| // Copyright 2009 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 "funcdata.h" |
| #include "textflag.h" |
| |
| // _rt0_arm is common startup code for most ARM systems when using |
| // internal linking. This is the entry point for the program from the |
| // kernel for an ordinary -buildmode=exe program. The stack holds the |
| // number of arguments and the C-style argv. |
| TEXT _rt0_arm(SB),NOSPLIT|NOFRAME,$0 |
| MOVW (R13), R0 // argc |
| MOVW $4(R13), R1 // argv |
| B runtime·rt0_go(SB) |
| |
| // main is common startup code for most ARM systems when using |
| // external linking. The C startup code will call the symbol "main" |
| // passing argc and argv in the usual C ABI registers R0 and R1. |
| TEXT main(SB),NOSPLIT|NOFRAME,$0 |
| B runtime·rt0_go(SB) |
| |
| // _rt0_arm_lib is common startup code for most ARM systems when |
| // using -buildmode=c-archive or -buildmode=c-shared. The linker will |
| // arrange to invoke this function as a global constructor (for |
| // c-archive) or when the shared library is loaded (for c-shared). |
| // We expect argc and argv to be passed in the usual C ABI registers |
| // R0 and R1. |
| TEXT _rt0_arm_lib(SB),NOSPLIT,$104 |
| // Preserve callee-save registers. Raspberry Pi's dlopen(), for example, |
| // actually cares that R11 is preserved. |
| MOVW R4, 12(R13) |
| MOVW R5, 16(R13) |
| MOVW R6, 20(R13) |
| MOVW R7, 24(R13) |
| MOVW R8, 28(R13) |
| MOVW g, 32(R13) |
| MOVW R11, 36(R13) |
| |
| // Skip floating point registers on GOARM < 6. |
| MOVB runtime·goarm(SB), R11 |
| CMP $6, R11 |
| BLT skipfpsave |
| MOVD F8, (40+8*0)(R13) |
| MOVD F9, (40+8*1)(R13) |
| MOVD F10, (40+8*2)(R13) |
| MOVD F11, (40+8*3)(R13) |
| MOVD F12, (40+8*4)(R13) |
| MOVD F13, (40+8*5)(R13) |
| MOVD F14, (40+8*6)(R13) |
| MOVD F15, (40+8*7)(R13) |
| skipfpsave: |
| // Save argc/argv. |
| MOVW R0, _rt0_arm_lib_argc<>(SB) |
| MOVW R1, _rt0_arm_lib_argv<>(SB) |
| |
| MOVW $0, g // Initialize g. |
| |
| // Synchronous initialization. |
| CALL runtime·libpreinit(SB) |
| |
| // Create a new thread to do the runtime initialization. |
| MOVW _cgo_sys_thread_create(SB), R2 |
| CMP $0, R2 |
| BEQ nocgo |
| MOVW $_rt0_arm_lib_go<>(SB), R0 |
| MOVW $0, R1 |
| BL (R2) |
| B rr |
| nocgo: |
| MOVW $0x800000, R0 // stacksize = 8192KB |
| MOVW $_rt0_arm_lib_go<>(SB), R1 // fn |
| MOVW R0, 4(R13) |
| MOVW R1, 8(R13) |
| BL runtime·newosproc0(SB) |
| rr: |
| // Restore callee-save registers and return. |
| MOVB runtime·goarm(SB), R11 |
| CMP $6, R11 |
| BLT skipfprest |
| MOVD (40+8*0)(R13), F8 |
| MOVD (40+8*1)(R13), F9 |
| MOVD (40+8*2)(R13), F10 |
| MOVD (40+8*3)(R13), F11 |
| MOVD (40+8*4)(R13), F12 |
| MOVD (40+8*5)(R13), F13 |
| MOVD (40+8*6)(R13), F14 |
| MOVD (40+8*7)(R13), F15 |
| skipfprest: |
| MOVW 12(R13), R4 |
| MOVW 16(R13), R5 |
| MOVW 20(R13), R6 |
| MOVW 24(R13), R7 |
| MOVW 28(R13), R8 |
| MOVW 32(R13), g |
| MOVW 36(R13), R11 |
| RET |
| |
| // _rt0_arm_lib_go initializes the Go runtime. |
| // This is started in a separate thread by _rt0_arm_lib. |
| TEXT _rt0_arm_lib_go<>(SB),NOSPLIT,$8 |
| MOVW _rt0_arm_lib_argc<>(SB), R0 |
| MOVW _rt0_arm_lib_argv<>(SB), R1 |
| B runtime·rt0_go(SB) |
| |
| DATA _rt0_arm_lib_argc<>(SB)/4,$0 |
| GLOBL _rt0_arm_lib_argc<>(SB),NOPTR,$4 |
| DATA _rt0_arm_lib_argv<>(SB)/4,$0 |
| GLOBL _rt0_arm_lib_argv<>(SB),NOPTR,$4 |
| |
| // using NOFRAME means do not save LR on stack. |
| // argc is in R0, argv is in R1. |
| TEXT runtime·rt0_go(SB),NOSPLIT|NOFRAME,$0 |
| MOVW $0xcafebabe, R12 |
| |
| // copy arguments forward on an even stack |
| // use R13 instead of SP to avoid linker rewriting the offsets |
