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/* 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_2ADDR.S
*
* Code: 64-bit integer multiply
*
* For: mul-long/2addr
*
* Description: Multiply two sources registers and store the result
* in the first source register.
*
* Format: B|A|op (12x)
*
* Syntax: op vA, vB
*/
/*
* 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, %edx # %edx<- BA+
shr $$4, rINST # rINST<- B
andl $$15, %edx # %edx<- A
movl %edx, sReg0 # sReg0<- A
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
movl 4(rFP, %edx, 4), %eax # %eax<- Y
imull (rFP, rINST, 4), %eax # %eax<- X*Y
addl %eax, %ecx # %ecx<- (WZ + XY)
movl (rFP, %edx, 4), %eax # %eax<- Z
mull (rFP, rINST, 4) # %edx:eax<- XZ
addl %edx, %ecx # %ecx<- carry + (WZ + XY)
movl sReg0, %edx # %edx<- A
movl %ecx, 4(rFP, %edx, 4) # vA+1<- results hi
movl %eax, (rFP, %edx, 4) # vA<- results lo
FINISH 1 # jump to next instruction