github.com/comwrg/go/src@v0.0.0-20220319063731-c238d0440370/runtime/time_windows_amd64.s (about)

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  //go:build !faketime
     6  // +build !faketime
     7  
     8  #include "go_asm.h"
     9  #include "textflag.h"
    10  #include "time_windows.h"
    11  
    12  TEXT time·now(SB),NOSPLIT,$0-24
    13  	CMPB	runtime·useQPCTime(SB), $0
    14  	JNE	useQPC
    15  
    16  	MOVQ	$_INTERRUPT_TIME, DI
    17  	MOVQ	time_lo(DI), AX
    18  	IMULQ	$100, AX
    19  	MOVQ	AX, mono+16(FP)
    20  
    21  	MOVQ	$_SYSTEM_TIME, DI
    22  	MOVQ	time_lo(DI), AX
    23  	MOVQ	$116444736000000000, DI
    24  	SUBQ	DI, AX
    25  	IMULQ	$100, AX
    26  
    27  	// generated code for
    28  	//	func f(x uint64) (uint64, uint64) { return x/1000000000, x%1000000000 }
    29  	// adapted to reduce duplication
    30  	MOVQ	AX, CX
    31  	MOVQ	$1360296554856532783, AX
    32  	MULQ	CX
    33  	ADDQ	CX, DX
    34  	RCRQ	$1, DX
    35  	SHRQ	$29, DX
    36  	MOVQ	DX, sec+0(FP)
    37  	IMULQ	$1000000000, DX
    38  	SUBQ	DX, CX
    39  	MOVL	CX, nsec+8(FP)
    40  	RET
    41  useQPC:
    42  	JMP	runtime·nowQPC(SB)
    43  	RET