|  | // 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. | 
|  |  | 
|  | #include "go_asm.h" | 
|  | #include "go_tls.h" | 
|  | #include "tls_arm64.h" | 
|  | #include "funcdata.h" | 
|  | #include "textflag.h" | 
|  |  | 
|  | TEXT runtime·rt0_go(SB),NOSPLIT,$0 | 
|  | // SP = stack; R0 = argc; R1 = argv | 
|  |  | 
|  | SUB	$32, RSP | 
|  | MOVW	R0, 8(RSP) // argc | 
|  | MOVD	R1, 16(RSP) // argv | 
|  |  | 
|  | // create istack out of the given (operating system) stack. | 
|  | // _cgo_init may update stackguard. | 
|  | MOVD	$runtime·g0(SB), g | 
|  | MOVD RSP, R7 | 
|  | MOVD	$(-64*1024)(R7), R0 | 
|  | MOVD	R0, g_stackguard0(g) | 
|  | MOVD	R0, g_stackguard1(g) | 
|  | MOVD	R0, (g_stack+stack_lo)(g) | 
|  | MOVD	R7, (g_stack+stack_hi)(g) | 
|  |  | 
|  | // if there is a _cgo_init, call it using the gcc ABI. | 
|  | MOVD	_cgo_init(SB), R12 | 
|  | CMP	$0, R12 | 
|  | BEQ	nocgo | 
|  |  | 
|  | MRS_TPIDR_R0			// load TLS base pointer | 
|  | MOVD	R0, R3			// arg 3: TLS base pointer | 
|  | #ifdef TLSG_IS_VARIABLE | 
|  | MOVD	$runtime·tls_g(SB), R2 	// arg 2: &tls_g | 
|  | #else | 
|  | MOVD	$0, R2		        // arg 2: not used when using platform's TLS | 
|  | #endif | 
|  | MOVD	$setg_gcc<>(SB), R1	// arg 1: setg | 
|  | MOVD	g, R0			// arg 0: G | 
|  | BL	(R12) | 
|  | MOVD	_cgo_init(SB), R12 | 
|  | CMP	$0, R12 | 
|  | BEQ	nocgo | 
|  |  | 
|  | nocgo: | 
|  | // update stackguard after _cgo_init | 
|  | MOVD	(g_stack+stack_lo)(g), R0 | 
|  | ADD	$const__StackGuard, R0 | 
|  | MOVD	R0, g_stackguard0(g) | 
|  | MOVD	R0, g_stackguard1(g) | 
|  |  | 
|  | // set the per-goroutine and per-mach "registers" | 
|  | MOVD	$runtime·m0(SB), R0 | 
|  |  | 
|  | // save m->g0 = g0 | 
|  | MOVD	g, m_g0(R0) | 
|  | // save m0 to g0->m | 
|  | MOVD	R0, g_m(g) | 
|  |  | 
|  | BL	runtime·check(SB) | 
|  |  | 
|  | MOVW	8(RSP), R0	// copy argc | 
|  | MOVW	R0, -8(RSP) | 
|  | MOVD	16(RSP), R0		// copy argv | 
|  | MOVD	R0, 0(RSP) | 
|  | BL	runtime·args(SB) | 
|  | BL	runtime·osinit(SB) | 
|  | BL	runtime·schedinit(SB) | 
|  |  | 
|  | // create a new goroutine to start program | 
|  | MOVD	$runtime·mainPC(SB), R0		// entry | 
|  | MOVD	RSP, R7 | 
|  | MOVD.W	$0, -8(R7) | 
|  | MOVD.W	R0, -8(R7) | 
|  | MOVD.W	$0, -8(R7) | 
|  | MOVD.W	$0, -8(R7) | 
|  | MOVD	R7, RSP | 
|  | BL	runtime·newproc(SB) | 
|  | ADD	$32, RSP | 
|  |  | 
|  | // start this M | 
|  | BL	runtime·mstart(SB) | 
|  |  | 
|  | MOVD	$0, R0 | 
|  | MOVD	R0, (R0)	// boom | 
|  | UNDEF | 
|  |  | 
|  | DATA	runtime·mainPC+0(SB)/8,$runtime·main(SB) | 
|  | GLOBL	runtime·mainPC(SB),RODATA,$8 | 
|  |  | 
|  | TEXT runtime·breakpoint(SB),NOSPLIT,$-8-0 | 
|  | BRK | 
|  | RET | 
|  |  | 
|  | TEXT runtime·asminit(SB),NOSPLIT,$-8-0 | 
|  | RET | 
|  |  | 
|  | /* | 
|  | *  go-routine | 
|  | */ | 
|  |  | 
|  | // void gosave(Gobuf*) | 
|  | // save state in Gobuf; setjmp | 
|  | TEXT runtime·gosave(SB), NOSPLIT, $-8-8 | 
|  | MOVD	buf+0(FP), R3 | 
|  | MOVD	RSP, R0 | 
|  | MOVD	R0, gobuf_sp(R3) | 
|  | MOVD	LR, gobuf_pc(R3) | 
|  | MOVD	g, gobuf_g(R3) | 
|  | MOVD	ZR, gobuf_lr(R3) | 
|  | MOVD	ZR, gobuf_ret(R3) | 
|  | // Assert ctxt is zero. See func save. | 
|  | MOVD	gobuf_ctxt(R3), R0 | 
|  | CMP	$0, R0 | 
|  | BEQ	2(PC) | 
|  | CALL	runtime·badctxt(SB) | 
|  | RET | 
|  |  | 
|  | // void gogo(Gobuf*) | 
|  | // restore state from Gobuf; longjmp | 
|  | TEXT runtime·gogo(SB), NOSPLIT, $24-8 | 
|  | MOVD	buf+0(FP), R5 | 
|  |  | 
|  | // If ctxt is not nil, invoke deletion barrier before overwriting. | 
