void m_xlt(float *M, const float *v) {
  M[0] = 1.f;
  M[4] = 0.f;
  M[8] = 0.f;
  M[12] = v[0];
  M[1] = 0.f;
  M[5] = 1.f;
  M[9] = 0.f;
  M[13] = v[1];
  M[2] = 0.f;
  M[6] = 0.f;
  M[10] = 1.f;
  M[14] = v[2];
  M[3] = 0.f;
  M[7] = 0.f;
  M[11] = 0.f;
  M[15] = 1.f;
}


x86 assembly (clang, -O0):
<m_xlt>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x8(%rbp),%rax
movss  0xee8(%rip),%xmm0
movss  %xmm0,(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x10(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x20(%rax)
mov    -0x10(%rbp),%rax
movss  (%rax),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x30(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x4(%rax)
mov    -0x8(%rbp),%rax
movss  0xea3(%rip),%xmm0
movss  %xmm0,0x14(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x24(%rax)
mov    -0x10(%rbp),%rax
movss  0x4(%rax),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x34(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x8(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x18(%rax)
mov    -0x8(%rbp),%rax
movss  0xe5c(%rip),%xmm0
movss  %xmm0,0x28(%rax)
mov    -0x10(%rbp),%rax
movss  0x8(%rax),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x38(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0xc(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x1c(%rax)
mov    -0x8(%rbp),%rax
xorps  %xmm0,%xmm0
movss  %xmm0,0x2c(%rax)
mov    -0x8(%rbp),%rax
movss  0xe15(%rip),%xmm0
movss  %xmm0,0x3c(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<m_xlt>:
movl   $0x3f800000,(%rdi)
movl   $0x0,0x10(%rdi)
movl   $0x0,0x20(%rdi)
movss  (%rsi),%xmm0
movss  %xmm0,0x30(%rdi)
movl   $0x0,0x4(%rdi)
movl   $0x3f800000,0x14(%rdi)
movl   $0x0,0x24(%rdi)
movss  0x4(%rsi),%xmm0
movss  %xmm0,0x34(%rdi)
movl   $0x0,0x8(%rdi)
movl   $0x0,0x18(%rdi)
movl   $0x3f800000,0x28(%rdi)
movss  0x8(%rsi),%xmm0
movss  %xmm0,0x38(%rdi)
movl   $0x0,0xc(%rdi)
movl   $0x0,0x1c(%rdi)
movl   $0x0,0x2c(%rdi)
movl   $0x3f800000,0x3c(%rdi)
ret

LLVM IR (-O0):
define void @m_xlt(float* %0, float* %1) {
%3 = alloca float*
%4 = alloca float*
store float* %0, float** %3
store float* %1, float** %4
%5 = load float*, float** %3
%6 = getelementptr inbounds float, float* %5, i64 0
store float 1.000000e+00, float* %6
%7 = load float*, float** %3
%8 = getelementptr inbounds float, float* %7, i64 4
store float 0.000000e+00, float* %8
%9 = load float*, float** %3
%10 = getelementptr inbounds float, float* %9, i64 8
store float 0.000000e+00, float* %10
%11 = load float*, float** %4
%12 = getelementptr inbounds float, float* %11, i64 0
%13 = load float, float* %12
%14 = load float*, float** %3
%15 = getelementptr inbounds float, float* %14, i64 12
store float %13, float* %15
%16 = load float*, float** %3
%17 = getelementptr inbounds float, float* %16, i64 1
store float 0.000000e+00, float* %17
%18 = load float*, float** %3
%19 = getelementptr inbounds float, float* %18, i64 5
store float 1.000000e+00, float* %19
%20 = load float*, float** %3
%21 = getelementptr inbounds float, float* %20, i64 9
store float 0.000000e+00, float* %21
%22 = load float*, float** %4
%23 = getelementptr inbounds float, float* %22, i64 1
%24 = load float, float* %23
%25 = load float*, float** %3
%26 = getelementptr inbounds float, float* %25, i64 13
store float %24, float* %26
%27 = load float*, float** %3
%28 = getelementptr inbounds float, float* %27, i64 2
store float 0.000000e+00, float* %28
%29 = load float*, float** %3
%30 = getelementptr inbounds float, float* %29, i64 6
store float 0.000000e+00, float* %30
%31 = load float*, float** %3
%32 = getelementptr inbounds float, float* %31, i64 10
store float 1.000000e+00, float* %32
%33 = load float*, float** %4
%34 = getelementptr inbounds float, float* %33, i64 2
%35 = load float, float* %34
%36 = load float*, float** %3
%37 = getelementptr inbounds float, float* %36, i64 14
store float %35, float* %37
%38 = load float*, float** %3
%39 = getelementptr inbounds float, float* %38, i64 3
store float 0.000000e+00, float* %39
%40 = load float*, float** %3
%41 = getelementptr inbounds float, float* %40, i64 7
store float 0.000000e+00, float* %41
%42 = load float*, float** %3
%43 = getelementptr inbounds float, float* %42, i64 11
store float 0.000000e+00, float* %43
%44 = load float*, float** %3
%45 = getelementptr inbounds float, float* %44, i64 15
store float 1.000000e+00, float* %45
ret void
}

LLVM IR (-O2):
define void @m_xlt(float* nocapture writeonly %0, float* nocapture %1) {
store float 1.000000e+00, float* %0
%3 = getelementptr inbounds float, float* %0, i64 4
store float 0.000000e+00, float* %3
%4 = getelementptr inbounds float, float* %0, i64 8
store float 0.000000e+00, float* %4
%5 = load float, float* %1
%6 = getelementptr inbounds float, float* %0, i64 12
store float %5, float* %6
%7 = getelementptr inbounds float, float* %0, i64 1
store float 0.000000e+00, float* %7
%8 = getelementptr inbounds float, float* %0, i64 5
store float 1.000000e+00, float* %8
%9 = getelementptr inbounds float, float* %0, i64 9
store float 0.000000e+00, float* %9
%10 = getelementptr inbounds float, float* %1, i64 1
%11 = load float, float* %10
%12 = getelementptr inbounds float, float* %0, i64 13
store float %11, float* %12
%13 = getelementptr inbounds float, float* %0, i64 2
store float 0.000000e+00, float* %13
%14 = getelementptr inbounds float, float* %0, i64 6
store float 0.000000e+00, float* %14
%15 = getelementptr inbounds float, float* %0, i64 10
store float 1.000000e+00, float* %15
%16 = getelementptr inbounds float, float* %1, i64 2
%17 = load float, float* %16
%18 = getelementptr inbounds float, float* %0, i64 14
store float %17, float* %18
%19 = getelementptr inbounds float, float* %0, i64 3
store float 0.000000e+00, float* %19
%20 = getelementptr inbounds float, float* %0, i64 7
store float 0.000000e+00, float* %20
%21 = getelementptr inbounds float, float* %0, i64 11
store float 0.000000e+00, float* %21
%22 = getelementptr inbounds float, float* %0, i64 15
store float 1.000000e+00, float* %22
ret void
}