void print_matrix(int *mat, int n, int m) {
  int i, j;
  for (i = 0; i < n; i++) {
    for (j = 0; j < m; j++) {
      printf("%d ", mat[(((i)*2) + (j))]);
    }
    printf("\n");
  }
  printf("----");
}


x86 assembly (clang, -O0):
<print_matrix>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
mov    %edx,-0x10(%rbp)
movl   $0x0,-0x14(%rbp)
mov    -0x14(%rbp),%eax
cmp    -0xc(%rbp),%eax
jge    1193 <print_matrix+0x83>
movl   $0x0,-0x18(%rbp)
mov    -0x18(%rbp),%eax
cmp    -0x10(%rbp),%eax
jge    1177 <print_matrix+0x67>
mov    -0x8(%rbp),%rax
mov    -0x14(%rbp),%ecx
shl    $0x1,%ecx
add    -0x18(%rbp),%ecx
movslq %ecx,%rcx
mov    (%rax,%rcx,4),%esi
lea    0xe9e(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x18(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x18(%rbp)
jmp    113c <print_matrix+0x2c>
lea    0xe86(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x14(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x14(%rbp)
jmp    1129 <print_matrix+0x19>
lea    0xe6c(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<print_matrix>:
push   %rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
push   %rax
mov    %edx,0x4(%rsp)
test   %esi,%esi
jle    1199 <print_matrix+0x79>
mov    %rdi,%rbx
mov    %esi,%r15d
mov    0x4(%rsp),%ebp
lea    0xebc(%rip),%r12
xor    %r13d,%r13d
jmp    1167 <print_matrix+0x47>
nopl   0x0(%rax)
mov    $0xa,%edi
call   1030 <putchar@plt>
add    $0x1,%r13
add    $0x8,%rbx
cmp    %r15,%r13
je     1199 <print_matrix+0x79>
cmpl   $0x0,0x4(%rsp)
jle    1150 <print_matrix+0x30>
xor    %r14d,%r14d
cs nopw 0x0(%rax,%rax,1)
nopl   0x0(%rax,%rax,1)
mov    (%rbx,%r14,4),%esi
mov    %r12,%rdi
xor    %eax,%eax
call   1040 <printf@plt>
add    $0x1,%r14
cmp    %r14,%rbp
jne    1180 <print_matrix+0x60>
jmp    1150 <print_matrix+0x30>
lea    0xe64(%rip),%rdi
xor    %eax,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
jmp    1040 <printf@plt>

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

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