| // Copyright 2018 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 "textflag.h" |
| |
| // void runtime·asmstdcall(void *c); |
| TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R4, R5, R14], (R13) // push {r4, r5, lr} |
| MOVW R0, R4 // put libcall * in r4 |
| MOVW R13, R5 // save stack pointer in r5 |
| |
| // SetLastError(0) |
| MOVW $0, R0 |
| MRC 15, 0, R1, C13, C0, 2 |
| MOVW R0, 0x34(R1) |
| |
| MOVW 8(R4), R12 // libcall->args |
| |
| // Do we have more than 4 arguments? |
| MOVW 4(R4), R0 // libcall->n |
| SUB.S $4, R0, R2 |
| BLE loadregs |
| |
| // Reserve stack space for remaining args |
| SUB R2<<2, R13 |
| BIC $0x7, R13 // alignment for ABI |
| |
| // R0: count of arguments |
| // R1: |
| // R2: loop counter, from 0 to (n-4) |
| // R3: scratch |
| // R4: pointer to libcall struct |
| // R12: libcall->args |
| MOVW $0, R2 |
| stackargs: |
| ADD $4, R2, R3 // r3 = args[4 + i] |
| MOVW R3<<2(R12), R3 |
| MOVW R3, R2<<2(R13) // stack[i] = r3 |
| |
| ADD $1, R2 // i++ |
| SUB $4, R0, R3 // while (i < (n - 4)) |
| CMP R3, R2 |
| BLT stackargs |
| |
| loadregs: |
| CMP $3, R0 |
| MOVW.GT 12(R12), R3 |
| |
| CMP $2, R0 |
| MOVW.GT 8(R12), R2 |
| |
| CMP $1, R0 |
| MOVW.GT 4(R12), R1 |
| |
| CMP $0, R0 |
| MOVW.GT 0(R12), R0 |
| |
| BIC $0x7, R13 // alignment for ABI |
| MOVW 0(R4), R12 // branch to libcall->fn |
| BL (R12) |
| |
| MOVW R5, R13 // free stack space |
| MOVW R0, 12(R4) // save return value to libcall->r1 |
| MOVW R1, 16(R4) |
| |
| // GetLastError |
| MRC 15, 0, R1, C13, C0, 2 |
| MOVW 0x34(R1), R0 |
| MOVW R0, 20(R4) // store in libcall->err |
| |
| MOVM.IA.W (R13), [R4, R5, R15] |
| |
| TEXT runtime·badsignal2(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R4, R14], (R13) // push {r4, lr} |
| MOVW R13, R4 // save original stack pointer |
| SUB $8, R13 // space for 2 variables |
| BIC $0x7, R13 // alignment for ABI |
| |
| // stderr |
| MOVW runtime·_GetStdHandle(SB), R1 |
| MOVW $-12, R0 |
| BL (R1) |
| |
| MOVW $runtime·badsignalmsg(SB), R1 // lpBuffer |
| MOVW $runtime·badsignallen(SB), R2 // lpNumberOfBytesToWrite |
| MOVW (R2), R2 |
| ADD $0x4, R13, R3 // lpNumberOfBytesWritten |
| MOVW $0, R12 // lpOverlapped |
| MOVW R12, (R13) |
| |
| MOVW runtime·_WriteFile(SB), R12 |
| BL (R12) |
| |
| MOVW R4, R13 // restore SP |
| MOVM.IA.W (R13), [R4, R15] // pop {r4, pc} |
| |
| TEXT runtime·getlasterror(SB),NOSPLIT,$0 |
| MRC 15, 0, R0, C13, C0, 2 |
| MOVW 0x34(R0), R0 |
| MOVW R0, ret+0(FP) |
| RET |
| |
| TEXT runtime·setlasterror(SB),NOSPLIT|NOFRAME,$0 |
| MRC 15, 0, R1, C13, C0, 2 |
| MOVW R0, 0x34(R1) |
| RET |
| |
| // Called by Windows as a Vectored Exception Handler (VEH). |
| // First argument is pointer to struct containing |
| // exception record and context pointers. |
| // Handler function is stored in R1 |
| // Return 0 for 'not handled', -1 for handled. |
| // int32_t sigtramp( |
| // PEXCEPTION_POINTERS ExceptionInfo, |
| // func *GoExceptionHandler); |
| TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R0, R4-R11, R14], (R13) // push {r0, r4-r11, lr} (SP-=40) |
| SUB $(8+20), R13 // reserve space for g, sp, and |
| // parameters/retval to go call |
| |
| MOVW R0, R6 // Save param0 |
| MOVW R1, R7 // Save param1 |
| |
| BL runtime·load_g(SB) |
| CMP $0, g // is there a current g? |
