// Copyright 2015 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

//go:build mips64 || mips64le

#include "go_asm.h"

#include "go_tls.h"

#include "funcdata.h"

#include "textflag.h"

#define REGCTXT R22

TEXT runtime·rt0_go(SB),NOSPLIT|TOPFRAME,$0

// R29 = stack; R4 = argc; R5 = argv

ADDV $-24, R29

MOVW R4, 8(R29) // argc

MOVV R5, 16(R29) // argv

// create istack out of the given (operating system) stack.

// _cgo_init may update stackguard.

MOVV $runtime·g0(SB), g

MOVV $(-64*1024), R23

ADDV R23, R29, R1

MOVV R1, g_stackguard0(g)

MOVV R1, g_stackguard1(g)

MOVV R1, (g_stack+stack_lo)(g)

MOVV R29, (g_stack+stack_hi)(g)

// if there is a _cgo_init, call it using the gcc ABI.

MOVV _cgo_init(SB), R25

BEQ R25, nocgo

MOVV R0, R7 // arg 3: not used

MOVV R0, R6 // arg 2: not used

MOVV $setg_gcc<>(SB), R5 // arg 1: setg

MOVV g, R4 // arg 0: G

JAL (R25)

nocgo:

// update stackguard after _cgo_init

MOVV (g_stack+stack_lo)(g), R1

ADDV $const_stackGuard, R1

MOVV R1, g_stackguard0(g)

MOVV R1, g_stackguard1(g)

// set the per-goroutine and per-mach "registers"

MOVV $runtime·m0(SB), R1

// save m->g0 = g0

MOVV g, m_g0(R1)

// save m0 to g0->m

MOVV R1, g_m(g)

JAL runtime·check(SB)

// args are already prepared

JAL runtime·args(SB)

JAL runtime·osinit(SB)

JAL runtime·schedinit(SB)

// create a new goroutine to start program

MOVV $runtime·mainPC(SB), R1 // entry

ADDV $-16, R29

MOVV R1, 8(R29)

MOVV R0, 0(R29)

JAL runtime·newproc(SB)

ADDV $16, R29

// start this M

JAL runtime·mstart(SB)

MOVV R0, 1(R0)

RET

DATA runtime·mainPC+0(SB)/8,$runtime·main(SB)

GLOBL runtime·mainPC(SB),RODATA,$8

TEXT runtime·breakpoint(SB),NOSPLIT|NOFRAME,$0-0

MOVV R0, 2(R0) // TODO: TD

RET

TEXT runtime·asminit(SB),NOSPLIT|NOFRAME,$0-0

RET

TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME,$0

JAL runtime·mstart0(SB)

RET // not reached

/*

* go-routine

*/

// void gogo(Gobuf*)

// restore state from Gobuf; longjmp

TEXT runtime·gogo(SB), NOSPLIT|NOFRAME, $0-8

MOVV buf+0(FP), R3

MOVV gobuf_g(R3), R4

MOVV 0(R4), R0 // make sure g != nil

JMP gogo<>(SB)

TEXT gogo<>(SB), NOSPLIT|NOFRAME, $0

MOVV R4, g

JAL runtime·save_g(SB)

MOVV 0(g), R2

MOVV gobuf_sp(R3), R29

MOVV gobuf_lr(R3), R31

MOVV gobuf_ctxt(R3), REGCTXT

MOVV R0, gobuf_sp(R3)

MOVV R0, gobuf_lr(R3)

MOVV R0, gobuf_ctxt(R3)

MOVV gobuf_pc(R3), R4

JMP (R4)

// void mcall(fn func(*g))

// Switch to m->g0's stack, call fn(g).

// Fn must never return. It should gogo(&g->sched)

// to keep running g.

TEXT runtime·mcall(SB), NOSPLIT|NOFRAME, $0-8

// Save caller state in g->sched

MOVV R29, (g_sched+gobuf_sp)(g)

MOVV R31, (g_sched+gobuf_pc)(g)

MOVV R0, (g_sched+gobuf_lr)(g)

// Switch to m->g0 & its stack, call fn.