|  | MOVD	gobuf_ctxt(R5), R0 | 
|  | CMP	$0, R0 | 
|  | BEQ	nilctxt | 
|  | MOVD	$gobuf_ctxt(R5), R0 | 
|  | MOVD	R0, 8(RSP) | 
|  | MOVD	ZR, 16(RSP) | 
|  | BL	runtime·writebarrierptr_prewrite(SB) | 
|  | MOVD	buf+0(FP), R5 | 
|  |  | 
|  | nilctxt: | 
|  | MOVD	gobuf_g(R5), g | 
|  | BL	runtime·save_g(SB) | 
|  |  | 
|  | MOVD	0(g), R4	// make sure g is not nil | 
|  | MOVD	gobuf_sp(R5), R0 | 
|  | MOVD	R0, RSP | 
|  | MOVD	gobuf_lr(R5), LR | 
|  | MOVD	gobuf_ret(R5), R0 | 
|  | MOVD	gobuf_ctxt(R5), R26 | 
|  | MOVD	$0, gobuf_sp(R5) | 
|  | MOVD	$0, gobuf_ret(R5) | 
|  | MOVD	$0, gobuf_lr(R5) | 
|  | MOVD	$0, gobuf_ctxt(R5) | 
|  | CMP	ZR, ZR // set condition codes for == test, needed by stack split | 
|  | MOVD	gobuf_pc(R5), R6 | 
|  | B	(R6) | 
|  |  | 
|  | // 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, $-8-8 | 
|  | // Save caller state in g->sched | 
|  | MOVD	RSP, R0 | 
|  | MOVD	R0, (g_sched+gobuf_sp)(g) | 
|  | MOVD	LR, (g_sched+gobuf_pc)(g) | 
|  | MOVD	$0, (g_sched+gobuf_lr)(g) | 
|  | MOVD	g, (g_sched+gobuf_g)(g) | 
|  |  | 
|  | // Switch to m->g0 & its stack, call fn. | 
|  | MOVD	g, R3 | 
|  | MOVD	g_m(g), R8 | 
|  | MOVD	m_g0(R8), g | 
|  | BL	runtime·save_g(SB) | 
|  | CMP	g, R3 | 
|  | BNE	2(PC) | 
|  | B	runtime·badmcall(SB) | 
|  | MOVD	fn+0(FP), R26			// context | 
|  | MOVD	0(R26), R4			// code pointer | 
|  | MOVD	(g_sched+gobuf_sp)(g), R0 | 
|  | MOVD	R0, RSP	// sp = m->g0->sched.sp | 
|  | MOVD	R3, -8(RSP) | 
|  | MOVD	$0, -16(RSP) | 
|  | SUB	$16, RSP | 
|  | BL	(R4) | 
|  | B	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 | 
|  | BL	(LR)	// make sure this function is not leaf | 
|  | RET | 
|  |  | 
|  | // func systemstack(fn func()) | 
|  | TEXT runtime·systemstack(SB), NOSPLIT, $0-8 | 
|  | MOVD	fn+0(FP), R3	// R3 = fn | 
|  | MOVD	R3, R26		// context | 
|  | MOVD	g_m(g), R4	// R4 = m | 
|  |  | 
|  | MOVD	m_gsignal(R4), R5	// R5 = gsignal | 
|  | CMP	g, R5 | 
|  | BEQ	noswitch | 
|  |  | 
|  | MOVD	m_g0(R4), R5	// R5 = g0 | 
|  | CMP	g, R5 | 
|  | BEQ	noswitch | 
|  |  | 
|  | MOVD	m_curg(R4), R6 | 
|  | CMP	g, R6 | 
|  | BEQ	switch | 
|  |  | 
|  | // Bad: g is not gsignal, not g0, not curg. What is it? | 
|  | // Hide call from linker nosplit analysis. | 
|  | MOVD	$runtime·badsystemstack(SB), R3 | 
|  | BL	(R3) | 
|  |  | 
|  | switch: | 
|  | // save our state in g->sched. Pretend to | 
|  | // be systemstack_switch if the G stack is scanned. | 
|  | MOVD	$runtime·systemstack_switch(SB), R6 | 
|  | ADD	$8, R6	// get past prologue | 
|  | MOVD	R6, (g_sched+gobuf_pc)(g) | 
|  | MOVD	RSP, R0 | 
|  | MOVD	R0, (g_sched+gobuf_sp)(g) | 
|  | MOVD	$0, (g_sched+gobuf_lr)(g) | 
|  | MOVD	g, (g_sched+gobuf_g)(g) | 
|  |  | 
|  | // switch to g0 | 
|  | MOVD	R5, g | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	(g_sched+gobuf_sp)(g), R3 | 
|  | // make it look like mstart called systemstack on g0, to stop traceback | 
|  | SUB	$16, R3 | 
|  | AND	$~15, R3 | 
|  | MOVD	$runtime·mstart(SB), R4 | 
|  | MOVD	R4, 0(R3) | 
|  | MOVD	R3, RSP | 
|  |  | 
|  | // call target function | 
|  | MOVD	0(R26), R3	// code pointer | 
|  | BL	(R3) | 
|  |  | 
|  | // switch back to g | 
|  | MOVD	g_m(g), R3 | 
|  | MOVD	m_curg(R3), g | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	(g_sched+gobuf_sp)(g), R0 | 
|  | MOVD	R0, RSP | 
|  | MOVD	$0, (g_sched+gobuf_sp)(g) | 
|  | RET | 
|  |  | 
|  | noswitch: | 
|  | // already on m stack, just call directly | 
|  | MOVD	0(R26), R3	// code pointer | 
|  | BL	(R3) | 
|  | RET | 
|  |  | 
