, src, bytes)
    ldr    r0, [r11]                       @ restore method*
    ldr    r1, [sp, #4]                    @ copy arg value for r1
    ldr    r2, [sp, #8]                    @ copy arg value for r2
    ldr    r3, [sp, #12]                   @ copy arg value for r3
    mov    ip, #0                          @ set ip to 0
    str    ip, [sp]                        @ store NULL for method* at bottom of frame
    ldr    ip, [r0, #METHOD_QUICK_CODE_OFFSET]  @ get pointer to the code
    blx    ip                              @ call the method
    mov    sp, r11                         @ restore the stack pointer
    ldr    ip, [sp, #24]                   @ load the result pointer
    strd   r0, [ip]                        @ store r0/r1 into result pointer
    pop    {r0, r4, r5, r9, r11, lr}       @ restore spill regs
    .cfi_restore r0
    .cfi_restore r4
    .cfi_restore r5
    .cfi_restore r9
    .cfi_restore lr
    .cfi_adjust_cfa_offset -24
    bx     lr
END art_quick_invoke_stub

    /*
     * On entry r0 is uint32_t* gprs_ and r1 is uint32_t* fprs_
     */
ARM_ENTRY art_quick_do_long_jump
    vldm r1, {s0-s31}     @ load all fprs from argument fprs_
    ldr  r2, [r0, #60]    @ r2 = r15 (PC from gprs_ 60=4*15)
    add  r0, r0, #12      @ increment r0 to skip gprs_[0..2] 12=4*3
    ldm  r0, {r3-r14}     @ load remaining gprs from argument gprs_
    mov  r0, #0           @ clear result registers r0 and r1
    mov  r1, #0
    bx   r2               @ do long jump
END art_quick_do_long_jump

    /*
     * Entry from managed code that calls artHandleFillArrayDataFromCode and delivers exception on
     * failure.
     */
    .extern artHandleFillArrayDataFromCode
ENTRY art_quick_handle_fill_data
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME  @ save callee saves in case exception allocation triggers GC
    mov    r2, r9                          @ pass Thread::Current
    mov    r3, sp                          @ pass SP
    bl     artHandleFillArrayDataFromCode  @ (Array*, const DexFile::Payload*, Thread*, SP)
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_handle_fill_data

    /*
     * Entry from managed code that calls artLockObjectFromCode, may block for GC. r0 holds the
     * possibly null object to lock.
     */
    .extern artLockObjectFromCode
ENTRY art_quick_lock_object
    cbz    r0, slow_lock
retry_lock:
    ldr    r2, [r9, #THREAD_ID_OFFSET]
    ldrex  r1, [r0, #LOCK_WORD_OFFSET]
    cbnz   r1, not_unlocked           @ already thin locked
    @ unlocked case - r2 holds thread id with count of 0
    strex  r3, r2, [r0, #LOCK_WORD_OFFSET]
    cbnz   r3, strex_fail             @ store failed, retry
    dmb    ish                        @ full (LoadLoad) memory barrier
    bx lr
strex_fail:
    b retry_lock                      @ unlikely forward branch, need to reload and recheck r1/r2
not_unlocked:
    lsr    r3, r1, 30
    cbnz   r3, slow_lock              @ if either of the top two bits are set, go slow path
    eor    r2, r1, r2                 @ lock_word.ThreadId() ^ self->ThreadId()
    uxth   r2, r2                     @ zero top 16 bits
    cbnz   r2, slow_lock              @ lock word and self thread id's match -> recursive lock
                                      @ else contention, go to slow path
    add    r2, r1, #65536             @ increment count in lock word placing in r2 for storing
    lsr    r1, r2, 30                 @ if either of the top two bits are set, we overflowed.
    cbnz   r1, slow_lock              @ if we overflow the count go slow path
    str    r2, [r0, #LOCK_WORD_OFFSET] @ no need for strex as we hold the lock
    bx lr
slow_lock:
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME  @ save callee saves in case we block
    mov    r1, r9                     @ pass Thread::Current
    mov    r2, sp                     @ pass SP
    bl     artLockObjectFromCode      @ (Object* obj, Thread*, SP)
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_lock_object

    /*
     * Entry from managed code that calls artUnlockObjectFromCode and delivers exception on failure.
     * r0 holds the possibly null object to lock.
     */
    .extern artUnlockObjectFromCode
ENTRY art_quick_unlock_object
    cbz    r0, slow_unlock
    ldr    r1, [r0, #LOCK_WORD_OFFSET]
    lsr    r2, r1, 30
    cbnz   r2, slow_unlock            @ if either of the top two bits are set, go slow path
    ldr    r2, [r9, #THREAD_ID_OFFSET]
    eor    r3, r1, r2                 @ lock_word.ThreadId() ^ self->ThreadId()
    uxth   r3, r3                     @ zero top 16 bits
    cbnz   r3, slow_unlock            @ do lock word and self thread id's match?
    cmp    r1, #65536
    bpl    recursive_thin_unlock
    @ transition to unlocked, r3 holds 0
    str    r3, [r0, #LOCK_WORD_OFFSET]
    dmb    ish                        @ full (StoreLoad) memory barrier
    bx     lr
recursive_thin_unlock:
    sub    r1, r1, #65536
    str    r1, [r0, #LOCK_WORD_OFFSET]
    bx     lr
slow_unlock:
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME  @ save callee saves in case exception allocation triggers GC
    mov    r1, r9                     @ pass Thread::Current
    mov    r2, sp                     @ pass SP
    bl     artUnlockObjectFromCode    @ (Object* obj, Thread*, SP)
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_unlock_object

