#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 /*<<< orphan*/);
char *getenv(char *);
int /*<<< orphan*/ printf(char *, char *, ...);
int strlen(char *);
int main(int argc, char *argv[]) {
  char *ptr;
  if (argc < 3) {
    printf("Usage: %s <environment variable> <target program name>\n", argv[0]);
    exit(0);
  }
  ptr = getenv(argv[1]);
  ptr += (strlen(argv[0]) - strlen(argv[2])) * 2;
  printf("%s will be at %p\n", argv[1], (void *)ptr);
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
cmpl   $0x3,-0x4(%rbp)
jge    1175 <main+0x35>
mov    -0x10(%rbp),%rax
mov    (%rax),%rsi
lea    0xe99(%rip),%rdi
mov    $0x0,%al
call   1050 <printf@plt>
xor    %edi,%edi
call   1060 <exit@plt>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1030 <getenv@plt>
mov    %rax,-0x18(%rbp)
mov    -0x10(%rbp),%rax
mov    (%rax),%rdi
call   1040 <strlen@plt>
mov    %eax,-0x1c(%rbp)
mov    -0x10(%rbp),%rax
mov    0x10(%rax),%rdi
call   1040 <strlen@plt>
mov    -0x1c(%rbp),%ecx
sub    %eax,%ecx
shl    $0x1,%ecx
mov    -0x18(%rbp),%rax
movslq %ecx,%rcx
add    %rcx,%rax
mov    %rax,-0x18(%rbp)
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rsi
mov    -0x18(%rbp),%rdx
lea    0xe6d(%rip),%rdi
mov    $0x0,%al
call   1050 <printf@plt>
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r14
push   %rbx
mov    %rsi,%rbx
cmp    $0x2,%edi
jle    118e <main+0x4e>
mov    0x8(%rbx),%rdi
call   1030 <getenv@plt>
mov    %rax,%r14
mov    (%rbx),%rdi
call   1040 <strlen@plt>
mov    %eax,%ebp
mov    0x10(%rbx),%rdi
call   1040 <strlen@plt>
sub    %eax,%ebp
add    %ebp,%ebp
movslq %ebp,%rdx
add    %r14,%rdx
mov    0x8(%rbx),%rsi
lea    0xeb8(%rip),%rdi
xor    %eax,%eax
call   1050 <printf@plt>
xor    %eax,%eax
pop    %rbx
pop    %r14
pop    %rbp
ret
mov    (%rbx),%rsi
lea    0xe68(%rip),%rdi
xor    %eax,%eax
call   1050 <printf@plt>
xor    %edi,%edi
call   1060 <exit@plt>

LLVM IR (-O0):
@.str = [56 x i8] c"Usage: %s <environment variable> <target program name>\0A\00"
@.str.1 = [18 x i8] c"%s will be at %p\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i8**
%5 = alloca i8*
store i32 %0, i32* %3
store i8** %1, i8*** %4
%6 = load i32, i32* %3
%7 = icmp slt i32 %6, 3
br i1 %7, label %8, label %14
8: ; preds = %2
%9 = load i8**, i8*** %4
%10 = getelementptr inbounds i8*, i8** %9, i64 0
%11 = load i8*, i8** %10
%12 = call i32 (i8*, i8*, ...) @printf(i8* getelementptr inbounds ([56 x i8], [56 x i8]* @.str, i64 0, i64 0), i8* %11)
%13 = call i32 @exit(i32 0)
unreachable
14: ; preds = %2
%15 = load i8**, i8*** %4
%16 = getelementptr inbounds i8*, i8** %15, i64 1
%17 = load i8*, i8** %16
%18 = call i8* @getenv(i8* %17)
store i8* %18, i8** %5
%19 = load i8**, i8*** %4
%20 = getelementptr inbounds i8*, i8** %19, i64 0
%21 = load i8*, i8** %20
%22 = call i32 @strlen(i8* %21)
%23 = load i8**, i8*** %4
%24 = getelementptr inbounds i8*, i8** %23, i64 2
%25 = load i8*, i8** %24
%26 = call i32 @strlen(i8* %25)
%27 = sub nsw i32 %22, %26
%28 = mul nsw i32 %27, 2
%29 = load i8*, i8** %5
%30 = sext i32 %28 to i64
%31 = getelementptr inbounds i8, i8* %29, i64 %30
store i8* %31, i8** %5
%32 = load i8**, i8*** %4
%33 = getelementptr inbounds i8*, i8** %32, i64 1
%34 = load i8*, i8** %33
%35 = load i8*, i8** %5
%36 = call i32 (i8*, i8*, ...) @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.1, i64 0, i64 0), i8* %34, i8* %35)
ret i32 0
}

LLVM IR (-O2):
@.str = [56 x i8] c"Usage: %s <environment variable> <target program name>\0A\00"
@.str.1 = [18 x i8] c"%s will be at %p\0A\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp slt i32 %0, 3
br i1 %3, label %4, label %8
4: ; preds = %2
%5 = load i8*, i8** %1
%6 = tail call i32 (i8*, i8*, ...) @printf(i8* getelementptr inbounds ([56 x i8], [56 x i8]* @.str, i64 0, i64 0), i8* %5)
%7 = tail call i32 @exit(i32 0)
unreachable
8: ; preds = %2
%9 = getelementptr inbounds i8*, i8** %1, i64 1
%10 = load i8*, i8** %9
%11 = tail call i8* @getenv(i8* %10)
%12 = load i8*, i8** %1
%13 = tail call i32 @strlen(i8* %12)
%14 = getelementptr inbounds i8*, i8** %1, i64 2
%15 = load i8*, i8** %14
%16 = tail call i32 @strlen(i8* %15)
%17 = sub nsw i32 %13, %16
%18 = shl nsw i32 %17, 1
%19 = sext i32 %18 to i64
%20 = getelementptr inbounds i8, i8* %11, i64 %19
%21 = load i8*, i8** %9
%22 = tail call i32 (i8*, i8*, ...) @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.1, i64 0, i64 0), i8* %21, i8* %20)
ret i32 0
}