#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*/ scanf(char *, int *);
void read(int mat[][2], int n) {
  int i = 0, j;
  for (i = 0; i < n; i++) {
    for (j = 0; j < 2; j++)
      scanf("%d", &mat[i][j]);
  }
}


x86 assembly (clang, -O0):
<read>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
movl   $0x0,-0x10(%rbp)
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
cmp    -0xc(%rbp),%eax
jge    1191 <read+0x81>
movl   $0x0,-0x14(%rbp)
cmpl   $0x2,-0x14(%rbp)
jge    117e <read+0x6e>
mov    -0x8(%rbp),%rsi
movslq -0x10(%rbp),%rax
shl    $0x3,%rax
add    %rax,%rsi
movslq -0x14(%rbp),%rax
shl    $0x2,%rax
add    %rax,%rsi
lea    0xe95(%rip),%rdi
call   1030 <scanf@plt>
mov    -0x14(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x14(%rbp)
jmp    1140 <read+0x30>
jmp    1183 <read+0x73>
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    112d <read+0x1d>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<read>:
push   %r15
push   %r14
push   %rbx
test   %esi,%esi
jle    1151 <read+0x41>
mov    %rdi,%rbx
mov    %esi,%r15d
lea    0xeda(%rip),%r14
cs nopw 0x0(%rax,%rax,1)
mov    %r14,%rdi
mov    %rbx,%rsi
call   1030 <scanf@plt>
lea    0x4(%rbx),%rsi
mov    %r14,%rdi
call   1030 <scanf@plt>
add    $0x8,%rbx
add    $0xffffffffffffffff,%r15
jne    1130 <read+0x20>
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [3 x i8] c"%d\00"
define void @read([2 x i32]* %0, i32 %1) {
%3 = alloca [2 x i32]*
%4 = alloca i32
%5 = alloca i32
%6 = alloca i32
store [2 x i32]* %0, [2 x i32]** %3
store i32 %1, i32* %4
store i32 0, i32* %5
store i32 0, i32* %5
br label %7
7: ; preds = %28, %2
%8 = load i32, i32* %5
%9 = load i32, i32* %4
%10 = icmp slt i32 %8, %9
br i1 %10, label %11, label %31
11: ; preds = %7
store i32 0, i32* %6
br label %12
12: ; preds = %24, %11
%13 = load i32, i32* %6
%14 = icmp slt i32 %13, 2
br i1 %14, label %15, label %27
15: ; preds = %12
%16 = load [2 x i32]*, [2 x i32]** %3
%17 = load i32, i32* %5
%18 = sext i32 %17 to i64
%19 = getelementptr inbounds [2 x i32], [2 x i32]* %16, i64 %18
%20 = load i32, i32* %6
%21 = sext i32 %20 to i64
%22 = getelementptr inbounds [2 x i32], [2 x i32]* %19, i64 0, i64 %21
%23 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %22)
br label %24
24: ; preds = %15
%25 = load i32, i32* %6
%26 = add nsw i32 %25, 1
store i32 %26, i32* %6
br label %12
27: ; preds = %12
br label %28
28: ; preds = %27
%29 = load i32, i32* %5
%30 = add nsw i32 %29, 1
store i32 %30, i32* %5
br label %7
31: ; preds = %7
ret void
}

LLVM IR (-O2):
@.str = [3 x i8] c"%d\00"
define void @read([2 x i32]* %0, i32 %1) {
%3 = icmp sgt i32 %1, 0
br i1 %3, label %4, label %14
4: ; preds = %2
%5 = zext i32 %1 to i64
br label %6
6: ; preds = %4, %6
%7 = phi i64 [ 0, %4 ], [ %12, %6 ]
%8 = getelementptr inbounds [2 x i32], [2 x i32]* %0, i64 %7, i64 0
%9 = tail call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %8)
%10 = getelementptr inbounds [2 x i32], [2 x i32]* %0, i64 %7, i64 1
%11 = tail call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i32* %10)
%12 = add nuw nsw i64 %7, 1
%13 = icmp eq i64 %12, %5
br i1 %13, label %14, label %6
14: ; preds = %6, %2
ret void
}