#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 dump_hex(const unsigned char *data, int len, const char *txt) {
  int i;
  if (txt != NULL)
    printf("%s: ", txt);
  for (i = 0; i < len; i++) {
    if ((i % 2) == 0)
      printf(" ");
    if ((i % 16) == 0)
      printf("\n");
    printf("%02x", data[i]);
  }
  printf("\n");
}


x86 assembly (clang, -O0):
<dump_hex>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
mov    %rdx,-0x18(%rbp)
cmpq   $0x0,-0x18(%rbp)
je     1140 <dump_hex+0x30>
mov    -0x18(%rbp),%rsi
lea    0xec7(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x0,-0x1c(%rbp)
mov    -0x1c(%rbp),%eax
cmp    -0xc(%rbp),%eax
jge    11bf <dump_hex+0xaf>
mov    -0x1c(%rbp),%eax
mov    $0x2,%ecx
cltd
idiv   %ecx
cmp    $0x0,%edx
jne    1175 <dump_hex+0x65>
lea    0xe95(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x1c(%rbp),%eax
mov    $0x10,%ecx
cltd
idiv   %ecx
cmp    $0x0,%edx
jne    1197 <dump_hex+0x87>
lea    0xe75(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x8(%rbp),%rax
movslq -0x1c(%rbp),%rcx
movzbl (%rax,%rcx,1),%esi
lea    0xe5d(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x1c(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x1c(%rbp)
jmp    1147 <dump_hex+0x37>
lea    0xe3f(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<dump_hex>:
push   %rbp
push   %r15
push   %r14
push   %rbx
push   %rax
mov    %esi,%ebp
mov    %rdi,%r15
test   %rdx,%rdx
je     1142 <dump_hex+0x22>
lea    0xec8(%rip),%rdi
mov    %rdx,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
test   %ebp,%ebp
jle    119c <dump_hex+0x7c>
mov    %ebp,%ebp
lea    0xeb6(%rip),%r14
xor    %ebx,%ebx
jmp    117d <dump_hex+0x5d>
cs nopw 0x0(%rax,%rax,1)
nopl   (%rax)
test   $0xf,%bl
je     1190 <dump_hex+0x70>
movzbl (%r15,%rbx,1),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
add    $0x1,%rbx
cmp    %rbx,%rbp
je     119c <dump_hex+0x7c>
test   $0x1,%bl
jne    1160 <dump_hex+0x40>
mov    $0x20,%edi
call   1030 <putchar@plt>
jmp    1160 <dump_hex+0x40>
xchg   %ax,%ax
mov    $0xa,%edi
call   1030 <putchar@plt>
jmp    1165 <dump_hex+0x45>
mov    $0xa,%edi
add    $0x8,%rsp
pop    %rbx
pop    %r14
pop    %r15
pop    %rbp
jmp    1030 <putchar@plt>

LLVM IR (-O0):
@.str = [5 x i8] c"%s: \00"
@.str.1 = [2 x i8] c" \00"
@.str.2 = [2 x i8] c"\0A\00"
@.str.3 = [5 x i8] c"%02x\00"
define void @dump_hex(i8* %0, i32 %1, i8* %2) {
%4 = alloca i8*
%5 = alloca i32
%6 = alloca i8*
%7 = alloca i32
store i8* %0, i8** %4
store i32 %1, i32* %5
store i8* %2, i8** %6
%8 = load i8*, i8** %6
%9 = icmp ne i8* %8, null
br i1 %9, label %10, label %13
10: ; preds = %3
%11 = load i8*, i8** %6
%12 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i8* %11)
br label %13
13: ; preds = %10, %3
store i32 0, i32* %7
br label %14
14: ; preds = %38, %13
%15 = load i32, i32* %7
%16 = load i32, i32* %5
%17 = icmp slt i32 %15, %16
br i1 %17, label %18, label %41
18: ; preds = %14
%19 = load i32, i32* %7
%20 = srem i32 %19, 2
%21 = icmp eq i32 %20, 0
br i1 %21, label %22, label %24
22: ; preds = %18
%23 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
br label %24
24: ; preds = %22, %18
%25 = load i32, i32* %7
%26 = srem i32 %25, 16
%27 = icmp eq i32 %26, 0
br i1 %27, label %28, label %30
28: ; preds = %24
%29 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.2, i64 0, i64 0))
br label %30
30: ; preds = %28, %24
%31 = load i8*, i8** %4
%32 = load i32, i32* %7
%33 = sext i32 %32 to i64
%34 = getelementptr inbounds i8, i8* %31, i64 %33
%35 = load i8, i8* %34
%36 = zext i8 %35 to i32
%37 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.3, i64 0, i64 0), i32 %36)
br label %38
38: ; preds = %30
%39 = load i32, i32* %7
%40 = add nsw i32 %39, 1
store i32 %40, i32* %7
br label %14
41: ; preds = %14
%42 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.2, i64 0, i64 0))
ret void
}

LLVM IR (-O2):
@.str = [5 x i8] c"%s: \00"
@.str.3 = [5 x i8] c"%02x\00"
define void @dump_hex(i8* nocapture %0, i32 %1, i8* %2) {
%4 = icmp eq i8* %2, null
br i1 %4, label %7, label %5
5: ; preds = %3
%6 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i8* %2)
br label %7
7: ; preds = %5, %3
%8 = icmp sgt i32 %1, 0
br i1 %8, label %9, label %30
9: ; preds = %7
%10 = zext i32 %1 to i64
br label %11
11: ; preds = %9, %23
%12 = phi i64 [ 0, %9 ], [ %28, %23 ]
%13 = trunc i64 %12 to i32
%14 = and i32 %13, 1
%15 = icmp eq i32 %14, 0
br i1 %15, label %16, label %18
16: ; preds = %11
%17 = tail call i32 @putchar(i32 32)
br label %18
18: ; preds = %16, %11
%19 = and i32 %13, 15
%20 = icmp eq i32 %19, 0
br i1 %20, label %21, label %23
21: ; preds = %18
%22 = tail call i32 @putchar(i32 10)
br label %23
23: ; preds = %21, %18
%24 = getelementptr inbounds i8, i8* %0, i64 %12
%25 = load i8, i8* %24
%26 = zext i8 %25 to i32
%27 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str.3, i64 0, i64 0), i32 %26)
%28 = add nuw nsw i64 %12, 1
%29 = icmp eq i64 %28, %10
br i1 %29, label %30, label %11
30: ; preds = %23, %7
%31 = tail call i32 @putchar(i32 10)
ret void
}