MOVV g, R1

MOVV g_m(g), R3

MOVV m_g0(R3), g

JAL runtime·save_g(SB)

BNE g, R1, 2(PC)

JMP runtime·badmcall(SB)

MOVV fn+0(FP), REGCTXT // context

MOVV 0(REGCTXT), R4 // code pointer

MOVV (g_sched+gobuf_sp)(g), R29 // sp = m->g0->sched.sp

ADDV $-16, R29

MOVV R1, 8(R29)

MOVV R0, 0(R29)

JAL (R4)

JMP runtime·badmcall2(SB)

// systemstack_switch is a dummy routine that systemstack leaves at the bottom

// of the G stack. We need to distinguish the routine that

// lives at the bottom of the G stack from the one that lives

// at the top of the system stack because the one at the top of

// the system stack terminates the stack walk (see topofstack()).

TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0

UNDEF

JAL (R31) // make sure this function is not leaf

RET

// func systemstack(fn func())

TEXT runtime·systemstack(SB), NOSPLIT, $0-8

MOVV fn+0(FP), R1 // R1 = fn

MOVV R1, REGCTXT // context

MOVV g_m(g), R2 // R2 = m

MOVV m_gsignal(R2), R3 // R3 = gsignal

BEQ g, R3, noswitch

MOVV m_g0(R2), R3 // R3 = g0

BEQ g, R3, noswitch

MOVV m_curg(R2), R4

BEQ g, R4, switch

// Bad: g is not gsignal, not g0, not curg. What is it?

// Hide call from linker nosplit analysis.

MOVV $runtime·badsystemstack(SB), R4

JAL (R4)

JAL runtime·abort(SB)

switch:

// save our state in g->sched. Pretend to

// be systemstack_switch if the G stack is scanned.

JAL gosave_systemstack_switch<>(SB)

// switch to g0

MOVV R3, g

JAL runtime·save_g(SB)

MOVV (g_sched+gobuf_sp)(g), R1

MOVV R1, R29

// call target function

MOVV 0(REGCTXT), R4 // code pointer

JAL (R4)

// switch back to g

MOVV g_m(g), R1

MOVV m_curg(R1), g

JAL runtime·save_g(SB)

MOVV (g_sched+gobuf_sp)(g), R29

MOVV R0, (g_sched+gobuf_sp)(g)

RET

noswitch:

// already on m stack, just call directly

// Using a tail call here cleans up tracebacks since we won't stop

// at an intermediate systemstack.

MOVV 0(REGCTXT), R4 // code pointer

MOVV 0(R29), R31 // restore LR

ADDV $8, R29

JMP (R4)

// func switchToCrashStack0(fn func())

TEXT runtime·switchToCrashStack0(SB), NOSPLIT, $0-8

MOVV fn+0(FP), REGCTXT // context register

MOVV g_m(g), R2 // curm

// set g to gcrash

MOVV $runtime·gcrash(SB), g // g = &gcrash

CALL runtime·save_g(SB)

MOVV R2, g_m(g) // g.m = curm

MOVV g, m_g0(R2) // curm.g0 = g

// switch to crashstack

MOVV (g_stack+stack_hi)(g), R2

ADDV $(-4*8), R2, R29

// call target function

MOVV 0(REGCTXT), R25

JAL (R25)

// should never return

CALL runtime·abort(SB)

UNDEF

/*

* support for morestack

*/

// Called during function prolog when more stack is needed.

// Caller has already loaded:

// R1: framesize, R2: argsize, R3: LR

//

// The traceback routines see morestack on a g0 as being

// the top of a stack (for example, morestack calling newstack

// calling the scheduler calling newm calling gc), so we must

// record an argument size. For that purpose, it has no arguments.

TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0

// Called from f.

// Set g->sched to context in f.

MOVV R29, (g_sched+gobuf_sp)(g)

MOVV R31, (g_sched+gobuf_pc)(g)

MOVV R3, (g_sched+gobuf_lr)(g)

MOVV REGCTXT, (g_sched+gobuf_ctxt)(g)

// Cannot grow scheduler stack (m->g0).