    /*
     * Entry from managed code that calls artIsAssignableFromCode and on failure calls
     * artThrowClassCastException.
     */
    .extern artThrowClassCastException
ENTRY art_quick_check_cast
    push {r0-r1, lr}                    @ save arguments, link register and pad
    .save {r0-r1, lr}
    .cfi_adjust_cfa_offset 12
    .cfi_rel_offset r0, 0
    .cfi_rel_offset r1, 4
    .cfi_rel_offset lr, 8
    sub sp, #4
    .pad #4
    .cfi_adjust_cfa_offset 4
    bl artIsAssignableFromCode
    cbz    r0, throw_class_cast_exception
    add sp, #4
    .cfi_adjust_cfa_offset -4
    pop {r0-r1, pc}
throw_class_cast_exception:
    add sp, #4
    .cfi_adjust_cfa_offset -4
    pop {r0-r1, lr}
    .cfi_restore r0
    .cfi_restore r1
    SETUP_SAVE_ALL_CALLEE_SAVE_FRAME  // save all registers as basis for long jump context
    mov r2, r9                      @ pass Thread::Current
    mov r3, sp                      @ pass SP
    b   artThrowClassCastException  @ (Class*, Class*, Thread*, SP)
    bkpt
END art_quick_check_cast

    /*
     * Entry from managed code for array put operations of objects where the value being stored
     * needs to be checked for compatibility.
     * r0 = array, r1 = index, r2 = value
     */
ENTRY art_quick_aput_obj_with_null_and_bound_check
    tst r0, r0
    bne art_quick_aput_obj_with_bound_check
    b art_quick_throw_null_pointer_exception
END art_quick_aput_obj_with_null_and_bound_check

ENTRY art_quick_aput_obj_with_bound_check
    ldr r3, [r0, #ARRAY_LENGTH_OFFSET]
    cmp r3, r1
    bhi art_quick_aput_obj
    mov r0, r1
    mov r1, r3
    b art_quick_throw_array_bounds
END art_quick_aput_obj_with_bound_check

ENTRY art_quick_aput_obj
    cbz r2, do_aput_null
    ldr r3, [r0, #CLASS_OFFSET]
    ldr ip, [r2, #CLASS_OFFSET]
    ldr r3, [r3, #CLASS_COMPONENT_TYPE_OFFSET]
    cmp r3, ip  @ value's type == array's component type - trivial assignability
    bne check_assignability
do_aput:
    add r3, r0, #OBJECT_ARRAY_DATA_OFFSET
    str r2, [r3, r1, lsl #2]
    ldr r3, [r9, #THREAD_CARD_TABLE_OFFSET]
    lsr r0, r0, #7
    strb r3, [r3, r0]
    blx lr
do_aput_null:
    add r3, r0, #OBJECT_ARRAY_DATA_OFFSET
    str r2, [r3, r1, lsl #2]
    blx lr
check_assignability:
    push {r0-r2, lr}                 @ save arguments
    mov r1, ip
    mov r0, r3
    bl artIsAssignableFromCode
    cbz r0, throw_array_store_exception
    pop {r0-r2, lr}
    add r3, r0, #OBJECT_ARRAY_DATA_OFFSET
    str r2, [r3, r1, lsl #2]
    ldr r3, [r9, #THREAD_CARD_TABLE_OFFSET]
    lsr r0, r0, #7
    strb r3, [r3, r0]
    blx lr
throw_array_store_exception:
    pop {r0-r2, lr}
    SETUP_SAVE_ALL_CALLEE_SAVE_FRAME
    mov r1, r2
    mov r2, r9                   @ pass Thread::Current
    mov r3, sp                   @ pass SP
    b artThrowArrayStoreException  @ (Class*, Class*, Thread*, SP)
    bkpt                         @ unreached
END art_quick_aput_obj

    /*
     * Entry from managed code when uninitialized static storage, this stub will run the class
     * initializer and deliver the exception on error. On success the static storage base is
     * returned.
     */
    .extern artInitializeStaticStorageFromCode
ENTRY art_quick_initialize_static_storage
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME           @ save callee saves in case of GC
    mov    r2, r9                              @ pass Thread::Current
    mov    r3, sp                              @ pass SP
    @ artInitializeStaticStorageFromCode(uint32_t type_idx, Method* referrer, Thread*, SP)
    bl     artInitializeStaticStorageFromCode
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_NON_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_initialize_static_storage

    /*
     * Entry from managed code when dex cache misses for a type_idx
     */
    .extern artInitializeTypeFromCode
ENTRY art_quick_initialize_type
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME           @ save callee saves in case of GC
    mov    r2, r9                              @ pass Thread::Current
    mov    r3, sp                              @ pass SP
    @ artInitializeTypeFromCode(uint32_t type_idx, Method* referrer, Thread*, SP)
    bl     artInitializeTypeFromCode
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_NON_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_initialize_type

