#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 */
typedef int uint8_t;

/* Variables and functions */
int /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ puts(char *);
void print_hex(const char *label, const uint8_t *array,
               const size_t num_bytes) {
  printf("%s: ", label);
  for (size_t i = 0; i < num_bytes; i++) {
    printf("%02x", array[i]);
  }
  puts("");
}


x86 assembly (clang, -O0):
<print_hex>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    -0x8(%rbp),%rsi
lea    0xec1(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
movq   $0x0,-0x20(%rbp)
mov    -0x20(%rbp),%rax
cmp    -0x18(%rbp),%rax
jae    1186 <print_hex+0x66>
mov    -0x10(%rbp),%rax
mov    -0x20(%rbp),%rcx
mov    (%rax,%rcx,4),%esi
lea    0xe97(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x20(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x20(%rbp)
jmp    114e <print_hex+0x2e>
lea    0xe77(%rip),%rdi
call   1030 <puts@plt>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<print_hex>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
mov    %rdx,%r12
mov    %rsi,%r14
mov    %rdi,%rsi
lea    0xec8(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
test   %r12,%r12
je     1167 <print_hex+0x47>
lea    0xeba(%rip),%r15
xor    %ebx,%ebx
nopl   (%rax)
mov    (%r14,%rbx,4),%esi
mov    %r15,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
add    $0x1,%rbx
cmp    %rbx,%r12
jne    1150 <print_hex+0x30>
mov    $0xa,%edi
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
jmp    1030 <putchar@plt>

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

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