#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 trim_trailing(char *buf) {
  char *end = buf + strlen(buf) - 1;
  while (end >= buf && (*end == ' ' || *end == '\t')) {
    *end = 0;
    end--;
  }
}


x86 assembly (clang, -O0):
<trim_trailing>:
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
add    $0xffffffffffffffff,%rax
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rcx
xor    %eax,%eax
cmp    -0x8(%rbp),%rcx
mov    %al,-0x19(%rbp)
jb     117f <trim_trailing+0x6f>
mov    -0x10(%rbp),%rax
movsbl (%rax),%ecx
mov    $0x1,%al
cmp    $0x20,%ecx
mov    %al,-0x1a(%rbp)
je     1179 <trim_trailing+0x69>
mov    -0x10(%rbp),%rax
movsbl (%rax),%eax
cmp    $0x9,%eax
sete   %al
mov    %al,-0x1a(%rbp)
mov    -0x1a(%rbp),%al
mov    %al,-0x19(%rbp)
mov    -0x19(%rbp),%al
test   $0x1,%al
jne    118f <trim_trailing+0x7f>
jmp    11a7 <trim_trailing+0x97>
mov    -0x10(%rbp),%rax
movb   $0x0,(%rax)
mov    -0x10(%rbp),%rax
add    $0xffffffffffffffff,%rax
mov    %rax,-0x10(%rbp)
jmp    1141 <trim_trailing+0x31>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<trim_trailing>:
push   %rbx
mov    %rdi,%rbx
call   1030 <strlen@plt>
cltq
add    %rbx,%rax
add    $0xffffffffffffffff,%rax
jmp    1137 <trim_trailing+0x27>
cs nopw 0x0(%rax,%rax,1)
xchg   %ax,%ax
movb   $0x0,(%rax)
add    $0xffffffffffffffff,%rax
cmp    %rbx,%rax
jb     1149 <trim_trailing+0x39>
movzbl (%rax),%ecx
cmp    $0x20,%cl
je     1130 <trim_trailing+0x20>
cmp    $0x9,%cl
je     1130 <trim_trailing+0x20>
pop    %rbx
ret

LLVM IR (-O0):
define void @trim_trailing(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
%9 = getelementptr inbounds i8, i8* %8, i64 -1
store i8* %9, i8** %3
br label %10
10: ; preds = %28, %1
%11 = load i8*, i8** %3
%12 = load i8*, i8** %2
%13 = icmp uge i8* %11, %12
br i1 %13, label %14, label %26
14: ; preds = %10
%15 = load i8*, i8** %3
%16 = load i8, i8* %15
%17 = sext i8 %16 to i32
%18 = icmp eq i32 %17, 32
br i1 %18, label %24, label %19
19: ; preds = %14
%20 = load i8*, i8** %3
%21 = load i8, i8* %20
%22 = sext i8 %21 to i32
%23 = icmp eq i32 %22, 9
br label %24
24: ; preds = %19, %14
%25 = phi i1 [ true, %14 ], [ %23, %19 ]
br label %26
26: ; preds = %24, %10
%27 = phi i1 [ false, %10 ], [ %25, %24 ]
br i1 %27, label %28, label %32
28: ; preds = %26
%29 = load i8*, i8** %3
store i8 0, i8* %29
%30 = load i8*, i8** %3
%31 = getelementptr inbounds i8, i8* %30, i32 -1
store i8* %31, i8** %3
br label %10
32: ; preds = %26
ret void
}

LLVM IR (-O2):
define void @trim_trailing(i8* %0) {
%2 = tail call i32 @strlen(i8* %0)
%3 = sext i32 %2 to i64
%4 = getelementptr inbounds i8, i8* %0, i64 %3
%5 = getelementptr inbounds i8, i8* %4, i64 -1
%6 = icmp ult i8* %5, %0
br i1 %6, label %13, label %7
7: ; preds = %1, %10
%8 = phi i8* [ %11, %10 ], [ %5, %1 ]
%9 = load i8, i8* %8
switch i8 %9, label %13 [
i8 32, label %10
i8 9, label %10
]
10: ; preds = %7, %7
store i8 0, i8* %8
%11 = getelementptr inbounds i8, i8* %8, i64 -1
%12 = icmp ult i8* %11, %0
br i1 %12, label %13, label %7
13: ; preds = %10, %7, %1
ret void
}