const char * vs const char []

const_pnt_vs_const_array.txt

#include <string.h>

size_t zob1(const char *c)
{
   const char *s = "abcdefghijklmnopqrstuvwxyz";
   return strspn(c, s);
}

size_t zob2(const char *c)
{
   const char s[] = "abcdefghijklmnopqrstuvwxyz";
   return strspn(c, s);
}



clang 2.9
=========
generates the same code for both functions:

zob1:                                   # @zob1
.Leh_func_begin0:
        movl    $.L.str, %esi
        jmp     strspn                  # TAILCALL
.Leh_func_end0:

...

zob2:                                   # @zob2
.Leh_func_begin1:
        movl    $.L.str, %esi
        jmp     strspn                  # TAILCALL
.Leh_func_end1:

...

.L.str:
        .asciz   "abcdefghijklmnopqrstuvwxyz"


gcc 4.6.1
=========

zob1:
	.cfi_startproc
	movl	$.LC0, %esi
	jmp	strspn
	.cfi_endproc

...

zob2:
	.cfi_startproc
	subq	$56, %rsp
	.cfi_def_cfa_offset 64
	movabsq	$8101815670912281193, %rdx
	movabsq	$8680537053616894577, %rcx
	movq	%fs:40, %rax
	movq	%rax, 40(%rsp)
	xorl	%eax, %eax
	movq	%rsp, %rsi
	movabsq	$7523094288207667809, %rax
	movq	%rdx, 8(%rsp)
	movq	%rax, (%rsp)
	movq	%rcx, 16(%rsp)
	movw	$31353, 24(%rsp)
	movb	$0, 26(%rsp)
	call	strspn
	movq	40(%rsp), %rdx
	xorq	%fs:40, %rdx
	jne	.L5
	addq	$56, %rsp
	.cfi_remember_state
	.cfi_def_cfa_offset 8
	ret

...

.LC0:
	.string	"abcdefghijklmnopqrstuvwxyz"