#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 strchomp(char *str) {
  char *ptr = str + strlen(str) - 1;
  while (ptr && ptr >= str && isspace(*ptr)) {
    *(ptr--) = '\0';
  }
}


x86 assembly (clang, -O0):
<strchomp>:
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)
xor    %eax,%eax
cmpq   $0x0,-0x10(%rbp)
mov    %al,-0x19(%rbp)
je     118a <strchomp+0x6a>
mov    -0x10(%rbp),%rcx
xor    %eax,%eax
cmp    -0x8(%rbp),%rcx
mov    %al,-0x19(%rbp)
jb     118a <strchomp+0x6a>
mov    -0x10(%rbp),%rax
movsbl (%rax),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
setne  %al
mov    %al,-0x19(%rbp)
mov    -0x19(%rbp),%al
test   $0x1,%al
jne    119a <strchomp+0x7a>
jmp    11b1 <strchomp+0x91>
mov    -0x10(%rbp),%rax
mov    %rax,%rcx
add    $0xffffffffffffffff,%rcx
mov    %rcx,-0x10(%rbp)
movb   $0x0,(%rax)
jmp    1151 <strchomp+0x31>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<strchomp>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%r14
call   1030 <strlen@plt>
cltq
lea    (%r14,%rax,1),%rbx
add    $0xffffffffffffffff,%rbx
cmp    %r14,%rbx
jb     1159 <strchomp+0x39>
nopl   0x0(%rax,%rax,1)
movsbl (%rbx),%edi
call   1040 <isspace@plt>
test   %rax,%rax
je     1159 <strchomp+0x39>
movb   $0x0,(%rbx)
add    $0xffffffffffffffff,%rbx
cmp    %r14,%rbx
jae    1140 <strchomp+0x20>
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
define void @strchomp(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 = %24, %1
%11 = load i8*, i8** %3
%12 = icmp ne i8* %11, null
br i1 %12, label %13, label %22
13: ; preds = %10
%14 = load i8*, i8** %3
%15 = load i8*, i8** %2
%16 = icmp uge i8* %14, %15
br i1 %16, label %17, label %22
17: ; preds = %13
%18 = load i8*, i8** %3
%19 = load i8, i8* %18
%20 = call i64 @isspace(i8 signext %19)
%21 = icmp ne i64 %20, 0
br label %22
22: ; preds = %17, %13, %10
%23 = phi i1 [ false, %13 ], [ false, %10 ], [ %21, %17 ]
br i1 %23, label %24, label %27
24: ; preds = %22
%25 = load i8*, i8** %3
%26 = getelementptr inbounds i8, i8* %25, i32 -1
store i8* %26, i8** %3
store i8 0, i8* %25
br label %10
27: ; preds = %22
ret void
}

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