    /*
     * Entry from managed code when type_idx needs to be checked for access and dex cache may also
     * miss.
     */
    .extern artInitializeTypeAndVerifyAccessFromCode
ENTRY art_quick_initialize_type_and_verify_access
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME           @ save callee saves in case of GC
    mov    r2, r9                              @ pass Thread::Current
    mov    r3, sp                              @ pass SP
    @ artInitializeTypeAndVerifyAccessFromCode(uint32_t type_idx, Method* referrer, Thread*, SP)
    bl     artInitializeTypeAndVerifyAccessFromCode
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_NON_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_initialize_type_and_verify_access

    /*
     * Called by managed code to resolve a static field and load a 32-bit primitive value.
     */
    .extern artGet32StaticFromCode
ENTRY art_quick_get32_static
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r1, [sp, #32]                 @ pass referrer
    mov    r2, r9                        @ pass Thread::Current
    mov    r3, sp                        @ pass SP
    bl     artGet32StaticFromCode        @ (uint32_t field_idx, const Method* referrer, Thread*, SP)
    ldr    r1, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    cbnz   r1, 1f                        @ success if no exception pending
    bx     lr                            @ return on success
1:
    DELIVER_PENDING_EXCEPTION
END art_quick_get32_static

    /*
     * Called by managed code to resolve a static field and load a 64-bit primitive value.
     */
    .extern artGet64StaticFromCode
ENTRY art_quick_get64_static
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r1, [sp, #32]                 @ pass referrer
    mov    r2, r9                        @ pass Thread::Current
    mov    r3, sp                        @ pass SP
    bl     artGet64StaticFromCode        @ (uint32_t field_idx, const Method* referrer, Thread*, SP)
    ldr    r2, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    cbnz   r2, 1f                        @ success if no exception pending
    bx     lr                            @ return on success
1:
    DELIVER_PENDING_EXCEPTION
END art_quick_get64_static

    /*
     * Called by managed code to resolve a static field and load an object reference.
     */
    .extern artGetObjStaticFromCode
ENTRY art_quick_get_obj_static
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r1, [sp, #32]                 @ pass referrer
    mov    r2, r9                        @ pass Thread::Current
    mov    r3, sp                        @ pass SP
    bl     artGetObjStaticFromCode       @ (uint32_t field_idx, const Method* referrer, Thread*, SP)
    ldr    r1, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    cbnz   r1, 1f                        @ success if no exception pending
    bx     lr                            @ return on success
1:
    DELIVER_PENDING_EXCEPTION
END art_quick_get_obj_static

    /*
     * Called by managed code to resolve an instance field and load a 32-bit primitive value.
     */
    .extern artGet32InstanceFromCode
ENTRY art_quick_get32_instance
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r2, [sp, #32]                 @ pass referrer
    mov    r3, r9                        @ pass Thread::Current
    mov    r12, sp
    str    r12, [sp, #-16]!              @ expand the frame and pass SP
    bl     artGet32InstanceFromCode      @ (field_idx, Object*, referrer, Thread*, SP)
    add    sp, #16                       @ strip the extra frame
    ldr    r1, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    cbnz   r1, 1f                        @ success if no exception pending
    bx     lr                            @ return on success
1:
    DELIVER_PENDING_EXCEPTION
END art_quick_get32_instance

    /*
     * Called by managed code to resolve an instance field and load a 64-bit primitive value.
     */
    .extern artGet64InstanceFromCode
ENTRY art_quick_get64_instance
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r2, [sp, #32]                 @ pass referrer
    mov    r3, r9                        @ pass Thread::Current
    mov    r12, sp
    str    r12, [sp, #-16]!              @ expand the frame and pass SP
    .pad #16
    .cfi_adjust_cfa_offset 16
    bl     artGet64InstanceFromCode      @ (field_idx, Object*, referrer, Thread*, SP)
    add    sp, #16                       @ strip the extra frame
    .cfi_adjust_cfa_offset -16
    ldr    r2, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    cbnz   r2, 1f                        @ success if no exception pending
    bx     lr                            @ return on success
1:
    DELIVER_PENDING_EXCEPTION
END art_quick_get64_instance

    /*
     * Called by managed code to resolve an instance field and load an object reference.
     */
    .extern artGetObjInstanceFromCode
ENTRY art_quick_get_obj_instance
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r2, [sp, #32]                 @ pass referrer
    mov    r3, r9                        @ pass Thread::Current
    mov    r12, sp
    str    r12, [sp, #-16]!              @ expand the frame and pass SP
    .pad #16
    .cfi_adjust_cfa_offset 16
    bl     artGetObjInstanceFromCode     @ (field_idx, Object*, referrer, Thread*, SP)
    add    sp, #16                       @ strip the extra frame
    .cfi_adjust_cfa_offset -16
    ldr    r1, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    cbnz   r1, 1f                        @ success if no exception pending
    bx     lr                            @ return on success
1:
    DELIVER_PENDING_EXCEPTION
END art_quick_get_obj_instance