|  | /* | 
|  | * support for morestack | 
|  | */ | 
|  |  | 
|  | // Called during function prolog when more stack is needed. | 
|  | // Caller has already loaded: | 
|  | // R3 prolog's LR (R30) | 
|  | // | 
|  | // The traceback routines see morestack on a g0 as being | 
|  | // the top of a stack (for example, morestack calling newstack | 
|  | // calling the scheduler calling newm calling gc), so we must | 
|  | // record an argument size. For that purpose, it has no arguments. | 
|  | TEXT runtime·morestack(SB),NOSPLIT,$-8-0 | 
|  | // Cannot grow scheduler stack (m->g0). | 
|  | MOVD	g_m(g), R8 | 
|  | MOVD	m_g0(R8), R4 | 
|  | CMP	g, R4 | 
|  | BNE	3(PC) | 
|  | BL	runtime·badmorestackg0(SB) | 
|  | B	runtime·abort(SB) | 
|  |  | 
|  | // Cannot grow signal stack (m->gsignal). | 
|  | MOVD	m_gsignal(R8), R4 | 
|  | CMP	g, R4 | 
|  | BNE	3(PC) | 
|  | BL	runtime·badmorestackgsignal(SB) | 
|  | B	runtime·abort(SB) | 
|  |  | 
|  | // Called from f. | 
|  | // Set g->sched to context in f | 
|  | MOVD	RSP, R0 | 
|  | MOVD	R0, (g_sched+gobuf_sp)(g) | 
|  | MOVD	LR, (g_sched+gobuf_pc)(g) | 
|  | MOVD	R3, (g_sched+gobuf_lr)(g) | 
|  | // newstack will fill gobuf.ctxt. | 
|  |  | 
|  | // Called from f. | 
|  | // Set m->morebuf to f's callers. | 
|  | MOVD	R3, (m_morebuf+gobuf_pc)(R8)	// f's caller's PC | 
|  | MOVD	RSP, R0 | 
|  | MOVD	R0, (m_morebuf+gobuf_sp)(R8)	// f's caller's RSP | 
|  | MOVD	g, (m_morebuf+gobuf_g)(R8) | 
|  |  | 
|  | // Call newstack on m->g0's stack. | 
|  | MOVD	m_g0(R8), g | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	(g_sched+gobuf_sp)(g), R0 | 
|  | MOVD	R0, RSP | 
|  | MOVD.W	$0, -16(RSP)	// create a call frame on g0 | 
|  | MOVD	R26, 8(RSP)	// ctxt argument | 
|  | BL	runtime·newstack(SB) | 
|  |  | 
|  | // Not reached, but make sure the return PC from the call to newstack | 
|  | // is still in this function, and not the beginning of the next. | 
|  | UNDEF | 
|  |  | 
|  | TEXT runtime·morestack_noctxt(SB),NOSPLIT,$-4-0 | 
|  | MOVW	$0, R26 | 
|  | B runtime·morestack(SB) | 
|  |  | 
|  | TEXT runtime·stackBarrier(SB),NOSPLIT,$0 | 
|  | // We came here via a RET to an overwritten LR. | 
|  | // R0 may be live (see return0). Other registers are available. | 
|  |  | 
|  | // Get the original return PC, g.stkbar[g.stkbarPos].savedLRVal. | 
|  | MOVD	(g_stkbar+slice_array)(g), R4 | 
|  | MOVD	g_stkbarPos(g), R5 | 
|  | MOVD	$stkbar__size, R6 | 
|  | MUL	R5, R6 | 
|  | ADD	R4, R6 | 
|  | MOVD	stkbar_savedLRVal(R6), R6 | 
|  | // Record that this stack barrier was hit. | 
|  | ADD	$1, R5 | 
|  | MOVD	R5, g_stkbarPos(g) | 
|  | // Jump to the original return PC. | 
|  | B	(R6) | 
|  |  | 
|  | // reflectcall: call a function with the given argument list | 
|  | // func call(argtype *_type, f *FuncVal, arg *byte, argsize, retoffset uint32). | 
|  | // 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)		\ | 
|  | MOVD	$MAXSIZE, R27;		\ | 
|  | CMP	R27, R16;		\ | 
|  | BGT	3(PC);			\ | 
|  | MOVD	$NAME(SB), R27;	\ | 
|  | B	(R27) | 
|  | // Note: can't just "B NAME(SB)" - bad inlining results. | 
|  |  | 
|  | TEXT reflect·call(SB), NOSPLIT, $0-0 | 
|  | B	·reflectcall(SB) | 
|  |  | 
|  | TEXT ·reflectcall(SB), NOSPLIT, $-8-32 | 
|  | MOVWU argsize+24(FP), R16 | 
|  | 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) | 
|  | MOVD	$runtime·badreflectcall(SB), R0 | 
|  | B	(R0) | 
|  |  | 
|  | #define CALLFN(NAME,MAXSIZE)			\ | 
|  | TEXT NAME(SB), WRAPPER, $MAXSIZE-24;		\ | 
|  | NO_LOCAL_POINTERS;			\ | 
|  | /* copy arguments to stack */		\ | 
