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      1 /*
      2  * Copyright (C) 2009 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 /*
     18  * Dalvik instruction fragments, useful when porting mterp.
     19  *
     20  * Compile this and examine the output to see what your compiler generates.
     21  * This can give you a head start on some of the more complicated operations.
     22  *
     23  * Example:
     24  *   % gcc -c -O2 -save-temps -fverbose-asm porting-proto.c
     25  *   % less porting-proto.s
     26  */
     27 #include <stdint.h>
     28 
     29 typedef int8_t s1;
     30 typedef uint8_t u1;
     31 typedef int16_t s2;
     32 typedef uint16_t u2;
     33 typedef int32_t s4;
     34 typedef uint32_t u4;
     35 typedef int64_t s8;
     36 typedef uint64_t u8;
     37 
     38 s4 iadd32(s4 x, s4 y) { return x + y; }
     39 s8 iadd64(s8 x, s8 y) { return x + y; }
     40 float fadd32(float x, float y) { return x + y; }
     41 double fadd64(double x, double y) { return x + y; }
     42 
     43 s4 isub32(s4 x, s4 y) { return x - y; }
     44 s8 isub64(s8 x, s8 y) { return x - y; }
     45 float fsub32(float x, float y) { return x - y; }
     46 double fsub64(double x, double y) { return x - y; }
     47 
     48 s4 irsub32lit8(s4 x) { return 25 - x; }
     49 
     50 s4 imul32(s4 x, s4 y) { return x * y; }
     51 s8 imul64(s8 x, s8 y) { return x * y; }
     52 float fmul32(float x, float y) { return x * y; }
     53 double fmul64(double x, double y) { return x * y; }
     54 
     55 s4 idiv32(s4 x, s4 y) { return x / y; }
     56 s8 idiv64(s8 x, s8 y) { return x / y; }
     57 float fdiv32(float x, float y) { return x / y; }
     58 double fdiv64(double x, double y) { return x / y; }
     59 
     60 s4 irem32(s4 x, s4 y) { return x % y; }
     61 s8 irem64(s8 x, s8 y) { return x % y; }
     62 
     63 s4 iand32(s4 x, s4 y) { return x & y; }
     64 s8 iand64(s8 x, s8 y) { return x & y; }
     65 
     66 s4 ior32(s4 x, s4 y) { return x | y; }
     67 s8 ior64(s8 x, s8 y) { return x | y; }
     68 
     69 s4 ixor32(s4 x, s4 y) { return x ^ y; }
     70 s8 ixor64(s8 x, s8 y) { return x ^ y; }
     71 
     72 s4 iasl32(s4 x, s4 count) { return x << (count & 0x1f); }
     73 s8 iasl64(s8 x, s4 count) { return x << (count & 0x3f); }
     74 
     75 s4 iasr32(s4 x, s4 count) { return x >> (count & 0x1f); }
     76 s8 iasr64(s8 x, s4 count) { return x >> (count & 0x3f); }
     77 
     78 s4 ilsr32(s4 x, s4 count) { return ((u4)x) >> (count & 0x1f); } // unsigned
     79 s8 ilsr64(s8 x, s4 count) { return ((u8)x) >> (count & 0x3f); } // unsigned
     80 
     81 s4 ineg32(s4 x) { return -x; }
     82 s8 ineg64(s8 x) { return -x; }
     83 float fneg32(float x) { return -x; }
     84 double fneg64(double x) { return -x; }
     85 
     86 s4 inot32(s4 x) { return x ^ -1; }
     87 s8 inot64(s8 x) { return x ^ -1LL; }
     88 
     89 s4 float2int(float x) { return (s4) x; }
     90 double float2double(float x) { return (double) x; }
     91 s4 double2int(double x) { return (s4) x; }
     92 float double2float(double x) { return (float) x; }
     93 
     94 /*
     95  * ARM lib doesn't clamp large values or NaN the way we want on these two.
     96  * If the simple version isn't correct, use the long version.  (You can use
     97  * dalvik/tests/041-narrowing to verify.)
