github.com/twelsh-aw/go/src@v0.0.0-20230516233729-a56fe86a7c81/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  
     7  #include "go_asm.h"
     8  #include "textflag.h"
     9  #include "time_windows.h"
    10  
    11  TEXT time·now(SB),NOSPLIT,$0-24
    12  	CMPB	runtime·useQPCTime(SB), $0
    13  	JNE	useQPC
    14  
    15  	MOVQ	$_INTERRUPT_TIME, DI
    16  	MOVQ	time_lo(DI), AX
    17  	IMULQ	$100, AX
    18  	MOVQ	AX, mono+16(FP)
    19  
    20  	MOVQ	$_SYSTEM_TIME, DI
    21  	MOVQ	time_lo(DI), AX
    22  	MOVQ	$116444736000000000, DI
    23  	SUBQ	DI, AX
    24  	IMULQ	$100, AX
    25  
    26  	// generated code for
    27  	//	func f(x uint64) (uint64, uint64) { return x/1000000000, x%1000000000 }
    28  	// adapted to reduce duplication
    29  	MOVQ	AX, CX
    30  	MOVQ	$1360296554856532783, AX
    31  	MULQ	CX
    32  	ADDQ	CX, DX
    33  	RCRQ	$1, DX
    34  	SHRQ	$29, DX
    35  	MOVQ	DX, sec+0(FP)
    36  	IMULQ	$1000000000, DX
    37  	SUBQ	DX, CX
    38  	MOVL	CX, nsec+8(FP)
    39  	RET
    40  useQPC:
    41  	JMP	runtime·nowQPC(SB)
    42  	RET