|  | MOVD	arg+16(FP), R3;			\ | 
|  | MOVWU	argsize+24(FP), R4;			\ | 
|  | MOVD	RSP, R5;				\ | 
|  | ADD	$(8-1), R5;			\ | 
|  | SUB	$1, R3;				\ | 
|  | ADD	R5, R4;				\ | 
|  | CMP	R5, R4;				\ | 
|  | BEQ	4(PC);				\ | 
|  | MOVBU.W	1(R3), R6;			\ | 
|  | MOVBU.W	R6, 1(R5);			\ | 
|  | B	-4(PC);				\ | 
|  | /* call function */			\ | 
|  | MOVD	f+8(FP), R26;			\ | 
|  | MOVD	(R26), R0;			\ | 
|  | PCDATA  $PCDATA_StackMapIndex, $0;	\ | 
|  | BL	(R0);				\ | 
|  | /* copy return values back */		\ | 
|  | MOVD	argtype+0(FP), R7;		\ | 
|  | MOVD	arg+16(FP), R3;			\ | 
|  | MOVWU	n+24(FP), R4;			\ | 
|  | MOVWU	retoffset+28(FP), R6;		\ | 
|  | ADD	$8, RSP, R5;			\ | 
|  | ADD	R6, R5; 			\ | 
|  | ADD	R6, R3;				\ | 
|  | SUB	R6, R4;				\ | 
|  | BL	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, $40-0 | 
|  | MOVD	R7, 8(RSP) | 
|  | MOVD	R3, 16(RSP) | 
|  | MOVD	R5, 24(RSP) | 
|  | MOVD	R4, 32(RSP) | 
|  | BL	runtime·reflectcallmove(SB) | 
|  | RET | 
|  |  | 
|  | // These have 8 added to make the overall frame size a multiple of 16, | 
|  | // as required by the ABI. (There is another +8 for the saved LR.) | 
|  | CALLFN(·call32, 40 ) | 
|  | CALLFN(·call64, 72 ) | 
|  | CALLFN(·call128, 136 ) | 
|  | CALLFN(·call256, 264 ) | 
|  | CALLFN(·call512, 520 ) | 
|  | CALLFN(·call1024, 1032 ) | 
|  | CALLFN(·call2048, 2056 ) | 
|  | CALLFN(·call4096, 4104 ) | 
|  | CALLFN(·call8192, 8200 ) | 
|  | CALLFN(·call16384, 16392 ) | 
|  | CALLFN(·call32768, 32776 ) | 
|  | CALLFN(·call65536, 65544 ) | 
|  | CALLFN(·call131072, 131080 ) | 
|  | CALLFN(·call262144, 262152 ) | 
|  | CALLFN(·call524288, 524296 ) | 
|  | CALLFN(·call1048576, 1048584 ) | 
|  | CALLFN(·call2097152, 2097160 ) | 
|  | CALLFN(·call4194304, 4194312 ) | 
|  | CALLFN(·call8388608, 8388616 ) | 
|  | CALLFN(·call16777216, 16777224 ) | 
|  | CALLFN(·call33554432, 33554440 ) | 
|  | CALLFN(·call67108864, 67108872 ) | 
|  | CALLFN(·call134217728, 134217736 ) | 
|  | CALLFN(·call268435456, 268435464 ) | 
|  | CALLFN(·call536870912, 536870920 ) | 
|  | CALLFN(·call1073741824, 1073741832 ) | 
|  |  | 
|  | // AES hashing not implemented for ARM64, issue #10109. | 
|  | TEXT runtime·aeshash(SB),NOSPLIT,$-8-0 | 
|  | MOVW	$0, R0 | 
|  | MOVW	(R0), R1 | 
|  | TEXT runtime·aeshash32(SB),NOSPLIT,$-8-0 | 
|  | MOVW	$0, R0 | 
|  | MOVW	(R0), R1 | 
|  | TEXT runtime·aeshash64(SB),NOSPLIT,$-8-0 | 
|  | MOVW	$0, R0 | 
|  | MOVW	(R0), R1 | 
|  | TEXT runtime·aeshashstr(SB),NOSPLIT,$-8-0 | 
|  | MOVW	$0, R0 | 
|  | MOVW	(R0), R1 | 
|  |  | 
|  | TEXT runtime·procyield(SB),NOSPLIT,$0-0 | 
|  | MOVWU	cycles+0(FP), R0 | 
|  | again: | 
|  | YIELD | 
|  | SUBW	$1, R0 | 
|  | CBNZ	R0, again | 
|  | RET | 
|  |  | 
|  | // void jmpdefer(fv, sp); | 
|  | // called from deferreturn. | 
|  | // 1. grab stored LR for caller | 
|  | // 2. sub 4 bytes to get back to BL deferreturn | 
|  | // 3. BR to fn | 
|  | TEXT runtime·jmpdefer(SB), NOSPLIT, $-8-16 | 
|  | MOVD	0(RSP), R0 | 
|  | SUB	$4, R0 | 
|  | MOVD	R0, LR | 
|  |  | 
|  | MOVD	fv+0(FP), R26 | 
|  | MOVD	argp+8(FP), R0 | 
|  | MOVD	R0, RSP | 
|  | SUB	$8, RSP | 
|  | MOVD	0(R26), R3 | 
|  | B	(R3) | 
|  |  | 
|  | // Save state of caller into g->sched. Smashes R0. | 
|  | TEXT gosave<>(SB),NOSPLIT,$-8 | 
|  | MOVD	LR, (g_sched+gobuf_pc)(g) | 
|  | MOVD RSP, R0 | 
|  | MOVD	R0, (g_sched+gobuf_sp)(g) | 
|  | MOVD	$0, (g_sched+gobuf_lr)(g) | 
|  | MOVD	$0, (g_sched+gobuf_ret)(g) | 
|  | // Assert ctxt is zero. See func save. | 
|  | MOVD	(g_sched+gobuf_ctxt)(g), R0 | 
