Text file
src/runtime/time_windows_arm64.s
Documentation: runtime
1 // Copyright 2018 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|NOFRAME,$0-24
13 MOVB runtime·useQPCTime(SB), R0
14 CMP $0, R0
15 BNE useQPC
16 MOVD $_INTERRUPT_TIME, R3
17 loop:
18 MOVWU time_hi1(R3), R1
19 MOVWU time_lo(R3), R0
20 MOVWU time_hi2(R3), R2
21 CMP R1, R2
22 BNE loop
23
24 // wintime = R1:R0, multiply by 100
25 ORR R1<<32, R0
26 MOVD $100, R1
27 MUL R1, R0
28 MOVD R0, mono+16(FP)
29
30 MOVD $_SYSTEM_TIME, R3
31 wall:
32 MOVWU time_hi1(R3), R1
33 MOVWU time_lo(R3), R0
34 MOVWU time_hi2(R3), R2
35 CMP R1, R2
36 BNE wall
37
38 // w = R1:R0 in 100ns units
39 // convert to Unix epoch (but still 100ns units)
40 #define delta 116444736000000000
41 ORR R1<<32, R0
42 SUB $delta, R0
43
44 // Convert to nSec
45 MOVD $100, R1
46 MUL R1, R0
47
48 // Code stolen from compiler output for:
49 //
50 // var x uint64
51 // func f() (sec uint64, nsec uint32) { return x / 1000000000, uint32(x % 100000000) }
52 //
53 LSR $1, R0, R1
54 MOVD $-8543223759426509416, R2
55 UMULH R2, R1, R1
56 LSR $28, R1, R1
57 MOVD R1, sec+0(FP)
58 MOVD $-6067343680855748867, R1
59 UMULH R0, R1, R1
60 LSR $26, R1, R1
61 MOVD $100000000, R2
62 MSUB R1, R0, R2, R0
63 MOVW R0, nsec+8(FP)
64 RET
65 useQPC:
66 B runtime·nowQPC(SB) // tail call
67
68
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