| SUB $64, R13 // plenty of scratch |
| AND $~7, R13 |
| MOVW R0, 60(R13) // save argc, argv away |
| MOVW R1, 64(R13) |
| |
| // set up g register |
| // g is R10 |
| MOVW $runtime·g0(SB), g |
| MOVW $runtime·m0(SB), R8 |
| |
| // save m->g0 = g0 |
| MOVW g, m_g0(R8) |
| // save g->m = m0 |
| MOVW R8, g_m(g) |
| |
| // create istack out of the OS stack |
| // (1MB of system stack is available on iOS and Android) |
| MOVW $(-64*1024+104)(R13), R0 |
| MOVW R0, g_stackguard0(g) |
| MOVW R0, g_stackguard1(g) |
| MOVW R0, (g_stack+stack_lo)(g) |
| MOVW R13, (g_stack+stack_hi)(g) |
| |
| BL runtime·emptyfunc(SB) // fault if stack check is wrong |
| |
| BL runtime·_initcgo(SB) // will clobber R0-R3 |
| |
| // update stackguard after _cgo_init |
| MOVW (g_stack+stack_lo)(g), R0 |
| ADD $const__StackGuard, R0 |
| MOVW R0, g_stackguard0(g) |
| MOVW R0, g_stackguard1(g) |
| |
| BL runtime·check(SB) |
| |
| // saved argc, argv |
| MOVW 60(R13), R0 |
| MOVW R0, 4(R13) |
| MOVW 64(R13), R1 |
| MOVW R1, 8(R13) |
| BL runtime·args(SB) |
| BL runtime·checkgoarm(SB) |
| BL runtime·osinit(SB) |
| BL runtime·schedinit(SB) |
| |
| // create a new goroutine to start program |
| MOVW $runtime·mainPC(SB), R0 |
| MOVW.W R0, -4(R13) |
| MOVW $8, R0 |
| MOVW.W R0, -4(R13) |
| MOVW $0, R0 |
| MOVW.W R0, -4(R13) // push $0 as guard |
| BL runtime·newproc(SB) |
| MOVW $12(R13), R13 // pop args and LR |
| |
| // start this M |
| BL runtime·mstart(SB) |
| |
| MOVW $1234, R0 |
| MOVW $1000, R1 |
| MOVW R0, (R1) // fail hard |
| |
| DATA runtime·mainPC+0(SB)/4,$runtime·main(SB) |
| GLOBL runtime·mainPC(SB),RODATA,$4 |
| |
| TEXT runtime·breakpoint(SB),NOSPLIT,$0-0 |
| // gdb won't skip this breakpoint instruction automatically, |
| // so you must manually "set $pc+=4" to skip it and continue. |
| #ifdef GOOS_nacl |
| WORD $0xe125be7f // BKPT 0x5bef, NACL_INSTR_ARM_BREAKPOINT |
| #else |
| #ifdef GOOS_plan9 |
| WORD $0xD1200070 // undefined instruction used as armv5 breakpoint in Plan 9 |
| #else |
| WORD $0xe7f001f0 // undefined instruction that gdb understands is a software breakpoint |
| #endif |
| #endif |
| RET |
| |
| TEXT runtime·asminit(SB),NOSPLIT,$0-0 |
| // disable runfast (flush-to-zero) mode of vfp if runtime.goarm > 5 |
| MOVB runtime·goarm(SB), R11 |
| CMP $5, R11 |
| BLE 4(PC) |
| WORD $0xeef1ba10 // vmrs r11, fpscr |
| BIC $(1<<24), R11 |
| WORD $0xeee1ba10 // vmsr fpscr, r11 |
| RET |
| |
| /* |
| * go-routine |
| */ |
| |
| // void gosave(Gobuf*) |
| // save state in Gobuf; setjmp |
| TEXT runtime·gosave(SB),NOSPLIT|NOFRAME,$0-4 |
| MOVW buf+0(FP), R0 |
| MOVW R13, gobuf_sp(R0) |
| MOVW LR, gobuf_pc(R0) |
| MOVW g, gobuf_g(R0) |
| MOVW $0, R11 |
| MOVW R11, gobuf_lr(R0) |
| MOVW R11, gobuf_ret(R0) |
| // Assert ctxt is zero. See func save. |
| MOVW gobuf_ctxt(R0), R0 |
| CMP R0, R11 |
| B.EQ 2(PC) |
| CALL runtime·badctxt(SB) |
| RET |
| |
| // void gogo(Gobuf*) |
| // restore state from Gobuf; longjmp |
| TEXT runtime·gogo(SB),NOSPLIT,$8-4 |
| MOVW buf+0(FP), R1 |
| MOVW gobuf_g(R1), R0 |
| BL setg<>(SB) |
| |
| // NOTE: We updated g above, and we are about to update SP. |
| // Until LR and PC are also updated, the g/SP/LR/PC quadruple |
| // are out of sync and must not be used as the basis of a traceback. |
| // Sigprof skips the traceback when SP is not within g's bounds, |
| // and when the PC is inside this function, runtime.gogo. |
| // Since we are about to update SP, until we complete runtime.gogo |
| // we must not leave this function. In particular, no calls |
| // after this point: it must be straight-line code until the |
