#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 *strip(char *buf) {
  char *pch = buf + strlen(buf) - 1;
  while (pch > buf && isspace(*pch))
    *pch-- = '\0';
  while (isspace(*buf))
    buf++;
  return buf;
}


x86 assembly (clang, -O0):
<strip>:
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)
jbe    117a <strip+0x5a>
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    118a <strip+0x6a>
jmp    11a1 <strip+0x81>
mov    -0x10(%rbp),%rax
mov    %rax,%rcx
add    $0xffffffffffffffff,%rcx
mov    %rcx,-0x10(%rbp)
movb   $0x0,(%rax)
jmp    1151 <strip+0x31>
jmp    11a6 <strip+0x86>
mov    -0x8(%rbp),%rax
movsbl (%rax),%edi
call   1040 <isspace@plt>
cmp    $0x0,%rax
je     11cd <strip+0xad>
mov    -0x8(%rbp),%rax
add    $0x1,%rax
mov    %rax,-0x8(%rbp)
jmp    11a6 <strip+0x86>
mov    -0x8(%rbp),%rax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<strip>:
push   %r14
push   %rbx
push   %rax
mov    %rdi,%rbx
call   1030 <strlen@plt>
cltq
lea    (%rbx,%rax,1),%r14
add    $0xffffffffffffffff,%r14
cmp    %rbx,%r14
jbe    115b <strip+0x3b>
nopl   0x0(%rax,%rax,1)
movsbl (%r14),%edi
call   1040 <isspace@plt>
test   %rax,%rax
je     115b <strip+0x3b>
movb   $0x0,(%r14)
add    $0xffffffffffffffff,%r14
cmp    %rbx,%r14
ja     1140 <strip+0x20>
add    $0xffffffffffffffff,%rbx
nop
movsbl 0x1(%rbx),%edi
add    $0x1,%rbx
call   1040 <isspace@plt>
test   %rax,%rax
jne    1160 <strip+0x40>
mov    %rbx,%rax
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret

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

LLVM IR (-O2):
define i8* @strip(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 ugt i8* %5, %0
br i1 %6, label %7, label %15
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 ugt i8* %13, %0
br i1 %14, label %7, label %15
15: ; preds = %7, %12, %1
br label %16
16: ; preds = %15, %16
%17 = phi i8* [ %21, %16 ], [ %0, %15 ]
%18 = load i8, i8* %17
%19 = tail call i64 @isspace(i8 signext %18)
%20 = icmp eq i64 %19, 0
%21 = getelementptr inbounds i8, i8* %17, i64 1
br i1 %20, label %22, label %16
22: ; preds = %16
ret i8* %17
}