Here is my c code test:
drew@drew-PC MSYS /e/examples/c
$ cat align.c
#include
typedef struct _A {
char a;
long long b;
} A;
int main() {
printf("%d\n", sizeof(int*));
printf("%d\n", sizeof(A));
}
drew@drew-PC MSYS /e/examples/c
$ gcc -o align align.c
drew
To Jan & Ohir, thanks for information.
Do you run my code example in GO plagground? The pointer size of `a` is 4
bytes, it shows go playground use 32bit go. As my test, the go playground
environment is:
GOOS: nacl
GOARCH: amd64p32
the Machine is amd64, but run 32bit GO.
My Machine is amd6
Dnia 2017-05-19, o godz. 04:28:53
xjdrew napisał(a):
> uint64 should aligin in 8 bytes, why it aligns in 4 bytes in
> go1.8.1.linux-386?
uint64 member IS 8 bytes wide. It is aligned to the machine word boundary
which is 4B (32/8) for 32bit architecture and 8B for 64b one (64/8).
> Could anyone
On Fri, May 19, 2017 at 1:29 PM xjdrew wrote:
> uint64 should aligin in 8 bytes, why it aligns in 4 bytes in
go1.8.1.linux-386?
https://en.wikipedia.org/wiki/Data_structure_alignment#Typical_alignment_of_C_structs_on_x86
> Could anyone tell me how I can get the same result with go playground?
Hello everyone,
Code as below, playground url(https://play.golang.org/p/XSx--6uF0E):
package main
import "fmt"
import "unsafe"
type A struct {
a uint8
b uint64
}
func main() {
a := &A{}
fmt.Println(unsafe.Sizeof(a))
fmt.Println(unsafe.Sizeof(*a))
}
When I run the code in go playground