| // final B instruction. |
| // See large comment in sigprof for more details. |
| MOVW gobuf_sp(R1), R13 // restore SP==R13 |
| MOVW gobuf_lr(R1), LR |
| MOVW gobuf_ret(R1), R0 |
| MOVW gobuf_ctxt(R1), R7 |
| MOVW $0, R11 |
| MOVW R11, gobuf_sp(R1) // clear to help garbage collector |
| MOVW R11, gobuf_ret(R1) |
| MOVW R11, gobuf_lr(R1) |
| MOVW R11, gobuf_ctxt(R1) |
| MOVW gobuf_pc(R1), R11 |
| CMP R11, R11 // set condition codes for == test, needed by stack split |
| B (R11) |
| |
| // func 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,$0-4 |
| // Save caller state in g->sched. |
| MOVW R13, (g_sched+gobuf_sp)(g) |
| MOVW LR, (g_sched+gobuf_pc)(g) |
| MOVW $0, R11 |
| MOVW R11, (g_sched+gobuf_lr)(g) |
| MOVW g, (g_sched+gobuf_g)(g) |
| |
| // Switch to m->g0 & its stack, call fn. |
| MOVW g, R1 |
| MOVW g_m(g), R8 |
| MOVW m_g0(R8), R0 |
| BL setg<>(SB) |
| CMP g, R1 |
| B.NE 2(PC) |
| B runtime·badmcall(SB) |
| MOVB runtime·iscgo(SB), R11 |
| CMP $0, R11 |
| BL.NE runtime·save_g(SB) |
| MOVW fn+0(FP), R0 |
| MOVW (g_sched+gobuf_sp)(g), R13 |
| SUB $8, R13 |
| MOVW R1, 4(R13) |
| MOVW R0, R7 |
| MOVW 0(R0), R0 |
| BL (R0) |
| B runtime·badmcall2(SB) |
| RET |
| |
| // 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 |
| MOVW $0, R0 |
| BL (R0) // clobber lr to ensure push {lr} is kept |
| RET |
| |
| // func systemstack(fn func()) |
| TEXT runtime·systemstack(SB),NOSPLIT,$0-4 |
| MOVW fn+0(FP), R0 // R0 = fn |
| MOVW g_m(g), R1 // R1 = m |
| |
| MOVW m_gsignal(R1), R2 // R2 = gsignal |
| CMP g, R2 |
| B.EQ noswitch |
| |
| MOVW m_g0(R1), R2 // R2 = g0 |
| CMP g, R2 |
| B.EQ noswitch |
| |
| MOVW m_curg(R1), R3 |
| CMP g, R3 |
| B.EQ switch |
| |
| // Bad: g is not gsignal, not g0, not curg. What is it? |
| // Hide call from linker nosplit analysis. |
| MOVW $runtime·badsystemstack(SB), R0 |
| BL (R0) |
| B runtime·abort(SB) |
| |
| switch: |
| // save our state in g->sched. Pretend to |
| // be systemstack_switch if the G stack is scanned. |
| MOVW $runtime·systemstack_switch(SB), R3 |
| #ifdef GOOS_nacl |
| ADD $4, R3, R3 // get past nacl-insert bic instruction |
| #endif |
| ADD $4, R3, R3 // get past push {lr} |
| MOVW R3, (g_sched+gobuf_pc)(g) |
| MOVW R13, (g_sched+gobuf_sp)(g) |
| MOVW LR, (g_sched+gobuf_lr)(g) |
| MOVW g, (g_sched+gobuf_g)(g) |
| |
| // switch to g0 |
| MOVW R0, R5 |
| MOVW R2, R0 |
| BL setg<>(SB) |
| MOVW R5, R0 |
| MOVW (g_sched+gobuf_sp)(R2), R3 |
| // make it look like mstart called systemstack on g0, to stop traceback |
| SUB $4, R3, R3 |
| MOVW $runtime·mstart(SB), R4 |
| MOVW R4, 0(R3) |
| MOVW R3, R13 |
| |
| // call target function |
| MOVW R0, R7 |
| MOVW 0(R0), R0 |
| BL (R0) |
| |
| // switch back to g |
| MOVW g_m(g), R1 |
| MOVW m_curg(R1), R0 |
| BL setg<>(SB) |
| MOVW (g_sched+gobuf_sp)(g), R13 |
| MOVW $0, R3 |
| MOVW R3, (g_sched+gobuf_sp)(g) |
| RET |
| |
| noswitch: |
| // Using a tail call here cleans up tracebacks since we won't stop |
| // at an intermediate systemstack. |
| MOVW R0, R7 |
| MOVW 0(R0), R0 |
| MOVW.P 4(R13), R14 // restore LR |
| B (R0) |
| |
| /* |
| * support for morestack |
| */ |
| |
| // Called during function prolog when more stack is needed. |
| // R3 prolog's LR |
| // using NOFRAME means do not save LR on stack. |
| // |
| // 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 |
| // Cannot grow scheduler stack (m->g0). |
| MOVW g_m(g), R8 |
| MOVW m_g0(R8), R4 |
| CMP g, R4 |
| BNE 3(PC) |
| BL runtime·badmorestackg0(SB) |
| B runtime·abort(SB) |
| |
| // Cannot grow signal stack (m->gsignal). |
| MOVW 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. |
