#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__ isspace(char);
int strlen(char *);
char *rtrim(char *s) {
  char *end = s + strlen(s);
  while ((end != s) && isspace(*(end - 1))) {
    --end;
  }
  *end = '\0';
  return s;
}


x86 assembly (clang, -O0):
<rtrim>:
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
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rcx
xor    %eax,%eax
cmp    -0x8(%rbp),%rcx
mov    %al,-0x19(%rbp)
je     1177 <rtrim+0x57>
mov    -0x10(%rbp),%rax
movsbl -0x1(%rax),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
setne  %al
mov    %al,-0x19(%rbp)
mov    -0x19(%rbp),%al
test   $0x1,%al
jne    1187 <rtrim+0x67>
jmp    1198 <rtrim+0x78>
mov    -0x10(%rbp),%rax
add    $0xffffffffffffffff,%rax
mov    %rax,-0x10(%rbp)
jmp    114d <rtrim+0x2d>
mov    -0x10(%rbp),%rax
movb   $0x0,(%rax)
mov    -0x8(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<rtrim>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%r14
call   1030 <strlen@plt>
movslq %eax,%rbx
nop
test   %rbx,%rbx
je     1153 <rtrim+0x33>
movsbl -0x1(%r14,%rbx,1),%edi
call   1040 <isspace@plt>
add    $0xffffffffffffffff,%rbx
test   %rax,%rax
jne    1130 <rtrim+0x10>
lea    (%r14,%rbx,1),%rax
add    $0x1,%rax
jmp    1156 <rtrim+0x36>
mov    %r14,%rax
movb   $0x0,(%rax)
mov    %r14,%rax
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
define i8* @rtrim(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
store i8* %8, i8** %3
br label %9
9: ; preds = %21, %1
%10 = load i8*, i8** %3
%11 = load i8*, i8** %2
%12 = icmp ne i8* %10, %11
br i1 %12, label %13, label %19
13: ; preds = %9
%14 = load i8*, i8** %3
%15 = getelementptr inbounds i8, i8* %14, i64 -1
%16 = load i8, i8* %15
%17 = call i64 @isspace(i8 signext %16)
%18 = icmp ne i64 %17, 0
br label %19
19: ; preds = %13, %9
%20 = phi i1 [ false, %9 ], [ %18, %13 ]
br i1 %20, label %21, label %24
21: ; preds = %19
%22 = load i8*, i8** %3
%23 = getelementptr inbounds i8, i8* %22, i32 -1
store i8* %23, i8** %3
br label %9
24: ; preds = %19
%25 = load i8*, i8** %3
store i8 0, i8* %25
%26 = load i8*, i8** %2
ret i8* %26
}

LLVM IR (-O2):
define i8* @rtrim(i8* returned %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = sext i32 %2 to i64
%4 = getelementptr inbounds i8, i8* %0, i64 %3
br label %5
5: ; preds = %8, %1
%6 = phi i8* [ %4, %1 ], [ %9, %8 ]
%7 = icmp eq i8* %6, %0
br i1 %7, label %13, label %8
8: ; preds = %5
%9 = getelementptr inbounds i8, i8* %6, i64 -1
%10 = load i8, i8* %9
%11 = tail call i64 @isspace(i8 signext %10)
%12 = icmp eq i64 %11, 0
br i1 %12, label %13, label %5
13: ; preds = %5, %8
%14 = phi i8* [ %0, %5 ], [ %6, %8 ]
store i8 0, i8* %14
ret i8* %0
}