void glmGenerateInertiaMatrixForBox4d(double m[16], double x, double y,
                                      double z, double mass) {
  mass /= 12.0;
  m[0] = mass * (y * y + z * z);
  m[4] = 0;
  m[8] = 0;
  m[12] = 0;
  m[1] = 0;
  m[5] = mass * (x * x + z * z);
  m[9] = 0;
  m[13] = 0;
  m[2] = 0;
  m[6] = 0;
  m[10] = mass * (x * x + y * y);
  m[14] = 0;
  m[3] = 0;
  m[7] = 0;
  m[11] = 0;
  m[15] = 1;
}


x86 assembly (clang, -O0):
<glmGenerateInertiaMatrixForBox4d>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
movsd  %xmm0,-0x10(%rbp)
movsd  %xmm1,-0x18(%rbp)
movsd  %xmm2,-0x20(%rbp)
movsd  %xmm3,-0x28(%rbp)
movsd  -0x28(%rbp),%xmm0
movsd  0xedf(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x28(%rbp)
movsd  -0x28(%rbp),%xmm0
movsd  -0x18(%rbp),%xmm1
movsd  -0x18(%rbp),%xmm3
movsd  -0x20(%rbp),%xmm2
mulsd  -0x20(%rbp),%xmm2
mulsd  %xmm3,%xmm1
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x20(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x40(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x60(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x8(%rax)
movsd  -0x28(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm3
movsd  -0x20(%rbp),%xmm2
mulsd  -0x20(%rbp),%xmm2
mulsd  %xmm3,%xmm1
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,0x28(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x48(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x68(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x10(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x30(%rax)
movsd  -0x28(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm3
movsd  -0x18(%rbp),%xmm2
mulsd  -0x18(%rbp),%xmm2
mulsd  %xmm3,%xmm1
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,0x50(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x70(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x18(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x38(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,0x58(%rax)
mov    -0x8(%rbp),%rax
movsd  0xda9(%rip),%xmm0
movsd  %xmm0,0x78(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<glmGenerateInertiaMatrixForBox4d>:
divsd  0xef8(%rip),%xmm3
mulsd  %xmm2,%xmm2
mulsd  %xmm1,%xmm1
movapd %xmm1,%xmm4
addsd  %xmm2,%xmm4
mulsd  %xmm3,%xmm4
movsd  %xmm4,(%rdi)
mulsd  %xmm0,%xmm0
addsd  %xmm0,%xmm2
mulsd  %xmm3,%xmm2
movsd  %xmm2,0x28(%rdi)
xorpd  %xmm2,%xmm2
movupd %xmm2,0x40(%rdi)
movupd %xmm2,0x8(%rdi)
addsd  %xmm1,%xmm0
mulsd  %xmm3,%xmm0
movsd  %xmm0,0x50(%rdi)
movupd %xmm2,0x68(%rdi)
movupd %xmm2,0x18(%rdi)
movupd %xmm2,0x30(%rdi)
movupd %xmm2,0x58(%rdi)
movabs $0x3ff0000000000000,%rax
mov    %rax,0x78(%rdi)
ret

