#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int /*<<< orphan*/ printf(char *, ...);
void print_buffer(unsigned char *buffer, unsigned long size) {
  unsigned long i, col;
  col = 0;
  for (i = 0; i < size; i++) {
    printf("%02x ", buffer[i]);
    if (col++ == 15) {
      printf("\n");
      col = 0;
    }
  }
  printf("\n");
}


x86 assembly (clang, -O0):
<print_buffer>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movq   $0x0,-0x20(%rbp)
movq   $0x0,-0x18(%rbp)
mov    -0x18(%rbp),%rax
cmp    -0x10(%rbp),%rax
jae    119d <print_buffer+0x8d>
mov    -0x8(%rbp),%rax
mov    -0x18(%rbp),%rcx
movzbl (%rax,%rcx,1),%esi
lea    0xeaf(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x20(%rbp),%rax
mov    %rax,%rcx
add    $0x1,%rcx
mov    %rcx,-0x20(%rbp)
cmp    $0xf,%rax
jne    1187 <print_buffer+0x77>
lea    0xe8e(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movq   $0x0,-0x20(%rbp)
jmp    118c <print_buffer+0x7c>
mov    -0x18(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x18(%rbp)
jmp    1130 <print_buffer+0x20>
lea    0xe62(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<print_buffer>:
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
test   %rsi,%rsi
je     1181 <print_buffer+0x61>
mov    %rsi,%r12
mov    %rdi,%r14
lea    0xec5(%rip),%r15
xor    %r13d,%r13d
xor    %ebx,%ebx
jmp    1166 <print_buffer+0x46>
cs nopw 0x0(%rax,%rax,1)
nopl   0x0(%rax)
mov    $0xa,%edi
call   1030 <putchar@plt>
xor    %r13d,%r13d
add    $0x1,%rbx
cmp    %rbx,%r12
je     1181 <print_buffer+0x61>
movzbl (%r14,%rbx,1),%esi
mov    %r15,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
cmp    $0xf,%r13
je     1150 <print_buffer+0x30>
add    $0x1,%r13
jmp    115d <print_buffer+0x3d>
mov    $0xa,%edi
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
jmp    1030 <putchar@plt>

LLVM IR (-O0):
@.str = [6 x i8] c"%02x \00"
@.str.1 = [2 x i8] c"\0A\00"
define void @print_buffer(i8* %0, i64 %1) {
%3 = alloca i8*
%4 = alloca i64
%5 = alloca i64
%6 = alloca i64
store i8* %0, i8** %3
store i64 %1, i64* %4
store i64 0, i64* %6
store i64 0, i64* %5
br label %7
7: ; preds = %24, %2
%8 = load i64, i64* %5
%9 = load i64, i64* %4
%10 = icmp ult i64 %8, %9
br i1 %10, label %11, label %27
11: ; preds = %7
%12 = load i8*, i8** %3
%13 = load i64, i64* %5
%14 = getelementptr inbounds i8, i8* %12, i64 %13
%15 = load i8, i8* %14
%16 = zext i8 %15 to i32
%17 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0), i32 %16)
%18 = load i64, i64* %6
%19 = add i64 %18, 1
store i64 %19, i64* %6
%20 = icmp eq i64 %18, 15
br i1 %20, label %21, label %23
21: ; preds = %11
%22 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
store i64 0, i64* %6
br label %23
23: ; preds = %21, %11
br label %24
24: ; preds = %23
%25 = load i64, i64* %5
%26 = add i64 %25, 1
store i64 %26, i64* %5
br label %7
27: ; preds = %7
%28 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
ret void
}

LLVM IR (-O2):
@.str = [6 x i8] c"%02x \00"
define void @print_buffer(i8* nocapture %0, i64 %1) {
%3 = icmp eq i64 %1, 0
br i1 %3, label %19, label %4
4: ; preds = %2, %15
%5 = phi i64 [ %16, %15 ], [ 0, %2 ]
%6 = phi i64 [ %17, %15 ], [ 0, %2 ]
%7 = getelementptr inbounds i8, i8* %0, i64 %6
%8 = load i8, i8* %7
%9 = zext i8 %8 to i32
%10 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0), i32 %9)
%11 = add i64 %5, 1
%12 = icmp eq i64 %5, 15
br i1 %12, label %13, label %15
13: ; preds = %4
%14 = tail call i32 @putchar(i32 10)
br label %15
15: ; preds = %4, %13
%16 = phi i64 [ 0, %13 ], [ %11, %4 ]
%17 = add nuw i64 %6, 1
%18 = icmp eq i64 %17, %1
br i1 %18, label %19, label %4
19: ; preds = %15, %2
%20 = tail call i32 @putchar(i32 10)
ret void
}