Adding upstream version 1.18.10.upstream/1.18.10upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 90 insertions, 0 deletions

diff --git a/src/runtime/time_windows_arm.s b/src/runtime/time_windows_arm.s
new file mode 100644
index 0000000..711af88
--- /dev/null
+++ b/src/runtime/time_windows_arm.s
@@ -0,0 +1,90 @@
+// 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
+
+#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
+	DMB	MB_ISH
+	MOVW	time_lo(R3), R0
+	DMB	MB_ISH
+	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
+	DMB	MB_ISH
+	MOVW	time_lo(R3), R0
+	DMB	MB_ISH
+	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
+