------- Comment #5 from rguenth at gcc dot gnu dot org 2005-11-21 14:06 -------
Disassembly with the first two checks removed (only the third aborts):
foo:
.LFB2:
subq $24, %rsp #,
.LCFI0:
movl x+8(%rip), %eax #, tmp62
movl 16(%rsp), %edx #, tmp60
movq %rdi, 8(%rsp) # a, a
andl $2147483647, %eax #, tmp62
andl $2147483647, %edx #, tmp60
cmpl %eax, %edx # tmp62, tmp60
jne .L6 #,
addq $24, %rsp #,
ret
.L6:
call abort #
main:
.LFB3:
subq $8, %rsp #,
.LCFI1:
movl x+8(%rip), %eax #, tmp62
movw $30216, x(%rip) #, x.a
movb $1, x+4(%rip) #, x.b.c.d
movq x(%rip), %rdi # x, x
andl $-2147483648, %eax #, tmp62
orl $32766, %eax #, tmp62
movl %eax, x+8(%rip) # tmp62,
call foo #
xorl %eax, %eax # <result>
addq $8, %rsp #,
ret
it looks like we are confused on where we passed the structure by value.
It's in %rdi and %eax, while we think it got passed on stack(!?) in foo.
Someone with more x86_64 ABI knowledge has to look into this.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hubicka at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24969