| BL.EQ runtime·badsignal2(SB) |
| |
| // save g and SP in case of stack switch |
| MOVW R13, 24(R13) |
| MOVW g, 20(R13) |
| |
| // do we need to switch to the g0 stack? |
| MOVW g, R5 // R5 = g |
| MOVW g_m(R5), R2 // R2 = m |
| MOVW m_g0(R2), R4 // R4 = g0 |
| CMP R5, R4 // if curg == g0 |
| BEQ g0 |
| |
| // switch to g0 stack |
| MOVW R4, g // g = g0 |
| MOVW (g_sched+gobuf_sp)(g), R3 // R3 = g->gobuf.sp |
| BL runtime·save_g(SB) |
| |
| // traceback will think that we've done PUSH and SUB |
| // on this stack, so subtract them here to match. |
| // (we need room for sighandler arguments anyway). |
| // and re-save old SP for restoring later. |
| SUB $(40+8+20), R3 |
| MOVW R13, 24(R3) // save old stack pointer |
| MOVW R3, R13 // switch stack |
| |
| g0: |
| MOVW 0(R6), R2 // R2 = ExceptionPointers->ExceptionRecord |
| MOVW 4(R6), R3 // R3 = ExceptionPointers->ContextRecord |
| |
| // make it look like mstart called us on g0, to stop traceback |
| MOVW $runtime·mstart(SB), R4 |
| |
| MOVW R4, 0(R13) // Save link register for traceback |
| MOVW R2, 4(R13) // Move arg0 (ExceptionRecord) into position |
| MOVW R3, 8(R13) // Move arg1 (ContextRecord) into position |
| MOVW R5, 12(R13) // Move arg2 (original g) into position |
| BL (R7) // Call the go routine |
| MOVW 16(R13), R4 // Fetch return value from stack |
| |
| // Compute the value of the g0 stack pointer after deallocating |
| // this frame, then allocating 8 bytes. We may need to store |
| // the resume SP and PC on the g0 stack to work around |
| // control flow guard when we resume from the exception. |
| ADD $(40+20), R13, R12 |
| |
| // switch back to original stack and g |
| MOVW 24(R13), R13 |
| MOVW 20(R13), g |
| BL runtime·save_g(SB) |
| |
| done: |
| MOVW R4, R0 // move retval into position |
| ADD $(8 + 20), R13 // free locals |
| MOVM.IA.W (R13), [R3, R4-R11, R14] // pop {r3, r4-r11, lr} |
| |
| // if return value is CONTINUE_SEARCH, do not set up control |
| // flow guard workaround |
| CMP $0, R0 |
| BEQ return |
| |
| // Check if we need to set up the control flow guard workaround. |
| // On Windows/ARM, the stack pointer must lie within system |
| // stack limits when we resume from exception. |
| // Store the resume SP and PC on the g0 stack, |
| // and return to returntramp on the g0 stack. returntramp |
| // pops the saved PC and SP from the g0 stack, resuming execution |
| // at the desired location. |
| // If returntramp has already been set up by a previous exception |
| // handler, don't clobber the stored SP and PC on the stack. |
| MOVW 4(R3), R3 // PEXCEPTION_POINTERS->Context |
| MOVW 0x40(R3), R2 // load PC from context record |
| MOVW $runtime·returntramp(SB), R1 |
| CMP R1, R2 |
| B.EQ return // do not clobber saved SP/PC |
| |
| // Save resume SP and PC on g0 stack |
| MOVW 0x38(R3), R2 // load SP from context record |
| MOVW R2, 0(R12) // Store resume SP on g0 stack |
| MOVW 0x40(R3), R2 // load PC from context record |
| MOVW R2, 4(R12) // Store resume PC on g0 stack |
| |
| // Set up context record to return to returntramp on g0 stack |
| MOVW R12, 0x38(R3) // save g0 stack pointer |
| // in context record |
| MOVW $runtime·returntramp(SB), R2 // save resume address |
| MOVW R2, 0x40(R3) // in context record |
| |
| return: |
| B (R14) // return |
| |
| // |
