ARMAssemblerInterface.cpp revision 4f6e8d7a00cbeda1e70cc15be9c4af1018bdad53 
1/* libs/pixelflinger/codeflinger/ARMAssemblerInterface.cpp
2**
3** Copyright 2006, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18
19#include <errno.h>
20#include <stdlib.h>
21#include <stdint.h>
22#include <sys/types.h>
23
24#include <cutils/log.h>
25#include "codeflinger/ARMAssemblerInterface.h"
26
27namespace android {
28
29// ----------------------------------------------------------------------------
30
31ARMAssemblerInterface::~ARMAssemblerInterface()
32{
33}
34
35int ARMAssemblerInterface::buildImmediate(
36        uint32_t immediate, uint32_t& rot, uint32_t& imm)
37{
38    rot = 0;
39    imm = immediate;
40    if (imm > 0x7F) { // skip the easy cases
41        while (!(imm&3)  || (imm&0xFC000000)) {
42            uint32_t newval;
43            newval = imm >> 2;
44            newval |= (imm&3) << 30;
45            imm = newval;
46            rot += 2;
47            if (rot == 32) {
48                rot = 0;
49                break;
50            }
51        }
52    }
53    rot = (16 - (rot>>1)) & 0xF;
54
55    if (imm>=0x100)
56        return -EINVAL;
57
58    if (((imm>>(rot<<1)) | (imm<<(32-(rot<<1)))) != immediate)
59        return -1;
60
61    return 0;
62}
63
64// shifters...
65
66bool ARMAssemblerInterface::isValidImmediate(uint32_t immediate)
67{
68    uint32_t rot, imm;
69    return buildImmediate(immediate, rot, imm) == 0;
70}
71
72uint32_t ARMAssemblerInterface::imm(uint32_t immediate)
73{
74    uint32_t rot, imm;
75    int err = buildImmediate(immediate, rot, imm);
76
77    LOG_ALWAYS_FATAL_IF(err==-EINVAL,
78                        "immediate %08x cannot be encoded",
79                        immediate);
80
81    LOG_ALWAYS_FATAL_IF(err,
82                        "immediate (%08x) encoding bogus!",
83                        immediate);
84
85    return (1<<25) | (rot<<8) | imm;
86}
87
88uint32_t ARMAssemblerInterface::reg_imm(int Rm, int type, uint32_t shift)
89{
90    return ((shift&0x1F)<<7) | ((type&0x3)<<5) | (Rm&0xF);
91}
92
93uint32_t ARMAssemblerInterface::reg_rrx(int Rm)
94{
95    return (ROR<<5) | (Rm&0xF);
96}
97
98uint32_t ARMAssemblerInterface::reg_reg(int Rm, int type, int Rs)
99{
100    return ((Rs&0xF)<<8) | ((type&0x3)<<5) | (1<<4) | (Rm&0xF);
101}
102
103// addressing modes...
104// LDR(B)/STR(B)/PLD (immediate and Rm can be negative, which indicate U=0)
105uint32_t ARMAssemblerInterface::immed12_pre(int32_t immed12, int W)
106{
107    LOG_ALWAYS_FATAL_IF(abs(immed12) >= 0x800,
108                        "LDR(B)/STR(B)/PLD immediate too big (%08x)",
109                        immed12);
110    return (1<<24) | (((uint32_t(immed12)>>31)^1)<<23) |
111            ((W&1)<<21) | (abs(immed12)&0x7FF);
112}
113
114uint32_t ARMAssemblerInterface::immed12_post(int32_t immed12)
115{
116    LOG_ALWAYS_FATAL_IF(abs(immed12) >= 0x800,
117                        "LDR(B)/STR(B)/PLD immediate too big (%08x)",
118                        immed12);
119
120    return (((uint32_t(immed12)>>31)^1)<<23) | (abs(immed12)&0x7FF);
121}
122
123uint32_t ARMAssemblerInterface::reg_scale_pre(int Rm, int type,
124        uint32_t shift, int W)
125{
126    return  (1<<25) | (1<<24) |
127            (((uint32_t(Rm)>>31)^1)<<23) | ((W&1)<<21) |
128            reg_imm(abs(Rm), type, shift);
129}
130
131uint32_t ARMAssemblerInterface::reg_scale_post(int Rm, int type, uint32_t shift)
132{
133    return (1<<25) | (((uint32_t(Rm)>>31)^1)<<23) | reg_imm(abs(Rm), type, shift);
134}
135
136// LDRH/LDRSB/LDRSH/STRH (immediate and Rm can be negative, which indicate U=0)
137uint32_t ARMAssemblerInterface::immed8_pre(int32_t immed8, int W)
138{
139    uint32_t offset = abs(immed8);
140
141    LOG_ALWAYS_FATAL_IF(abs(immed8) >= 0x100,
142                        "LDRH/LDRSB/LDRSH/STRH immediate too big (%08x)",
143                        immed8);
144
145    return  (1<<24) | (1<<22) | (((uint32_t(immed8)>>31)^1)<<23) |
146            ((W&1)<<21) | (((offset&0xF0)<<4)|(offset&0xF));
147}
148
149uint32_t ARMAssemblerInterface::immed8_post(int32_t immed8)
150{
151    uint32_t offset = abs(immed8);
152
153    LOG_ALWAYS_FATAL_IF(abs(immed8) >= 0x100,
154                        "LDRH/LDRSB/LDRSH/STRH immediate too big (%08x)",
155                        immed8);
156
157    return (1<<22) | (((uint32_t(immed8)>>31)^1)<<23) |
158            (((offset&0xF0)<<4) | (offset&0xF));
159}
160
161uint32_t ARMAssemblerInterface::reg_pre(int Rm, int W)
162{
163    return (1<<24) | (((uint32_t(Rm)>>31)^1)<<23) | ((W&1)<<21) | (abs(Rm)&0xF);
164}
165
166uint32_t ARMAssemblerInterface::reg_post(int Rm)
167{
168    return (((uint32_t(Rm)>>31)^1)<<23) | (abs(Rm)&0xF);
169}
170
171
172}; // namespace android
173
174