#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 trim_cr(char *s) {
  int n = 0;
  while (s[strlen(s) - 1] == '\n') {
    s[strlen(s) - 1] = 0;
    n++;
  }
  return n;
}


x86 assembly (clang, -O0):
<trim_cr>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
movl   $0x0,-0xc(%rbp)
mov    -0x8(%rbp),%rax
mov    %rax,-0x18(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x18(%rbp),%rax
sub    $0x1,%ecx
movslq %ecx,%rcx
movsbl (%rax,%rcx,1),%eax
cmp    $0xa,%eax
jne    117c <trim_cr+0x6c>
mov    -0x8(%rbp),%rax
mov    %rax,-0x20(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x20(%rbp),%rax
sub    $0x1,%ecx
movslq %ecx,%rcx
movb   $0x0,(%rax,%rcx,1)
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    1123 <trim_cr+0x13>
mov    -0xc(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<trim_cr>:
push   %rbp
push   %rbx
push   %rax
mov    %rdi,%rbx
call   1030 <strlen@plt>
cltq
xor    %ebp,%ebp
cmpb   $0xa,-0x1(%rax,%rbx,1)
jne    1153 <trim_cr+0x43>
xor    %ebp,%ebp
nopl   0x0(%rax,%rax,1)
mov    %rbx,%rdi
call   1030 <strlen@plt>
cltq
movb   $0x0,-0x1(%rax,%rbx,1)
add    $0x1,%ebp
mov    %rbx,%rdi
call   1030 <strlen@plt>
cltq
cmpb   $0xa,-0x1(%rax,%rbx,1)
je     1130 <trim_cr+0x20>
mov    %ebp,%eax
add    $0x8,%rsp
pop    %rbx
pop    %rbp
ret

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

LLVM IR (-O2):
define i32 @trim_cr(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = add nsw i32 %2, -1
%4 = sext i32 %3 to i64
%5 = getelementptr inbounds i8, i8* %0, i64 %4
%6 = load i8, i8* %5
%7 = icmp eq i8 %6, 10
br i1 %7, label %8, label %21
8: ; preds = %1, %8
%9 = phi i32 [ %14, %8 ], [ 0, %1 ]
%10 = tail call i32 @strlen(i8* %0)
%11 = add nsw i32 %10, -1
%12 = sext i32 %11 to i64
%13 = getelementptr inbounds i8, i8* %0, i64 %12
store i8 0, i8* %13
%14 = add nuw nsw i32 %9, 1
%15 = tail call i32 @strlen(i8* %0)
%16 = add nsw i32 %15, -1
%17 = sext i32 %16 to i64
%18 = getelementptr inbounds i8, i8* %0, i64 %17
%19 = load i8, i8* %18
%20 = icmp eq i8 %19, 10
br i1 %20, label %8, label %21
21: ; preds = %8, %1
%22 = phi i32 [ 0, %1 ], [ %14, %8 ]
ret i32 %22
}