MOVV g_m(g), R7

MOVV m_g0(R7), R8

BNE g, R8, 3(PC)

JAL runtime·badmorestackg0(SB)

JAL runtime·abort(SB)

// Cannot grow signal stack (m->gsignal).

MOVV m_gsignal(R7), R8

BNE g, R8, 3(PC)

JAL runtime·badmorestackgsignal(SB)

JAL runtime·abort(SB)

// Called from f.

// Set m->morebuf to f's caller.

MOVV R3, (m_morebuf+gobuf_pc)(R7) // f's caller's PC

MOVV R29, (m_morebuf+gobuf_sp)(R7) // f's caller's SP

MOVV g, (m_morebuf+gobuf_g)(R7)

// Call newstack on m->g0's stack.

MOVV m_g0(R7), g

JAL runtime·save_g(SB)

MOVV (g_sched+gobuf_sp)(g), R29

// Create a stack frame on g0 to call newstack.

MOVV R0, -8(R29) // Zero saved LR in frame

ADDV $-8, R29

JAL runtime·newstack(SB)

// Not reached, but make sure the return PC from the call to newstack

// is still in this function, and not the beginning of the next.

UNDEF

TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0

// Force SPWRITE. This function doesn't actually write SP,

// but it is called with a special calling convention where

// the caller doesn't save LR on stack but passes it as a

// register (R3), and the unwinder currently doesn't understand.

// Make it SPWRITE to stop unwinding. (See issue 54332)

MOVV R29, R29

MOVV R0, REGCTXT

JMP runtime·morestack(SB)

// reflectcall: call a function with the given argument list

// func call(stackArgsType *_type, f *FuncVal, stackArgs *byte, stackArgsSize, stackRetOffset, frameSize uint32, regArgs *abi.RegArgs).

// we don't have variable-sized frames, so we use a small number

// of constant-sized-frame functions to encode a few bits of size in the pc.

// Caution: ugly multiline assembly macros in your future!

#define DISPATCH(NAME,MAXSIZE) \

MOVV $MAXSIZE, R23; \

SGTU R1, R23, R23; \

BNE R23, 3(PC); \

MOVV $NAME(SB), R4; \

JMP (R4)

// Note: can't just "BR NAME(SB)" - bad inlining results.

TEXT ·reflectcall(SB), NOSPLIT|NOFRAME, $0-48

MOVWU frameSize+32(FP), R1

DISPATCH(runtime·call16, 16)

DISPATCH(runtime·call32, 32)

DISPATCH(runtime·call64, 64)

DISPATCH(runtime·call128, 128)

DISPATCH(runtime·call256, 256)

DISPATCH(runtime·call512, 512)

DISPATCH(runtime·call1024, 1024)

DISPATCH(runtime·call2048, 2048)

DISPATCH(runtime·call4096, 4096)

DISPATCH(runtime·call8192, 8192)

DISPATCH(runtime·call16384, 16384)

DISPATCH(runtime·call32768, 32768)

DISPATCH(runtime·call65536, 65536)

DISPATCH(runtime·call131072, 131072)

DISPATCH(runtime·call262144, 262144)

DISPATCH(runtime·call524288, 524288)

DISPATCH(runtime·call1048576, 1048576)

DISPATCH(runtime·call2097152, 2097152)

DISPATCH(runtime·call4194304, 4194304)

DISPATCH(runtime·call8388608, 8388608)

DISPATCH(runtime·call16777216, 16777216)

DISPATCH(runtime·call33554432, 33554432)

DISPATCH(runtime·call67108864, 67108864)

DISPATCH(runtime·call134217728, 134217728)

DISPATCH(runtime·call268435456, 268435456)

DISPATCH(runtime·call536870912, 536870912)

DISPATCH(runtime·call1073741824, 1073741824)

MOVV $runtime·badreflectcall(SB), R4

JMP (R4)

