1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
|
/* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* File: OP_MUL_LONG.S
*
* Code: 64-bit integer multiply
*
* For: mul-long
*
* Description: Multiply two source registers and store the
* result in a destination register.
*
* Format: AA|op CC|BB (23x)
*
* Syntax: op vAA, vBB, vCC
*/
/*
* Signed 64-bit integer multiply.
*
* Consider WXxYZ (r1r0 x r3r2) with a long multiply:
* WX
* x YZ
* --------
* ZW ZX
* YW YX
*
* The low word of the result holds ZX, the high word holds
* (ZW+YX) + (the high overflow from ZX). YW doesn't matter because
* it doesn't fit in the low 64 bits.
*/
movl rINST, -4(%esp) # -4(%esp)<- AA+
FETCH_BB 1, rINST # rINST<- BB
FETCH_CC 1, %edx # %edx<- CC
jmp .L${opcode}_finish
%break
/*
* X = (rFP, rINST, 4)
* W = 4(rFP, rINST, 4)
* Z = (rFP, %edx, 4)
* Y = 4(rFP, %edx, 4)
*/
.L${opcode}_finish:
movl 4(rFP, rINST, 4), %ecx # %ecx<- W
imull (rFP, %edx, 4), %ecx # %ecx<- WxZ
mov 4(rFP, %edx, 4), %eax # %ecx<- Y
imull (rFP, rINST, 4), %eax # %eax<- XxY
addl %eax, %ecx # %ecx<- (WZ + XY)
movl (rFP, %edx, 4), %eax # %eax<- Z
mull (rFP, rINST, 4) # %edx:eax<- XZ
movzbl -4(%esp), rINST # rINST<- AA
addl %edx, %ecx # %ecx<- carry + (WZ + XY)
movl %ecx, 4(rFP, rINST, 4) # vAA+1<- results hi
movl %eax, (rFP, rINST, 4) # vAA<- results lo
FINISH 2 # jump to next instruction
|
