#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 *, ...);
int print_hex(unsigned char *buf, int len) {
  for (int i = 0; i < len; i++)
    printf("%02x", buf[i]);
  printf("\n");
  return (0);
}


x86 assembly (clang, -O0):
<print_hex>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
cmp    -0xc(%rbp),%eax
jge    115a <print_hex+0x4a>
mov    -0x8(%rbp),%rax
movslq -0x10(%rbp),%rcx
movzbl (%rax,%rcx,1),%esi
lea    0xebb(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    1126 <print_hex+0x16>
lea    0xea4(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<print_hex>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
test   %esi,%esi
jle    1158 <print_hex+0x38>
mov    %rdi,%r15
mov    %esi,%r12d
lea    0xec7(%rip),%r14
xor    %ebx,%ebx
nopl   0x0(%rax,%rax,1)
movzbl (%r15,%rbx,1),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
add    $0x1,%rbx
cmp    %rbx,%r12
jne    1140 <print_hex+0x20>
mov    $0xa,%edi
call   1030 <putchar@plt>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

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

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