#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 /*<<< orphan*/ exit(int);
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *);
char *malloc(scalar_t__);
int /*<<< orphan*/ stderr;
int /*<<< orphan*/ strcat(char *, char *);
int /*<<< orphan*/ strcpy(char *, char *);
scalar_t__ strlen(char *);
char *strcatcopy(char *str1, char *str2, char *str3) {
  char *p = malloc(strlen(str1) + strlen(str2) + strlen(str3) + 1);
  if (!p) {
    fprintf(stderr, "out of memory\n");
    exit(-1);
  }
  strcpy(p, str1);
  strcat(p, str2);
  strcat(p, str3);
  return (p);
}


x86 assembly (clang, -O0):
<strcatcopy>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    -0x8(%rbp),%rdi
call   1040 <strlen@plt>
mov    %rax,-0x30(%rbp)
mov    -0x10(%rbp),%rdi
call   1040 <strlen@plt>
mov    %rax,%rcx
mov    -0x30(%rbp),%rax
add    %rcx,%rax
mov    %rax,-0x28(%rbp)
mov    -0x18(%rbp),%rdi
call   1040 <strlen@plt>
mov    -0x28(%rbp),%rdi
add    %rax,%rdi
add    $0x1,%rdi
call   1060 <malloc@plt>
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jne    11df <strcatcopy+0x7f>
mov    0x2e19(%rip),%rax
mov    (%rax),%edi
lea    0xe30(%rip),%rsi
call   1050 <fprintf@plt>
mov    $0xffffffff,%edi
call   1080 <exit@plt>
mov    -0x20(%rbp),%rdi
mov    -0x8(%rbp),%rsi
call   1030 <strcpy@plt>
mov    -0x20(%rbp),%rdi
mov    -0x10(%rbp),%rsi
call   1070 <strcat@plt>
mov    -0x20(%rbp),%rdi
mov    -0x18(%rbp),%rsi
call   1070 <strcat@plt>
mov    -0x20(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<strcatcopy>:
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
mov    %rdx,%r14
mov    %rsi,%r15
mov    %rdi,%r12
call   1040 <strlen@plt>
mov    %rax,%r13
mov    %r15,%rdi
call   1040 <strlen@plt>
mov    %rax,%rbx
mov    %r14,%rdi
call   1040 <strlen@plt>
add    %r13,%rbx
lea    (%rax,%rbx,1),%rdi
add    $0x1,%rdi
call   1060 <malloc@plt>
test   %rax,%rax
je     11d3 <strcatcopy+0x73>
mov    %rax,%rbx
mov    %rax,%rdi
mov    %r12,%rsi
call   1030 <strcpy@plt>
mov    %rbx,%rdi
mov    %r15,%rsi
call   1070 <strcat@plt>
mov    %rbx,%rdi
mov    %r14,%rsi
call   1070 <strcat@plt>
mov    %rbx,%rax
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
ret
mov    0x2e06(%rip),%rax
mov    (%rax),%edi
lea    0xe1d(%rip),%rsi
call   1050 <fprintf@plt>
mov    $0xffffffff,%edi
call   1080 <exit@plt>

LLVM IR (-O0):
@stderr = global i32 0
@.str = [15 x i8] c"out of memory\0A\00"
define i8* @strcatcopy(i8* %0, i8* %1, i8* %2) {
%4 = alloca i8*
%5 = alloca i8*
%6 = alloca i8*
%7 = alloca i8*
store i8* %0, i8** %4
store i8* %1, i8** %5
store i8* %2, i8** %6
%8 = load i8*, i8** %4
%9 = call i64 @strlen(i8* %8)
%10 = load i8*, i8** %5
%11 = call i64 @strlen(i8* %10)
%12 = add nsw i64 %9, %11
%13 = load i8*, i8** %6
%14 = call i64 @strlen(i8* %13)
%15 = add nsw i64 %12, %14
%16 = add nsw i64 %15, 1
%17 = call i8* @malloc(i64 %16)
store i8* %17, i8** %7
%18 = load i8*, i8** %7
%19 = icmp ne i8* %18, null
br i1 %19, label %24, label %20
20: ; preds = %3
%21 = load i32, i32* @stderr
%22 = call i32 @fprintf(i32 %21, i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0))
%23 = call i32 @exit(i32 -1)
unreachable
24: ; preds = %3
%25 = load i8*, i8** %7
%26 = load i8*, i8** %4
%27 = call i32 @strcpy(i8* %25, i8* %26)
%28 = load i8*, i8** %7
%29 = load i8*, i8** %5
%30 = call i32 @strcat(i8* %28, i8* %29)
%31 = load i8*, i8** %7
%32 = load i8*, i8** %6
%33 = call i32 @strcat(i8* %31, i8* %32)
%34 = load i8*, i8** %7
ret i8* %34
}

LLVM IR (-O2):
@stderr = global i32 0
@.str = [15 x i8] c"out of memory\0A\00"
define i8* @strcatcopy(i8* %0, i8* %1, i8* %2) {
%4 = tail call i64 @strlen(i8* dereferenceable(1) %0)
%5 = tail call i64 @strlen(i8* dereferenceable(1) %1)
%6 = tail call i64 @strlen(i8* dereferenceable(1) %2)
%7 = add i64 %4, 1
%8 = add i64 %7, %5
%9 = add i64 %8, %6
%10 = tail call i8* @malloc(i64 %9)
%11 = icmp eq i8* %10, null
br i1 %11, label %12, label %16
12: ; preds = %3
%13 = load i32, i32* @stderr
%14 = tail call i32 @fprintf(i32 %13, i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0))
%15 = tail call i32 @exit(i32 -1)
unreachable
16: ; preds = %3
%17 = tail call i32 @strcpy(i8* %10, i8* %0)
%18 = tail call i32 @strcat(i8* %10, i8* %1)
%19 = tail call i32 @strcat(i8* %10, i8* %2)
ret i8* %10
}