asm statement syntax

1 asm
1 __asm
1 __asm__
2? volatile
3 (
4 code_format_string
4.1+ :
4.1? 
4.1 output
4.1 input
4.1 clobbers
4.1.1 )

input:

1+ ,
1 constraint ( C_expression )

output:

1+ ,
1 constraint ( C_expression )