mirror of
https://github.com/golang/go
synced 2024-11-07 12:26:16 -07:00
c96fec9036
Build other definitions with the !faketime build tag. This makes it easy for us to add new assembly implementations of time.now. Change-Id: I4e48e41a4a04ab001030e6d1cdd9cebfa0161b0d Reviewed-on: https://go-review.googlesource.com/c/go/+/314274 Trust: Ian Lance Taylor <iant@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
88 lines
2.1 KiB
ArmAsm
88 lines
2.1 KiB
ArmAsm
// 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.
|
|
|
|
//go:build !faketime
|
|
// +build !faketime
|
|
|
|
#include "go_asm.h"
|
|
#include "textflag.h"
|
|
#include "time_windows.h"
|
|
|
|
TEXT time·now(SB),NOSPLIT|NOFRAME,$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
|
|
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·nowQPC(SB) // tail call
|
|
|