#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__ strcasecmp(char const *, char *);
int str2bool(const char *p) {
  if (strcasecmp(p, "true") == 0)
    return 1;
  if (strcasecmp(p, "t") == 0)
    return 1;
  if (strcasecmp(p, "on") == 0)
    return 1;
  if (strcasecmp(p, "1") == 0)
    return 1;
  return 0;
}


x86 assembly (clang, -O0):
<str2bool>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x10(%rbp)
mov    -0x10(%rbp),%rdi
lea    0xed9(%rip),%rsi
call   1030 <strcasecmp@plt>
cmp    $0x0,%rax
jne    1142 <str2bool+0x32>
movl   $0x1,-0x4(%rbp)
jmp    11bb <str2bool+0xab>
mov    -0x10(%rbp),%rdi
lea    0xeb8(%rip),%rsi
call   1030 <strcasecmp@plt>
cmp    $0x0,%rax
jne    1168 <str2bool+0x58>
movl   $0x1,-0x4(%rbp)
jmp    11bb <str2bool+0xab>
mov    -0x10(%rbp),%rdi
lea    0xe94(%rip),%rsi
call   1030 <strcasecmp@plt>
cmp    $0x0,%rax
jne    118e <str2bool+0x7e>
movl   $0x1,-0x4(%rbp)
jmp    11bb <str2bool+0xab>
mov    -0x10(%rbp),%rdi
lea    0xe71(%rip),%rsi
call   1030 <strcasecmp@plt>
cmp    $0x0,%rax
jne    11b4 <str2bool+0xa4>
movl   $0x1,-0x4(%rbp)
jmp    11bb <str2bool+0xab>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<str2bool>:
push   %rbp
push   %rbx
push   %rax
mov    %rdi,%rbx
lea    0xee3(%rip),%rsi
call   1030 <strcasecmp@plt>
mov    $0x1,%ebp
test   %rax,%rax
je     116c <str2bool+0x5c>
lea    0xed2(%rip),%rsi
mov    %rbx,%rdi
call   1030 <strcasecmp@plt>
test   %rax,%rax
je     116c <str2bool+0x5c>
lea    0xec0(%rip),%rsi
mov    %rbx,%rdi
call   1030 <strcasecmp@plt>
test   %rax,%rax
je     116c <str2bool+0x5c>
lea    0xeaf(%rip),%rsi
mov    %rbx,%rdi
call   1030 <strcasecmp@plt>
xor    %ebp,%ebp
test   %rax,%rax
sete   %bpl
mov    %ebp,%eax
add    $0x8,%rsp
pop    %rbx
pop    %rbp
ret

LLVM IR (-O0):
@.str = [5 x i8] c"true\00"
@.str.1 = [2 x i8] c"t\00"
@.str.2 = [3 x i8] c"on\00"
@.str.3 = [2 x i8] c"1\00"
define i32 @str2bool(i8* %0) {
%2 = alloca i32
%3 = alloca i8*
store i8* %0, i8** %3
%4 = load i8*, i8** %3
%5 = call i64 @strcasecmp(i8* %4, i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0))
%6 = icmp eq i64 %5, 0
br i1 %6, label %7, label %8
7: ; preds = %1
store i32 1, i32* %2
br label %24
8: ; preds = %1
%9 = load i8*, i8** %3
%10 = call i64 @strcasecmp(i8* %9, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
%11 = icmp eq i64 %10, 0
br i1 %11, label %12, label %13
12: ; preds = %8
store i32 1, i32* %2
br label %24
13: ; preds = %8
%14 = load i8*, i8** %3
%15 = call i64 @strcasecmp(i8* %14, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0))
%16 = icmp eq i64 %15, 0
br i1 %16, label %17, label %18
17: ; preds = %13
store i32 1, i32* %2
br label %24
18: ; preds = %13
%19 = load i8*, i8** %3
%20 = call i64 @strcasecmp(i8* %19, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.3, i64 0, i64 0))
%21 = icmp eq i64 %20, 0
br i1 %21, label %22, label %23
22: ; preds = %18
store i32 1, i32* %2
br label %24
23: ; preds = %18
store i32 0, i32* %2
br label %24
24: ; preds = %23, %22, %17, %12, %7
%25 = load i32, i32* %2
ret i32 %25
}

LLVM IR (-O2):
@.str = [5 x i8] c"true\00"
@.str.1 = [2 x i8] c"t\00"
@.str.2 = [3 x i8] c"on\00"
@.str.3 = [2 x i8] c"1\00"
define i32 @str2bool(i8* nocapture %0) {
%2 = tail call i64 @strcasecmp(i8* %0, i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str, i64 0, i64 0))
%3 = icmp eq i64 %2, 0
br i1 %3, label %14, label %4
4: ; preds = %1
%5 = tail call i64 @strcasecmp(i8* %0, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
%6 = icmp eq i64 %5, 0
br i1 %6, label %14, label %7
7: ; preds = %4
%8 = tail call i64 @strcasecmp(i8* %0, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0))
%9 = icmp eq i64 %8, 0
br i1 %9, label %14, label %10
10: ; preds = %7
%11 = tail call i64 @strcasecmp(i8* %0, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.3, i64 0, i64 0))
%12 = icmp eq i64 %11, 0
%13 = zext i1 %12 to i32
br label %14
14: ; preds = %10, %7, %4, %1
%15 = phi i32 [ 1, %1 ], [ 1, %4 ], [ 1, %7 ], [ %13, %10 ]
ret i32 %15
}