#define CALLFN(NAME,MAXSIZE) \

TEXT NAME(SB), WRAPPER, $MAXSIZE-48; \

NO_LOCAL_POINTERS; \

/* copy arguments to stack */ \

MOVV stackArgs+16(FP), R1; \

MOVWU stackArgsSize+24(FP), R2; \

MOVV R29, R3; \

ADDV $8, R3; \

ADDV R3, R2; \

BEQ R3, R2, 6(PC); \

MOVBU (R1), R4; \

ADDV $1, R1; \

MOVBU R4, (R3); \

ADDV $1, R3; \

JMP -5(PC); \

/* call function */ \

MOVV f+8(FP), REGCTXT; \

MOVV (REGCTXT), R4; \

PCDATA $PCDATA_StackMapIndex, $0; \

JAL (R4); \

/* copy return values back */ \

MOVV stackArgsType+0(FP), R5; \

MOVV stackArgs+16(FP), R1; \

MOVWU stackArgsSize+24(FP), R2; \

MOVWU stackRetOffset+28(FP), R4; \

ADDV $8, R29, R3; \

ADDV R4, R3; \

ADDV R4, R1; \

SUBVU R4, R2; \

JAL callRet<>(SB); \

RET

// callRet copies return values back at the end of call*. This is a

// separate function so it can allocate stack space for the arguments

// to reflectcallmove. It does not follow the Go ABI; it expects its

// arguments in registers.

TEXT callRet<>(SB), NOSPLIT, $40-0

MOVV R5, 8(R29)

MOVV R1, 16(R29)

MOVV R3, 24(R29)

MOVV R2, 32(R29)

MOVV $0, 40(R29)

JAL runtime·reflectcallmove(SB)

RET

CALLFN(·call16, 16)

CALLFN(·call32, 32)

CALLFN(·call64, 64)

CALLFN(·call128, 128)

CALLFN(·call256, 256)

CALLFN(·call512, 512)

CALLFN(·call1024, 1024)

CALLFN(·call2048, 2048)

CALLFN(·call4096, 4096)

CALLFN(·call8192, 8192)

CALLFN(·call16384, 16384)

CALLFN(·call32768, 32768)

CALLFN(·call65536, 65536)

CALLFN(·call131072, 131072)

CALLFN(·call262144, 262144)

CALLFN(·call524288, 524288)

CALLFN(·call1048576, 1048576)

CALLFN(·call2097152, 2097152)

CALLFN(·call4194304, 4194304)

CALLFN(·call8388608, 8388608)

CALLFN(·call16777216, 16777216)

CALLFN(·call33554432, 33554432)

CALLFN(·call67108864, 67108864)

CALLFN(·call134217728, 134217728)

CALLFN(·call268435456, 268435456)

CALLFN(·call536870912, 536870912)

CALLFN(·call1073741824, 1073741824)

TEXT runtime·procyield(SB),NOSPLIT,$0-0

RET

// Save state of caller into g->sched,

// but using fake PC from systemstack_switch.

// Must only be called from functions with no locals ($0)

// or else unwinding from systemstack_switch is incorrect.

// Smashes R1.

TEXT gosave_systemstack_switch<>(SB),NOSPLIT|NOFRAME,$0

MOVV $runtime·systemstack_switch(SB), R1

ADDV $8, R1 // get past prologue

MOVV R1, (g_sched+gobuf_pc)(g)

MOVV R29, (g_sched+gobuf_sp)(g)

MOVV R0, (g_sched+gobuf_lr)(g)

// Assert ctxt is zero. See func save.

MOVV (g_sched+gobuf_ctxt)(g), R1

BEQ R1, 2(PC)

JAL runtime·abort(SB)

RET

// func asmcgocall_no_g(fn, arg unsafe.Pointer)

// Call fn(arg) aligned appropriately for the gcc ABI.

// Called on a system stack, and there may be no g yet (during needm).

TEXT ·asmcgocall_no_g(SB),NOSPLIT,$0-16

MOVV fn+0(FP), R25

MOVV arg+8(FP), R4

JAL (R25)

RET

// func asmcgocall(fn, arg unsafe.Pointer) int32

// Call fn(arg) on the scheduler stack,

// aligned appropriately for the gcc ABI.

// See cgocall.go for more details.

TEXT ·asmcgocall(SB),NOSPLIT,$0-20

MOVV fn+0(FP), R25

MOVV arg+8(FP), R4

MOVV R29, R3 // save original stack pointer

MOVV g, R2

// Figure out if we need to switch to m->g0 stack.

