#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*/ printf(char *, ...);
int main(int argc, char *argv[]) {
  int i;
  for (i = 0; i < argc; i++)
    printf("argv[%d] is %s\n", i, argv[i]);
  printf("Use argv[argc] == NULL\n");
  for (i = 0; argv[i] != NULL; i++)
    printf("argv[%d] is %s\n", i, argv[i]);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movl   $0x0,-0x14(%rbp)
mov    -0x14(%rbp),%eax
cmp    -0x8(%rbp),%eax
jge    1164 <main+0x54>
mov    -0x14(%rbp),%esi
mov    -0x10(%rbp),%rax
movslq -0x14(%rbp),%rcx
mov    (%rax,%rcx,8),%rdx
lea    0xeb1(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x14(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x14(%rbp)
jmp    112d <main+0x1d>
lea    0xea5(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x0,-0x14(%rbp)
mov    -0x10(%rbp),%rax
movslq -0x14(%rbp),%rcx
cmpq   $0x0,(%rax,%rcx,8)
je     11b7 <main+0xa7>
mov    -0x14(%rbp),%esi
mov    -0x10(%rbp),%rax
movslq -0x14(%rbp),%rcx
mov    (%rax,%rcx,8),%rdx
lea    0xe5e(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x14(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x14(%rbp)
jmp    1179 <main+0x69>
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
mov    %rsi,%r15
test   %edi,%edi
jle    1159 <main+0x39>
mov    %edi,%r12d
lea    0xec7(%rip),%r14
xor    %ebx,%ebx
nopl   0x0(%rax,%rax,1)
mov    (%r15,%rbx,8),%rdx
mov    %r14,%rdi
mov    %ebx,%esi
xor    %eax,%eax
call   1040 <printf@plt>
add    $0x1,%rbx
cmp    %rbx,%r12
jne    1140 <main+0x20>
lea    0xeb0(%rip),%rdi
call   1030 <puts@plt>
mov    (%r15),%rdx
test   %rdx,%rdx
je     119a <main+0x7a>
lea    0xe8c(%rip),%r14
xor    %ebx,%ebx
cs nopw 0x0(%rax,%rax,1)
mov    %r14,%rdi
mov    %ebx,%esi
xor    %eax,%eax
call   1040 <printf@plt>
mov    0x8(%r15,%rbx,8),%rdx
add    $0x1,%rbx
test   %rdx,%rdx
jne    1180 <main+0x60>
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [16 x i8] c"argv[%d] is %s\0A\00"
@.str.1 = [24 x i8] c"Use argv[argc] == NULL\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i32
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
store i32 0, i32* %6
br label %7
7: ; preds = %19, %2
%8 = load i32, i32* %6
%9 = load i32, i32* %4
%10 = icmp slt i32 %8, %9
br i1 %10, label %11, label %22
11: ; preds = %7
%12 = load i32, i32* %6
%13 = load i8**, i8*** %5
%14 = load i32, i32* %6
%15 = sext i32 %14 to i64
%16 = getelementptr inbounds i8*, i8** %13, i64 %15
%17 = load i8*, i8** %16
%18 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([16 x i8], [16 x i8]* @.str, i64 0, i64 0), i32 %12, i8* %17)
br label %19
19: ; preds = %11
%20 = load i32, i32* %6
%21 = add nsw i32 %20, 1
store i32 %21, i32* %6
br label %7
22: ; preds = %7
%23 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.1, i64 0, i64 0))
store i32 0, i32* %6
br label %24
24: ; preds = %39, %22
%25 = load i8**, i8*** %5
%26 = load i32, i32* %6
%27 = sext i32 %26 to i64
%28 = getelementptr inbounds i8*, i8** %25, i64 %27
%29 = load i8*, i8** %28
%30 = icmp ne i8* %29, null
br i1 %30, label %31, label %42
31: ; preds = %24
%32 = load i32, i32* %6
%33 = load i8**, i8*** %5
%34 = load i32, i32* %6
%35 = sext i32 %34 to i64
%36 = getelementptr inbounds i8*, i8** %33, i64 %35
%37 = load i8*, i8** %36
%38 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([16 x i8], [16 x i8]* @.str, i64 0, i64 0), i32 %32, i8* %37)
br label %39
39: ; preds = %31
%40 = load i32, i32* %6
%41 = add nsw i32 %40, 1
store i32 %41, i32* %6
br label %24
42: ; preds = %24
ret i32 0
}

LLVM IR (-O2):
@.str = [16 x i8] c"argv[%d] is %s\0A\00"
@str = [23 x i8] c"Use argv[argc] == NULL\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp sgt i32 %0, 0
br i1 %3, label %4, label %14
4: ; preds = %2
%5 = zext i32 %0 to i64
br label %6
6: ; preds = %4, %6
%7 = phi i64 [ 0, %4 ], [ %12, %6 ]
%8 = getelementptr inbounds i8*, i8** %1, i64 %7
%9 = load i8*, i8** %8
%10 = trunc i64 %7 to i32
%11 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([16 x i8], [16 x i8]* @.str, i64 0, i64 0), i32 %10, i8* %9)
%12 = add nuw nsw i64 %7, 1
%13 = icmp eq i64 %12, %5
br i1 %13, label %14, label %6
14: ; preds = %6, %2
%15 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([23 x i8], [23 x i8]* @str, i64 0, i64 0))
%16 = load i8*, i8** %1
%17 = icmp eq i8* %16, null
br i1 %17, label %27, label %18
18: ; preds = %14, %18
%19 = phi i64 [ %23, %18 ], [ 0, %14 ]
%20 = phi i8* [ %25, %18 ], [ %16, %14 ]
%21 = trunc i64 %19 to i32
%22 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([16 x i8], [16 x i8]* @.str, i64 0, i64 0), i32 %21, i8* %20)
%23 = add nuw i64 %19, 1
%24 = getelementptr inbounds i8*, i8** %1, i64 %23
%25 = load i8*, i8** %24
%26 = icmp eq i8* %25, null
br i1 %26, label %27, label %18
27: ; preds = %18, %14
ret i32 0
}