    /*
     * Called by managed code to resolve a static field and store a 32-bit primitive value.
     */
    .extern artSet32StaticFromCode
ENTRY art_quick_set32_static
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r2, [sp, #32]                 @ pass referrer
    mov    r3, r9                        @ pass Thread::Current
    mov    r12, sp
    str    r12, [sp, #-16]!              @ expand the frame and pass SP
    .pad #16
    .cfi_adjust_cfa_offset 16
    bl     artSet32StaticFromCode        @ (field_idx, new_val, referrer, Thread*, SP)
    add    sp, #16                       @ strip the extra frame
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_set32_static

    /*
     * Called by managed code to resolve a static field and store a 64-bit primitive value.
     * On entry r0 holds field index, r1:r2 hold new_val
     */
    .extern artSet64StaticFromCode
ENTRY art_quick_set64_static
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    mov    r3, r2                        @ pass one half of wide argument
    mov    r2, r1                        @ pass other half of wide argument
    ldr    r1, [sp, #32]                 @ pass referrer
    mov    r12, sp                       @ save SP
    sub    sp, #8                        @ grow frame for alignment with stack args
    .pad #8
    .cfi_adjust_cfa_offset 8
    push   {r9, r12}                     @ pass Thread::Current and SP
    .save {r9, r12}
    .cfi_adjust_cfa_offset 8
    .cfi_rel_offset r9, 0
    bl     artSet64StaticFromCode        @ (field_idx, referrer, new_val, Thread*, SP)
    add    sp, #16                       @ release out args
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME   @ TODO: we can clearly save an add here
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_set64_static

    /*
     * Called by managed code to resolve a static field and store an object reference.
     */
    .extern artSetObjStaticFromCode
ENTRY art_quick_set_obj_static
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r2, [sp, #32]                 @ pass referrer
    mov    r3, r9                        @ pass Thread::Current
    mov    r12, sp
    str    r12, [sp, #-16]!              @ expand the frame and pass SP
    .pad #16
    .cfi_adjust_cfa_offset 16
    bl     artSetObjStaticFromCode       @ (field_idx, new_val, referrer, Thread*, SP)
    add    sp, #16                       @ strip the extra frame
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_set_obj_static

    /*
     * Called by managed code to resolve an instance field and store a 32-bit primitive value.
     */
    .extern artSet32InstanceFromCode
ENTRY art_quick_set32_instance
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r3, [sp, #32]                 @ pass referrer
    mov    r12, sp                       @ save SP
    sub    sp, #8                        @ grow frame for alignment with stack args
    .pad #8
    .cfi_adjust_cfa_offset 8
    push   {r9, r12}                     @ pass Thread::Current and SP
    .save {r9, r12}
    .cfi_adjust_cfa_offset 8
    .cfi_rel_offset r9, 0
    .cfi_rel_offset r12, 4
    bl     artSet32InstanceFromCode      @ (field_idx, Object*, new_val, referrer, Thread*, SP)
    add    sp, #16                       @ release out args
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME   @ TODO: we can clearly save an add here
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_set32_instance

    /*
     * Called by managed code to resolve an instance field and store a 64-bit primitive value.
     */
    .extern artSet32InstanceFromCode
ENTRY art_quick_set64_instance
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    mov    r12, sp                       @ save SP
    sub    sp, #8                        @ grow frame for alignment with stack args
    .pad #8
    .cfi_adjust_cfa_offset 8
    push   {r9, r12}                     @ pass Thread::Current and SP
    .save {r9, r12}
    .cfi_adjust_cfa_offset 8
    .cfi_rel_offset r9, 0
    bl     artSet64InstanceFromCode      @ (field_idx, Object*, new_val, Thread*, SP)
    add    sp, #16                       @ release out args
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME   @ TODO: we can clearly save an add here
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_set64_instance

    /*
     * Called by managed code to resolve an instance field and store an object reference.
     */
    .extern artSetObjInstanceFromCode
ENTRY art_quick_set_obj_instance
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME     @ save callee saves in case of GC
    ldr    r3, [sp, #32]                 @ pass referrer
    mov    r12, sp                       @ save SP
    sub    sp, #8                        @ grow frame for alignment with stack args
    .pad #8
    .cfi_adjust_cfa_offset 8
    push   {r9, r12}                     @ pass Thread::Current and SP
    .save {r9, r12}
    .cfi_adjust_cfa_offset 8
    .cfi_rel_offset r9, 0
    bl     artSetObjInstanceFromCode     @ (field_idx, Object*, new_val, referrer, Thread*, SP)
    add    sp, #16                       @ release out args
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME   @ TODO: we can clearly save an add here
    RETURN_IF_RESULT_IS_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_set_obj_instance

    /*
     * Entry from managed code to resolve a string, this stub will allocate a String and deliver an
     * exception on error. On success the String is returned. R0 holds the referring method,
     * R1 holds the string index. The fast path check for hit in strings cache has already been
     * performed.
     */
    .extern artResolveStringFromCode
ENTRY art_quick_resolve_string
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME  @ save callee saves in case of GC
    mov    r2, r9                     @ pass Thread::Current
    mov    r3, sp                     @ pass SP
    @ artResolveStringFromCode(Method* referrer, uint32_t string_idx, Thread*, SP)
    bl     artResolveStringFromCode
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    RETURN_IF_RESULT_IS_NON_ZERO
    DELIVER_PENDING_EXCEPTION
END art_quick_resolve_string