| MOVW R13, (g_sched+gobuf_sp)(g) |
| MOVW LR, (g_sched+gobuf_pc)(g) |
| MOVW R3, (g_sched+gobuf_lr)(g) |
| MOVW R7, (g_sched+gobuf_ctxt)(g) |
| |
| // Called from f. |
| // Set m->morebuf to f's caller. |
| MOVW R3, (m_morebuf+gobuf_pc)(R8) // f's caller's PC |
| MOVW R13, (m_morebuf+gobuf_sp)(R8) // f's caller's SP |
| MOVW g, (m_morebuf+gobuf_g)(R8) |
| |
| // Call newstack on m->g0's stack. |
| MOVW m_g0(R8), R0 |
| BL setg<>(SB) |
| MOVW (g_sched+gobuf_sp)(g), R13 |
| MOVW $0, R0 |
| MOVW.W R0, -4(R13) // create a call frame on g0 (saved LR) |
| 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. |
| RET |
| |
| TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVW $0, R7 |
| B runtime·morestack(SB) |
| |
| // 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) \ |
| CMP $MAXSIZE, R0; \ |
| B.HI 3(PC); \ |
| MOVW $NAME(SB), R1; \ |
| B (R1) |
| |
| TEXT ·reflectcall(SB),NOSPLIT|NOFRAME,$0-20 |
| MOVW argsize+12(FP), R0 |
| 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) |
| MOVW $runtime·badreflectcall(SB), R1 |
| B (R1) |
| |
| #define CALLFN(NAME,MAXSIZE) \ |
| TEXT NAME(SB), WRAPPER, $MAXSIZE-20; \ |
| NO_LOCAL_POINTERS; \ |
| /* copy arguments to stack */ \ |
| MOVW argptr+8(FP), R0; \ |
| MOVW argsize+12(FP), R2; \ |
| ADD $4, R13, R1; \ |
| CMP $0, R2; \ |
| B.EQ 5(PC); \ |
| MOVBU.P 1(R0), R5; \ |
| MOVBU.P R5, 1(R1); \ |
| SUB $1, R2, R2; \ |
| B -5(PC); \ |
| /* call function */ \ |
| MOVW f+4(FP), R7; \ |
| MOVW (R7), R0; \ |
| PCDATA $PCDATA_StackMapIndex, $0; \ |
| BL (R0); \ |
| /* copy return values back */ \ |
| MOVW argtype+0(FP), R4; \ |
| MOVW argptr+8(FP), R0; \ |
| MOVW argsize+12(FP), R2; \ |
| MOVW retoffset+16(FP), R3; \ |
| ADD $4, R13, R1; \ |
| ADD R3, R1; \ |
| ADD R3, R0; \ |
| SUB R3, R2; \ |
| 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, $16-0 |
| MOVW R4, 4(R13) |
| MOVW R0, 8(R13) |
| MOVW R1, 12(R13) |
| MOVW R2, 16(R13) |
| BL 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) |
| |
| // void jmpdefer(fn, sp); |
| // called from deferreturn. |
| // 1. grab stored LR for caller |
| // 2. sub 4 bytes to get back to BL deferreturn |
| // 3. B to fn |
| // TODO(rsc): Push things on stack and then use pop |
| // to load all registers simultaneously, so that a profiling |
| // interrupt can never see mismatched SP/LR/PC. |
| // (And double-check that pop is atomic in that way.) |
| TEXT runtime·jmpdefer(SB),NOSPLIT,$0-8 |
| MOVW 0(R13), LR |
| MOVW $-4(LR), LR // BL deferreturn |
| MOVW fv+0(FP), R7 |
| MOVW argp+4(FP), R13 |
| MOVW $-4(R13), R13 // SP is 4 below argp, due to saved LR |
| MOVW 0(R7), R1 |
| B (R1) |
| |
| // Save state of caller into g->sched. Smashes R11. |
| TEXT gosave<>(SB),NOSPLIT|NOFRAME,$0 |
| MOVW LR, (g_sched+gobuf_pc)(g) |
| MOVW R13, (g_sched+gobuf_sp)(g) |
| MOVW $0, R11 |
| MOVW R11, (g_sched+gobuf_lr)(g) |
| MOVW R11, (g_sched+gobuf_ret)(g) |
| MOVW R11, (g_sched+gobuf_ctxt)(g) |
| // Assert ctxt is zero. See func save. |
| MOVW (g_sched+gobuf_ctxt)(g), R11 |
| CMP $0, R11 |
| B.EQ 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,$0-12 |
| MOVW fn+0(FP), R1 |
| MOVW arg+4(FP), R0 |
| |
| MOVW R13, R2 |
| CMP $0, g |
| BEQ nosave |
| MOVW 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. |
| MOVW g_m(g), R8 |
| MOVW m_gsignal(R8), R3 |
| CMP R3, g |
| BEQ nosave |
| MOVW m_g0(R8), R3 |
| CMP R3, g |
| BEQ nosave |
| BL gosave<>(SB) |
| MOVW R0, R5 |
| MOVW R3, R0 |
| BL setg<>(SB) |
| MOVW R5, R0 |
| MOVW (g_sched+gobuf_sp)(g), R13 |
| |
| // Now on a scheduling stack (a pthread-created stack). |
| SUB $24, R13 |
