1// Inferno's libkern/vlop-386.s
2// https://bitbucket.org/inferno-os/inferno-os/src/master/libkern/vlop-386.s
3//
4//         Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
5//         Revisions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com).  All rights reserved.
6//         Portions Copyright 2009 The Go Authors. All rights reserved.
7//
8// Permission is hereby granted, free of charge, to any person obtaining a copy
9// of this software and associated documentation files (the "Software"), to deal
10// in the Software without restriction, including without limitation the rights
11// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12// copies of the Software, and to permit persons to whom the Software is
13// furnished to do so, subject to the following conditions:
14//
15// The above copyright notice and this permission notice shall be included in
16// all copies or substantial portions of the Software.
17//
18// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
21// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24// THE SOFTWARE.
25
26#include "textflag.h"
27
28/*
29 * C runtime for 64-bit divide.
30 */
31
32// runtime·_mul64x32(lo64 *uint64, a uint64, b uint32) (hi32 uint32)
33// sets *lo64 = low 64 bits of 96-bit product a*b; returns high 32 bits.
34TEXT runtime·_mul64by32(SB), NOSPLIT, $0
35	MOVL	lo64+0(FP), CX
36	MOVL	a_lo+4(FP), AX
37	MULL	b+12(FP)
38	MOVL	AX, 0(CX)
39	MOVL	DX, BX
40	MOVL	a_hi+8(FP), AX
41	MULL	b+12(FP)
42	ADDL	AX, BX
43	ADCL	$0, DX
44	MOVL	BX, 4(CX)
45	MOVL	DX, AX
46	MOVL	AX, hi32+16(FP)
47	RET
48
49TEXT runtime·_div64by32(SB), NOSPLIT, $0
50	MOVL	r+12(FP), CX
51	MOVL	a_lo+0(FP), AX
52	MOVL	a_hi+4(FP), DX
53	DIVL	b+8(FP)
54	MOVL	DX, 0(CX)
55	MOVL	AX, q+16(FP)
56	RET
57