#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*/ kprintf(char *, ...);
void hexdump(void *buffer, int len) {
  int i;
  char *buf = buffer;
  for (i = 0; i < len; i++) {
    if (i && ((i % 16) == 0))
      kprintf("\n");
    kprintf("%02X ", buf[i] & 0xFF);
  }
  kprintf("\n");
}


x86 assembly (clang, -O0):
<hexdump>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
mov    -0x8(%rbp),%rax
mov    %rax,-0x18(%rbp)
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
cmp    -0xc(%rbp),%eax
jge    1194 <hexdump+0x84>
cmpl   $0x0,-0x10(%rbp)
je     1166 <hexdump+0x56>
mov    -0x10(%rbp),%eax
mov    $0x10,%ecx
cltd
idiv   %ecx
cmp    $0x0,%edx
jne    1166 <hexdump+0x56>
lea    0xea1(%rip),%rdi
mov    $0x0,%al
call   1030 <kprintf@plt>
mov    -0x18(%rbp),%rax
movslq -0x10(%rbp),%rcx
movsbl (%rax,%rcx,1),%esi
and    $0xff,%esi
lea    0xe83(%rip),%rdi
mov    $0x0,%al
call   1030 <kprintf@plt>
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    112e <hexdump+0x1e>
lea    0xe65(%rip),%rdi
mov    $0x0,%al
call   1030 <kprintf@plt>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<hexdump>:
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
test   %esi,%esi
jle    1173 <hexdump+0x63>
mov    %rdi,%r12
mov    %esi,%r13d
lea    0xed6(%rip),%r14
lea    0xed1(%rip),%r15
xor    %ebx,%ebx
jmp    1158 <hexdump+0x48>
cs nopw 0x0(%rax,%rax,1)
nop
movzbl (%r12,%rbx,1),%esi
mov    %r15,%rdi
xor    %eax,%eax
call   1030 <kprintf@plt>
add    $0x1,%rbx
cmp    %rbx,%r13
je     1173 <hexdump+0x63>
test   %rbx,%rbx
je     1140 <hexdump+0x30>
mov    %ebx,%eax
and    $0xf,%eax
test   %rax,%rax
jne    1140 <hexdump+0x30>
mov    %r14,%rdi
xor    %eax,%eax
call   1030 <kprintf@plt>
jmp    1140 <hexdump+0x30>
lea    0xe86(%rip),%rdi
xor    %eax,%eax
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
jmp    1030 <kprintf@plt>

LLVM IR (-O0):
@.str = [2 x i8] c"\0A\00"
@.str.1 = [6 x i8] c"%02X \00"
define void @hexdump(i8* %0, i32 %1) {
%3 = alloca i8*
%4 = alloca i32
%5 = alloca i32
%6 = alloca i8*
store i8* %0, i8** %3
store i32 %1, i32* %4
%7 = load i8*, i8** %3
store i8* %7, i8** %6
store i32 0, i32* %5
br label %8
8: ; preds = %30, %2
%9 = load i32, i32* %5
%10 = load i32, i32* %4
%11 = icmp slt i32 %9, %10
br i1 %11, label %12, label %33
12: ; preds = %8
%13 = load i32, i32* %5
%14 = icmp ne i32 %13, 0
br i1 %14, label %15, label %21
15: ; preds = %12
%16 = load i32, i32* %5
%17 = srem i32 %16, 16
%18 = icmp eq i32 %17, 0
br i1 %18, label %19, label %21
19: ; preds = %15
%20 = call i32 (i8*, ...) @kprintf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
br label %21
21: ; preds = %19, %15, %12
%22 = load i8*, i8** %6
%23 = load i32, i32* %5
%24 = sext i32 %23 to i64
%25 = getelementptr inbounds i8, i8* %22, i64 %24
%26 = load i8, i8* %25
%27 = sext i8 %26 to i32
%28 = and i32 %27, 255
%29 = call i32 (i8*, ...) @kprintf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), i32 %28)
br label %30
30: ; preds = %21
%31 = load i32, i32* %5
%32 = add nsw i32 %31, 1
store i32 %32, i32* %5
br label %8
33: ; preds = %8
%34 = call i32 (i8*, ...) @kprintf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
ret void
}

LLVM IR (-O2):
@.str = [2 x i8] c"\0A\00"
@.str.1 = [6 x i8] c"%02X \00"
define void @hexdump(i8* nocapture %0, i32 %1) {
%3 = icmp sgt i32 %1, 0
br i1 %3, label %4, label %21
4: ; preds = %2
%5 = zext i32 %1 to i64
br label %6
6: ; preds = %4, %14
%7 = phi i64 [ 0, %4 ], [ %19, %14 ]
%8 = icmp ne i64 %7, 0
%9 = and i64 %7, 15
%10 = icmp eq i64 %9, 0
%11 = and i1 %8, %10
br i1 %11, label %12, label %14
12: ; preds = %6
%13 = tail call i32 (i8*, ...) @kprintf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
br label %14
14: ; preds = %12, %6
%15 = getelementptr inbounds i8, i8* %0, i64 %7
%16 = load i8, i8* %15
%17 = zext i8 %16 to i32
%18 = tail call i32 (i8*, ...) @kprintf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), i32 %17)
%19 = add nuw nsw i64 %7, 1
%20 = icmp eq i64 %19, %5
br i1 %20, label %21, label %6
21: ; preds = %14, %2
%22 = tail call i32 (i8*, ...) @kprintf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
ret void
}