sysrap/tests/sbigint_test.cc

0001 /* Copyright (C) Arm Limited, 2023 All rights reserved.
0002
0003 https://developer.arm.com/documentation/ka004805/latest/
0004
0005 The example code is provided to you as an aid to learning when working
0006 with Arm-based technology, including but not limited to programming tutorials.
0007 Arm hereby grants to you, subject to the terms and conditions of this Licence,
0008 a non-exclusive, non-transferable, non-sub-licensable, free-of-charge licence,
0009 to use and copy the Software solely for the purpose of demonstration and
0010 evaluation.
0011
0012 You accept that the Software has not been tested by Arm therefore the Software
0013 is provided "as is", without warranty of any kind, express or implied. In no
0014 event shall the authors or copyright holders be liable for any claim, damages
0015 or other liability, whether in action or contract, tort or otherwise, arising
0016 from, out of or in connection with the Software or the use of Software. */
0017
0018 #include <stdint.h>
0019 #include <stdlib.h>
0020 #include <stdio.h>
0021
0022 // Macro to help create 128-bit literals from two 64-bit literals
0023 #define MAKE128CONST(hi,lo) ((((__uint128_t)hi << 64) | lo))
0024
0025 // Helper type to use to print 128-bit literals as hexadecimal values
0026 typedef union
0027 {
0028     __uint128_t as_128;
0029     struct
0030     {
0031         uint64_t lo;
0032         uint64_t hi;
0033     }  as_2x64;
0034 } reinterpret128_t;
0035
0036 // Function to write a 128-bit value to memory
0037 __attribute__((always_inline)) static void reg128_write(uint64_t addr, __uint128_t data)
0038 {
0039     volatile __uint128_t *as_ptr = (volatile __uint128_t *)addr;
0040     *as_ptr = data;
0041 }
0042
0043 // Function to read a 128-bit value from memory
0044 __attribute((always_inline)) static __uint128_t reg128_read(uint64_t addr)
0045 {
0046     volatile __uint128_t *as_ptr = (volatile __uint128_t *)addr;
0047     return *as_ptr;
0048 }
0049
0050 // Function to convert a 128-bit value to a zero-padded hexadecimcal string
0051 __attribute__((always_inline)) static const char * reg128_as_hex(__uint128_t data)
0052 {
0053     reinterpret128_t temp = *((reinterpret128_t *)(&data));
0054     char * buffer = (char*)malloc(33);
0055     sprintf(buffer, "%016llx%016llx", temp.as_2x64.hi, temp.as_2x64.lo);
0056     return buffer;
0057 }
0058
0059 int main(void)
0060 {
0061     // 128-bit literals are not supported. Instead, use the MAKE128CONST macro.
0062     // __uint128_t data = 0x44444444333333332222222211111111;
0063
0064     uint64_t buffer[2] ;
0065     uint64_t* ptr = &buffer[0] ;
0066     uint64_t iptr = (uint64_t)(ptr) ;
0067
0068     // Write 128-bit constant value to an address.
0069     reg128_write(iptr, MAKE128CONST(0x4444444433333333ULL, 0x2222222211111111ULL));
0070
0071     // Print 128-bit value read from an address.
0072     // The helper function reg128_as_hex is used to convert a 128-bit value to a hex string without the '0x' suffix.
0073     printf("0x%s\n", reg128_as_hex(reg128_read(iptr)));
0074
0075     return 0;
0076 }
0077