double _sal(double xr, double xt) {
  return ((((2.7081 * xr - 7.0261) * xr + 14.0941) * xr + 25.3851) * xr -
          0.1692) *
             xr +
         0.0080 +
         (xt / (1.0 + 0.0162 * xt)) *
             (((((-0.0144 * xr + 0.0636) * xr - 0.0375) * xr - 0.0066) * xr -
               0.0056) *
                  xr +
              0.0005);
}


x86 assembly (clang, -O0):
<_sal>:
push   %rbp
mov    %rsp,%rbp
movsd  %xmm0,-0x8(%rbp)
movsd  %xmm1,-0x10(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  0xf45(%rip),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xf41(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x8(%rbp),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xf1c(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x8(%rbp),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xeff(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x8(%rbp),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xee2(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x8(%rbp),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xec5(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm2
movsd  0xe9f(%rip),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe9b(%rip),%xmm3
addsd  %xmm3,%xmm2
divsd  %xmm2,%xmm0
movsd  -0x8(%rbp),%xmm2
movsd  0xe6e(%rip),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe6a(%rip),%xmm3
addsd  %xmm3,%xmm2
movsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe45(%rip),%xmm3
addsd  %xmm3,%xmm2
movsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe28(%rip),%xmm3
addsd  %xmm3,%xmm2
movsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe0b(%rip),%xmm3
addsd  %xmm3,%xmm2
movsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xdee(%rip),%xmm3
addsd  %xmm3,%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
pop    %rbp
ret

x86 assembly (clang, -O2):
<_sal>:
movsd  0xef8(%rip),%xmm2
mulsd  %xmm0,%xmm2
addsd  0xef4(%rip),%xmm2
mulsd  %xmm0,%xmm2
addsd  0xef0(%rip),%xmm2
mulsd  %xmm0,%xmm2
addsd  0xeec(%rip),%xmm2
mulsd  %xmm0,%xmm2
addsd  0xee8(%rip),%xmm2
mulsd  %xmm0,%xmm2
addsd  0xee4(%rip),%xmm2
movsd  0xee4(%rip),%xmm3
mulsd  %xmm1,%xmm3
addsd  0xee0(%rip),%xmm3
movsd  0xee0(%rip),%xmm4
mulsd  %xmm0,%xmm4
addsd  0xedc(%rip),%xmm4
mulsd  %xmm0,%xmm4
addsd  0xed8(%rip),%xmm4
divsd  %xmm3,%xmm1
mulsd  %xmm0,%xmm4
addsd  0xed0(%rip),%xmm4
mulsd  %xmm0,%xmm4
addsd  0xecc(%rip),%xmm4
mulsd  %xmm4,%xmm0
addsd  0xec8(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  %xmm2,%xmm0
ret

LLVM IR (-O0):
define double @_sal(double %0, double %1) {
%3 = alloca double
%4 = alloca double
store double %0, double* %3
store double %1, double* %4
%5 = load double, double* %3
%6 = call double @llvm.fmuladd.f64(double 2.708100e+00, double %5, double -7.026100e+00)
%7 = load double, double* %3
%8 = call double @llvm.fmuladd.f64(double %6, double %7, double 1.409410e+01)
%9 = load double, double* %3
%10 = call double @llvm.fmuladd.f64(double %8, double %9, double 2.538510e+01)
%11 = load double, double* %3
%12 = call double @llvm.fmuladd.f64(double %10, double %11, double -1.692000e-01)
%13 = load double, double* %3
%14 = call double @llvm.fmuladd.f64(double %12, double %13, double 8.000000e-03)
%15 = load double, double* %4
%16 = load double, double* %4
%17 = call double @llvm.fmuladd.f64(double 1.620000e-02, double %16, double 1.000000e+00)
%18 = fdiv double %15, %17
%19 = load double, double* %3
%20 = call double @llvm.fmuladd.f64(double -1.440000e-02, double %19, double 6.360000e-02)
%21 = load double, double* %3
%22 = call double @llvm.fmuladd.f64(double %20, double %21, double -3.750000e-02)
%23 = load double, double* %3
%24 = call double @llvm.fmuladd.f64(double %22, double %23, double -6.600000e-03)
%25 = load double, double* %3
%26 = call double @llvm.fmuladd.f64(double %24, double %25, double -5.600000e-03)
%27 = load double, double* %3
%28 = call double @llvm.fmuladd.f64(double %26, double %27, double 5.000000e-04)
%29 = call double @llvm.fmuladd.f64(double %18, double %28, double %14)
ret double %29
}

LLVM IR (-O2):
define double @_sal(double %0, double %1) {
%3 = tail call double @llvm.fmuladd.f64(double %0, double 2.708100e+00, double -7.026100e+00)
%4 = tail call double @llvm.fmuladd.f64(double %3, double %0, double 1.409410e+01)
%5 = tail call double @llvm.fmuladd.f64(double %4, double %0, double 2.538510e+01)
%6 = tail call double @llvm.fmuladd.f64(double %5, double %0, double -1.692000e-01)
%7 = tail call double @llvm.fmuladd.f64(double %6, double %0, double 8.000000e-03)
%8 = tail call double @llvm.fmuladd.f64(double %1, double 1.620000e-02, double 1.000000e+00)
%9 = fdiv double %1, %8
%10 = tail call double @llvm.fmuladd.f64(double %0, double -1.440000e-02, double 6.360000e-02)
%11 = tail call double @llvm.fmuladd.f64(double %10, double %0, double -3.750000e-02)
%12 = tail call double @llvm.fmuladd.f64(double %11, double %0, double -6.600000e-03)
%13 = tail call double @llvm.fmuladd.f64(double %12, double %0, double -5.600000e-03)
%14 = tail call double @llvm.fmuladd.f64(double %13, double %0, double 5.000000e-04)
%15 = tail call double @llvm.fmuladd.f64(double %9, double %14, double %7)
ret double %15
}