// Macro to facilitate adding new allocation entrypoints.
.macro TWO_ARG_DOWNCALL name, entrypoint, return
    .extern \entrypoint
ENTRY \name
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME  @ save callee saves in case of GC
    mov    r2, r9                     @ pass Thread::Current
    mov    r3, sp                     @ pass SP
    bl     \entrypoint     @ (uint32_t type_idx, Method* method, Thread*, SP)
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    \return
    DELIVER_PENDING_EXCEPTION
END \name
.endm

// Macro to facilitate adding new array allocation entrypoints.
.macro THREE_ARG_DOWNCALL name, entrypoint, return
    .extern \entrypoint
ENTRY \name
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME  @ save callee saves in case of GC
    mov    r3, r9                     @ pass Thread::Current
    mov    r12, sp
    str    r12, [sp, #-16]!           @ expand the frame and pass SP
    .pad #16
    .cfi_adjust_cfa_offset 16
    @ (uint32_t type_idx, Method* method, int32_t component_count, Thread*, SP)
    bl     \entrypoint
    add    sp, #16                    @ strip the extra frame
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    \return
    DELIVER_PENDING_EXCEPTION
END \name
.endm

// Generate the allocation entrypoints for each allocator.
GENERATE_ALL_ALLOC_ENTRYPOINTS

    /*
     * Called by managed code when the value in rSUSPEND has been decremented to 0.
     */
    .extern artTestSuspendFromCode
ENTRY art_quick_test_suspend
    ldrh    r0, [rSELF, #THREAD_FLAGS_OFFSET]
    mov    rSUSPEND, #SUSPEND_CHECK_INTERVAL  @ reset rSUSPEND to SUSPEND_CHECK_INTERVAL
    cbnz   r0, 1f                             @ check Thread::Current()->suspend_count_ == 0
    bx     lr                                 @ return if suspend_count_ == 0
1:
    mov    r0, rSELF
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME          @ save callee saves for stack crawl
    mov    r1, sp
    bl     artTestSuspendFromCode             @ (Thread*, SP)
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME_AND_RETURN
END art_quick_test_suspend

    /*
     * Called by managed code that is attempting to call a method on a proxy class. On entry
     * r0 holds the proxy method and r1 holds the receiver; r2 and r3 may contain arguments. The
     * frame size of the invoked proxy method agrees with a ref and args callee save frame.
     */
     .extern artQuickProxyInvokeHandler
ENTRY art_quick_proxy_invoke_handler
    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
    str     r0, [sp, #0]           @ place proxy method at bottom of frame
    mov     r2, r9                 @ pass Thread::Current
    mov     r3, sp                 @ pass SP
    blx     artQuickProxyInvokeHandler  @ (Method* proxy method, receiver, Thread*, SP)
    ldr     r2, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    add     sp, #16                @ skip r1-r3, 4 bytes padding.
    .cfi_adjust_cfa_offset -16
    cbnz    r2, 1f                 @ success if no exception is pending
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    bx      lr                     @ return on success
1:
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    DELIVER_PENDING_EXCEPTION
END art_quick_proxy_invoke_handler

    /*
     * Called to resolve an imt conflict. r12 is a hidden argument that holds the target method's
     * dex method index.
     */
ENTRY art_quick_imt_conflict_trampoline
    ldr    r0, [sp, #0]            @ load caller Method*
    ldr    r0, [r0, #METHOD_DEX_CACHE_METHODS_OFFSET]  @ load dex_cache_resolved_methods
    add    r0, #OBJECT_ARRAY_DATA_OFFSET  @ get starting address of data
    ldr    r0, [r0, r12, lsl 2]    @ load the target method
    b art_quick_invoke_interface_trampoline
END art_quick_imt_conflict_trampoline

    .extern artQuickResolutionTrampoline
ENTRY art_quick_resolution_trampoline
    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
    mov     r2, r9                 @ pass Thread::Current
    mov     r3, sp                 @ pass SP
    blx     artQuickResolutionTrampoline  @ (Method* called, receiver, Thread*, SP)
    cbz     r0, 1f                 @ is code pointer null? goto exception
    mov     r12, r0
    ldr  r0, [sp, #0]              @ load resolved method in r0
    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
    bx      r12                    @ tail-call into actual code
1:
    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
    DELIVER_PENDING_EXCEPTION
END art_quick_resolution_trampoline

    .extern artQuickToInterpreterBridge
ENTRY art_quick_to_interpreter_bridge
    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
    mov     r1, r9                 @ pass Thread::Current
    mov     r2, sp                 @ pass SP
    blx     artQuickToInterpreterBridge    @ (Method* method, Thread*, SP)
    ldr     r2, [r9, #THREAD_EXCEPTION_OFFSET]  @ load Thread::Current()->exception_
    add     sp, #16                @ skip r1-r3, 4 bytes padding.
    .cfi_adjust_cfa_offset -16
    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
    cbnz    r2, 1f                 @ success if no exception is pending
    bx    lr                       @ return on success
1:
    DELIVER_PENDING_EXCEPTION
END art_quick_to_interpreter_bridge

