double _dsal(double xr, double xt) {
  return ((((13.5405 * xr - 28.1044) * xr + 42.2823) * xr + 50.7702) * xr -
          0.1692) +
         (xt / (1.0 + 0.0162 * xt)) *
             ((((-0.0720 * xr + 0.2544) * xr - 0.1125) * xr - 0.0132) * xr -
              0.0056);
}


x86 assembly (clang, -O0):
<_dsal>:
push   %rbp
mov    %rsp,%rbp
movsd  %xmm0,-0x8(%rbp)
movsd  %xmm1,-0x10(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  0xf35(%rip),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xf31(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x8(%rbp),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xf0c(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x8(%rbp),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xeef(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x8(%rbp),%xmm0
mulsd  %xmm0,%xmm1
movsd  0xed2(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm2
movsd  0xeac(%rip),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xea8(%rip),%xmm3
addsd  %xmm3,%xmm2
divsd  %xmm2,%xmm0
movsd  -0x8(%rbp),%xmm2
movsd  0xe7b(%rip),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe77(%rip),%xmm3
addsd  %xmm3,%xmm2
movsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe52(%rip),%xmm3
addsd  %xmm3,%xmm2
movsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe35(%rip),%xmm3
addsd  %xmm3,%xmm2
movsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe18(%rip),%xmm3
addsd  %xmm3,%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
pop    %rbp
ret

x86 assembly (clang, -O2):
<_dsal>:
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
movsd  0xee8(%rip),%xmm3
mulsd  %xmm1,%xmm3
addsd  0xee4(%rip),%xmm3
movsd  0xee4(%rip),%xmm4
mulsd  %xmm0,%xmm4
addsd  0xee0(%rip),%xmm4
divsd  %xmm3,%xmm1
mulsd  %xmm0,%xmm4
addsd  0xed8(%rip),%xmm4
mulsd  %xmm0,%xmm4
addsd  0xed4(%rip),%xmm4
mulsd  %xmm4,%xmm0
addsd  0xed0(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  %xmm2,%xmm0
ret

LLVM IR (-O0):
define double @_dsal(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 1.354050e+01, double %5, double -2.810440e+01)
%7 = load double, double* %3
%8 = call double @llvm.fmuladd.f64(double %6, double %7, double 4.228230e+01)
%9 = load double, double* %3
%10 = call double @llvm.fmuladd.f64(double %8, double %9, double 5.077020e+01)
%11 = load double, double* %3
%12 = call double @llvm.fmuladd.f64(double %10, double %11, double -1.692000e-01)
%13 = load double, double* %4
%14 = load double, double* %4
%15 = call double @llvm.fmuladd.f64(double 1.620000e-02, double %14, double 1.000000e+00)
%16 = fdiv double %13, %15
%17 = load double, double* %3
%18 = call double @llvm.fmuladd.f64(double 0xBFB26E978D4FDF3B, double %17, double 2.544000e-01)
%19 = load double, double* %3
%20 = call double @llvm.fmuladd.f64(double %18, double %19, double -1.125000e-01)
%21 = load double, double* %3
%22 = call double @llvm.fmuladd.f64(double %20, double %21, double -1.320000e-02)
%23 = load double, double* %3
%24 = call double @llvm.fmuladd.f64(double %22, double %23, double -5.600000e-03)
%25 = call double @llvm.fmuladd.f64(double %16, double %24, double %12)
ret double %25
}

LLVM IR (-O2):
define double @_dsal(double %0, double %1) {
%3 = tail call double @llvm.fmuladd.f64(double %0, double 1.354050e+01, double -2.810440e+01)
%4 = tail call double @llvm.fmuladd.f64(double %3, double %0, double 4.228230e+01)
%5 = tail call double @llvm.fmuladd.f64(double %4, double %0, double 5.077020e+01)
%6 = tail call double @llvm.fmuladd.f64(double %5, double %0, double -1.692000e-01)
%7 = tail call double @llvm.fmuladd.f64(double %1, double 1.620000e-02, double 1.000000e+00)
%8 = fdiv double %1, %7
%9 = tail call double @llvm.fmuladd.f64(double %0, double 0xBFB26E978D4FDF3B, double 2.544000e-01)
%10 = tail call double @llvm.fmuladd.f64(double %9, double %0, double -1.125000e-01)
%11 = tail call double @llvm.fmuladd.f64(double %10, double %0, double -1.320000e-02)
%12 = tail call double @llvm.fmuladd.f64(double %11, double %0, double -5.600000e-03)
%13 = tail call double @llvm.fmuladd.f64(double %8, double %12, double %6)
ret double %13
}