| BIC $0x7, R13 // alignment for gcc ABI |
| MOVW R4, 20(R13) // save old g |
| MOVW (g_stack+stack_hi)(R4), R4 |
| SUB R2, R4 |
| MOVW R4, 16(R13) // save depth in stack (can't just save SP, as stack might be copied during a callback) |
| BL (R1) |
| |
| // Restore registers, g, stack pointer. |
| MOVW R0, R5 |
| MOVW 20(R13), R0 |
| BL setg<>(SB) |
| MOVW (g_stack+stack_hi)(g), R1 |
| MOVW 16(R13), R2 |
| SUB R2, R1 |
| MOVW R5, R0 |
| MOVW R1, R13 |
| |
| MOVW R0, ret+8(FP) |
| RET |
| |
| nosave: |
| // Running on a system stack, perhaps even without a g. |
| // Having no g can happen during thread creation or thread teardown |
| // (see needm/dropm on Solaris, for example). |
| // This code is like the above sequence but without saving/restoring g |
| // and without worrying about the stack moving out from under us |
| // (because we're on a system stack, not a goroutine stack). |
| // The above code could be used directly if already on a system stack, |
| // but then the only path through this code would be a rare case on Solaris. |
| // Using this code for all "already on system stack" calls exercises it more, |
| // which should help keep it correct. |
| SUB $24, R13 |
| BIC $0x7, R13 // alignment for gcc ABI |
| // save null g in case someone looks during debugging. |
| MOVW $0, R4 |
| MOVW R4, 20(R13) |
| MOVW R2, 16(R13) // Save old stack pointer. |
| BL (R1) |
| // Restore stack pointer. |
| MOVW 16(R13), R2 |
| MOVW R2, R13 |
| MOVW R0, ret+8(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,$16-16 |
| MOVW $fn+0(FP), R0 |
| MOVW R0, 4(R13) |
| MOVW frame+4(FP), R0 |
| MOVW R0, 8(R13) |
| MOVW framesize+8(FP), R0 |
| MOVW R0, 12(R13) |
| MOVW ctxt+12(FP), R0 |
| MOVW R0, 16(R13) |
| MOVW $runtime·cgocallback_gofunc(SB), R0 |
| BL (R0) |
| RET |
| |
| // cgocallback_gofunc(void (*fn)(void*), void *frame, uintptr framesize, uintptr ctxt) |
| // See cgocall.go for more details. |
| TEXT ·cgocallback_gofunc(SB),NOSPLIT,$8-16 |
| NO_LOCAL_POINTERS |
| |
| // Load m and g from thread-local storage. |
| MOVB runtime·iscgo(SB), R0 |
| CMP $0, R0 |
| BL.NE runtime·load_g(SB) |
| |
| // 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 |
| B.EQ needm |
| |
| MOVW g_m(g), R8 |
| MOVW R8, savedm-4(SP) |
| B havem |
| |
| needm: |
| MOVW g, savedm-4(SP) // g is zero, so is m. |
| MOVW $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. |
| MOVW g_m(g), R8 |
| MOVW m_g0(R8), R3 |
| MOVW R13, (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 4(R13) aka savedsp-8(SP). |
| MOVW m_g0(R8), R3 |
| MOVW (g_sched+gobuf_sp)(R3), R4 |
| MOVW R4, savedsp-8(SP) |
| MOVW R13, (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, -4(SP) is unused (where SP refers to |
| // m->curg's SP while we're setting it up, before we've adjusted it). |
| MOVW m_curg(R8), R0 |
| BL setg<>(SB) |
| MOVW (g_sched+gobuf_sp)(g), R4 // prepare stack as R4 |
| MOVW (g_sched+gobuf_pc)(g), R5 |
| MOVW R5, -12(R4) |
| MOVW ctxt+12(FP), R0 |
| MOVW R0, -8(R4) |
| MOVW $-12(R4), R13 |
| BL runtime·cgocallbackg(SB) |
| |
| // Restore g->sched (== m->curg->sched) from saved values. |
| MOVW 0(R13), R5 |
| MOVW R5, (g_sched+gobuf_pc)(g) |
| MOVW $12(R13), R4 |
| MOVW 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.) |
| MOVW g_m(g), R8 |
| MOVW m_g0(R8), R0 |
| BL setg<>(SB) |
| MOVW (g_sched+gobuf_sp)(g), R13 |
| MOVW savedsp-8(SP), R4 |
| MOVW 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. |
| MOVW savedm-4(SP), R6 |
| CMP $0, R6 |
| B.NE 3(PC) |
| MOVW $runtime·dropm(SB), R0 |
| BL (R0) |
| |
| // Done! |
| RET |
| |
| // void setg(G*); set g. for use by needm. |