| // Trampoline to resume execution from exception handler. |
| // This is part of the control flow guard workaround. |
| // It switches stacks and jumps to the continuation address. |
| // |
| TEXT runtime·returntramp(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.IA (R13), [R13, R15] // ldm sp, [sp, pc] |
| |
| TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0 |
| MOVW $runtime·exceptionhandler(SB), R1 |
| B runtime·sigtramp(SB) |
| |
| TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0 |
| MOVW $runtime·firstcontinuehandler(SB), R1 |
| B runtime·sigtramp(SB) |
| |
| TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0 |
| MOVW $runtime·lastcontinuehandler(SB), R1 |
| B runtime·sigtramp(SB) |
| |
| TEXT runtime·ctrlhandler(SB),NOSPLIT|NOFRAME,$0 |
| MOVW $runtime·ctrlhandler1(SB), R1 |
| B runtime·externalthreadhandler(SB) |
| |
| TEXT runtime·profileloop(SB),NOSPLIT|NOFRAME,$0 |
| MOVW $runtime·profileloop1(SB), R1 |
| B runtime·externalthreadhandler(SB) |
| |
| // int32 externalthreadhandler(uint32 arg, int (*func)(uint32)) |
| // stack layout: |
| // +----------------+ |
| // | callee-save | |
| // | registers | |
| // +----------------+ |
| // | m | |
| // +----------------+ |
| // 20| g | |
| // +----------------+ |
| // 16| func ptr (r1) | |
| // +----------------+ |
| // 12| argument (r0) | |
| //---+----------------+ |
| // 8 | param1 | |
| // +----------------+ |
| // 4 | param0 | |
| // +----------------+ |
| // 0 | retval | |
| // +----------------+ |
| // |
| TEXT runtime·externalthreadhandler(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} |
| SUB $(m__size + g__size + 20), R13 // space for locals |
| MOVW R0, 12(R13) |
| MOVW R1, 16(R13) |
| |
| // zero out m and g structures |
| ADD $20, R13, R0 // compute pointer to g |
| MOVW R0, 4(R13) |
| MOVW $(m__size + g__size), R0 |
| MOVW R0, 8(R13) |
| BL runtime·memclrNoHeapPointers(SB) |
| |
| // initialize m and g structures |
| ADD $20, R13, R2 // R2 = g |
| ADD $(20 + g__size), R13, R3 // R3 = m |
| MOVW R2, m_g0(R3) // m->g0 = g |
| MOVW R3, g_m(R2) // g->m = m |
| MOVW R2, m_curg(R3) // m->curg = g |
| |
| MOVW R2, g |
| BL runtime·save_g(SB) |
| |
| // set up stackguard stuff |
| MOVW R13, R0 |
| MOVW R0, g_stack+stack_hi(g) |
| SUB $(32*1024), R0 |
| MOVW R0, (g_stack+stack_lo)(g) |
| MOVW R0, g_stackguard0(g) |
| MOVW R0, g_stackguard1(g) |
| |
| // move argument into position and call function |
| MOVW 12(R13), R0 |
| MOVW R0, 4(R13) |
| MOVW 16(R13), R1 |
| BL (R1) |
| |
| // clear g |
| MOVW $0, g |
| BL runtime·save_g(SB) |
| |
| MOVW 0(R13), R0 // load return value |
| ADD $(m__size + g__size + 20), R13 // free locals |
| MOVM.IA.W (R13), [R4-R11, R15] // pop {r4-r11, pc} |
| |
| GLOBL runtime·cbctxts(SB), NOPTR, $4 |
| |
| TEXT runtime·callbackasm1(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} |
| SUB $36, R13 // space for locals |
| |
| // save callback arguments to stack. We currently support up to 4 arguments |
| ADD $16, R13, R4 |
| MOVM.IA [R0-R3], (R4) |
| |
| // load cbctxts[i]. The trampoline in zcallback_windows.s puts the callback |
| // index in R12 |
| MOVW runtime·cbctxts(SB), R4 |
| MOVW R12<<2(R4), R4 // R4 holds pointer to wincallbackcontext structure |
| |
| // extract callback context |
| MOVW wincallbackcontext_argsize(R4), R5 |
