A case for %Pn in GCC inline ASM

a.asm

cat test.c
 
------------------------------------------------------------
int main(int argc, char * argv[]) {
	__asm__ ("call __foo_bar_%P0" : : "i"(42));
	return 0;
}
------------------------------------------------------------
gcc -S test.c
cat test.s     
-------------------------------------------------------------                              
	.file	"test.c"
	.text
	.globl	main
	.type	main, @function
main:
.LFB0:
	.cfi_startproc
	pushq	%rbp
	.cfi_def_cfa_offset 16
	.cfi_offset 6, -16
	movq	%rsp, %rbp
	.cfi_def_cfa_register 6
	movl	%edi, -4(%rbp)
	movq	%rsi, -16(%rbp)
#APP
# 3 "test.c" 1
	call __foo_bar_42
# 0 "" 2
#NO_APP
	movl	$0, %eax
	popq	%rbp
	.cfi_def_cfa 7, 8
	ret
	.cfi_endproc
.LFE0:
	.size	main, .-main
	.ident	"GCC: 4.8.1"
	.section	.note.GNU-stack,"",@progbits