#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 *);
void rtrim(char *str) {
  char *s = str;
  register int i;
  for (i = strlen(s) - 1; isspace(*(s + i)); i--)
    *(s + i) = '\0';
  while ((*str++ = *s++))
    ;
}


x86 assembly (clang, -O0):
<rtrim>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rax
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rdi
call   1030 <strlen@plt>
sub    $0x1,%eax
mov    %eax,-0x14(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x14(%rbp),%rcx
movsbl (%rax,%rcx,1),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
je     1178 <rtrim+0x58>
mov    -0x10(%rbp),%rax
movslq -0x14(%rbp),%rcx
movb   $0x0,(%rax,%rcx,1)
mov    -0x14(%rbp),%eax
add    $0xffffffff,%eax
mov    %eax,-0x14(%rbp)
jmp    1143 <rtrim+0x23>
jmp    117d <rtrim+0x5d>
mov    -0x10(%rbp),%rax
mov    %rax,%rcx
add    $0x1,%rcx
mov    %rcx,-0x10(%rbp)
mov    (%rax),%al
mov    -0x8(%rbp),%rcx
mov    %rcx,%rdx
add    $0x1,%rdx
mov    %rdx,-0x8(%rbp)
mov    %al,(%rcx)
cmp    $0x0,%al
je     11ac <rtrim+0x8c>
jmp    117d <rtrim+0x5d>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<rtrim>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%rbx
call   1030 <strlen@plt>
movslq %eax,%r14
movsbl -0x1(%r14,%rbx,1),%edi
call   1040 <isspace@plt>
test   %rax,%rax
je     1165 <rtrim+0x45>
add    %r14,%rbx
add    $0xffffffffffffffff,%rbx
cs nopw 0x0(%rax,%rax,1)
movb   $0x0,(%rbx)
movsbl -0x1(%rbx),%edi
add    $0xffffffffffffffff,%rbx
call   1040 <isspace@plt>
test   %rax,%rax
jne    1150 <rtrim+0x30>
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
define void @rtrim(i8* %0) {
%2 = alloca i8*
%3 = alloca i8*
%4 = alloca i32
store i8* %0, i8** %2
%5 = load i8*, i8** %2
store i8* %5, i8** %3
%6 = load i8*, i8** %3
%7 = call i32 @strlen(i8* %6)
%8 = sub nsw i32 %7, 1
store i32 %8, i32* %4
br label %9
9: ; preds = %22, %1
%10 = load i8*, i8** %3
%11 = load i32, i32* %4
%12 = sext i32 %11 to i64
%13 = getelementptr inbounds i8, i8* %10, i64 %12
%14 = load i8, i8* %13
%15 = call i64 @isspace(i8 signext %14)
%16 = icmp ne i64 %15, 0
br i1 %16, label %17, label %25
17: ; preds = %9
%18 = load i8*, i8** %3
%19 = load i32, i32* %4
%20 = sext i32 %19 to i64
%21 = getelementptr inbounds i8, i8* %18, i64 %20
store i8 0, i8* %21
br label %22
22: ; preds = %17
%23 = load i32, i32* %4
%24 = add nsw i32 %23, -1
store i32 %24, i32* %4
br label %9
25: ; preds = %9
br label %26
26: ; preds = %33, %25
%27 = load i8*, i8** %3
%28 = getelementptr inbounds i8, i8* %27, i32 1
store i8* %28, i8** %3
%29 = load i8, i8* %27
%30 = load i8*, i8** %2
%31 = getelementptr inbounds i8, i8* %30, i32 1
store i8* %31, i8** %2
store i8 %29, i8* %30
%32 = icmp ne i8 %29, 0
br i1 %32, label %33, label %34
33: ; preds = %26
br label %26
34: ; preds = %26
ret void
}

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