#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 */
scalar_t__ atoi(char *);
char *log2(double);
int /*<<< orphan*/ printf(char *, ...);
int main(int argc, char *argv[]) {
  if (argc < 2) {
    printf("Please provide a numeric parameter, e.g.:\n\t");
    printf("%s 8\n", argv[0]);
    return 0;
  }
  printf("%lf\n", log2((double)atoi(argv[1])));
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
cmpl   $0x2,-0x8(%rbp)
jge    117f <main+0x4f>
lea    0xea9(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x10(%rbp),%rax
mov    (%rax),%rsi
lea    0xec0(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
movl   $0x0,-0x4(%rbp)
jmp    11ae <main+0x7e>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1050 <atoi@plt>
cvtsi2sd %rax,%xmm0
call   1030 <log2@plt>
mov    %rax,%rsi
lea    0xe92(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
mov    %rsi,%rbx
cmp    $0x1,%edi
jg     1153 <main+0x23>
lea    0xec0(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    (%rbx),%rsi
lea    0xedb(%rip),%rdi
jmp    1170 <main+0x40>
mov    0x8(%rbx),%rdi
call   1050 <atoi@plt>
cvtsi2sd %rax,%xmm0
call   1030 <log2@plt>
lea    0xec5(%rip),%rdi
mov    %rax,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
pop    %rbx
ret

LLVM IR (-O0):
@.str = [44 x i8] c"Please provide a numeric parameter, e.g.:\0A\09\00"
@.str.1 = [6 x i8] c"%s 8\0A\00"
@.str.2 = [5 x i8] c"%lf\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%6 = load i32, i32* %4
%7 = icmp slt i32 %6, 2
br i1 %7, label %8, label %14
8: ; preds = %2
%9 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([44 x i8], [44 x i8]* @.str, i64 0, i64 0))
%10 = load i8**, i8*** %5
%11 = getelementptr inbounds i8*, i8** %10, i64 0
%12 = load i8*, i8** %11
%13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), i8* %12)
store i32 0, i32* %3
br label %22
14: ; preds = %2
%15 = load i8**, i8*** %5
%16 = getelementptr inbounds i8*, i8** %15, i64 1
%17 = load i8*, i8** %16
%18 = call i64 @atoi(i8* %17)
%19 = sitofp i64 %18 to double
%20 = call i8* @log2(double %19)
%21 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.2, i64 0, i64 0), i8* %20)
store i32 0, i32* %3
br label %22
22: ; preds = %14, %8
%23 = load i32, i32* %3
ret i32 %23
}

LLVM IR (-O2):
@.str = [44 x i8] c"Please provide a numeric parameter, e.g.:\0A\09\00"
@.str.1 = [6 x i8] c"%s 8\0A\00"
@.str.2 = [5 x i8] c"%lf\0A\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp slt i32 %0, 2
br i1 %3, label %4, label %8
4: ; preds = %2
%5 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([44 x i8], [44 x i8]* @.str, i64 0, i64 0))
%6 = load i8*, i8** %1
%7 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0), i8* %6)
br label %15
8: ; preds = %2
%9 = getelementptr inbounds i8*, i8** %1, i64 1
%10 = load i8*, i8** %9
%11 = tail call i64 @atoi(i8* %10)
%12 = sitofp i64 %11 to double
%13 = tail call i8* @log2(double %12)
%14 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @.str.2, i64 0, i64 0), i8* %13)
br label %15
15: ; preds = %8, %4
ret i32 0
}