    /*
     * Routine that intercepts method calls and returns.
     */
    .extern artInstrumentationMethodEntryFromCode
    .extern artInstrumentationMethodExitFromCode
ENTRY art_quick_instrumentation_entry
    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
    str   r0, [sp, #4]     @ preserve r0
    mov   r12, sp          @ remember sp
    str   lr, [sp, #-16]!  @ expand the frame and pass LR
    .pad #16
    .cfi_adjust_cfa_offset 16
    .cfi_rel_offset lr, 0
    mov   r2, r9         @ pass Thread::Current
    mov   r3, r12        @ pass SP
    blx   artInstrumentationMethodEntryFromCode  @ (Method*, Object*, Thread*, SP, LR)
    add   sp, #16        @ remove out argument and padding from stack
    .cfi_adjust_cfa_offset -16
    mov   r12, r0        @ r12 holds reference to code
    ldr   r0, [sp, #4]   @ restore r0
    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
    blx   r12            @ call method with lr set to art_quick_instrumentation_exit
END art_quick_instrumentation_entry
    .type art_quick_instrumentation_exit, #function
    .global art_quick_instrumentation_exit
art_quick_instrumentation_exit:
    .cfi_startproc
    .fnstart
    mov   lr, #0         @ link register is to here, so clobber with 0 for later checks
    SETUP_REF_ONLY_CALLEE_SAVE_FRAME
    mov   r12, sp        @ remember bottom of caller's frame
    push  {r0-r1}        @ save return value
    .save {r0-r1}
    .cfi_adjust_cfa_offset 8
    .cfi_rel_offset r0, 0
    .cfi_rel_offset r1, 4
    sub   sp, #8         @ space for return value argument
    .pad #8
    .cfi_adjust_cfa_offset 8
    strd r0, [sp]        @ r0/r1 -> [sp] for fpr_res
    mov   r2, r0         @ pass return value as gpr_res
    mov   r3, r1
    mov   r0, r9         @ pass Thread::Current
    mov   r1, r12        @ pass SP
    blx   artInstrumentationMethodExitFromCode  @ (Thread*, SP, gpr_res, fpr_res)
    add   sp, #8
    .cfi_adjust_cfa_offset -8

    mov   r2, r0         @ link register saved by instrumentation
    mov   lr, r1         @ r1 is holding link register if we're to bounce to deoptimize
    pop   {r0, r1}       @ restore return value
    .cfi_restore r0
    .cfi_restore r1
    add sp, #32          @ remove callee save frame
    .cfi_adjust_cfa_offset -32
    bx    r2             @ return
END art_quick_instrumentation_exit

    /*
     * Instrumentation has requested that we deoptimize into the interpreter. The deoptimization
     * will long jump to the upcall with a special exception of -1.
     */
    .extern artDeoptimize
ENTRY art_quick_deoptimize
    SETUP_SAVE_ALL_CALLEE_SAVE_FRAME
    mov    r0, r9         @ Set up args.
    mov    r1, sp
    blx    artDeoptimize  @ artDeoptimize(Thread*, SP)
END art_quick_deoptimize

    /*
     * Signed 64-bit integer multiply.
     *
     * Consider WXxYZ (r1r0 x r3r2) with a long multiply:
     *        WX
     *      x YZ
     *  --------
     *     ZW ZX
     *  YW YX
     *
     * The low word of the result holds ZX, the high word holds
     * (ZW+YX) + (the high overflow from ZX).  YW doesn't matter because
     * it doesn't fit in the low 64 bits.
     *
     * Unlike most ARM math operations, multiply instructions have
     * restrictions on using the same register more than once (Rd and Rm
     * cannot be the same).
     */
    /* mul-long vAA, vBB, vCC */
ENTRY art_quick_mul_long
    push    {r9 - r10}
    .save {r9 - r10}
    .cfi_adjust_cfa_offset 8
    .cfi_rel_offset r9, 0
    .cfi_rel_offset r10, 4
    mul     ip, r2, r1                  @  ip<- ZxW
    umull   r9, r10, r2, r0             @  r9/r10 <- ZxX
    mla     r2, r0, r3, ip              @  r2<- YxX + (ZxW)
    add     r10, r2, r10                @  r10<- r10 + low(ZxW + (YxX))
    mov     r0,r9
    mov     r1,r10
    pop     {r9 - r10}
    .cfi_adjust_cfa_offset -8
    .cfi_restore r9
    .cfi_restore r10
    bx      lr
END art_quick_mul_long