// We get called to create new OS threads too, and those

// come in on the m->g0 stack already. Or we might already

// be on the m->gsignal stack.

MOVV g_m(g), R5

MOVV m_gsignal(R5), R6

BEQ R6, g, g0

MOVV m_g0(R5), R6

BEQ R6, g, g0

JAL gosave_systemstack_switch<>(SB)

MOVV R6, g

JAL runtime·save_g(SB)

MOVV (g_sched+gobuf_sp)(g), R29

// Now on a scheduling stack (a pthread-created stack).

g0:

// Save room for two of our pointers.

ADDV $-16, R29

MOVV R2, 0(R29) // save old g on stack

MOVV (g_stack+stack_hi)(R2), R2

SUBVU R3, R2

MOVV R2, 8(R29) // save depth in old g stack (can't just save SP, as stack might be copied during a callback)

JAL (R25)

// Restore g, stack pointer. R2 is return value.

MOVV 0(R29), g

JAL runtime·save_g(SB)

MOVV (g_stack+stack_hi)(g), R5

MOVV 8(R29), R6

SUBVU R6, R5

MOVV R5, R29

MOVW R2, ret+16(FP)

RET

// func cgocallback(fn, frame unsafe.Pointer, ctxt uintptr)

// See cgocall.go for more details.

TEXT ·cgocallback(SB),NOSPLIT,$24-24

NO_LOCAL_POINTERS

// Skip cgocallbackg, just dropm when fn is nil, and frame is the saved g.

// It is used to dropm while thread is exiting.

MOVV fn+0(FP), R5

BNE R5, loadg

// Restore the g from frame.

MOVV frame+8(FP), g

JMP dropm

loadg:

// Load m and g from thread-local storage.

MOVB runtime·iscgo(SB), R1

BEQ R1, nocgo

JAL runtime·load_g(SB)

nocgo:

// If g is nil, Go did not create the current thread,

// or if this thread never called into Go on pthread platforms.

// Call needm to obtain one for temporary use.

// In this case, we're running on the thread stack, so there's

// lots of space, but the linker doesn't know. Hide the call from

// the linker analysis by using an indirect call.

BEQ g, needm

MOVV g_m(g), R3

MOVV R3, savedm-8(SP)

JMP havem

needm:

MOVV g, savedm-8(SP) // g is zero, so is m.

MOVV $runtime·needAndBindM(SB), R4

JAL (R4)

// Set m->sched.sp = SP, so that if a panic happens

// during the function we are about to execute, it will

// have a valid SP to run on the g0 stack.

// The next few lines (after the havem label)

// will save this SP onto the stack and then write

// the same SP back to m->sched.sp. That seems redundant,

// but if an unrecovered panic happens, unwindm will

// restore the g->sched.sp from the stack location

// and then systemstack will try to use it. If we don't set it here,

// that restored SP will be uninitialized (typically 0) and

// will not be usable.

MOVV g_m(g), R3

MOVV m_g0(R3), R1

MOVV R29, (g_sched+gobuf_sp)(R1)

havem:

// Now there's a valid m, and we're running on its m->g0.

// Save current m->g0->sched.sp on stack and then set it to SP.

// Save current sp in m->g0->sched.sp in preparation for

// switch back to m->curg stack.

// NOTE: unwindm knows that the saved g->sched.sp is at 8(R29) aka savedsp-16(SP).

MOVV m_g0(R3), R1

MOVV (g_sched+gobuf_sp)(R1), R2

MOVV R2, savedsp-24(SP) // must match frame size

MOVV R29, (g_sched+gobuf_sp)(R1)

// Switch to m->curg stack and call runtime.cgocallbackg.

// Because we are taking over the execution of m->curg

// but *not* resuming what had been running, we need to

// save that information (m->curg->sched) so we can restore it.

// We can restore m->curg->sched.sp easily, because calling

// runtime.cgocallbackg leaves SP unchanged upon return.

// To save m->curg->sched.pc, we push it onto the curg stack and

// open a frame the same size as cgocallback's g0 frame.