| TEXT runtime·setg(SB),NOSPLIT|NOFRAME,$0-4 |
| MOVW gg+0(FP), R0 |
| B setg<>(SB) |
| |
| TEXT setg<>(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVW R0, g |
| |
| // Save g to thread-local storage. |
| #ifdef GOOS_windows |
| B runtime·save_g(SB) |
| #else |
| MOVB runtime·iscgo(SB), R0 |
| CMP $0, R0 |
| B.EQ 2(PC) |
| B runtime·save_g(SB) |
| |
| MOVW g, R0 |
| RET |
| #endif |
| |
| TEXT runtime·emptyfunc(SB),0,$0-0 |
| RET |
| |
| TEXT runtime·abort(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVW $0, R0 |
| MOVW (R0), R1 |
| |
| // armPublicationBarrier is a native store/store barrier for ARMv7+. |
| // On earlier ARM revisions, armPublicationBarrier is a no-op. |
| // This will not work on SMP ARMv6 machines, if any are in use. |
| // To implement publicationBarrier in sys_$GOOS_arm.s using the native |
| // instructions, use: |
| // |
| // TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0 |
| // B runtime·armPublicationBarrier(SB) |
| // |
| TEXT runtime·armPublicationBarrier(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVB runtime·goarm(SB), R11 |
| CMP $7, R11 |
| BLT 2(PC) |
| DMB MB_ST |
| RET |
| |
| // AES hashing not implemented for ARM |
| TEXT runtime·aeshash(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVW $0, R0 |
| MOVW (R0), R1 |
| TEXT runtime·aeshash32(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVW $0, R0 |
| MOVW (R0), R1 |
| TEXT runtime·aeshash64(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVW $0, R0 |
| MOVW (R0), R1 |
| TEXT runtime·aeshashstr(SB),NOSPLIT|NOFRAME,$0-0 |
| MOVW $0, R0 |
| MOVW (R0), R1 |
| |
| TEXT runtime·return0(SB),NOSPLIT,$0 |
| MOVW $0, R0 |
| RET |
| |
| TEXT runtime·procyield(SB),NOSPLIT|NOFRAME,$0 |
| MOVW cycles+0(FP), R1 |
| MOVW $0, R0 |
| yieldloop: |
| WORD $0xe320f001 // YIELD (NOP pre-ARMv6K) |
| CMP R0, R1 |
| B.NE 2(PC) |
| RET |
| SUB $1, R1 |
| B yieldloop |
| |
| // Called from cgo wrappers, this function returns g->m->curg.stack.hi. |
| // Must obey the gcc calling convention. |
| TEXT _cgo_topofstack(SB),NOSPLIT,$8 |
| // R11 and g register are clobbered by load_g. They are |
| // callee-save in the gcc calling convention, so save them here. |
| MOVW R11, saveR11-4(SP) |
| MOVW g, saveG-8(SP) |
| |
| BL runtime·load_g(SB) |
| MOVW g_m(g), R0 |
| MOVW m_curg(R0), R0 |
| MOVW (g_stack+stack_hi)(R0), R0 |
| |
| MOVW saveG-8(SP), g |
| MOVW saveR11-4(SP), R11 |
| RET |
| |
| // The top-most function running on a goroutine |
| // returns to goexit+PCQuantum. |
| TEXT runtime·goexit(SB),NOSPLIT|NOFRAME|TOPFRAME,$0-0 |
| MOVW R0, R0 // NOP |
| BL runtime·goexit1(SB) // does not return |
| // traceback from goexit1 must hit code range of goexit |
| MOVW R0, R0 // NOP |
| |
| // x -> x/1000000, x%1000000, called from Go with args, results on stack. |
| TEXT runtime·usplit(SB),NOSPLIT,$0-12 |
| MOVW x+0(FP), R0 |
| CALL runtime·usplitR0(SB) |
| MOVW R0, q+4(FP) |
| MOVW R1, r+8(FP) |
| RET |
| |
| // R0, R1 = R0/1000000, R0%1000000 |
| TEXT runtime·usplitR0(SB),NOSPLIT,$0 |
| // magic multiply to avoid software divide without available m. |
| // see output of go tool compile -S for x/1000000. |
| MOVW R0, R3 |
| MOVW $1125899907, R1 |
| MULLU R1, R0, (R0, R1) |
| MOVW R0>>18, R0 |
| MOVW $1000000, R1 |
| MULU R0, R1 |
| SUB R1, R3, R1 |
| RET |
| |
| TEXT runtime·sigreturn(SB),NOSPLIT,$0-0 |
| RET |
| |
| #ifndef GOOS_nacl |
| // This is called from .init_array and follows the platform, not Go, ABI. |
| TEXT runtime·addmoduledata(SB),NOSPLIT,$0-8 |
| MOVW R9, saver9-4(SP) // The access to global variables below implicitly uses R9, which is callee-save |
