#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 *);
char *chop(char *src) {
  char *p = src + strlen(src) - 1;
  while (p >= src) {
    if (*p == '\n' || *p == '\r') {
      *p-- = 0;
    } else {
      break;
    }
  }
  return (src);
}


x86 assembly (clang, -O0):
<chop>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rax
mov    %rax,-0x18(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x18(%rbp),%rax
movslq %ecx,%rcx
add    %rcx,%rax
add    $0xffffffffffffffff,%rax
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rax
cmp    -0x8(%rbp),%rax
jb     1190 <chop+0x80>
mov    -0x10(%rbp),%rax
movsbl (%rax),%eax
cmp    $0xa,%eax
je     116f <chop+0x5f>
mov    -0x10(%rbp),%rax
movsbl (%rax),%eax
cmp    $0xd,%eax
jne    1186 <chop+0x76>
mov    -0x10(%rbp),%rax
mov    %rax,%rcx
add    $0xffffffffffffffff,%rcx
mov    %rcx,-0x10(%rbp)
movb   $0x0,(%rax)
jmp    118b <chop+0x7b>
jmp    1190 <chop+0x80>
jmp    1141 <chop+0x31>
mov    -0x8(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<chop>:
push   %rbx
mov    %rdi,%rbx
call   1030 <strlen@plt>
cltq
add    %rbx,%rax
add    $0xffffffffffffffff,%rax
jmp    1137 <chop+0x27>
cs nopw 0x0(%rax,%rax,1)
xchg   %ax,%ax
movb   $0x0,(%rax)
add    $0xffffffffffffffff,%rax
cmp    %rbx,%rax
jb     1149 <chop+0x39>
movzbl (%rax),%ecx
cmp    $0xd,%cl
je     1130 <chop+0x20>
cmp    $0xa,%cl
je     1130 <chop+0x20>
mov    %rbx,%rax
pop    %rbx
ret

LLVM IR (-O0):
define i8* @chop(i8* %0) {
%2 = alloca i8*
%3 = alloca i8*
store i8* %0, i8** %2
%4 = load i8*, i8** %2
%5 = load i8*, i8** %2
%6 = call i32 @strlen(i8* %5)
%7 = sext i32 %6 to i64
%8 = getelementptr inbounds i8, i8* %4, i64 %7
%9 = getelementptr inbounds i8, i8* %8, i64 -1
store i8* %9, i8** %3
br label %10
10: ; preds = %28, %1
%11 = load i8*, i8** %3
%12 = load i8*, i8** %2
%13 = icmp uge i8* %11, %12
br i1 %13, label %14, label %29
14: ; preds = %10
%15 = load i8*, i8** %3
%16 = load i8, i8* %15
%17 = sext i8 %16 to i32
%18 = icmp eq i32 %17, 10
br i1 %18, label %24, label %19
19: ; preds = %14
%20 = load i8*, i8** %3
%21 = load i8, i8* %20
%22 = sext i8 %21 to i32
%23 = icmp eq i32 %22, 13
br i1 %23, label %24, label %27
24: ; preds = %19, %14
%25 = load i8*, i8** %3
%26 = getelementptr inbounds i8, i8* %25, i32 -1
store i8* %26, i8** %3
store i8 0, i8* %25
br label %28
27: ; preds = %19
br label %29
28: ; preds = %24
br label %10
29: ; preds = %27, %10
%30 = load i8*, i8** %2
ret i8* %30
}

LLVM IR (-O2):
define i8* @chop(i8* returned %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = sext i32 %2 to i64
%4 = getelementptr inbounds i8, i8* %0, i64 %3
%5 = getelementptr inbounds i8, i8* %4, i64 -1
%6 = icmp ult i8* %5, %0
br i1 %6, label %13, label %7
7: ; preds = %1, %10
%8 = phi i8* [ %11, %10 ], [ %5, %1 ]
%9 = load i8, i8* %8
switch i8 %9, label %13 [
i8 10, label %10
i8 13, label %10
]
10: ; preds = %7, %7
store i8 0, i8* %8
%11 = getelementptr inbounds i8, i8* %8, i64 -1
%12 = icmp ult i8* %11, %0
br i1 %12, label %13, label %7
13: ; preds = %10, %7, %1
ret i8* %0
}