#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*/ SEEK_CUR;
int /*<<< orphan*/ STDIN_FILENO;
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *);
int lseek(int /*<<< orphan*/, int /*<<< orphan*/, int /*<<< orphan*/);
int /*<<< orphan*/ printf(char *);
int /*<<< orphan*/ stderr;
int main(int argc, char const *argv[]) {
  if (lseek(STDIN_FILENO, 0, SEEK_CUR) == -1) {
    fprintf(stderr, "Can not seek on stdin.\n");
  } else {
    printf("Seek OK on stdin.\n");
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    0x2e83(%rip),%rax
mov    (%rax),%edi
mov    0x2e92(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1040 <lseek@plt>
cmp    $0xffffffff,%eax
jne    1182 <main+0x52>
mov    0x2e69(%rip),%rax
mov    (%rax),%edi
lea    0xe88(%rip),%rsi
call   1050 <fprintf@plt>
jmp    118e <main+0x5e>
lea    0xe8f(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
mov    0x2e98(%rip),%rax
mov    (%rax),%edi
mov    0x2ea7(%rip),%rax
mov    (%rax),%edx
xor    %esi,%esi
call   1040 <lseek@plt>
cmp    $0xffffffff,%eax
je     115d <main+0x2d>
lea    0xec2(%rip),%rdi
call   1030 <puts@plt>
jmp    1172 <main+0x42>
mov    0x2e74(%rip),%rax
mov    (%rax),%edi
lea    0xe93(%rip),%rsi
call   1050 <fprintf@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@STDIN_FILENO = global i32 0
@SEEK_CUR = global i32 0
@stderr = global i32 0
@.str = [24 x i8] c"Can not seek on stdin.\0A\00"
@.str.1 = [19 x i8] c"Seek OK on stdin.\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%6 = load i32, i32* @STDIN_FILENO
%7 = load i32, i32* @SEEK_CUR
%8 = call i32 @lseek(i32 %6, i32 0, i32 %7)
%9 = icmp eq i32 %8, -1
br i1 %9, label %10, label %13
10: ; preds = %2
%11 = load i32, i32* @stderr
%12 = call i32 @fprintf(i32 %11, i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str, i64 0, i64 0))
br label %15
13: ; preds = %2
%14 = call i32 @printf(i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.1, i64 0, i64 0))
br label %15
15: ; preds = %13, %10
ret i32 0
}

LLVM IR (-O2):
@STDIN_FILENO = global i32 0
@SEEK_CUR = global i32 0
@stderr = global i32 0
@.str = [24 x i8] c"Can not seek on stdin.\0A\00"
@str = [18 x i8] c"Seek OK on stdin.\00"
define i32 @main(i32 %0, i8** nocapture readnone %1) {
%3 = load i32, i32* @STDIN_FILENO
%4 = load i32, i32* @SEEK_CUR
%5 = tail call i32 @lseek(i32 %3, i32 0, i32 %4)
%6 = icmp eq i32 %5, -1
br i1 %6, label %7, label %10
7: ; preds = %2
%8 = load i32, i32* @stderr
%9 = tail call i32 @fprintf(i32 %8, i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str, i64 0, i64 0))
br label %12
10: ; preds = %2
%11 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([18 x i8], [18 x i8]* @str, i64 0, i64 0))
br label %12
12: ; preds = %10, %7
ret i32 0
}