| MOVW R11, saver11-8(SP) // Likewise, R11 is the temp register, but callee-save in C ABI |
| MOVW runtime·lastmoduledatap(SB), R1 |
| MOVW R0, moduledata_next(R1) |
| MOVW R0, runtime·lastmoduledatap(SB) |
| MOVW saver11-8(SP), R11 |
| MOVW saver9-4(SP), R9 |
| RET |
| #endif |
| |
| TEXT ·checkASM(SB),NOSPLIT,$0-1 |
| MOVW $1, R3 |
| MOVB R3, ret+0(FP) |
| RET |
| |
| // gcWriteBarrier performs a heap pointer write and informs the GC. |
| // |
| // gcWriteBarrier does NOT follow the Go ABI. It takes two arguments: |
| // - R2 is the destination of the write |
| // - R3 is the value being written at R2 |
| // It clobbers condition codes. |
| // It does not clobber any other general-purpose registers, |
| // but may clobber others (e.g., floating point registers). |
| // The act of CALLing gcWriteBarrier will clobber R14 (LR). |
| TEXT runtime·gcWriteBarrier(SB),NOSPLIT|NOFRAME,$0 |
| // Save the registers clobbered by the fast path. |
| MOVM.DB.W [R0,R1], (R13) |
| MOVW g_m(g), R0 |
| MOVW m_p(R0), R0 |
| MOVW (p_wbBuf+wbBuf_next)(R0), R1 |
| // Increment wbBuf.next position. |
| ADD $8, R1 |
| MOVW R1, (p_wbBuf+wbBuf_next)(R0) |
| MOVW (p_wbBuf+wbBuf_end)(R0), R0 |
| CMP R1, R0 |
| // Record the write. |
| MOVW R3, -8(R1) // Record value |
| MOVW (R2), R0 // TODO: This turns bad writes into bad reads. |
| MOVW R0, -4(R1) // Record *slot |
| // Is the buffer full? (flags set in CMP above) |
| B.EQ flush |
| ret: |
| MOVM.IA.W (R13), [R0,R1] |
| // Do the write. |
| MOVW R3, (R2) |
| // Normally RET on nacl clobbers R12, but because this |
| // function has no frame it doesn't have to usual epilogue. |
| RET |
| |
| flush: |
| // Save all general purpose registers since these could be |
| // clobbered by wbBufFlush and were not saved by the caller. |
| // |
| // R0 and R1 were saved at entry. |
| // R10 is g, so preserved. |
| // R11 is linker temp, so no need to save. |
| // R13 is stack pointer. |
| // R15 is PC. |
| // |
| // This also sets up R2 and R3 as the arguments to wbBufFlush. |
| MOVM.DB.W [R2-R9,R12], (R13) |
| // Save R14 (LR) because the fast path above doesn't save it, |
| // but needs it to RET. This is after the MOVM so it appears below |
| // the arguments in the stack frame. |
| MOVM.DB.W [R14], (R13) |
| |
| // This takes arguments R2 and R3. |
| CALL runtime·wbBufFlush(SB) |
| |
| MOVM.IA.W (R13), [R14] |
| MOVM.IA.W (R13), [R2-R9,R12] |
| JMP ret |
| |
| // 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,$0-8 |
| MOVW R0, x+0(FP) |
| MOVW R1, y+4(FP) |
| JMP runtime·goPanicIndex(SB) |
| TEXT runtime·panicIndexU(SB),NOSPLIT,$0-8 |
| MOVW R0, x+0(FP) |
| MOVW R1, y+4(FP) |
| JMP runtime·goPanicIndexU(SB) |
| TEXT runtime·panicSliceAlen(SB),NOSPLIT,$0-8 |
| MOVW R1, x+0(FP) |
| MOVW R2, y+4(FP) |
| JMP runtime·goPanicSliceAlen(SB) |
| TEXT runtime·panicSliceAlenU(SB),NOSPLIT,$0-8 |
| MOVW R1, x+0(FP) |
| MOVW R2, y+4(FP) |
| JMP runtime·goPanicSliceAlenU(SB) |
| TEXT runtime·panicSliceAcap(SB),NOSPLIT,$0-8 |
| MOVW R1, x+0(FP) |
| MOVW R2, y+4(FP) |
| JMP runtime·goPanicSliceAcap(SB) |
| TEXT runtime·panicSliceAcapU(SB),NOSPLIT,$0-8 |
| MOVW R1, x+0(FP) |
| MOVW R2, y+4(FP) |
| JMP runtime·goPanicSliceAcapU(SB) |
| TEXT runtime·panicSliceB(SB),NOSPLIT,$0-8 |
| MOVW R0, x+0(FP) |
| MOVW R1, y+4(FP) |
| JMP runtime·goPanicSliceB(SB) |
| TEXT runtime·panicSliceBU(SB),NOSPLIT,$0-8 |
| MOVW R0, x+0(FP) |
| MOVW R1, y+4(FP) |
| JMP runtime·goPanicSliceBU(SB) |
| TEXT runtime·panicSlice3Alen(SB),NOSPLIT,$0-8 |
| MOVW R2, x+0(FP) |
| MOVW R3, y+4(FP) |
| JMP runtime·goPanicSlice3Alen(SB) |
