#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__ strchr(char const *, char const);
size_t strcspn(const char *src, const char *reg) {
  size_t ret = 0;
  while (*src) {
    if (strchr(reg, *src))
      return ret;
    else
      src++, ret++;
  }
  return ret;
}


x86 assembly (clang, -O0):
<strcspn>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x10(%rbp)
mov    %rsi,-0x18(%rbp)
movq   $0x0,-0x20(%rbp)
mov    -0x10(%rbp),%rax
cmpb   $0x0,(%rax)
je     1179 <strcspn+0x69>
mov    -0x18(%rbp),%rdi
mov    -0x10(%rbp),%rax
movsbl (%rax),%esi
call   1030 <strchr@plt>
cmp    $0x0,%rax
je     115c <strcspn+0x4c>
mov    -0x20(%rbp),%rax
mov    %rax,-0x8(%rbp)
jmp    1181 <strcspn+0x71>
mov    -0x10(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x10(%rbp)
mov    -0x20(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x20(%rbp)
jmp    1128 <strcspn+0x18>
mov    -0x20(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<strcspn>:
push   %r15
push   %r14
push   %rbx
mov    (%rdi),%al
test   %al,%al
je     1150 <strcspn+0x40>
mov    %rsi,%r14
mov    %rdi,%r15
xor    %ebx,%ebx
cs nopw 0x0(%rax,%rax,1)
nopl   (%rax)
movsbl %al,%esi
mov    %r14,%rdi
call   1030 <strchr@plt>
test   %rax,%rax
jne    1152 <strcspn+0x42>
movzbl 0x1(%r15,%rbx,1),%eax
add    $0x1,%rbx
test   %al,%al
jne    1130 <strcspn+0x20>
jmp    1152 <strcspn+0x42>
xor    %ebx,%ebx
mov    %rbx,%rax
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
define i64 @strcspn(i8* %0, i8* %1) {
%3 = alloca i64
%4 = alloca i8*
%5 = alloca i8*
%6 = alloca i64
store i8* %0, i8** %4
store i8* %1, i8** %5
store i64 0, i64* %6
br label %7
7: ; preds = %24, %2
%8 = load i8*, i8** %4
%9 = load i8, i8* %8
%10 = icmp ne i8 %9, 0
br i1 %10, label %11, label %25
11: ; preds = %7
%12 = load i8*, i8** %5
%13 = load i8*, i8** %4
%14 = load i8, i8* %13
%15 = call i64 @strchr(i8* %12, i8 signext %14)
%16 = icmp ne i64 %15, 0
br i1 %16, label %17, label %19
17: ; preds = %11
%18 = load i64, i64* %6
store i64 %18, i64* %3
br label %27
19: ; preds = %11
%20 = load i8*, i8** %4
%21 = getelementptr inbounds i8, i8* %20, i32 1
store i8* %21, i8** %4
%22 = load i64, i64* %6
%23 = add i64 %22, 1
store i64 %23, i64* %6
br label %24
24: ; preds = %19
br label %7
25: ; preds = %7
%26 = load i64, i64* %6
store i64 %26, i64* %3
br label %27
27: ; preds = %25, %17
%28 = load i64, i64* %3
ret i64 %28
}

LLVM IR (-O2):
define i64 @strcspn(i8* nocapture %0, i8* %1) {
%3 = load i8, i8* %0
%4 = icmp eq i8 %3, 0
br i1 %4, label %16, label %5
5: ; preds = %2, %11
%6 = phi i8 [ %14, %11 ], [ %3, %2 ]
%7 = phi i64 [ %13, %11 ], [ 0, %2 ]
%8 = phi i8* [ %12, %11 ], [ %0, %2 ]
%9 = tail call i64 @strchr(i8* %1, i8 signext %6)
%10 = icmp eq i64 %9, 0
br i1 %10, label %11, label %16
11: ; preds = %5
%12 = getelementptr inbounds i8, i8* %8, i64 1
%13 = add i64 %7, 1
%14 = load i8, i8* %12
%15 = icmp eq i8 %14, 0
br i1 %15, label %16, label %5
16: ; preds = %5, %11, %2
%17 = phi i64 [ 0, %2 ], [ %13, %11 ], [ %7, %5 ]
ret i64 %17
}