int main() {
  int i, j, k;
  int N = 2000;
  double A[2000][2000];
  double B[2000][2000];
  double C[2000][2000];
  for (i = 0; i < N; i++) {
    for (j = 0; j < N; j++) {
      A[i][j] = 1.0;
      B[i][j] = 1.0;
    }
  }
  for (i = 0; i < N; i++) {
    for (j = 0; j < N; j++) {
      C[i][j] = 0;
      for (k = 0; k < N; k++) {
        C[i][j] = C[i][j] + A[i][k] * B[k][j];
      }
    }
  }
  return -1;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x5b8d7a0,%rsp
movl   $0x0,-0x4(%rbp)
movl   $0x7d0,-0x14(%rbp)
movl   $0x0,-0x8(%rbp)
mov    -0x8(%rbp),%eax
cmp    -0x14(%rbp),%eax
jge    11ac <main+0xac>
movl   $0x0,-0xc(%rbp)
mov    -0xc(%rbp),%eax
cmp    -0x14(%rbp),%eax
jge    1199 <main+0x99>
movslq -0x8(%rbp),%rcx
lea    -0x1e84820(%rbp),%rax
imul   $0x3e80,%rcx,%rcx
add    %rcx,%rax
movslq -0xc(%rbp),%rcx
movsd  0xea0(%rip),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
movslq -0x8(%rbp),%rcx
lea    -0x3d09020(%rbp),%rax
imul   $0x3e80,%rcx,%rcx
add    %rcx,%rax
movslq -0xc(%rbp),%rcx
movsd  0xe7a(%rip),%xmm0
movsd  %xmm0,(%rax,%rcx,8)
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    1133 <main+0x33>
jmp    119e <main+0x9e>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    1120 <main+0x20>
movl   $0x0,-0x8(%rbp)
mov    -0x8(%rbp),%eax
cmp    -0x14(%rbp),%eax
jge    12ba <main+0x1ba>
movl   $0x0,-0xc(%rbp)
mov    -0xc(%rbp),%eax
cmp    -0x14(%rbp),%eax
jge    12a7 <main+0x1a7>
movslq -0x8(%rbp),%rcx
lea    -0x5b8d820(%rbp),%rax
imul   $0x3e80,%rcx,%rcx
add    %rcx,%rax
movslq -0xc(%rbp),%rcx
xorps  %xmm0,%xmm0
movsd  %xmm0,(%rax,%rcx,8)
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
cmp    -0x14(%rbp),%eax
jge    1294 <main+0x194>
movslq -0x8(%rbp),%rcx
lea    -0x5b8d820(%rbp),%rax
imul   $0x3e80,%rcx,%rcx
add    %rcx,%rax
movslq -0xc(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm1
movslq -0x8(%rbp),%rcx
lea    -0x1e84820(%rbp),%rax
imul   $0x3e80,%rcx,%rcx
add    %rcx,%rax
movslq -0x10(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
movslq -0x10(%rbp),%rcx
lea    -0x3d09020(%rbp),%rax
imul   $0x3e80,%rcx,%rcx
add    %rcx,%rax
movslq -0xc(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movslq -0x8(%rbp),%rcx
lea    -0x5b8d820(%rbp),%rax
imul   $0x3e80,%rcx,%rcx
add    %rcx,%rax
movslq -0xc(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    11fa <main+0xfa>
jmp    1299 <main+0x199>
mov    -0xc(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0xc(%rbp)
jmp    11c6 <main+0xc6>
jmp    12ac <main+0x1ac>
mov    -0x8(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x8(%rbp)
jmp    11b3 <main+0xb3>
mov    $0xffffffff,%eax
add    $0x5b8d7a0,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
mov    $0xffffffff,%eax
ret

LLVM IR (-O0):
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32
%5 = alloca i32
%6 = alloca [2000 x [2000 x double]]
%7 = alloca [2000 x [2000 x double]]
%8 = alloca [2000 x [2000 x double]]
store i32 0, i32* %1
store i32 2000, i32* %5
store i32 0, i32* %2
br label %9
9: ; preds = %35, %0
%10 = load i32, i32* %2
%11 = load i32, i32* %5
%12 = icmp slt i32 %10, %11
br i1 %12, label %13, label %38
13: ; preds = %9
store i32 0, i32* %3
br label %14
14: ; preds = %31, %13
%15 = load i32, i32* %3
%16 = load i32, i32* %5
%17 = icmp slt i32 %15, %16
br i1 %17, label %18, label %34
18: ; preds = %14
%19 = load i32, i32* %2
%20 = sext i32 %19 to i64
%21 = getelementptr inbounds [2000 x [2000 x double]], [2000 x [2000 x double]]* %6, i64 0, i64 %20
