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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>
68 lines
1.3 KiB
ArmAsm
68 lines
1.3 KiB
ArmAsm
// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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//go:build !faketime
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// +build !faketime
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#include "go_asm.h"
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#include "textflag.h"
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#include "time_windows.h"
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TEXT time·now(SB),NOSPLIT|NOFRAME,$0-24
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MOVB runtime·useQPCTime(SB), R0
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CMP $0, R0
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BNE useQPC
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MOVD $_INTERRUPT_TIME, R3
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loop:
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MOVWU time_hi1(R3), R1
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MOVWU time_lo(R3), R0
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MOVWU time_hi2(R3), R2
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CMP R1, R2
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BNE loop
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// wintime = R1:R0, multiply by 100
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ORR R1<<32, R0
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MOVD $100, R1
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MUL R1, R0
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MOVD R0, mono+16(FP)
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MOVD $_SYSTEM_TIME, R3
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wall:
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MOVWU time_hi1(R3), R1
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MOVWU time_lo(R3), R0
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MOVWU time_hi2(R3), R2
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CMP R1, R2
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BNE wall
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// w = R1:R0 in 100ns units
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// convert to Unix epoch (but still 100ns units)
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#define delta 116444736000000000
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ORR R1<<32, R0
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SUB $delta, R0
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// Convert to nSec
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MOVD $100, R1
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MUL R1, R0
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// Code stolen from compiler output for:
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//
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// var x uint64
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// func f() (sec uint64, nsec uint32) { return x / 1000000000, uint32(x % 100000000) }
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//
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LSR $1, R0, R1
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MOVD $-8543223759426509416, R2
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UMULH R2, R1, R1
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LSR $28, R1, R1
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MOVD R1, sec+0(FP)
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MOVD $-6067343680855748867, R1
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UMULH R0, R1, R1
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LSR $26, R1, R1
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MOVD $100000000, R2
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MSUB R1, R0, R2, R0
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MOVW R0, nsec+8(FP)
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RET
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useQPC:
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B runtime·nowQPC(SB) // tail call
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