     98  */
     99 s8 float2long(float x) { return (s8) x; }
    100 s8 float2long_clamp(float x)
    101 {
    102     static const float kMaxLong = (float)0x7fffffffffffffffULL;
    103     static const float kMinLong = (float)0x8000000000000000ULL;
    104 
    105     if (x >= kMaxLong) {
    106         return 0x7fffffffffffffffULL;
    107     } else if (x <= kMinLong) {
    108         return 0x8000000000000000ULL;
    109     } else if (x != x) {
    110         return 0;
    111     } else {
    112         return (s8) x;
    113     }
    114 }
    115 s8 double2long(double x) { return (s8) x; }
    116 s8 double2long_clamp(double x)
    117 {
    118     static const double kMaxLong = (double)0x7fffffffffffffffULL;
    119     static const double kMinLong = (double)0x8000000000000000ULL;
    120 
    121     if (x >= kMaxLong) {
    122         return 0x7fffffffffffffffULL;
    123     } else if (x <= kMinLong) {
    124         return 0x8000000000000000ULL;
    125     } else if (x != x) {
    126         return 0;
    127     } else {
    128         return (s8) x;
    129     }
    130 }
    131 
    132 s1 int2byte(s4 x) { return (s1) x; }
    133 s2 int2short(s4 x) { return (s2) x; }
    134 u2 int2char(s4 x) { return (u2) x; }
    135 s8 int2long(s4 x) { return (s8) x; }
    136 float int2float(s4 x) { return (float) x; }
    137 double int2double(s4 x) { return (double) x; }
    138 
    139 s4 long2int(s8 x) { return (s4) x; }
    140 float long2float(s8 x) { return (float) x; }
    141 double long2double(s8 x) { return (double) x; }
    142 
    143 int cmpl_float(float x, float y)
    144 {
    145     int result;
    146 
    147     if (x == y)
    148         result = 0;
    149     else if (x > y)
    150         result = 1;
    151     else /* (x < y) or NaN */
    152         result = -1;
    153     return result;
    154 }
    155 
    156 int cmpg_float(float x, float y)
    157 {
    158     int result;
    159 
    160     if (x == y)
    161         result = 0;
    162     else if (x < y)
    163         result = -1;
    164     else /* (x > y) or NaN */
    165         result = 1;
    166     return result;
    167 }
    168 
    169 int cmpl_double(double x, double y)
    170 {
    171     int result;
    172 
    173     if (x == y)
    174         result = 0;
    175     else if (x > y)
    176         result = 1;
    177     else /* (x < y) or NaN */
    178         result = -1;
    179     return result;
    180 }
    181 
    182 int cmpg_double(double x, double y)
    183 {
    184     int result;
    185 
    186     if (x == y)
    187         result = 0;
    188     else if (x < y)
    189         result = -1;
    190     else /* (x > y) or NaN */
    191         result = 1;
    192     return result;
    193 }
    194 
    195 int cmp_long(s8 x, s8 y)
    196 {
    197     int result;
    198 
    199     if (x == y)
    200         result = 0;
    201     else if (x < y)
    202         result = -1;
    203     else /* (x > y) */
    204         result = 1;
    205     return result;
    206 }
    207 
    208 /* instruction decoding fragments */
    209 u1 unsignedAA(u2 x) { return x >> 8; }
    210 s1 signedAA(u2 x) { return (s4)(x << 16) >> 24; }
    211 s2 signedBB(u2 x) { return (s2) x; }
    212 u1 unsignedA(u2 x) { return (x >> 8) & 0x0f; }
    213 u1 unsignedB(u2 x) { return x >> 12; }
    214 
    215 /* some handy immediate constants when working with float/double */
    216 u4 const_43e00000(u4 highword) { return 0x43e00000; }
    217 u4 const_c3e00000(u4 highword) { return 0xc3e00000; }
    218 u4 const_ffc00000(u4 highword) { return 0xffc00000; }
    219 u4 const_41dfffff(u4 highword) { return 0x41dfffff; }
    220 u4 const_c1e00000(u4 highword) { return 0xc1e00000; }
    221 
    222 /*
    223  * Test for some gcc-defined symbols.  If you're frequently switching
    224  * between different cross-compiler architectures or CPU feature sets,
    225  * this can help you keep track of which one you're compiling for.
    226  */
    227 #ifdef __arm__
    228 # warning "found __arm__"
    229 #endif
    230 #ifdef __ARM_EABI__
    231 # warning "found __ARM_EABI__"
    232 #endif
    233 #ifdef __VFP_FP__
    234 # warning "found __VFP_FP__"    /* VFP-format doubles used; may not have VFP */
    235 #endif
    236 #if defined(__VFP_FP__) && !defined(__SOFTFP__)
    237 # warning "VFP in use"
    238 #endif
    239 #ifdef __ARM_ARCH_5TE__
    240 # warning "found __ARM_ARCH_5TE__"
    241 #endif
    242 #ifdef __ARM_ARCH_7A__
    243 # warning "found __ARM_ARCH_7A__"
    244 #endif
    245