#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 */
typedef unsigned char uint8_t;

/* Variables and functions */
int /*<<< orphan*/ printf(char *, ...);
void phex(uint8_t *str) {
  uint8_t len = 16;
  unsigned char i;
  for (i = 0; i < len; ++i)
    printf("%.2x", str[i]);
  printf("\n");
}


x86 assembly (clang, -O0):
<phex>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
movb   $0x10,-0x9(%rbp)
movb   $0x0,-0xa(%rbp)
movzbl -0xa(%rbp),%eax
movzbl -0x9(%rbp),%ecx
cmp    %ecx,%eax
jge    115b <phex+0x4b>
mov    -0x8(%rbp),%rax
movzbl -0xa(%rbp),%ecx
movzbl (%rax,%rcx,1),%esi
lea    0xeb9(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0xa(%rbp),%al
add    $0x1,%al
mov    %al,-0xa(%rbp)
jmp    1124 <phex+0x14>
lea    0xea3(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<phex>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%rbx
movzbl (%rdi),%esi
lea    0xecf(%rip),%r14
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x1(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x2(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x3(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x4(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x5(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x6(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x7(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x8(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0x9(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0xa(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0xb(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0xc(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0xd(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0xe(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
movzbl 0xf(%rbx),%esi
mov    %r14,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    $0xa,%edi
add    $0x8,%rsp
pop    %rbx
pop    %r14
jmp    1030 <putchar@plt>

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

LLVM IR (-O2):
@.str = [5 x i8] c"%.2x\00"
define void @phex(i8* nocapture %0) {
%2 = load i8, i8* %0
%3 = zext i8 %2 to i32
%4 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %3)
%5 = getelementptr inbounds i8, i8* %0, i64 1
%6 = load i8, i8* %5
%7 = zext i8 %6 to i32
%8 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %7)
%9 = getelementptr inbounds i8, i8* %0, i64 2
%10 = load i8, i8* %9
%11 = zext i8 %10 to i32
%12 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %11)
%13 = getelementptr inbounds i8, i8* %0, i64 3
%14 = load i8, i8* %13
%15 = zext i8 %14 to i32
%16 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %15)
%17 = getelementptr inbounds i8, i8* %0, i64 4
%18 = load i8, i8* %17
%19 = zext i8 %18 to i32
%20 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %19)
%21 = getelementptr inbounds i8, i8* %0, i64 5
%22 = load i8, i8* %21
%23 = zext i8 %22 to i32
%24 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %23)
%25 = getelementptr inbounds i8, i8* %0, i64 6
%26 = load i8, i8* %25
%27 = zext i8 %26 to i32
%28 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %27)
%29 = getelementptr inbounds i8, i8* %0, i64 7
%30 = load i8, i8* %29
%31 = zext i8 %30 to i32
%32 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %31)
%33 = getelementptr inbounds i8, i8* %0, i64 8
%34 = load i8, i8* %33
%35 = zext i8 %34 to i32
%36 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %35)
%37 = getelementptr inbounds i8, i8* %0, i64 9
%38 = load i8, i8* %37
%39 = zext i8 %38 to i32
%40 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %39)
%41 = getelementptr inbounds i8, i8* %0, i64 10
%42 = load i8, i8* %41
%43 = zext i8 %42 to i32
%44 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %43)
%45 = getelementptr inbounds i8, i8* %0, i64 11
%46 = load i8, i8* %45
%47 = zext i8 %46 to i32
%48 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %47)
%49 = getelementptr inbounds i8, i8* %0, i64 12
%50 = load i8, i8* %49
%51 = zext i8 %50 to i32
%52 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %51)
%53 = getelementptr inbounds i8, i8* %0, i64 13
%54 = load i8, i8* %53
%55 = zext i8 %54 to i32
%56 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %55)
%57 = getelementptr inbounds i8, i8* %0, i64 14
%58 = load i8, i8* %57
%59 = zext i8 %58 to i32
%60 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %59)
%61 = getelementptr inbounds i8, i8* %0, i64 15
%62 = load i8, i8* %61
%63 = zext i8 %62 to i32
%64 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0), i32 %63)
%65 = tail call i32 @putchar(i32 10)
ret void
}