#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 *, char, char);
void print_hex(char *buf, int len) {
  int i;
  for (i = 0; i < len; i++) {
    printf("%02hhx%c", buf[i], i == len - 1 ? '\n' : ':');
  }
}


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    1175 <print_hex+0x65>
mov    -0x8(%rbp),%rax
movslq -0x10(%rbp),%rcx
mov    (%rax,%rcx,1),%cl
mov    -0x10(%rbp),%esi
mov    -0xc(%rbp),%edi
sub    $0x1,%edi
mov    $0x3a,%eax
mov    $0xa,%edx
cmp    %edi,%esi
cmove  %edx,%eax
lea    0xea4(%rip),%rdi
movsbl %cl,%esi
movsbl %al,%edx
call   1030 <printf@plt>
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    1126 <print_hex+0x16>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<print_hex>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
push   %rax
test   %esi,%esi
jle    1161 <print_hex+0x51>
mov    %rdi,%r15
lea    -0x1(%rsi),%r12d
mov    %esi,%r13d
xor    %ebx,%ebx
mov    $0xa,%ebp
lea    0xec9(%rip),%r14
nopw   0x0(%rax,%rax,1)
movsbl (%r15,%rbx,1),%esi
cmp    %rbx,%r12
mov    $0x3a,%edx
cmove  %ebp,%edx
mov    %r14,%rdi
call   1030 <printf@plt>
add    $0x1,%rbx
cmp    %rbx,%r13
jne    1140 <print_hex+0x30>
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret

LLVM IR (-O0):
@.str = [9 x i8] c"%02hhx%c\00"
define void @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 = %24, %2
%7 = load i32, i32* %5
%8 = load i32, i32* %4
%9 = icmp slt i32 %7, %8
br i1 %9, label %10, label %27
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 = load i32, i32* %5
%17 = load i32, i32* %4
%18 = sub nsw i32 %17, 1
%19 = icmp eq i32 %16, %18
%20 = zext i1 %19 to i64
%21 = select i1 %19, i32 10, i32 58
%22 = trunc i32 %21 to i8
%23 = call i32 @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str, i64 0, i64 0), i8 signext %15, i8 signext %22)
br label %24
24: ; preds = %10
%25 = load i32, i32* %5
%26 = add nsw i32 %25, 1
store i32 %26, i32* %5
br label %6
27: ; preds = %6
ret void
}

LLVM IR (-O2):
@.str = [9 x i8] c"%02hhx%c\00"
define void @print_hex(i8* nocapture %0, i32 %1) {
%3 = icmp sgt i32 %1, 0
br i1 %3, label %4, label %17
4: ; preds = %2
%5 = add nsw i32 %1, -1
%6 = zext i32 %5 to i64
%7 = zext i32 %1 to i64
br label %8
8: ; preds = %4, %8
%9 = phi i64 [ 0, %4 ], [ %15, %8 ]
%10 = getelementptr inbounds i8, i8* %0, i64 %9
%11 = load i8, i8* %10
%12 = icmp eq i64 %9, %6
%13 = select i1 %12, i8 10, i8 58
%14 = tail call i32 @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str, i64 0, i64 0), i8 signext %11, i8 signext %13)
%15 = add nuw nsw i64 %9, 1
%16 = icmp eq i64 %15, %7
br i1 %16, label %17, label %8
17: ; preds = %8, %2
ret void
}