// Once we switch to the curg stack, the pushed PC will appear

// to be the return PC of cgocallback, so that the traceback

// will seamlessly trace back into the earlier calls.

MOVV m_curg(R3), g

JAL runtime·save_g(SB)

MOVV (g_sched+gobuf_sp)(g), R2 // prepare stack as R2

MOVV (g_sched+gobuf_pc)(g), R4

MOVV R4, -(24+8)(R2) // "saved LR"; must match frame size

// Gather our arguments into registers.

MOVV fn+0(FP), R5

MOVV frame+8(FP), R6

MOVV ctxt+16(FP), R7

MOVV $-(24+8)(R2), R29 // switch stack; must match frame size

MOVV R5, 8(R29)

MOVV R6, 16(R29)

MOVV R7, 24(R29)

JAL runtime·cgocallbackg(SB)

// Restore g->sched (== m->curg->sched) from saved values.

MOVV 0(R29), R4

MOVV R4, (g_sched+gobuf_pc)(g)

MOVV $(24+8)(R29), R2 // must match frame size

MOVV R2, (g_sched+gobuf_sp)(g)

// Switch back to m->g0's stack and restore m->g0->sched.sp.

// (Unlike m->curg, the g0 goroutine never uses sched.pc,

// so we do not have to restore it.)

MOVV g_m(g), R3

MOVV m_g0(R3), g

JAL runtime·save_g(SB)

MOVV (g_sched+gobuf_sp)(g), R29

MOVV savedsp-24(SP), R2 // must match frame size

MOVV R2, (g_sched+gobuf_sp)(g)

// If the m on entry was nil, we called needm above to borrow an m,

// 1. for the duration of the call on non-pthread platforms,

// 2. or the duration of the C thread alive on pthread platforms.

// If the m on entry wasn't nil,

// 1. the thread might be a Go thread,

// 2. or it wasn't the first call from a C thread on pthread platforms,

// since then we skip dropm to reuse the m in the first call.

MOVV savedm-8(SP), R3

BNE R3, droppedm

// Skip dropm to reuse it in the next call, when a pthread key has been created.

MOVV _cgo_pthread_key_created(SB), R3

// It means cgo is disabled when _cgo_pthread_key_created is a nil pointer, need dropm.

BEQ R3, dropm

MOVV (R3), R3

BNE R3, droppedm

dropm:

MOVV $runtime·dropm(SB), R4

JAL (R4)

droppedm:

// Done!

RET

// void setg(G*); set g. for use by needm.

TEXT runtime·setg(SB), NOSPLIT, $0-8

MOVV gg+0(FP), g

// This only happens if iscgo, so jump straight to save_g

JAL runtime·save_g(SB)

RET

// void setg_gcc(G*); set g called from gcc with g in R1

TEXT setg_gcc<>(SB),NOSPLIT,$0-0

MOVV R1, g

JAL runtime·save_g(SB)

RET

TEXT runtime·abort(SB),NOSPLIT|NOFRAME,$0-0

MOVW (R0), R0

UNDEF

// AES hashing not implemented for mips64

TEXT runtime·memhash(SB),NOSPLIT|NOFRAME,$0-32

JMP runtime·memhashFallback(SB)

TEXT runtime·strhash(SB),NOSPLIT|NOFRAME,$0-24

JMP runtime·strhashFallback(SB)

TEXT runtime·memhash32(SB),NOSPLIT|NOFRAME,$0-24

JMP runtime·memhash32Fallback(SB)

TEXT runtime·memhash64(SB),NOSPLIT|NOFRAME,$0-24

JMP runtime·memhash64Fallback(SB)

// Called from cgo wrappers, this function returns g->m->curg.stack.hi.

// Must obey the gcc calling convention.

TEXT _cgo_topofstack(SB),NOSPLIT,$16

// g (R30) and REGTMP (R23) might be clobbered by load_g. They

// are callee-save in the gcc calling convention, so save them.

MOVV R23, savedR23-16(SP)

MOVV g, savedG-8(SP)

JAL runtime·load_g(SB)

MOVV g_m(g), R1

MOVV m_curg(R1), R1

MOVV (g_stack+stack_hi)(R1), R2 // return value in R2

MOVV savedG-8(SP), g

MOVV savedR23-16(SP), R23

RET

// The top-most function running on a goroutine

// returns to goexit+PCQuantum.