| TEXT runtime·panicSlice3AlenU(SB),NOSPLIT,$0-8 |
| MOVW R2, x+0(FP) |
| MOVW R3, y+4(FP) |
| JMP runtime·goPanicSlice3AlenU(SB) |
| TEXT runtime·panicSlice3Acap(SB),NOSPLIT,$0-8 |
| MOVW R2, x+0(FP) |
| MOVW R3, y+4(FP) |
| JMP runtime·goPanicSlice3Acap(SB) |
| TEXT runtime·panicSlice3AcapU(SB),NOSPLIT,$0-8 |
| MOVW R2, x+0(FP) |
| MOVW R3, y+4(FP) |
| JMP runtime·goPanicSlice3AcapU(SB) |
| TEXT runtime·panicSlice3B(SB),NOSPLIT,$0-8 |
| MOVW R1, x+0(FP) |
| MOVW R2, y+4(FP) |
| JMP runtime·goPanicSlice3B(SB) |
| TEXT runtime·panicSlice3BU(SB),NOSPLIT,$0-8 |
| MOVW R1, x+0(FP) |
| MOVW R2, y+4(FP) |
| JMP runtime·goPanicSlice3BU(SB) |
| TEXT runtime·panicSlice3C(SB),NOSPLIT,$0-8 |
| MOVW R0, x+0(FP) |
| MOVW R1, y+4(FP) |
| JMP runtime·goPanicSlice3C(SB) |
| TEXT runtime·panicSlice3CU(SB),NOSPLIT,$0-8 |
| MOVW R0, x+0(FP) |
| MOVW R1, y+4(FP) |
| JMP runtime·goPanicSlice3CU(SB) |
| |
| // Extended versions for 64-bit indexes. |
| TEXT runtime·panicExtendIndex(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R0, lo+4(FP) |
| MOVW R1, y+8(FP) |
| JMP runtime·goPanicExtendIndex(SB) |
| TEXT runtime·panicExtendIndexU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R0, lo+4(FP) |
| MOVW R1, y+8(FP) |
| JMP runtime·goPanicExtendIndexU(SB) |
| TEXT runtime·panicExtendSliceAlen(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R1, lo+4(FP) |
| MOVW R2, y+8(FP) |
| JMP runtime·goPanicExtendSliceAlen(SB) |
| TEXT runtime·panicExtendSliceAlenU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R1, lo+4(FP) |
| MOVW R2, y+8(FP) |
| JMP runtime·goPanicExtendSliceAlenU(SB) |
| TEXT runtime·panicExtendSliceAcap(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R1, lo+4(FP) |
| MOVW R2, y+8(FP) |
| JMP runtime·goPanicExtendSliceAcap(SB) |
| TEXT runtime·panicExtendSliceAcapU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R1, lo+4(FP) |
| MOVW R2, y+8(FP) |
| JMP runtime·goPanicExtendSliceAcapU(SB) |
| TEXT runtime·panicExtendSliceB(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R0, lo+4(FP) |
| MOVW R1, y+8(FP) |
| JMP runtime·goPanicExtendSliceB(SB) |
| TEXT runtime·panicExtendSliceBU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R0, lo+4(FP) |
| MOVW R1, y+8(FP) |
| JMP runtime·goPanicExtendSliceBU(SB) |
| TEXT runtime·panicExtendSlice3Alen(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R2, lo+4(FP) |
| MOVW R3, y+8(FP) |
| JMP runtime·goPanicExtendSlice3Alen(SB) |
| TEXT runtime·panicExtendSlice3AlenU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R2, lo+4(FP) |
| MOVW R3, y+8(FP) |
| JMP runtime·goPanicExtendSlice3AlenU(SB) |
| TEXT runtime·panicExtendSlice3Acap(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R2, lo+4(FP) |
| MOVW R3, y+8(FP) |
| JMP runtime·goPanicExtendSlice3Acap(SB) |
| TEXT runtime·panicExtendSlice3AcapU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R2, lo+4(FP) |
| MOVW R3, y+8(FP) |
| JMP runtime·goPanicExtendSlice3AcapU(SB) |
| TEXT runtime·panicExtendSlice3B(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R1, lo+4(FP) |
| MOVW R2, y+8(FP) |
| JMP runtime·goPanicExtendSlice3B(SB) |
| TEXT runtime·panicExtendSlice3BU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R1, lo+4(FP) |
| MOVW R2, y+8(FP) |
| JMP runtime·goPanicExtendSlice3BU(SB) |
| TEXT runtime·panicExtendSlice3C(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R0, lo+4(FP) |
| MOVW R1, y+8(FP) |
| JMP runtime·goPanicExtendSlice3C(SB) |
| TEXT runtime·panicExtendSlice3CU(SB),NOSPLIT,$0-12 |
| MOVW R4, hi+0(FP) |
| MOVW R0, lo+4(FP) |
| MOVW R1, y+8(FP) |
| JMP runtime·goPanicExtendSlice3CU(SB) |
