diff options
Diffstat (limited to '3/9_data_structures/43_dest.c')
| -rw-r--r-- | 3/9_data_structures/43_dest.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/3/9_data_structures/43_dest.c b/3/9_data_structures/43_dest.c new file mode 100644 index 0000000..67bb630 --- /dev/null +++ b/3/9_data_structures/43_dest.c @@ -0,0 +1,43 @@ +#define type long; + +typedef union { + struct { + long u; + short v; + char w; + } t1; + struct { + int a[2]; + char *p; + } t2; +} u_type; + +// Kinda confused when I'm moving a memory address +// Forgot it was a union +// Also forgot I had to move to dest +// +// up and dest in rdi and rsi +// +// expr type code +// +// up->t1.u long movq (%rdi), %rax +// movq %rax, (%rsi) +// +// up->t1.v short movw 8(%rdi), %ax +// movw %ax, (%rsi) +// +// &up->t1.w char* addq 10, %rdi +// movq %rdi, (%rsi) +// +// up->t2.a int * movq %rdi, (%rsi) +// +// up->t2.a[up->t1.u] int movq (%rdi), %rax // What's interesting: rdi is the t2.a int* and the t1.u long, and they are being used in the same expression! +// movl (%rdi, %rax, 4), %eax +// movl %eax, (%rsi) +// +// *up->t2.p char movq 8(%rdi), %rax +// movb (%rax), %al // Remember, you cannot have Memory -- Memory moves! +// movb %al, (%rsi) +void get(u_type *up, type *dest) { + *dest = ___; +} |