    /*
     * Long integer shift.  This is different from the generic 32/64-bit
     * binary operations because vAA/vBB are 64-bit but vCC (the shift
     * distance) is 32-bit.  Also, Dalvik requires us to ignore all but the low
     * 6 bits.
     * On entry:
     *   r0: low word
     *   r1: high word
     *   r2: shift count
     */
    /* shl-long vAA, vBB, vCC */
ARM_ENTRY art_quick_shl_long            @ ARM code as thumb code requires spills
    and     r2, r2, #63                 @ r2<- r2 & 0x3f
    mov     r1, r1, asl r2              @  r1<- r1 << r2
    rsb     r3, r2, #32                 @  r3<- 32 - r2
    orr     r1, r1, r0, lsr r3          @  r1<- r1 | (r0 << (32-r2))
    subs    ip, r2, #32                 @  ip<- r2 - 32
    movpl   r1, r0, asl ip              @  if r2 >= 32, r1<- r0 << (r2-32)
    mov     r0, r0, asl r2              @  r0<- r0 << r2
    bx      lr
END art_quick_shl_long

    /*
     * Long integer shift.  This is different from the generic 32/64-bit
     * binary operations because vAA/vBB are 64-bit but vCC (the shift
     * distance) is 32-bit.  Also, Dalvik requires us to ignore all but the low
     * 6 bits.
     * On entry:
     *   r0: low word
     *   r1: high word
     *   r2: shift count
     */
    /* shr-long vAA, vBB, vCC */
ARM_ENTRY art_quick_shr_long            @ ARM code as thumb code requires spills
    and     r2, r2, #63                 @ r0<- r0 & 0x3f
    mov     r0, r0, lsr r2              @  r0<- r2 >> r2
    rsb     r3, r2, #32                 @  r3<- 32 - r2
    orr     r0, r0, r1, asl r3          @  r0<- r0 | (r1 << (32-r2))
    subs    ip, r2, #32                 @  ip<- r2 - 32
    movpl   r0, r1, asr ip              @  if r2 >= 32, r0<-r1 >> (r2-32)
    mov     r1, r1, asr r2              @  r1<- r1 >> r2
    bx      lr
END art_quick_shr_long

    /*
     * Long integer shift.  This is different from the generic 32/64-bit
     * binary operations because vAA/vBB are 64-bit but vCC (the shift
     * distance) is 32-bit.  Also, Dalvik requires us to ignore all but the low
     * 6 bits.
     * On entry:
     *   r0: low word
     *   r1: high word
     *   r2: shift count
     */
    /* ushr-long vAA, vBB, vCC */
ARM_ENTRY art_quick_ushr_long           @ ARM code as thumb code requires spills
    and     r2, r2, #63                 @ r0<- r0 & 0x3f
    mov     r0, r0, lsr r2              @  r0<- r2 >> r2
    rsb     r3, r2, #32                 @  r3<- 32 - r2
    orr     r0, r0, r1, asl r3          @  r0<- r0 | (r1 << (32-r2))
    subs    ip, r2, #32                 @  ip<- r2 - 32
    movpl   r0, r1, lsr ip              @  if r2 >= 32, r0<-r1 >>> (r2-32)
    mov     r1, r1, lsr r2              @  r1<- r1 >>> r2
    bx      lr
END art_quick_ushr_long

    /*
     * String's indexOf.
     *
     * On entry:
     *    r0:   string object (known non-null)
     *    r1:   char to match (known <= 0xFFFF)
     *    r2:   Starting offset in string data
     */
ENTRY art_quick_indexof
    push {r4, r10-r11, lr} @ 4 words of callee saves
    .save {r4, r10-r11, lr}
    .cfi_adjust_cfa_offset 16
    .cfi_rel_offset r4, 0
    .cfi_rel_offset r10, 4
    .cfi_rel_offset r11, 8
    .cfi_rel_offset lr, 12
    ldr   r3, [r0, #STRING_COUNT_OFFSET]
    ldr   r12, [r0, #STRING_OFFSET_OFFSET]
    ldr   r0, [r0, #STRING_VALUE_OFFSET]

    /* Clamp start to [0..count] */
    cmp   r2, #0
    it    lt
    movlt r2, #0
    cmp   r2, r3
    it    gt
    movgt r2, r3

    /* Build a pointer to the start of string data */
    add   r0, #STRING_DATA_OFFSET
    add   r0, r0, r12, lsl #1

    /* Save a copy in r12 to later compute result */
    mov   r12, r0

    /* Build pointer to start of data to compare and pre-bias */
    add   r0, r0, r2, lsl #1
    sub   r0, #2

    /* Compute iteration count */
    sub   r2, r3, r2

    /*
     * At this point we have:
     *   r0: start of data to test
     *   r1: char to compare
     *   r2: iteration count
     *   r12: original start of string data
     *   r3, r4, r10, r11 available for loading string data
     */

    subs  r2, #4
    blt   indexof_remainder

indexof_loop4:
    ldrh  r3, [r0, #2]!
    ldrh  r4, [r0, #2]!
    ldrh  r10, [r0, #2]!
    ldrh  r11, [r0, #2]!
    cmp   r3, r1
    beq   match_0
    cmp   r4, r1
    beq   match_1
    cmp   r10, r1
    beq   match_2
    cmp   r11, r1
    beq   match_3
    subs  r2, #4
    bge   indexof_loop4

indexof_remainder:
    adds    r2, #4
    beq     indexof_nomatch

indexof_loop1:
    ldrh  r3, [r0, #2]!
    cmp   r3, r1
    beq   match_3
    subs  r2, #1
    bne   indexof_loop1

indexof_nomatch:
    mov   r0, #-1
    pop {r4, r10-r11, pc}

match_0:
    sub   r0, #6
    sub   r0, r12
    asr   r0, r0, #1
    pop {r4, r10-r11, pc}
match_1:
    sub   r0, #4
    sub   r0, r12
    asr   r0, r0, #1
    pop {r4, r10-r11, pc}
match_2:
    sub   r0, #2
    sub   r0, r12
    asr   r0, r0, #1
    pop {r4, r10-r11, pc}
match_3:
    sub   r0, r12
    asr   r0, r0, #1
    pop {r4, r10-r11, pc}
END art_quick_indexof