LLVM IR (-O0):
define void @glmGenerateInertiaMatrixForBox4d(double* %0, double %1, double %2, double %3, double %4) {
%6 = alloca double*
%7 = alloca double
%8 = alloca double
%9 = alloca double
%10 = alloca double
store double* %0, double** %6
store double %1, double* %7
store double %2, double* %8
store double %3, double* %9
store double %4, double* %10
%11 = load double, double* %10
%12 = fdiv double %11, 1.200000e+01
store double %12, double* %10
%13 = load double, double* %10
%14 = load double, double* %8
%15 = load double, double* %8
%16 = load double, double* %9
%17 = load double, double* %9
%18 = fmul double %16, %17
%19 = call double @llvm.fmuladd.f64(double %14, double %15, double %18)
%20 = fmul double %13, %19
%21 = load double*, double** %6
%22 = getelementptr inbounds double, double* %21, i64 0
store double %20, double* %22
%23 = load double*, double** %6
%24 = getelementptr inbounds double, double* %23, i64 4
store double 0.000000e+00, double* %24
%25 = load double*, double** %6
%26 = getelementptr inbounds double, double* %25, i64 8
store double 0.000000e+00, double* %26
%27 = load double*, double** %6
%28 = getelementptr inbounds double, double* %27, i64 12
store double 0.000000e+00, double* %28
%29 = load double*, double** %6
%30 = getelementptr inbounds double, double* %29, i64 1
store double 0.000000e+00, double* %30
%31 = load double, double* %10
%32 = load double, double* %7
%33 = load double, double* %7
%34 = load double, double* %9
%35 = load double, double* %9
%36 = fmul double %34, %35
%37 = call double @llvm.fmuladd.f64(double %32, double %33, double %36)
%38 = fmul double %31, %37
%39 = load double*, double** %6
%40 = getelementptr inbounds double, double* %39, i64 5
store double %38, double* %40
%41 = load double*, double** %6
%42 = getelementptr inbounds double, double* %41, i64 9
store double 0.000000e+00, double* %42
%43 = load double*, double** %6
%44 = getelementptr inbounds double, double* %43, i64 13
store double 0.000000e+00, double* %44
%45 = load double*, double** %6
%46 = getelementptr inbounds double, double* %45, i64 2
store double 0.000000e+00, double* %46
%47 = load double*, double** %6
%48 = getelementptr inbounds double, double* %47, i64 6
store double 0.000000e+00, double* %48
%49 = load double, double* %10
%50 = load double, double* %7
%51 = load double, double* %7
%52 = load double, double* %8
%53 = load double, double* %8
%54 = fmul double %52, %53
%55 = call double @llvm.fmuladd.f64(double %50, double %51, double %54)
%56 = fmul double %49, %55
%57 = load double*, double** %6
%58 = getelementptr inbounds double, double* %57, i64 10
store double %56, double* %58
%59 = load double*, double** %6
%60 = getelementptr inbounds double, double* %59, i64 14
store double 0.000000e+00, double* %60
%61 = load double*, double** %6
%62 = getelementptr inbounds double, double* %61, i64 3
store double 0.000000e+00, double* %62
%63 = load double*, double** %6
%64 = getelementptr inbounds double, double* %63, i64 7
store double 0.000000e+00, double* %64
%65 = load double*, double** %6
%66 = getelementptr inbounds double, double* %65, i64 11
store double 0.000000e+00, double* %66
%67 = load double*, double** %6
%68 = getelementptr inbounds double, double* %67, i64 15
store double 1.000000e+00, double* %68
ret void
}

LLVM IR (-O2):
define void @glmGenerateInertiaMatrixForBox4d(double* nocapture writeonly %0, double %1, double %2, double %3, double %4) {
%6 = fdiv double %4, 1.200000e+01
%7 = fmul double %3, %3
%8 = tail call double @llvm.fmuladd.f64(double %2, double %2, double %7)
%9 = fmul double %6, %8
store double %9, double* %0
%10 = getelementptr inbounds double, double* %0, i64 8
%11 = getelementptr inbounds double, double* %0, i64 1
%12 = tail call double @llvm.fmuladd.f64(double %1, double %1, double %7)
%13 = fmul double %6, %12
%14 = getelementptr inbounds double, double* %0, i64 5
store double %13, double* %14
%15 = bitcast double* %10 to <2 x double>*
store <2 x double> zeroinitializer, <2 x double>* %15
%16 = getelementptr inbounds double, double* %0, i64 13
%17 = bitcast double* %11 to <2 x double>*
store <2 x double> zeroinitializer, <2 x double>* %17
%18 = getelementptr inbounds double, double* %0, i64 6
%19 = fmul double %2, %2
%20 = tail call double @llvm.fmuladd.f64(double %1, double %1, double %19)
%21 = fmul double %20, %6
%22 = getelementptr inbounds double, double* %0, i64 10
store double %21, double* %22
%23 = bitcast double* %16 to <2 x double>*
store <2 x double> zeroinitializer, <2 x double>* %23
%24 = getelementptr inbounds double, double* %0, i64 3
%25 = bitcast double* %24 to <2 x double>*
store <2 x double> zeroinitializer, <2 x double>* %25
%26 = bitcast double* %18 to <2 x double>*
store <2 x double> zeroinitializer, <2 x double>* %26
%27 = getelementptr inbounds double, double* %0, i64 11
%28 = bitcast double* %27 to <2 x double>*
store <2 x double> zeroinitializer, <2 x double>* %28
%29 = getelementptr inbounds double, double* %0, i64 15
store double 1.000000e+00, double* %29
ret void
}