double monobf(double ustar, double rho, double Cp, double K, double H,
              double LE, double tcair) {
  double Gravity = 9.8;
  double tkair, lambdav, term, L;
  tkair = tcair + 273.15;
  lambdav = 2501300.0 - 2366.0 * tcair;
  term = (H / (Cp * tkair)) + (0.61 * LE / lambdav);
  L = -rho * (ustar * ustar * ustar) / (K * Gravity * term);
  return (L);
}


x86 assembly (clang, -O0):
<monobf>:
push   %rbp
mov    %rsp,%rbp
movsd  %xmm0,-0x8(%rbp)
movsd  %xmm1,-0x10(%rbp)
movsd  %xmm2,-0x18(%rbp)
movsd  %xmm3,-0x20(%rbp)
movsd  %xmm4,-0x28(%rbp)
movsd  %xmm5,-0x30(%rbp)
movsd  %xmm6,-0x38(%rbp)
movsd  0xef1(%rip),%xmm0
movsd  %xmm0,-0x40(%rbp)
movsd  0xedc(%rip),%xmm0
addsd  -0x38(%rbp),%xmm0
movsd  %xmm0,-0x48(%rbp)
movsd  -0x38(%rbp),%xmm0
movsd  0xeb5(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xeb1(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x50(%rbp)
movsd  -0x28(%rbp),%xmm0
movsd  -0x18(%rbp),%xmm1
mulsd  -0x48(%rbp),%xmm1
divsd  %xmm1,%xmm0
movsd  0xe7d(%rip),%xmm1
mulsd  -0x30(%rbp),%xmm1
divsd  -0x50(%rbp),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x58(%rbp)
movsd  -0x10(%rbp),%xmm0
movq   %xmm0,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm0
movsd  -0x8(%rbp),%xmm1
mulsd  -0x8(%rbp),%xmm1
mulsd  -0x8(%rbp),%xmm1
mulsd  %xmm1,%xmm0
movsd  -0x20(%rbp),%xmm1
mulsd  -0x40(%rbp),%xmm1
mulsd  -0x58(%rbp),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x60(%rbp)
movsd  -0x60(%rbp),%xmm0
pop    %rbp
ret

x86 assembly (clang, -O2):
<monobf>:
movsd  0xef8(%rip),%xmm7
addsd  %xmm6,%xmm7
mulsd  0xef4(%rip),%xmm6
addsd  0xef4(%rip),%xmm6
mulsd  %xmm2,%xmm7
mulsd  0xef0(%rip),%xmm5
unpcklpd %xmm7,%xmm6
unpcklpd %xmm4,%xmm5
divpd  %xmm6,%xmm5
movapd %xmm5,%xmm2
unpckhpd %xmm5,%xmm2
addsd  %xmm5,%xmm2
movapd %xmm0,%xmm4
mulsd  %xmm0,%xmm4
mulsd  %xmm4,%xmm0
mulsd  %xmm1,%xmm0
mulsd  0xec8(%rip),%xmm3
mulsd  %xmm2,%xmm3
divsd  %xmm3,%xmm0
ret

LLVM IR (-O0):
define double @monobf(double %0, double %1, double %2, double %3, double %4, double %5, double %6) {
%8 = alloca double
%9 = alloca double
%10 = alloca double
%11 = alloca double
%12 = alloca double
%13 = alloca double
%14 = alloca double
%15 = alloca double
%16 = alloca double
%17 = alloca double
%18 = alloca double
%19 = alloca double
store double %0, double* %8
store double %1, double* %9
store double %2, double* %10
store double %3, double* %11
store double %4, double* %12
store double %5, double* %13
store double %6, double* %14
store double 9.800000e+00, double* %15
%20 = load double, double* %14
%21 = fadd double %20, 2.731500e+02
store double %21, double* %16
%22 = load double, double* %14
%23 = call double @llvm.fmuladd.f64(double -2.366000e+03, double %22, double 2.501300e+06)
store double %23, double* %17
%24 = load double, double* %12
%25 = load double, double* %10
%26 = load double, double* %16
%27 = fmul double %25, %26
%28 = fdiv double %24, %27
%29 = load double, double* %13
%30 = fmul double 6.100000e-01, %29
%31 = load double, double* %17
%32 = fdiv double %30, %31
%33 = fadd double %28, %32
store double %33, double* %18
%34 = load double, double* %9
%35 = fneg double %34
%36 = load double, double* %8
%37 = load double, double* %8
%38 = fmul double %36, %37
%39 = load double, double* %8
%40 = fmul double %38, %39
%41 = fmul double %35, %40
%42 = load double, double* %11
%43 = load double, double* %15
%44 = fmul double %42, %43
%45 = load double, double* %18
%46 = fmul double %44, %45
%47 = fdiv double %41, %46
store double %47, double* %19
%48 = load double, double* %19
ret double %48
}

LLVM IR (-O2):
define double @monobf(double %0, double %1, double %2, double %3, double %4, double %5, double %6) {
%8 = fadd double %6, 2.731500e+02
%9 = tail call double @llvm.fmuladd.f64(double %6, double -2.366000e+03, double 2.501300e+06)
%10 = fmul double %8, %2
%11 = fmul double %5, 6.100000e-01
%12 = insertelement <2 x double> poison, double %4, i64 1
%13 = insertelement <2 x double> %12, double %11, i64 0
%14 = insertelement <2 x double> poison, double %9, i64 0
%15 = insertelement <2 x double> %14, double %10, i64 1
%16 = fdiv <2 x double> %13, %15
%17 = shufflevector <2 x double> %16, <2 x double> poison, <2 x i32> <i32 1, i32 undef>
%18 = fadd <2 x double> %16, %17
%19 = extractelement <2 x double> %18, i64 0
%20 = fneg double %1
%21 = fmul double %0, %0
%22 = fmul double %21, %0
%23 = fmul double %22, %20
%24 = fmul double %3, 9.800000e+00
%25 = fmul double %24, %19
%26 = fdiv double %23, %25
ret double %26
}