|  | CMP	$0, R0 | 
|  | BEQ	2(PC) | 
|  | CALL	runtime·badctxt(SB) | 
|  | 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 | 
|  | MOVD	fn+0(FP), R1 | 
|  | MOVD	arg+8(FP), R0 | 
|  |  | 
|  | MOVD	RSP, R2		// save original stack pointer | 
|  | MOVD	g, R4 | 
|  |  | 
|  | // 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. | 
|  | MOVD	g_m(g), R8 | 
|  | MOVD	m_g0(R8), R3 | 
|  | CMP	R3, g | 
|  | BEQ	g0 | 
|  | MOVD	R0, R9	// gosave<> and save_g might clobber R0 | 
|  | BL	gosave<>(SB) | 
|  | MOVD	R3, g | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	(g_sched+gobuf_sp)(g), R0 | 
|  | MOVD	R0, RSP | 
|  | MOVD	R9, R0 | 
|  |  | 
|  | // Now on a scheduling stack (a pthread-created stack). | 
|  | g0: | 
|  | // Save room for two of our pointers /*, plus 32 bytes of callee | 
|  | // save area that lives on the caller stack. */ | 
|  | MOVD	RSP, R13 | 
|  | SUB	$16, R13 | 
|  | MOVD	R13, RSP | 
|  | MOVD	R4, 0(RSP)	// save old g on stack | 
|  | MOVD	(g_stack+stack_hi)(R4), R4 | 
|  | SUB	R2, R4 | 
|  | MOVD	R4, 8(RSP)	// save depth in old g stack (can't just save SP, as stack might be copied during a callback) | 
|  | BL	(R1) | 
|  | MOVD	R0, R9 | 
|  |  | 
|  | // Restore g, stack pointer. R0 is errno, so don't touch it | 
|  | MOVD	0(RSP), g | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	(g_stack+stack_hi)(g), R5 | 
|  | MOVD	8(RSP), R6 | 
|  | SUB	R6, R5 | 
|  | MOVD	R9, R0 | 
|  | MOVD	R5, RSP | 
|  |  | 
|  | MOVW	R0, ret+16(FP) | 
|  | RET | 
|  |  | 
|  | // cgocallback(void (*fn)(void*), void *frame, uintptr framesize, uintptr ctxt) | 
|  | // Turn the fn into a Go func (by taking its address) and call | 
|  | // cgocallback_gofunc. | 
|  | TEXT runtime·cgocallback(SB),NOSPLIT,$40-32 | 
|  | MOVD	$fn+0(FP), R0 | 
|  | MOVD	R0, 8(RSP) | 
|  | MOVD	frame+8(FP), R0 | 
|  | MOVD	R0, 16(RSP) | 
|  | MOVD	framesize+16(FP), R0 | 
|  | MOVD	R0, 24(RSP) | 
|  | MOVD	ctxt+24(FP), R0 | 
|  | MOVD	R0, 32(RSP) | 
|  | MOVD	$runtime·cgocallback_gofunc(SB), R0 | 
|  | BL	(R0) | 
|  | RET | 
|  |  | 
|  | // cgocallback_gofunc(FuncVal*, void *frame, uintptr framesize, uintptr ctxt) | 
|  | // See cgocall.go for more details. | 
|  | TEXT ·cgocallback_gofunc(SB),NOSPLIT,$24-32 | 
|  | NO_LOCAL_POINTERS | 
|  |  | 
|  | // Load g from thread-local storage. | 
|  | MOVB	runtime·iscgo(SB), R3 | 
|  | CMP	$0, R3 | 
|  | BEQ	nocgo | 
|  | BL	runtime·load_g(SB) | 
|  | nocgo: | 
|  |  | 
|  | // If g is nil, Go did not create the current thread. | 
|  | // 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. | 
|  | CMP	$0, g | 
|  | BEQ	needm | 
|  |  | 
|  | MOVD	g_m(g), R8 | 
|  | MOVD	R8, savedm-8(SP) | 
|  | B	havem | 
|  |  | 
|  | needm: | 
|  | MOVD	g, savedm-8(SP) // g is zero, so is m. | 
|  | MOVD	$runtime·needm(SB), R0 | 
|  | BL	(R0) | 
|  |  | 
|  | // 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. | 
|  | MOVD	g_m(g), R8 | 
|  | MOVD	m_g0(R8), R3 | 
|  | MOVD	RSP, R0 | 
|  | MOVD	R0, (g_sched+gobuf_sp)(R3) | 
|  |  | 
|  | 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 16(RSP) aka savedsp-16(SP). | 
|  | // Beware that the frame size is actually 32. | 
|  | MOVD	m_g0(R8), R3 | 
|  | MOVD	(g_sched+gobuf_sp)(R3), R4 | 
|  | MOVD	R4, savedsp-16(SP) | 
|  | MOVD	RSP, R0 | 
|  | MOVD	R0, (g_sched+gobuf_sp)(R3) | 
|  |  | 
|  | // 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 stack. | 
|  | // This has the added benefit that it looks to the traceback | 
|  | // routine like cgocallbackg is going to return to that | 
