#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_spaces(char *str) {
  int i, len;
  len = strlen(str);
  for (i = (len - 1); i > -1; i--) {
    if (str[i] != ' ')
      break;
  }
  str[i + 1] = 0;
}


x86 assembly (clang, -O0):
<remove_trailing_spaces>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,-0x10(%rbp)
mov    -0x10(%rbp),%eax
sub    $0x1,%eax
mov    %eax,-0xc(%rbp)
cmpl   $0xffffffff,-0xc(%rbp)
jle    1168 <remove_trailing_spaces+0x58>
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
movsbl (%rax,%rcx,1),%eax
cmp    $0x20,%eax
je     1155 <remove_trailing_spaces+0x45>
jmp    1168 <remove_trailing_spaces+0x58>
jmp    115a <remove_trailing_spaces+0x4a>
mov    -0xc(%rbp),%eax
add    $0xffffffff,%eax
mov    %eax,-0xc(%rbp)
jmp    1131 <remove_trailing_spaces+0x21>
mov    -0x8(%rbp),%rax
mov    -0xc(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movb   $0x0,(%rax,%rcx,1)
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<remove_trailing_spaces>:
push   %rbx
mov    %rdi,%rbx
call   1030 <strlen@plt>
mov    %eax,%edx
xor    %ecx,%ecx
test   %eax,%eax
cmovs  %eax,%ecx
cs nopw 0x0(%rax,%rax,1)
nopl   0x0(%rax)
test   %edx,%edx
jle    1147 <remove_trailing_spaces+0x37>
lea    -0x1(%rdx),%rax
cmpb   $0x20,-0x1(%rbx,%rdx,1)
mov    %rax,%rdx
je     1130 <remove_trailing_spaces+0x20>
add    $0x1,%eax
mov    %eax,%ecx
movslq %ecx,%rax
movb   $0x0,(%rbx,%rax,1)
pop    %rbx
ret

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

LLVM IR (-O2):
define void @remove_trailing_spaces(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = zext i32 %2 to i64
%4 = call i32 @llvm.smin.i32(i32 %2, i32 0)
br label %5
5: ; preds = %10, %1
%6 = phi i64 [ %7, %10 ], [ %3, %1 ]
%7 = add nsw i64 %6, -1
%8 = trunc i64 %6 to i32
%9 = icmp sgt i32 %8, 0
br i1 %9, label %10, label %16
10: ; preds = %5
%11 = getelementptr inbounds i8, i8* %0, i64 %7
%12 = load i8, i8* %11
%13 = icmp eq i8 %12, 32
br i1 %13, label %5, label %14
14: ; preds = %10
%15 = trunc i64 %6 to i32
br label %16
16: ; preds = %5, %14
%17 = phi i32 [ %15, %14 ], [ %4, %5 ]
%18 = sext i32 %17 to i64
%19 = getelementptr inbounds i8, i8* %0, i64 %18
store i8 0, i8* %19
ret void
}