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


x86 assembly (clang, -O0):
<trim>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rax
movsbl (%rax),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
je     1153 <trim+0x33>
mov    -0x8(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x8(%rbp)
jmp    112c <trim+0xc>
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)
jbe    11a1 <trim+0x81>
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    11b1 <trim+0x91>
jmp    11c2 <trim+0xa2>
mov    -0x10(%rbp),%rax
add    $0xffffffffffffffff,%rax
mov    %rax,-0x10(%rbp)
jmp    1178 <trim+0x58>
mov    -0x10(%rbp),%rax
movb   $0x0,0x1(%rax)
mov    -0x8(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

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

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

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