|  | // PC (because the frame we allocate below has the same | 
|  | // size as cgocallback_gofunc's frame declared above) | 
|  | // so that the traceback will seamlessly trace back into | 
|  | // the earlier calls. | 
|  | // | 
|  | // In the new goroutine, -8(SP) is unused (where SP refers to | 
|  | // m->curg's SP while we're setting it up, before we've adjusted it). | 
|  | MOVD	m_curg(R8), g | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	(g_sched+gobuf_sp)(g), R4 // prepare stack as R4 | 
|  | MOVD	(g_sched+gobuf_pc)(g), R5 | 
|  | MOVD	R5, -(24+8)(R4) | 
|  | MOVD	ctxt+24(FP), R0 | 
|  | MOVD	R0, -(16+8)(R4) | 
|  | MOVD	$-(24+8)(R4), R0 // maintain 16-byte SP alignment | 
|  | MOVD	R0, RSP | 
|  | BL	runtime·cgocallbackg(SB) | 
|  |  | 
|  | // Restore g->sched (== m->curg->sched) from saved values. | 
|  | MOVD	0(RSP), R5 | 
|  | MOVD	R5, (g_sched+gobuf_pc)(g) | 
|  | MOVD	RSP, R4 | 
|  | ADD	$(24+8), R4, R4 | 
|  | MOVD	R4, (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.) | 
|  | MOVD	g_m(g), R8 | 
|  | MOVD	m_g0(R8), g | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	(g_sched+gobuf_sp)(g), R0 | 
|  | MOVD	R0, RSP | 
|  | MOVD	savedsp-16(SP), R4 | 
|  | MOVD	R4, (g_sched+gobuf_sp)(g) | 
|  |  | 
|  | // If the m on entry was nil, we called needm above to borrow an m | 
|  | // for the duration of the call. Since the call is over, return it with dropm. | 
|  | MOVD	savedm-8(SP), R6 | 
|  | CMP	$0, R6 | 
|  | BNE	droppedm | 
|  | MOVD	$runtime·dropm(SB), R0 | 
|  | BL	(R0) | 
|  | droppedm: | 
|  |  | 
|  | // Done! | 
|  | RET | 
|  |  | 
|  | // Called from cgo wrappers, this function returns g->m->curg.stack.hi. | 
|  | // Must obey the gcc calling convention. | 
|  | TEXT _cgo_topofstack(SB),NOSPLIT,$24 | 
|  | // g (R28) and REGTMP (R27)  might be clobbered by load_g. They | 
|  | // are callee-save in the gcc calling convention, so save them. | 
|  | MOVD	R27, savedR27-8(SP) | 
|  | MOVD	g, saveG-16(SP) | 
|  |  | 
|  | BL	runtime·load_g(SB) | 
|  | MOVD	g_m(g), R0 | 
|  | MOVD	m_curg(R0), R0 | 
|  | MOVD	(g_stack+stack_hi)(R0), R0 | 
|  |  | 
|  | MOVD	saveG-16(SP), g | 
|  | MOVD	savedR28-8(SP), R27 | 
|  | RET | 
|  |  | 
|  | // void setg(G*); set g. for use by needm. | 
|  | TEXT runtime·setg(SB), NOSPLIT, $0-8 | 
|  | MOVD	gg+0(FP), g | 
|  | // This only happens if iscgo, so jump straight to save_g | 
|  | BL	runtime·save_g(SB) | 
|  | RET | 
|  |  | 
|  | // void setg_gcc(G*); set g called from gcc | 
|  | TEXT setg_gcc<>(SB),NOSPLIT,$8 | 
|  | MOVD	R0, g | 
|  | MOVD	R27, savedR27-8(SP) | 
|  | BL	runtime·save_g(SB) | 
|  | MOVD	savedR27-8(SP), R27 | 
|  | RET | 
|  |  | 
|  | TEXT runtime·getcallerpc(SB),NOSPLIT,$8-16 | 
|  | MOVD	16(RSP), R0		// LR saved by caller | 
|  | MOVD	runtime·stackBarrierPC(SB), R1 | 
|  | CMP	R0, R1 | 
|  | BNE	nobar | 
|  | // Get original return PC. | 
|  | BL	runtime·nextBarrierPC(SB) | 
|  | MOVD	8(RSP), R0 | 
|  | nobar: | 
|  | MOVD	R0, ret+8(FP) | 
|  | RET | 
|  |  | 
|  | TEXT runtime·setcallerpc(SB),NOSPLIT,$8-16 | 
|  | MOVD	pc+8(FP), R0 | 
|  | MOVD	16(RSP), R1 | 
|  | MOVD	runtime·stackBarrierPC(SB), R2 | 
|  | CMP	R1, R2 | 
|  | BEQ	setbar | 
|  | MOVD	R0, 16(RSP)		// set LR in caller | 
|  | RET | 
|  | setbar: | 
|  | // Set the stack barrier return PC. | 
|  | MOVD	R0, 8(RSP) | 
|  | BL	runtime·setNextBarrierPC(SB) | 
|  | RET | 
|  |  | 
|  | TEXT runtime·abort(SB),NOSPLIT,$-8-0 | 
|  | B	(ZR) | 
|  | UNDEF | 
|  |  | 
|  | // memhash_varlen(p unsafe.Pointer, h seed) uintptr | 
