#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 trimTrailingSpaces(char *str) {
  int last = strlen(str) - 1;
  while (last > -1 && isspace(str[last]))
    str[last--] = 0;
}


x86 assembly (clang, -O0):
<trimTrailingSpaces>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rdi
call   1030 <strlen@plt>
sub    $0x1,%eax
mov    %eax,-0xc(%rbp)
xor    %eax,%eax
cmpl   $0xffffffff,-0xc(%rbp)
mov    %al,-0xd(%rbp)
jle    1165 <trimTrailingSpaces+0x45>
mov    -0x8(%rbp),%rax
movslq -0xc(%rbp),%rcx
movsbl (%rax,%rcx,1),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
setne  %al
mov    %al,-0xd(%rbp)
mov    -0xd(%rbp),%al
test   $0x1,%al
jne    1175 <trimTrailingSpaces+0x55>
jmp    1190 <trimTrailingSpaces+0x70>
mov    -0x8(%rbp),%rax
mov    -0xc(%rbp),%ecx
mov    %ecx,%edx
add    $0xffffffff,%edx
mov    %edx,-0xc(%rbp)
movslq %ecx,%rcx
movb   $0x0,(%rax,%rcx,1)
jmp    113b <trimTrailingSpaces+0x1b>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<trimTrailingSpaces>:
push   %r15
push   %r14
push   %rbx
mov    %rdi,%r14
call   1030 <strlen@plt>
test   %eax,%eax
jle    1162 <trimTrailingSpaces+0x42>
mov    %eax,%ebx
add    $0x1,%rbx
nopw   0x0(%rax,%rax,1)
lea    -0x2(%rbx),%r15d
movsbl (%r14,%r15,1),%edi
call   1040 <isspace@plt>
test   %rax,%rax
je     1162 <trimTrailingSpaces+0x42>
movb   $0x0,(%r14,%r15,1)
add    $0xffffffffffffffff,%rbx
cmp    $0x1,%rbx
ja     1140 <trimTrailingSpaces+0x20>
pop    %rbx
pop    %r14
pop    %r15
ret

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

LLVM IR (-O2):
define void @trimTrailingSpaces(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = icmp sgt i32 %2, 0
br i1 %3, label %4, label %16
4: ; preds = %1
%5 = zext i32 %2 to i64
br label %6
6: ; preds = %4, %14
%7 = phi i64 [ %5, %4 ], [ %8, %14 ]
%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 = tail call i64 @isspace(i8 signext %11)
%13 = icmp eq i64 %12, 0
br i1 %13, label %16, label %14
14: ; preds = %6
store i8 0, i8* %10
%15 = icmp ugt i64 %7, 1
br i1 %15, label %6, label %16
16: ; preds = %6, %14, %1
ret void
}