TEXT runtime·goexit(SB),NOSPLIT|NOFRAME|TOPFRAME,$0-0

NOR R0, R0 // NOP

JAL runtime·goexit1(SB) // does not return

// traceback from goexit1 must hit code range of goexit

NOR R0, R0 // NOP

TEXT ·checkASM(SB),NOSPLIT,$0-1

MOVW $1, R1

MOVB R1, ret+0(FP)

RET

// gcWriteBarrier informs the GC about heap pointer writes.

//

// gcWriteBarrier does NOT follow the Go ABI. It accepts the

// number of bytes of buffer needed in R25, and returns a pointer

// to the buffer space in R25.

// It clobbers R23 (the linker temp register).

// The act of CALLing gcWriteBarrier will clobber R31 (LR).

// It does not clobber any other general-purpose registers,

// but may clobber others (e.g., floating point registers).

TEXT gcWriteBarrier<>(SB),NOSPLIT,$192

// Save the registers clobbered by the fast path.

MOVV R1, 184(R29)

MOVV R2, 192(R29)

retry:

MOVV g_m(g), R1

MOVV m_p(R1), R1

MOVV (p_wbBuf+wbBuf_next)(R1), R2

MOVV (p_wbBuf+wbBuf_end)(R1), R23 // R23 is linker temp register

// Increment wbBuf.next position.

ADDV R25, R2

// Is the buffer full?

SGTU R2, R23, R23

BNE R23, flush

// Commit to the larger buffer.

MOVV R2, (p_wbBuf+wbBuf_next)(R1)

// Make return value (the original next position)

SUBV R25, R2, R25

// Restore registers.

MOVV 184(R29), R1

MOVV 192(R29), R2

RET

flush:

// Save all general purpose registers since these could be

// clobbered by wbBufFlush and were not saved by the caller.

MOVV R20, 8(R29)

MOVV R21, 16(R29)

// R1 already saved

// R2 already saved

MOVV R3, 24(R29)

MOVV R4, 32(R29)

MOVV R5, 40(R29)

MOVV R6, 48(R29)

MOVV R7, 56(R29)

MOVV R8, 64(R29)

MOVV R9, 72(R29)

MOVV R10, 80(R29)

MOVV R11, 88(R29)

MOVV R12, 96(R29)

MOVV R13, 104(R29)

MOVV R14, 112(R29)

MOVV R15, 120(R29)

MOVV R16, 128(R29)

MOVV R17, 136(R29)

MOVV R18, 144(R29)

MOVV R19, 152(R29)

// R20 already saved

// R21 already saved.

MOVV R22, 160(R29)

// R23 is tmp register.

MOVV R24, 168(R29)

MOVV R25, 176(R29)

// R26 is reserved by kernel.

// R27 is reserved by kernel.

// R28 is REGSB (not modified by Go code).

// R29 is SP.

// R30 is g.

// R31 is LR, which was saved by the prologue.

CALL runtime·wbBufFlush(SB)

MOVV 8(R29), R20

MOVV 16(R29), R21

MOVV 24(R29), R3

MOVV 32(R29), R4

MOVV 40(R29), R5

MOVV 48(R29), R6

MOVV 56(R29), R7

MOVV 64(R29), R8

MOVV 72(R29), R9

MOVV 80(R29), R10

MOVV 88(R29), R11

MOVV 96(R29), R12

MOVV 104(R29), R13

MOVV 112(R29), R14

MOVV 120(R29), R15

MOVV 128(R29), R16

MOVV 136(R29), R17

MOVV 144(R29), R18

MOVV 152(R29), R19

MOVV 160(R29), R22

MOVV 168(R29), R24

MOVV 176(R29), R25

JMP retry

TEXT runtime·gcWriteBarrier1<ABIInternal>(SB),NOSPLIT,$0

MOVV $8, R25

JMP gcWriteBarrier<>(SB)

