Source Code Porting Modification Levels

Rule

To run your program on the Kunpeng platform, the code must be modified.

Replace any -m64 compilation option with -mabi=lp64. Otherwise, the program cannot run on the Kunpeng platform.

Example code:

abc = -m64

Modify it as follows:

abc = -mabi=lp64

Suggestion_Optimization

The compilation may still succeed, but runtime performance or platform compatibility is affected. Decide whether to modify the code based on your requirements.

The -march compilation option is not specified. The compiler uses only the basic instruction set and general optimizations, without leveraging any instruction set extensions. As a result, the hardware performance of the Kunpeng platform cannot be fully utilized.

Example code:

CFLAGS=-g3 -W -Wall -m3dnow -Wno-unused-but-set-variable -O4 -DVERSION="$(VERSION)" -DRELEASE="$(RELEASE)" -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -mpopcnt -msse4.2

Modify it as follows:

CFLAGS=-g3 -W -Wall -m3dnow -Wno-unused-but-set-variable -O4 -DVERSION="$(VERSION)" -DRELEASE="$(RELEASE)" -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -mpopcnt -msse4.2 -march=armv8-a

Suggestion_Standards

The compilation may still succeed, but potential compatibility issues may exist in syntax, precision, or function usage. It is recommended that you check and adjust the code.

To ensure that the default behavior of common characters on the Kunpeng platform is the same as that on the x86 platform, use -fsigned-char to explicitly specify these characters as a signed type.

Example code:

CFLAGS=-g3 -W -Wall -m32 -m3dnow -Wno-unused-but-set-variable -O0 -DDEBUG=1 -DVERSION="$(VERSION)" -DRELEASE="$(RELEASE)" -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -mpopcnt -msse4.2

Modify it as follows:

CFLAGS=-g3 -W -Wall -m32 -m3dnow -Wno-unused-but-set-variable -O0 -DDEBUG=1 -DVERSION="$(VERSION)" -DRELEASE="$(RELEASE)" -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE -mpopcnt -msse4.2 -fsigned-char

Suggestion_General

The compilation may still succeed. However, to improve code universality and platform compatibility, it is recommended that you modify the code based on the suggestions.

The x86 and Kunpeng platforms differ in their registers, operand order, and constraints. The code may produce errors on a Kunpeng server, so it is recommended that you modify the code accordingly.

Example code:

_asm("crc32b %1, %0" : "+r"(crc) : "rm"(v));

Modify it as follows:

#if defined(__x86_64__)
        _asm("crc32b %1, %0" : "+r"(crc) : "rm"(v));
#elif defined(__aarch64__)
    __asm__ __volatile__("crc32cb %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value));
#endif