|  | // redirects to memhash(p, h, size) using the size | 
|  | // stored in the closure. | 
|  | TEXT runtime·memhash_varlen(SB),NOSPLIT,$40-24 | 
|  | GO_ARGS | 
|  | NO_LOCAL_POINTERS | 
|  | MOVD	p+0(FP), R3 | 
|  | MOVD	h+8(FP), R4 | 
|  | MOVD	8(R26), R5 | 
|  | MOVD	R3, 8(RSP) | 
|  | MOVD	R4, 16(RSP) | 
|  | MOVD	R5, 24(RSP) | 
|  | BL	runtime·memhash(SB) | 
|  | MOVD	32(RSP), R3 | 
|  | MOVD	R3, ret+16(FP) | 
|  | RET | 
|  |  | 
|  | // memequal(p, q unsafe.Pointer, size uintptr) bool | 
|  | TEXT runtime·memequal(SB),NOSPLIT,$-8-25 | 
|  | MOVD	a+0(FP), R1 | 
|  | MOVD	b+8(FP), R2 | 
|  | MOVD	size+16(FP), R3 | 
|  | ADD	R1, R3, R6 | 
|  | MOVD	$1, R0 | 
|  | MOVB	R0, ret+24(FP) | 
|  | CMP	R1, R2 | 
|  | BEQ	done | 
|  | loop: | 
|  | CMP	R1, R6 | 
|  | BEQ	done | 
|  | MOVBU.P	1(R1), R4 | 
|  | MOVBU.P	1(R2), R5 | 
|  | CMP	R4, R5 | 
|  | BEQ	loop | 
|  |  | 
|  | MOVB	$0, ret+24(FP) | 
|  | done: | 
|  | RET | 
|  |  | 
|  | // memequal_varlen(a, b unsafe.Pointer) bool | 
|  | TEXT runtime·memequal_varlen(SB),NOSPLIT,$40-17 | 
|  | MOVD	a+0(FP), R3 | 
|  | MOVD	b+8(FP), R4 | 
|  | CMP	R3, R4 | 
|  | BEQ	eq | 
|  | MOVD	8(R26), R5    // compiler stores size at offset 8 in the closure | 
|  | MOVD	R3, 8(RSP) | 
|  | MOVD	R4, 16(RSP) | 
|  | MOVD	R5, 24(RSP) | 
|  | BL	runtime·memequal(SB) | 
|  | MOVBU	32(RSP), R3 | 
|  | MOVB	R3, ret+16(FP) | 
|  | RET | 
|  | eq: | 
|  | MOVD	$1, R3 | 
|  | MOVB	R3, ret+16(FP) | 
|  | RET | 
|  |  | 
|  | TEXT runtime·cmpstring(SB),NOSPLIT,$-4-40 | 
|  | MOVD	s1_base+0(FP), R2 | 
|  | MOVD	s1_len+8(FP), R0 | 
|  | MOVD	s2_base+16(FP), R3 | 
|  | MOVD	s2_len+24(FP), R1 | 
|  | ADD	$40, RSP, R7 | 
|  | B	runtime·cmpbody<>(SB) | 
|  |  | 
|  | TEXT bytes·Compare(SB),NOSPLIT,$-4-56 | 
|  | MOVD	s1+0(FP), R2 | 
|  | MOVD	s1+8(FP), R0 | 
|  | MOVD	s2+24(FP), R3 | 
|  | MOVD	s2+32(FP), R1 | 
|  | ADD	$56, RSP, R7 | 
|  | B	runtime·cmpbody<>(SB) | 
|  |  | 
|  | // On entry: | 
|  | // R0 is the length of s1 | 
|  | // R1 is the length of s2 | 
|  | // R2 points to the start of s1 | 
|  | // R3 points to the start of s2 | 
|  | // R7 points to return value (-1/0/1 will be written here) | 
|  | // | 
|  | // On exit: | 
|  | // R4, R5, and R6 are clobbered | 
|  | TEXT runtime·cmpbody<>(SB),NOSPLIT,$-4-0 | 
|  | CMP	R2, R3 | 
|  | BEQ	samebytes // same starting pointers; compare lengths | 
|  | CMP	R0, R1 | 
|  | CSEL    LT, R1, R0, R6 // R6 is min(R0, R1) | 
|  |  | 
|  | ADD	R2, R6	// R2 is current byte in s1, R6 is last byte in s1 to compare | 
|  | loop: | 
|  | CMP	R2, R6 | 
|  | BEQ	samebytes // all compared bytes were the same; compare lengths | 
|  | MOVBU.P	1(R2), R4 | 
|  | MOVBU.P	1(R3), R5 | 
|  | CMP	R4, R5 | 
|  | BEQ	loop | 
|  | // bytes differed | 
|  | MOVD	$1, R4 | 
|  | CSNEG	LT, R4, R4, R4 | 
|  | MOVD	R4, (R7) | 
|  | RET | 
|  | samebytes: | 
|  | MOVD	$1, R4 | 
|  | CMP	R0, R1 | 
|  | CSNEG	LT, R4, R4, R4 | 
|  | CSEL	EQ, ZR, R4, R4 | 
|  | MOVD	R4, (R7) | 
|  | RET | 
|  |  | 
|  | // eqstring tests whether two strings are equal. | 
|  | // The compiler guarantees that strings passed | 
|  | // to eqstring have equal length. | 
|  | // See runtime_test.go:eqstring_generic for | 
|  | // equivalent Go code. | 
|  | TEXT runtime·eqstring(SB),NOSPLIT,$0-33 | 
|  | MOVD	s1_base+0(FP), R0 | 
|  | MOVD	s1_len+8(FP), R1 | 
|  | MOVD	s2_base+16(FP), R2 | 
|  | ADD	R0, R1		// end | 
|  | loop: | 
|  | CMP	R0, R1 | 
|  | BEQ	equal		// reaches the end | 
|  | MOVBU.P	1(R0), R4 | 
|  | MOVBU.P	1(R2), R5 | 
|  | CMP	R4, R5 | 