| MOVW wincallbackcontext_gobody(R4), R4 |
| |
| // we currently support up to 4 arguments |
| CMP $(4 * 4), R5 |
| BL.GT runtime·abort(SB) |
| |
| // extend argsize by size of return value |
| ADD $4, R5 |
| |
| // Build 'type args struct' |
| MOVW R4, 4(R13) // fn |
| ADD $16, R13, R0 // arg (points to r0-r3, ret on stack) |
| MOVW R0, 8(R13) |
| MOVW R5, 12(R13) // argsize |
| |
| BL runtime·load_g(SB) |
| BL runtime·cgocallback_gofunc(SB) |
| |
| ADD $16, R13, R0 // load arg |
| MOVW 12(R13), R1 // load argsize |
| SUB $4, R1 // offset to return value |
| MOVW R1<<0(R0), R0 // load return value |
| |
| ADD $36, R13 // free locals |
| MOVM.IA.W (R13), [R4-R11, R15] // pop {r4-r11, pc} |
| |
| // uint32 tstart_stdcall(M *newm); |
| TEXT runtime·tstart_stdcall(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R4-R11, R14], (R13) // push {r4-r11, lr} |
| |
| MOVW m_g0(R0), g |
| MOVW R0, g_m(g) |
| BL runtime·save_g(SB) |
| |
| // Layout new m scheduler stack on os stack. |
| MOVW R13, R0 |
| MOVW R0, g_stack+stack_hi(g) |
| SUB $(64*1024), R0 |
| MOVW R0, (g_stack+stack_lo)(g) |
| MOVW R0, g_stackguard0(g) |
| MOVW R0, g_stackguard1(g) |
| |
| BL runtime·emptyfunc(SB) // fault if stack check is wrong |
| BL runtime·mstart(SB) |
| |
| // Exit the thread. |
| MOVW $0, R0 |
| MOVM.IA.W (R13), [R4-R11, R15] // pop {r4-r11, pc} |
| |
| // onosstack calls fn on OS stack. |
| // adapted from asm_arm.s : systemstack |
| // func onosstack(fn unsafe.Pointer, arg uint32) |
| TEXT runtime·onosstack(SB),NOSPLIT,$0 |
| MOVW fn+0(FP), R5 // R5 = fn |
| MOVW arg+4(FP), R6 // R6 = arg |
| |
| // This function can be called when there is no g, |
| // for example, when we are handling a callback on a non-go thread. |
| // In this case we're already on the system stack. |
| CMP $0, g |
| BEQ noswitch |
| |
| 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 |
| 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 R2, g |
| 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 R6, R0 // arg |
| BL (R5) |
| |
| // switch back to g |
| MOVW g_m(g), R1 |
| MOVW m_curg(R1), g |
| 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.P 4(R13), R14 // restore LR |
| MOVW R6, R0 // arg |
| B (R5) |
| |
| // Runs on OS stack. Duration (in 100ns units) is in R0. |
| TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R4, R14], (R13) // push {r4, lr} |
| MOVW R13, R4 // Save SP |
| SUB $8, R13 // R13 = R13 - 8 |
| BIC $0x7, R13 // Align SP for ABI |
| RSB $0, R0, R3 // R3 = -R0 |
| MOVW $0, R1 // R1 = FALSE (alertable) |
| MOVW $-1, R0 // R0 = handle |
| MOVW R13, R2 // R2 = pTime |
| MOVW R3, 0(R2) // time_lo |
| MOVW R0, 4(R2) // time_hi |
| MOVW runtime·_NtWaitForSingleObject(SB), R3 |
| BL (R3) |
| MOVW R4, R13 // Restore SP |
| MOVM.IA.W (R13), [R4, R15] // pop {R4, pc} |
| |
| // Runs on OS stack. |
| TEXT runtime·switchtothread(SB),NOSPLIT|NOFRAME,$0 |
| MOVM.DB.W [R4, R14], (R13) // push {R4, lr} |
| MOVW R13, R4 |
| BIC $0x7, R13 // alignment for ABI |
| MOVW runtime·_SwitchToThread(SB), R0 |
| BL (R0) |
| MOVW R4, R13 // restore stack pointer |
| MOVM.IA.W (R13), [R4, R15] // pop {R4, pc} |
| |
| TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0 |
| B runtime·armPublicationBarrier(SB) |
| |
| // never called (cgo not supported) |
| TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0 |
| MOVW $0xabcd, R0 |
| MOVW R0, (R0) |
| RET |
| |
| // See http://www.dcl.hpi.uni-potsdam.de/research/WRK/2007/08/getting-os-information-the-kuser_shared_data-structure/ |
| // Must read hi1, then lo, then hi2. The snapshot is valid if hi1 == hi2. |
| #define _INTERRUPT_TIME 0x7ffe0008 |
| #define _SYSTEM_TIME 0x7ffe0014 |
| #define time_lo 0 |
| #define time_hi1 4 |
| #define time_hi2 8 |
| |
| TEXT runtime·nanotime(SB),NOSPLIT,$0-8 |
| MOVW $0, R0 |
| MOVB runtime·useQPCTime(SB), R0 |
| CMP $0, R0 |
| BNE useQPC |
| MOVW $_INTERRUPT_TIME, R3 |
| loop: |
| MOVW time_hi1(R3), R1 |
| MOVW time_lo(R3), R0 |
| MOVW time_hi2(R3), R2 |
| CMP R1, R2 |
| BNE loop |
| |
| // wintime = R1:R0, multiply by 100 |
| MOVW $100, R2 |
| MULLU R0, R2, (R4, R3) // R4:R3 = R1:R0 * R2 |
| MULA R1, R2, R4, R4 |
| |
| // wintime*100 = R4:R3, subtract startNano and return |
| MOVW runtime·startNano+0(SB), R0 |
| MOVW runtime·startNano+4(SB), R1 |
| SUB.S R0, R3 |
| SBC R1, R4 |
| MOVW R3, ret_lo+0(FP) |
| MOVW R4, ret_hi+4(FP) |
| RET |
| useQPC: |
| B runtime·nanotimeQPC(SB) // tail call |
| RET |
| |
| TEXT time·now(SB),NOSPLIT,$0-20 |
| MOVW $0, R0 |
| MOVB runtime·useQPCTime(SB), R0 |
| CMP $0, R0 |
| BNE useQPC |
| MOVW $_INTERRUPT_TIME, R3 |
| loop: |
| MOVW time_hi1(R3), R1 |
| MOVW time_lo(R3), R0 |
| MOVW time_hi2(R3), R2 |
| CMP R1, R2 |
| BNE loop |
| |
| // wintime = R1:R0, multiply by 100 |
| MOVW $100, R2 |
| MULLU R0, R2, (R4, R3) // R4:R3 = R1:R0 * R2 |
| MULA R1, R2, R4, R4 |
| |
| // wintime*100 = R4:R3, subtract startNano and return |
| MOVW runtime·startNano+0(SB), R0 |
| MOVW runtime·startNano+4(SB), R1 |
| SUB.S R0, R3 |
| SBC R1, R4 |
| MOVW R3, mono+12(FP) |
| MOVW R4, mono+16(FP) |
| |
| MOVW $_SYSTEM_TIME, R3 |
| wall: |
| MOVW time_hi1(R3), R1 |
| MOVW time_lo(R3), R0 |
| MOVW time_hi2(R3), R2 |
| CMP R1, R2 |
| BNE wall |
| |
| // w = R1:R0 in 100ns untis |
| // convert to Unix epoch (but still 100ns units) |
| #define delta 116444736000000000 |
| SUB.S $(delta & 0xFFFFFFFF), R0 |
| SBC $(delta >> 32), R1 |
| |
| // Convert to nSec |
| MOVW $100, R2 |
| MULLU R0, R2, (R4, R3) // R4:R3 = R1:R0 * R2 |
| MULA R1, R2, R4, R4 |
| // w = R2:R1 in nSec |
| MOVW R3, R1 // R4:R3 -> R2:R1 |
| MOVW R4, R2 |
| |
| // multiply nanoseconds by reciprocal of 10**9 (scaled by 2**61) |
| // to get seconds (96 bit scaled result) |
| MOVW $0x89705f41, R3 // 2**61 * 10**-9 |
| MULLU R1,R3,(R6,R5) // R7:R6:R5 = R2:R1 * R3 |
| MOVW $0,R7 |
| MULALU R2,R3,(R7,R6) |
| |
| // unscale by discarding low 32 bits, shifting the rest by 29 |
| MOVW R6>>29,R6 // R7:R6 = (R7:R6:R5 >> 61) |
| ORR R7<<3,R6 |
| MOVW R7>>29,R7 |
| |
| // subtract (10**9 * sec) from nsec to get nanosecond remainder |
| MOVW $1000000000, R5 // 10**9 |
| MULLU R6,R5,(R9,R8) // R9:R8 = R7:R6 * R5 |
| MULA R7,R5,R9,R9 |
| SUB.S R8,R1 // R2:R1 -= R9:R8 |
| SBC R9,R2 |
| |
| // because reciprocal was a truncated repeating fraction, quotient |
| // may be slightly too small -- adjust to make remainder < 10**9 |
| CMP R5,R1 // if remainder > 10**9 |
| SUB.HS R5,R1 // remainder -= 10**9 |
| ADD.HS $1,R6 // sec += 1 |
| |
| MOVW R6,sec_lo+0(FP) |
| MOVW R7,sec_hi+4(FP) |
| MOVW R1,nsec+8(FP) |
| RET |
| useQPC: |
| B runtime·nanotimeQPC(SB) // tail call |
| RET |
| |
