#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*/ sprintf(char *, char *, unsigned char);
char *int_to_hex(unsigned char *input, char *buf, int len) {
  int i;
  for (i = 0; i < len; i++)
    sprintf(buf + i * 2, "%.2x", input[i]);
  *(buf + len * 2) = '\0';
  return buf;
}


x86 assembly (clang, -O0):
<int_to_hex>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %edx,-0x14(%rbp)
movl   $0x0,-0x18(%rbp)
mov    -0x18(%rbp),%eax
cmp    -0x14(%rbp),%eax
jge    116b <int_to_hex+0x5b>
mov    -0x10(%rbp),%rdi
mov    -0x18(%rbp),%eax
shl    $0x1,%eax
cltq
add    %rax,%rdi
mov    -0x8(%rbp),%rax
movslq -0x18(%rbp),%rcx
lea    0xeac(%rip),%rsi
movzbl (%rax,%rcx,1),%edx
call   1030 <sprintf@plt>
mov    -0x18(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x18(%rbp)
jmp    112a <int_to_hex+0x1a>
mov    -0x10(%rbp),%rax
mov    -0x14(%rbp),%ecx
shl    $0x1,%ecx
movslq %ecx,%rcx
movb   $0x0,(%rax,%rcx,1)
mov    -0x10(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<int_to_hex>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
push   %rax
mov    %edx,%r15d
mov    %rsi,(%rsp)
test   %edx,%edx
jle    115e <int_to_hex+0x4e>
mov    %rdi,%r13
mov    %r15d,%ebx
xor    %r14d,%r14d
lea    0xeca(%rip),%r12
mov    (%rsp),%rbp
nopw   0x0(%rax,%rax,1)
movzbl 0x0(%r13,%r14,1),%edx
mov    %rbp,%rdi
mov    %r12,%rsi
call   1030 <sprintf@plt>
add    $0x1,%r14
add    $0x2,%rbp
cmp    %r14,%rbx
jne    1140 <int_to_hex+0x30>
movslq %r15d,%rcx
mov    (%rsp),%rax
movb   $0x0,(%rax,%rcx,2)
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret

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

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