TEXT runtime·gcWriteBarrier2<ABIInternal>(SB),NOSPLIT,$0

MOVV $16, R25

JMP gcWriteBarrier<>(SB)

TEXT runtime·gcWriteBarrier3<ABIInternal>(SB),NOSPLIT,$0

MOVV $24, R25

JMP gcWriteBarrier<>(SB)

TEXT runtime·gcWriteBarrier4<ABIInternal>(SB),NOSPLIT,$0

MOVV $32, R25

JMP gcWriteBarrier<>(SB)

TEXT runtime·gcWriteBarrier5<ABIInternal>(SB),NOSPLIT,$0

MOVV $40, R25

JMP gcWriteBarrier<>(SB)

TEXT runtime·gcWriteBarrier6<ABIInternal>(SB),NOSPLIT,$0

MOVV $48, R25

JMP gcWriteBarrier<>(SB)

TEXT runtime·gcWriteBarrier7<ABIInternal>(SB),NOSPLIT,$0

MOVV $56, R25

JMP gcWriteBarrier<>(SB)

TEXT runtime·gcWriteBarrier8<ABIInternal>(SB),NOSPLIT,$0

MOVV $64, R25

JMP gcWriteBarrier<>(SB)

// Note: these functions use a special calling convention to save generated code space.

// Arguments are passed in registers, but the space for those arguments are allocated

// in the caller's stack frame. These stubs write the args into that stack space and

// then tail call to the corresponding runtime handler.

// The tail call makes these stubs disappear in backtraces.

TEXT runtime·panicIndex(SB),NOSPLIT,$0-16

MOVV R1, x+0(FP)

MOVV R2, y+8(FP)

JMP runtime·goPanicIndex(SB)

TEXT runtime·panicIndexU(SB),NOSPLIT,$0-16

MOVV R1, x+0(FP)

MOVV R2, y+8(FP)

JMP runtime·goPanicIndexU(SB)

TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-16

MOVV R2, x+0(FP)

MOVV R3, y+8(FP)

JMP runtime·goPanicSliceAlen(SB)

TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-16

MOVV R2, x+0(FP)

MOVV R3, y+8(FP)

JMP runtime·goPanicSliceAlenU(SB)

TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-16

MOVV R2, x+0(FP)

MOVV R3, y+8(FP)

JMP runtime·goPanicSliceAcap(SB)

TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-16

MOVV R2, x+0(FP)

MOVV R3, y+8(FP)

JMP runtime·goPanicSliceAcapU(SB)

TEXT runtime·panicSliceB(SB),NOSPLIT,$0-16

MOVV R1, x+0(FP)

MOVV R2, y+8(FP)

JMP runtime·goPanicSliceB(SB)

TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-16

MOVV R1, x+0(FP)

MOVV R2, y+8(FP)

JMP runtime·goPanicSliceBU(SB)

TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-16

MOVV R3, x+0(FP)

MOVV R4, y+8(FP)

JMP runtime·goPanicSlice3Alen(SB)

TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-16

MOVV R3, x+0(FP)

MOVV R4, y+8(FP)

JMP runtime·goPanicSlice3AlenU(SB)

TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-16

MOVV R3, x+0(FP)

MOVV R4, y+8(FP)

JMP runtime·goPanicSlice3Acap(SB)

TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-16

MOVV R3, x+0(FP)

MOVV R4, y+8(FP)

JMP runtime·goPanicSlice3AcapU(SB)

TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-16

MOVV R2, x+0(FP)

MOVV R3, y+8(FP)

JMP runtime·goPanicSlice3B(SB)

TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-16

MOVV R2, x+0(FP)

MOVV R3, y+8(FP)

JMP runtime·goPanicSlice3BU(SB)

TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-16

MOVV R1, x+0(FP)

MOVV R2, y+8(FP)

JMP runtime·goPanicSlice3C(SB)

TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-16

MOVV R1, x+0(FP)

MOVV R2, y+8(FP)

JMP runtime·goPanicSlice3CU(SB)

TEXT runtime·panicSliceConvert(SB),NOSPLIT,$0-16

MOVV R3, x+0(FP)

MOVV R4, y+8(FP)

JMP runtime·goPanicSliceConvert(SB)