   /*
     * String's compareTo.
     *
     * Requires rARG0/rARG1 to have been previously checked for null.  Will
     * return negative if this's string is < comp, 0 if they are the
     * same and positive if >.
     *
     * On entry:
     *    r0:   this object pointer
     *    r1:   comp object pointer
     *
     */
    .extern __memcmp16
ENTRY art_quick_string_compareto
    mov    r2, r0         @ this to r2, opening up r0 for return value
    sub    r0, r2, r1     @ Same?
    cbnz   r0,1f
    bx     lr
1:                        @ Same strings, return.

    push {r4, r7-r12, lr} @ 8 words - keep alignment
    .save {r4, r7-r12, lr}
    .cfi_adjust_cfa_offset 32
    .cfi_rel_offset r4, 0
    .cfi_rel_offset r7, 4
    .cfi_rel_offset r8, 8
    .cfi_rel_offset r9, 12
    .cfi_rel_offset r10, 16
    .cfi_rel_offset r11, 20
    .cfi_rel_offset r12, 24
    .cfi_rel_offset lr, 28

    ldr    r4, [r2, #STRING_OFFSET_OFFSET]
    ldr    r9, [r1, #STRING_OFFSET_OFFSET]
    ldr    r7, [r2, #STRING_COUNT_OFFSET]
    ldr    r10, [r1, #STRING_COUNT_OFFSET]
    ldr    r2, [r2, #STRING_VALUE_OFFSET]
    ldr    r1, [r1, #STRING_VALUE_OFFSET]

    /*
     * At this point, we have:
     *    value:  r2/r1
     *    offset: r4/r9
     *    count:  r7/r10
     * We're going to compute
     *    r11 <- countDiff
     *    r10 <- minCount
     */
     subs  r11, r7, r10
     it    ls
     movls r10, r7

     /* Now, build pointers to the string data */
     add   r2, r2, r4, lsl #1
     add   r1, r1, r9, lsl #1
     /*
      * Note: data pointers point to previous element so we can use pre-index
      * mode with base writeback.
      */
     add   r2, #STRING_DATA_OFFSET-2   @ offset to contents[-1]
     add   r1, #STRING_DATA_OFFSET-2   @ offset to contents[-1]

     /*
      * At this point we have:
      *   r2: *this string data
      *   r1: *comp string data
      *   r10: iteration count for comparison
      *   r11: value to return if the first part of the string is equal
      *   r0: reserved for result
      *   r3, r4, r7, r8, r9, r12 available for loading string data
      */

    subs  r10, #2
    blt   do_remainder2

      /*
       * Unroll the first two checks so we can quickly catch early mismatch
       * on long strings (but preserve incoming alignment)
       */

    ldrh  r3, [r2, #2]!
    ldrh  r4, [r1, #2]!
    ldrh  r7, [r2, #2]!
    ldrh  r8, [r1, #2]!
    subs  r0, r3, r4
    it    eq
    subseq  r0, r7, r8
    bne   done
    cmp   r10, #28
    bgt   do_memcmp16
    subs  r10, #3
    blt   do_remainder

loopback_triple:
    ldrh  r3, [r2, #2]!
    ldrh  r4, [r1, #2]!
    ldrh  r7, [r2, #2]!
    ldrh  r8, [r1, #2]!
    ldrh  r9, [r2, #2]!
    ldrh  r12,[r1, #2]!
    subs  r0, r3, r4
    it    eq
    subseq  r0, r7, r8
    it    eq
    subseq  r0, r9, r12
    bne   done
    subs  r10, #3
    bge   loopback_triple

do_remainder:
    adds  r10, #3
    beq   returnDiff

loopback_single:
    ldrh  r3, [r2, #2]!
    ldrh  r4, [r1, #2]!
    subs  r0, r3, r4
    bne   done
    subs  r10, #1
    bne     loopback_single

returnDiff:
    mov   r0, r11
    pop   {r4, r7-r12, pc}

do_remainder2:
    adds  r10, #2
    bne   loopback_single
    mov   r0, r11
    pop   {r4, r7-r12, pc}

    /* Long string case */
do_memcmp16:
    mov   r7, r11
    add   r0, r2, #2
    add   r1, r1, #2
    mov   r2, r10
    bl    __memcmp16
    cmp   r0, #0
    it    eq
    moveq r0, r7
done:
    pop   {r4, r7-r12, pc}
END art_quick_string_compareto