|  | BEQ	loop | 
|  | notequal: | 
|  | MOVB	ZR, ret+32(FP) | 
|  | RET | 
|  | equal: | 
|  | MOVD	$1, R0 | 
|  | MOVB	R0, ret+32(FP) | 
|  | RET | 
|  |  | 
|  | // | 
|  | // functions for other packages | 
|  | // | 
|  | TEXT bytes·IndexByte(SB),NOSPLIT,$0-40 | 
|  | MOVD	b+0(FP), R0 | 
|  | MOVD	b_len+8(FP), R1 | 
|  | MOVBU	c+24(FP), R2	// byte to find | 
|  | MOVD	R0, R4		// store base for later | 
|  | ADD	R0, R1		// end | 
|  | loop: | 
|  | CMP	R0, R1 | 
|  | BEQ	notfound | 
|  | MOVBU.P	1(R0), R3 | 
|  | CMP	R2, R3 | 
|  | BNE	loop | 
|  |  | 
|  | SUB	$1, R0		// R0 will be one beyond the position we want | 
|  | SUB	R4, R0		// remove base | 
|  | MOVD	R0, ret+32(FP) | 
|  | RET | 
|  |  | 
|  | notfound: | 
|  | MOVD	$-1, R0 | 
|  | MOVD	R0, ret+32(FP) | 
|  | RET | 
|  |  | 
|  | TEXT strings·IndexByte(SB),NOSPLIT,$0-32 | 
|  | MOVD	s+0(FP), R0 | 
|  | MOVD	s_len+8(FP), R1 | 
|  | MOVBU	c+16(FP), R2	// byte to find | 
|  | MOVD	R0, R4		// store base for later | 
|  | ADD	R0, R1		// end | 
|  | loop: | 
|  | CMP	R0, R1 | 
|  | BEQ	notfound | 
|  | MOVBU.P	1(R0), R3 | 
|  | CMP	R2, R3 | 
|  | BNE	loop | 
|  |  | 
|  | SUB	$1, R0		// R0 will be one beyond the position we want | 
|  | SUB	R4, R0		// remove base | 
|  | MOVD	R0, ret+24(FP) | 
|  | RET | 
|  |  | 
|  | notfound: | 
|  | MOVD	$-1, R0 | 
|  | MOVD	R0, ret+24(FP) | 
|  | RET | 
|  |  | 
|  | // TODO: share code with memequal? | 
|  | TEXT bytes·Equal(SB),NOSPLIT,$0-49 | 
|  | MOVD	a_len+8(FP), R1 | 
|  | MOVD	b_len+32(FP), R3 | 
|  | CMP	R1, R3		// unequal lengths are not equal | 
|  | BNE	notequal | 
|  | MOVD	a+0(FP), R0 | 
|  | MOVD	b+24(FP), R2 | 
|  | ADD	R0, R1		// end | 
|  | loop: | 
|  | CMP	R0, R1 | 
|  | BEQ	equal		// reaches the end | 
|  | MOVBU.P	1(R0), R4 | 
|  | MOVBU.P	1(R2), R5 | 
|  | CMP	R4, R5 | 
|  | BEQ	loop | 
|  | notequal: | 
|  | MOVB	ZR, ret+48(FP) | 
|  | RET | 
|  | equal: | 
|  | MOVD	$1, R0 | 
|  | MOVB	R0, ret+48(FP) | 
|  | RET | 
|  |  | 
|  | TEXT runtime·fastrand(SB),NOSPLIT,$-8-4 | 
|  | MOVD	g_m(g), R1 | 
|  | MOVWU	m_fastrand(R1), R0 | 
|  | ADD	R0, R0 | 
|  | CMPW	$0, R0 | 
|  | BGE	notneg | 
|  | EOR	$0x88888eef, R0 | 
|  | notneg: | 
|  | MOVW	R0, m_fastrand(R1) | 
|  | MOVW	R0, ret+0(FP) | 
|  | RET | 
|  |  | 
|  | TEXT runtime·return0(SB), NOSPLIT, $0 | 
|  | MOVW	$0, R0 | 
|  | RET | 
|  |  | 
|  | // The top-most function running on a goroutine | 
|  | // returns to goexit+PCQuantum. | 
|  | TEXT runtime·goexit(SB),NOSPLIT,$-8-0 | 
|  | MOVD	R0, R0	// NOP | 
|  | BL	runtime·goexit1(SB)	// does not return | 
|  |  | 
|  | // TODO(aram): use PRFM here. | 
|  | TEXT runtime·prefetcht0(SB),NOSPLIT,$0-8 | 
|  | RET | 
|  |  | 
|  | TEXT runtime·prefetcht1(SB),NOSPLIT,$0-8 | 
|  | RET | 
|  |  | 
|  | TEXT runtime·prefetcht2(SB),NOSPLIT,$0-8 | 
|  | RET | 
|  |  | 
|  | TEXT runtime·prefetchnta(SB),NOSPLIT,$0-8 | 
|  | RET | 
|  |  | 
|  | TEXT runtime·sigreturn(SB),NOSPLIT,$0-0 | 
|  | RET | 
|  |  | 
|  | // This is called from .init_array and follows the platform, not Go, ABI. | 
|  | TEXT runtime·addmoduledata(SB),NOSPLIT,$0-0 | 
|  | SUB	$0x10, RSP | 
|  | MOVD	R27, 8(RSP) // The access to global variables below implicitly uses R27, which is callee-save | 
|  | MOVD	runtime·lastmoduledatap(SB), R1 | 
|  | MOVD	R0, moduledata_next(R1) | 
|  | MOVD	R0, runtime·lastmoduledatap(SB) | 
|  | MOVD	8(RSP), R27 | 
|  | ADD	$0x10, RSP | 
|  | RET | 
|  |  | 
|  | TEXT ·checkASM(SB),NOSPLIT,$0-1 | 
|  | MOVW	$1, R3 | 
|  | MOVB	R3, ret+0(FP) | 
|  | RET |