#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 *);
void remove_trailing_whitespace(char *str) {
  int len = strlen(str);
  while (len >= 1 && str[len - 1] == '\n') {
    str[--len] = 0;
  }
}


x86 assembly (clang, -O0):
<remove_trailing_whitespace>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,-0xc(%rbp)
xor    %eax,%eax
cmpl   $0x1,-0xc(%rbp)
mov    %al,-0xd(%rbp)
jl     1151 <remove_trailing_whitespace+0x41>
mov    -0x8(%rbp),%rax
mov    -0xc(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsbl (%rax,%rcx,1),%eax
cmp    $0xa,%eax
sete   %al
mov    %al,-0xd(%rbp)
mov    -0xd(%rbp),%al
test   $0x1,%al
jne    1161 <remove_trailing_whitespace+0x51>
jmp    117a <remove_trailing_whitespace+0x6a>
mov    -0x8(%rbp),%rax
mov    -0xc(%rbp),%ecx
add    $0xffffffff,%ecx
mov    %ecx,-0xc(%rbp)
movslq %ecx,%rcx
movb   $0x0,(%rax,%rcx,1)
jmp    1128 <remove_trailing_whitespace+0x18>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<remove_trailing_whitespace>:
push   %rbx
mov    %rdi,%rbx
call   1030 <strlen@plt>
test   %eax,%eax
jle    1147 <remove_trailing_whitespace+0x37>
mov    %eax,%eax
add    $0x1,%rax
cs nopw 0x0(%rax,%rax,1)
nopl   (%rax)
lea    -0x2(%rax),%ecx
cmpb   $0xa,(%rbx,%rcx,1)
jne    1147 <remove_trailing_whitespace+0x37>
movb   $0x0,(%rbx,%rcx,1)
add    $0xffffffffffffffff,%rax
cmp    $0x1,%rax
ja     1130 <remove_trailing_whitespace+0x20>
pop    %rbx
ret

LLVM IR (-O0):
define void @remove_trailing_whitespace(i8* %0) {
%2 = alloca i8*
%3 = alloca i32
store i8* %0, i8** %2
%4 = load i8*, i8** %2
%5 = call i32 @strlen(i8* %4)
store i32 %5, i32* %3
br label %6
6: ; preds = %20, %1
%7 = load i32, i32* %3
%8 = icmp sge i32 %7, 1
br i1 %8, label %9, label %18
9: ; preds = %6
%10 = load i8*, i8** %2
%11 = load i32, i32* %3
%12 = sub nsw i32 %11, 1
%13 = sext i32 %12 to i64
%14 = getelementptr inbounds i8, i8* %10, i64 %13
%15 = load i8, i8* %14
%16 = sext i8 %15 to i32
%17 = icmp eq i32 %16, 10
br label %18
18: ; preds = %9, %6
%19 = phi i1 [ false, %6 ], [ %17, %9 ]
br i1 %19, label %20, label %26
20: ; preds = %18
%21 = load i8*, i8** %2
%22 = load i32, i32* %3
%23 = add nsw i32 %22, -1
store i32 %23, i32* %3
%24 = sext i32 %23 to i64
%25 = getelementptr inbounds i8, i8* %21, i64 %24
store i8 0, i8* %25
br label %6
26: ; preds = %18
ret void
}

LLVM IR (-O2):
define void @remove_trailing_whitespace(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = icmp sgt i32 %2, 0
br i1 %3, label %4, label %15
4: ; preds = %1
%5 = zext i32 %2 to i64
br label %6
6: ; preds = %4, %13
%7 = phi i64 [ %5, %4 ], [ %8, %13 ]
%8 = add nsw i64 %7, -1
%9 = and i64 %8, 4294967295
%10 = getelementptr inbounds i8, i8* %0, i64 %9
%11 = load i8, i8* %10
%12 = icmp eq i8 %11, 10
br i1 %12, label %13, label %15
13: ; preds = %6
store i8 0, i8* %10
%14 = icmp ugt i64 %7, 1
br i1 %14, label %6, label %15
15: ; preds = %6, %13, %1
ret void
}