Compiler reordering

Can compiler reorder function calls?
In most compiled languages, the compiler is free to order the function calls f , g , and h as it finds convenient, resulting in large-scale changes of program memory order..
How do I prevent GCC from reordering?
To prevent compiler reorderings at other times, you must use a compiler-specific barrier.
GCC uses __asm__ __volatile__("":::"memory"); for this purpose.
This is different from CPU reordering, a.k.a. the memory-ordering model..
How do I prevent reordering in GCC?
To prevent compiler reorderings at other times, you must use a compiler-specific barrier.
GCC uses __asm__ __volatile__("":::"memory"); for this purpose.
This is different from CPU reordering, a.k.a. the memory-ordering model..
What is compiler reordering?
Both the compiler and the hardware will reorder instructions with the goal of executing the program more efficiently.
This is not new technology: compilers have done this for a long time, and this is one reason why an optimized build runs faster than a non-optimized build..
What is reordering of instructions?
Memory reordering refers to the reordering of instructions when the execution order of the instructions is inconsistent with the order written in the code.
It usually occurs in the following two procedures: Compiler Reordering (Compile Time) CPU Reordering (Run Time)_{Mar 15, 2021}.
A compiler requires more memory capacity because it generates an intermediary object code.
Object code refers to the binary code, which it directly stores in a file.
This means that a compiler may require an external memory source, such as disk storage, to store machine code.
In most compiled languages, the compiler is free to order the function calls f , g , and h as it finds convenient, resulting in large-scale changes of program memory order.
Memory reordering refers to the reordering of instructions when the execution order of the instructions is inconsistent with the order written in the code.
It usually occurs in the following two procedures: Compiler Reordering (Compile Time) CPU Reordering (Run Time)_{Mar 15, 2021}
To prevent compiler reorderings at other times, you must use a compiler-specific barrier.
GCC uses __asm__ __volatile__("":::"memory"); for this purpose.
This is different from CPU reordering, a.k.a. the memory-ordering model.

Oct 23, 2019Generated code The compiler reordered the code it generated. In particular it called GetTickCount twice in succession (lines from 1 to 7 above)

Both the compiler and the hardware will reorder instructions with the goal of executing the program more efficiently. This is not new technology: compilers have done this for a long time, and this is one reason why an optimized build runs faster than a non-optimized build.

Compiler reordering

Can compiler reorder function calls?

How do I prevent GCC from reordering?

How do I prevent reordering in GCC?

What is compiler reordering?

What is reordering of instructions?