int main(void) {
  register int i = 5;
  volatile const int b = 20;
  printf("%p\n", &b);
  for (i = 0; i < 5; i++)
    printf("%d万岁万岁万万岁!\n", i);
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
movl   $0x5,-0x8(%rbp)
movl   $0x14,-0xc(%rbp)
lea    0xecc(%rip),%rdi
lea    -0xc(%rbp),%rsi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x0,-0x8(%rbp)
cmpl   $0x5,-0x8(%rbp)
jge    116f <main+0x5f>
mov    -0x8(%rbp),%esi
lea    0xeaa(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    1146 <main+0x36>
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
sub    $0x10,%rsp
movl   $0x14,0xc(%rsp)
lea    0xedc(%rip),%rdi
lea    0xc(%rsp),%rsi
xor    %eax,%eax
call   1030 <printf@plt>
lea    0xecd(%rip),%rbx
mov    %rbx,%rdi
xor    %esi,%esi
xor    %eax,%eax
call   1030 <printf@plt>
mov    %rbx,%rdi
mov    $0x1,%esi
xor    %eax,%eax
call   1030 <printf@plt>
mov    %rbx,%rdi
mov    $0x2,%esi
xor    %eax,%eax
call   1030 <printf@plt>
mov    %rbx,%rdi
mov    $0x3,%esi
xor    %eax,%eax
call   1030 <printf@plt>
mov    %rbx,%rdi
mov    $0x4,%esi
xor    %eax,%eax
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [4 x i8] c"%p\0A\00"
@.str.1 = [26 x i8] c"%d\E4\B8\87\E5\B2\81\E4\B8\87\E5\B2\81\E4\B8\87\E4\B8\87\E5\B2\81!\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
store i32 0, i32* %1
store i32 5, i32* %2
store volatile i32 20, i32* %3
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i32* %3)
store i32 0, i32* %2
br label %5
5: ; preds = %11, %0
%6 = load i32, i32* %2
%7 = icmp slt i32 %6, 5
br i1 %7, label %8, label %14
8: ; preds = %5
%9 = load i32, i32* %2
%10 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str.1, i64 0, i64 0), i32 %9)
br label %11
11: ; preds = %8
%12 = load i32, i32* %2
%13 = add nsw i32 %12, 1
store i32 %13, i32* %2
br label %5
14: ; preds = %5
%15 = load i32, i32* %1
ret i32 %15
}

LLVM IR (-O2):
@.str = [4 x i8] c"%p\0A\00"
@.str.1 = [26 x i8] c"%d\E4\B8\87\E5\B2\81\E4\B8\87\E5\B2\81\E4\B8\87\E4\B8\87\E5\B2\81!\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
store volatile i32 20, i32* %1
%3 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i32* %1)
%4 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str.1, i64 0, i64 0), i32 0)
%5 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str.1, i64 0, i64 0), i32 1)
%6 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str.1, i64 0, i64 0), i32 2)
%7 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str.1, i64 0, i64 0), i32 3)
%8 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([26 x i8], [26 x i8]* @.str.1, i64 0, i64 0), i32 4)
ret i32 0
}