#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 *);
char *trim_whitespace(char *s) {
  char *end;
  while (isspace(*s)) {
    s++;
  }
  if (*s == 0) {
    return s;
  }
  end = s + strlen(s) - 1;
  while (end > s && isspace(*end)) {
    end--;
  }
  *(end + 1) = 0;
  return s;
}


x86 assembly (clang, -O0):
<trim_whitespace>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x10(%rbp)
mov    -0x10(%rbp),%rax
movsbl (%rax),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
je     1153 <trim_whitespace+0x33>
mov    -0x10(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x10(%rbp)
jmp    112c <trim_whitespace+0xc>
mov    -0x10(%rbp),%rax
movsbl (%rax),%eax
cmp    $0x0,%eax
jne    1170 <trim_whitespace+0x50>
mov    -0x10(%rbp),%rax
mov    %rax,-0x8(%rbp)
jmp    11ef <trim_whitespace+0xcf>
mov    -0x10(%rbp),%rax
mov    %rax,-0x20(%rbp)
mov    -0x10(%rbp),%rdi
call   1030 <strlen@plt>
mov    %eax,%ecx
mov    -0x20(%rbp),%rax
movslq %ecx,%rcx
add    %rcx,%rax
add    $0xffffffffffffffff,%rax
mov    %rax,-0x18(%rbp)
mov    -0x18(%rbp),%rcx
xor    %eax,%eax
cmp    -0x10(%rbp),%rcx
mov    %al,-0x21(%rbp)
jbe    11be <trim_whitespace+0x9e>
mov    -0x18(%rbp),%rax
movsbl (%rax),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
setne  %al
mov    %al,-0x21(%rbp)
mov    -0x21(%rbp),%al
test   $0x1,%al
jne    11ce <trim_whitespace+0xae>
jmp    11df <trim_whitespace+0xbf>
mov    -0x18(%rbp),%rax
add    $0xffffffffffffffff,%rax
mov    %rax,-0x18(%rbp)
jmp    1195 <trim_whitespace+0x75>
mov    -0x18(%rbp),%rax
movb   $0x0,0x1(%rax)
mov    -0x10(%rbp),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<trim_whitespace>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
mov    %rdi,%rbx
add    $0xffffffffffffffff,%rbx
nop
movsbl 0x1(%rbx),%edi
add    $0x1,%rbx
call   1040 <isspace@plt>
test   %rax,%rax
jne    1130 <trim_whitespace+0x10>
cmpb   $0x0,(%rbx)
je     1185 <trim_whitespace+0x65>
lea    -0x1(%rbx),%r12
mov    %rbx,%rdi
call   1030 <strlen@plt>
movslq %eax,%r14
cs nopw 0x0(%rax,%rax,1)
mov    %r12,%r15
lea    (%r12,%r14,1),%rax
cmp    %rbx,%rax
jbe    117f <trim_whitespace+0x5f>
movsbl (%r15,%r14,1),%edi
call   1040 <isspace@plt>
lea    -0x1(%r15),%r12
test   %rax,%rax
jne    1160 <trim_whitespace+0x40>
movb   $0x0,0x1(%r15,%r14,1)
mov    %rbx,%rax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
define i8* @trim_whitespace(i8* %0) {
%2 = alloca i8*
%3 = alloca i8*
%4 = alloca i8*
store i8* %0, i8** %3
br label %5
5: ; preds = %10, %1
%6 = load i8*, i8** %3
%7 = load i8, i8* %6
%8 = call i64 @isspace(i8 signext %7)
%9 = icmp ne i64 %8, 0
br i1 %9, label %10, label %13
10: ; preds = %5
%11 = load i8*, i8** %3
%12 = getelementptr inbounds i8, i8* %11, i32 1
store i8* %12, i8** %3
br label %5
13: ; preds = %5
%14 = load i8*, i8** %3
%15 = load i8, i8* %14
%16 = sext i8 %15 to i32
%17 = icmp eq i32 %16, 0
br i1 %17, label %18, label %20
18: ; preds = %13
%19 = load i8*, i8** %3
store i8* %19, i8** %2
br label %45
20: ; preds = %13
%21 = load i8*, i8** %3
%22 = load i8*, i8** %3
%23 = call i32 @strlen(i8* %22)
%24 = sext i32 %23 to i64
%25 = getelementptr inbounds i8, i8* %21, i64 %24
%26 = getelementptr inbounds i8, i8* %25, i64 -1
store i8* %26, i8** %4
br label %27
27: ; preds = %38, %20
%28 = load i8*, i8** %4
%29 = load i8*, i8** %3
%30 = icmp ugt i8* %28, %29
br i1 %30, label %31, label %36
31: ; preds = %27
%32 = load i8*, i8** %4
%33 = load i8, i8* %32
%34 = call i64 @isspace(i8 signext %33)
%35 = icmp ne i64 %34, 0
br label %36
36: ; preds = %31, %27
%37 = phi i1 [ false, %27 ], [ %35, %31 ]
br i1 %37, label %38, label %41
38: ; preds = %36
%39 = load i8*, i8** %4
%40 = getelementptr inbounds i8, i8* %39, i32 -1
store i8* %40, i8** %4
br label %27
41: ; preds = %36
%42 = load i8*, i8** %4
%43 = getelementptr inbounds i8, i8* %42, i64 1
store i8 0, i8* %43
%44 = load i8*, i8** %3
store i8* %44, i8** %2
br label %45
45: ; preds = %41, %18
%46 = load i8*, i8** %2
ret i8* %46
}

LLVM IR (-O2):
define i8* @trim_whitespace(i8* %0) {
br label %2
2: ; preds = %2, %1
%3 = phi i8* [ %0, %1 ], [ %7, %2 ]
%4 = load i8, i8* %3
%5 = tail call i64 @isspace(i8 signext %4)
%6 = icmp eq i64 %5, 0
%7 = getelementptr inbounds i8, i8* %3, i64 1
br i1 %6, label %8, label %2
8: ; preds = %2
%9 = load i8, i8* %3
%10 = icmp eq i8 %9, 0
br i1 %10, label %24, label %11
11: ; preds = %8
%12 = tail call i32 @strlen(i8* %3)
%13 = sext i32 %12 to i64
%14 = getelementptr inbounds i8, i8* %3, i64 %13
br label %15
15: ; preds = %19, %11
%16 = phi i8* [ %14, %11 ], [ %17, %19 ]
%17 = getelementptr inbounds i8, i8* %16, i64 -1
%18 = icmp ugt i8* %17, %3
br i1 %18, label %19, label %23
19: ; preds = %15
%20 = load i8, i8* %17
%21 = tail call i64 @isspace(i8 signext %20)
%22 = icmp eq i64 %21, 0
br i1 %22, label %23, label %15
23: ; preds = %15, %19
store i8 0, i8* %16
br label %24
24: ; preds = %8, %23
ret i8* %3
}