#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__ Malloc(scalar_t__);
int /*<<< orphan*/ sprintf(char *, char *, char *, char *, char *);
scalar_t__ strlen(char *);
char *strcat3(char *s1, char *s2, char *s3) {
  char *s;
  s = (char *)Malloc(strlen(s1) + strlen(s2) + strlen(s3) + 1);
  sprintf(s, "%s%s%s", s1, s2, s3);
  return s;
}


x86 assembly (clang, -O0):
<strcat3>:
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   1030 <Malloc@plt>
mov    %rax,-0x20(%rbp)
mov    -0x20(%rbp),%rdi
mov    -0x8(%rbp),%rdx
mov    -0x10(%rbp),%rcx
mov    -0x18(%rbp),%r8
lea    0xe64(%rip),%rsi
call   1050 <sprintf@plt>
mov    -0x20(%rbp),%rax
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<strcat3>:
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
mov    %rdx,%r14
mov    %rsi,%r15
mov    %rdi,%r13
call   1040 <strlen@plt>
mov    %rax,%r12
mov    %r15,%rdi
call   1040 <strlen@plt>
mov    %rax,%rbx
mov    %r14,%rdi
call   1040 <strlen@plt>
add    %r12,%rbx
lea    (%rax,%rbx,1),%rdi
add    $0x1,%rdi
call   1030 <Malloc@plt>
mov    %rax,%rbx
lea    0xe89(%rip),%rsi
mov    %rax,%rdi
mov    %r13,%rdx
mov    %r15,%rcx
mov    %r14,%r8
call   1050 <sprintf@plt>
mov    %rbx,%rax
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [7 x i8] c"%s%s%s\00"
define i8* @strcat3(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 i64 @Malloc(i64 %16)
%18 = inttoptr i64 %17 to i8*
store i8* %18, i8** %7
%19 = load i8*, i8** %7
%20 = load i8*, i8** %4
%21 = load i8*, i8** %5
%22 = load i8*, i8** %6
%23 = call i32 @sprintf(i8* %19, i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str, i64 0, i64 0), i8* %20, i8* %21, i8* %22)
%24 = load i8*, i8** %7
ret i8* %24
}

LLVM IR (-O2):
@.str = [7 x i8] c"%s%s%s\00"
define i8* @strcat3(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 i64 @Malloc(i64 %9)
%11 = inttoptr i64 %10 to i8*
%12 = tail call i32 @sprintf(i8* dereferenceable(1) %11, i8* dereferenceable(1) getelementptr inbounds ([7 x i8], [7 x i8]* @.str, i64 0, i64 0), i8* %0, i8* %1, i8* %2)
ret i8* %11
}