#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 strlen(char *);
int BinStrToInt(char *str) {
  int c, n;
  for (c = n = 0; c < strlen(str); c++) {
    n <<= 1;
    n |= str[c] == '1' ? 1 : 0;
  }
  return n;
}


x86 assembly (clang, -O0):
<BinStrToInt>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
movl   $0x0,-0x10(%rbp)
movl   $0x0,-0xc(%rbp)
mov    -0xc(%rbp),%eax
mov    %eax,-0x14(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x14(%rbp),%eax
cmp    %ecx,%eax
jge    117c <BinStrToInt+0x6c>
mov    -0x10(%rbp),%eax
shl    $0x1,%eax
mov    %eax,-0x10(%rbp)
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
movsbl (%rax,%rcx,1),%edx
xor    %eax,%eax
mov    $0x1,%ecx
cmp    $0x31,%edx
cmove  %ecx,%eax
or     -0x10(%rbp),%eax
mov    %eax,-0x10(%rbp)
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    112a <BinStrToInt+0x1a>
mov    -0x10(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<BinStrToInt>:
push   %r15
push   %r14
push   %rbx
mov    %rdi,%r14
call   1030 <strlen@plt>
test   %eax,%eax
jle    1153 <BinStrToInt+0x43>
xor    %ebx,%ebx
xor    %r15d,%r15d
cs nopw 0x0(%rax,%rax,1)
xor    %eax,%eax
cmpb   $0x31,(%r14,%rbx,1)
sete   %al
lea    (%rax,%r15,2),%r15d
add    $0x1,%rbx
mov    %r14,%rdi
call   1030 <strlen@plt>
cltq
cmp    %rax,%rbx
jl     1130 <BinStrToInt+0x20>
jmp    1156 <BinStrToInt+0x46>
xor    %r15d,%r15d
mov    %r15d,%eax
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
define i32 @BinStrToInt(i8* %0) {
%2 = alloca i8*
%3 = alloca i32
%4 = alloca i32
store i8* %0, i8** %2
store i32 0, i32* %4
store i32 0, i32* %3
br label %5
5: ; preds = %24, %1
%6 = load i32, i32* %3
%7 = load i8*, i8** %2
%8 = call i32 @strlen(i8* %7)
%9 = icmp slt i32 %6, %8
br i1 %9, label %10, label %27
10: ; preds = %5
%11 = load i32, i32* %4
%12 = shl i32 %11, 1
store i32 %12, i32* %4
%13 = load i8*, i8** %2
%14 = load i32, i32* %3
%15 = sext i32 %14 to i64
%16 = getelementptr inbounds i8, i8* %13, i64 %15
%17 = load i8, i8* %16
%18 = sext i8 %17 to i32
%19 = icmp eq i32 %18, 49
%20 = zext i1 %19 to i64
%21 = select i1 %19, i32 1, i32 0
%22 = load i32, i32* %4
%23 = or i32 %22, %21
store i32 %23, i32* %4
br label %24
24: ; preds = %10
%25 = load i32, i32* %3
%26 = add nsw i32 %25, 1
store i32 %26, i32* %3
br label %5
27: ; preds = %5
%28 = load i32, i32* %4
ret i32 %28
}

LLVM IR (-O2):
define i32 @BinStrToInt(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = icmp sgt i32 %2, 0
br i1 %3, label %4, label %17
4: ; preds = %1, %4
%5 = phi i64 [ %13, %4 ], [ 0, %1 ]
%6 = phi i32 [ %12, %4 ], [ 0, %1 ]
%7 = shl i32 %6, 1
%8 = getelementptr inbounds i8, i8* %0, i64 %5
%9 = load i8, i8* %8
%10 = icmp eq i8 %9, 49
%11 = zext i1 %10 to i32
%12 = or i32 %7, %11
%13 = add nuw nsw i64 %5, 1
%14 = tail call i32 @strlen(i8* %0)
%15 = sext i32 %14 to i64
%16 = icmp slt i64 %13, %15
br i1 %16, label %4, label %17
17: ; preds = %4, %1
%18 = phi i32 [ 0, %1 ], [ %12, %4 ]
ret i32 %18
}