%22 = load i32, i32* %3
%23 = sext i32 %22 to i64
%24 = getelementptr inbounds [2000 x double], [2000 x double]* %21, i64 0, i64 %23
store double 1.000000e+00, double* %24
%25 = load i32, i32* %2
%26 = sext i32 %25 to i64
%27 = getelementptr inbounds [2000 x [2000 x double]], [2000 x [2000 x double]]* %7, i64 0, i64 %26
%28 = load i32, i32* %3
%29 = sext i32 %28 to i64
%30 = getelementptr inbounds [2000 x double], [2000 x double]* %27, i64 0, i64 %29
store double 1.000000e+00, double* %30
br label %31
31: ; preds = %18
%32 = load i32, i32* %3
%33 = add nsw i32 %32, 1
store i32 %33, i32* %3
br label %14
34: ; preds = %14
br label %35
35: ; preds = %34
%36 = load i32, i32* %2
%37 = add nsw i32 %36, 1
store i32 %37, i32* %2
br label %9
38: ; preds = %9
store i32 0, i32* %2
br label %39
39: ; preds = %96, %38
%40 = load i32, i32* %2
%41 = load i32, i32* %5
%42 = icmp slt i32 %40, %41
br i1 %42, label %43, label %99
43: ; preds = %39
store i32 0, i32* %3
br label %44
44: ; preds = %92, %43
%45 = load i32, i32* %3
%46 = load i32, i32* %5
%47 = icmp slt i32 %45, %46
br i1 %47, label %48, label %95
48: ; preds = %44
%49 = load i32, i32* %2
%50 = sext i32 %49 to i64
%51 = getelementptr inbounds [2000 x [2000 x double]], [2000 x [2000 x double]]* %8, i64 0, i64 %50
%52 = load i32, i32* %3
%53 = sext i32 %52 to i64
%54 = getelementptr inbounds [2000 x double], [2000 x double]* %51, i64 0, i64 %53
store double 0.000000e+00, double* %54
store i32 0, i32* %4
br label %55
55: ; preds = %88, %48
%56 = load i32, i32* %4
%57 = load i32, i32* %5
%58 = icmp slt i32 %56, %57
br i1 %58, label %59, label %91
59: ; preds = %55
%60 = load i32, i32* %2
%61 = sext i32 %60 to i64
%62 = getelementptr inbounds [2000 x [2000 x double]], [2000 x [2000 x double]]* %8, i64 0, i64 %61
%63 = load i32, i32* %3
%64 = sext i32 %63 to i64
%65 = getelementptr inbounds [2000 x double], [2000 x double]* %62, i64 0, i64 %64
%66 = load double, double* %65
%67 = load i32, i32* %2
%68 = sext i32 %67 to i64
%69 = getelementptr inbounds [2000 x [2000 x double]], [2000 x [2000 x double]]* %6, i64 0, i64 %68
%70 = load i32, i32* %4
%71 = sext i32 %70 to i64
%72 = getelementptr inbounds [2000 x double], [2000 x double]* %69, i64 0, i64 %71
%73 = load double, double* %72
%74 = load i32, i32* %4
%75 = sext i32 %74 to i64
%76 = getelementptr inbounds [2000 x [2000 x double]], [2000 x [2000 x double]]* %7, i64 0, i64 %75
%77 = load i32, i32* %3
%78 = sext i32 %77 to i64
%79 = getelementptr inbounds [2000 x double], [2000 x double]* %76, i64 0, i64 %78
%80 = load double, double* %79
%81 = call double @llvm.fmuladd.f64(double %73, double %80, double %66)
%82 = load i32, i32* %2
%83 = sext i32 %82 to i64
%84 = getelementptr inbounds [2000 x [2000 x double]], [2000 x [2000 x double]]* %8, i64 0, i64 %83
%85 = load i32, i32* %3
%86 = sext i32 %85 to i64
%87 = getelementptr inbounds [2000 x double], [2000 x double]* %84, i64 0, i64 %86
store double %81, double* %87
br label %88
88: ; preds = %59
%89 = load i32, i32* %4
%90 = add nsw i32 %89, 1
store i32 %90, i32* %4
br label %55
91: ; preds = %55
br label %92
92: ; preds = %91
%93 = load i32, i32* %3
%94 = add nsw i32 %93, 1
store i32 %94, i32* %3
br label %44
95: ; preds = %44
br label %96
96: ; preds = %95
%97 = load i32, i32* %2
%98 = add nsw i32 %97, 1
store i32 %98, i32* %2
br label %39
99: ; preds = %39
ret i32 -1
}

LLVM IR (-O2):
define i32 @main() {
ret i32 -1
}