compile with g++ -S -O3 unroll.cc

gistfile1.asm

.file	"unroll.cc"
	.section	.rodata.str1.1,"aMS",@progbits,1
.LC0:
	.string	"%d\n"
	.text
	.p2align 4,,15
	.globl	_Z3bari
	.type	_Z3bari, @function
_Z3bari: ;; (would still get unrolled -funroll-loops)
.LFB48:
	.cfi_startproc
	pushq	%rbp
	.cfi_def_cfa_offset 16
	.cfi_offset 6, -16
	movl	%edi, %ebp
	pushq	%rbx
	.cfi_def_cfa_offset 24
	.cfi_offset 3, -24
	subq	$8, %rsp
	.cfi_def_cfa_offset 32
	testl	%edi, %edi
	jle	.L1
	xorl	%ebx, %ebx
	.p2align 4,,10
	.p2align 3
.L3:
	movl	%ebx, %edx
	xorl	%eax, %eax
	movl	$.LC0, %esi
	movl	$1, %edi
	addl	$1, %ebx
	call	__printf_chk
	cmpl	%ebp, %ebx
	jne	.L3
.L1:
	addq	$8, %rsp
	.cfi_def_cfa_offset 24
	popq	%rbx
	.cfi_def_cfa_offset 16
	popq	%rbp
	.cfi_def_cfa_offset 8
	ret
	.cfi_endproc
.LFE48:
	.size	_Z3bari, .-_Z3bari
	.section	.text.startup,"ax",@progbits
	.p2align 4,,15
	.globl	main
	.type	main, @function
main:
.LFB49:
	.cfi_startproc ;; (-O3 auto unrolls and inlines foo)
	subq	$8, %rsp
	.cfi_def_cfa_offset 16
	xorl	%edx, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$1, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$2, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$3, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$4, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$5, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$6, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$7, %edx
	movl	$.LC0, %esi
	movl	$1, %edi
	xorl	%eax, %eax
	call	__printf_chk
	movl	$8, %edi
	call	_Z3bari
	xorl	%eax, %eax
	addq	$8, %rsp
	.cfi_def_cfa_offset 8
	ret
	.cfi_endproc
.LFE49:
	.size	main, .-main
	.ident	"GCC: (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1"
	.section	.note.GNU-stack,"",@progbits

unroll.cc

#include <cstdio>
#include <cstdlib>

template<int N>
void foo() {
    for (int i = 0; i < N; ++i) {
        printf("%d\n", i);
    }
}

void bar(int n) {
    for (int i = 0; i < n; ++i) {
        printf("%d\n", i);
    }
}

int main(int argc, char **argv) {
    foo<8>();
    bar(8);
    return EXIT_SUCCESS;
}