On 04/12/2016 06:34 AM, sztfg@xxxxxxxxx wrote:
test:
subq $8, %rsp # why?
call dummy
xorl %eax, %eax
addq $8, %rsp # why?
ret
.size test, .-test
Why need to do this subq addq?
The x86_64 ABI requires that the stack pointer is a multiple of 16 before the CALL instruction is executed. This simplifies code in functions which need to store vector register values on the stack.
Florian
