double ut12gmst(double ut1) {
  double T;
  double gmst;
  T = (ut1 - (2451545.0)) / 36525;
  gmst =
      67310.54841 + (T * (8640184.812866 + (T * (0.093104 + (T * -6.2e-6)))));
  gmst /= 3600.0;
  gmst += 876600.0 * T;
  gmst = ((gmst) * ((3.14159265358979323846) / 12.0));
  gmst = r2r(gmst);
  return (gmst);
}


x86 assembly (clang, -O0):
<ut12gmst>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movsd  %xmm0,-0x8(%rbp)
movsd  -0x8(%rbp),%xmm0
movsd  0xf16(%rip),%xmm1
subsd  %xmm1,%xmm0
movsd  0xf02(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x10(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm2
movsd  0xed2(%rip),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xece(%rip),%xmm3
addsd  %xmm3,%xmm2
mulsd  %xmm2,%xmm1
movsd  0xeae(%rip),%xmm2
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
movsd  0xe96(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x18(%rbp),%xmm0
movsd  0xe78(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  -0x18(%rbp),%xmm1
movsd  0xe55(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  0xe38(%rip),%xmm0
mulsd  -0x18(%rbp),%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x18(%rbp),%xmm0
mov    $0x1,%al
call   1030 <r2r@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x18(%rbp),%xmm0
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<ut12gmst>:
push   %rax
addsd  0xee7(%rip),%xmm0
divsd  0xee7(%rip),%xmm0
movsd  0xee7(%rip),%xmm1
mulsd  %xmm0,%xmm1
addsd  0xee3(%rip),%xmm1
mulsd  %xmm0,%xmm1
addsd  0xedf(%rip),%xmm1
mulsd  %xmm0,%xmm1
addsd  0xedb(%rip),%xmm1
divsd  0xedb(%rip),%xmm1
mulsd  0xedb(%rip),%xmm0
addsd  %xmm1,%xmm0
mulsd  0xed7(%rip),%xmm0
mov    $0x1,%al
call   1030 <r2r@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
pop    %rax
ret

LLVM IR (-O0):
define double @ut12gmst(double %0) {
%2 = alloca double
%3 = alloca double
%4 = alloca double
store double %0, double* %2
%5 = load double, double* %2
%6 = fsub double %5, 0x4142B42C80000000
%7 = fdiv double %6, 3.652500e+04
store double %7, double* %3
%8 = load double, double* %3
%9 = load double, double* %3
%10 = load double, double* %3
%11 = call double @llvm.fmuladd.f64(double %10, double -6.200000e-06, double 9.310400e-02)
%12 = call double @llvm.fmuladd.f64(double %9, double %11, double 0x41607AD71A02FF8F)
%13 = call double @llvm.fmuladd.f64(double %8, double %12, double 0x40F06EE8C649906D)
store double %13, double* %4
%14 = load double, double* %4
%15 = fdiv double %14, 3.600000e+03
store double %15, double* %4
%16 = load double, double* %3
%17 = load double, double* %4
%18 = call double @llvm.fmuladd.f64(double 8.766000e+05, double %16, double %17)
store double %18, double* %4
%19 = load double, double* %4
%20 = fmul double %19, 0x3FD0C152382D7365
store double %20, double* %4
%21 = load double, double* %4
%22 = call i32 (double, ...) bitcast (i32 (...)* @r2r to i32 (double, ...)*)(double %21)
%23 = sitofp i32 %22 to double
store double %23, double* %4
%24 = load double, double* %4
ret double %24
}

LLVM IR (-O2):
define double @ut12gmst(double %0) {
%2 = fadd double %0, 0xC142B42C80000000
%3 = fdiv double %2, 3.652500e+04
%4 = tail call double @llvm.fmuladd.f64(double %3, double -6.200000e-06, double 9.310400e-02)
%5 = tail call double @llvm.fmuladd.f64(double %3, double %4, double 0x41607AD71A02FF8F)
%6 = tail call double @llvm.fmuladd.f64(double %3, double %5, double 0x40F06EE8C649906D)
%7 = fdiv double %6, 3.600000e+03
%8 = tail call double @llvm.fmuladd.f64(double %3, double 8.766000e+05, double %7)
%9 = fmul double %8, 0x3FD0C152382D7365
%10 = tail call i32 (double, ...) bitcast (i32 (...)* @r2r to i32 (double, ...)*)(double %9)
%11 = sitofp i32 %10 to double
ret double %11
}