void fk52ecl(double *dtheta, double *dphi, double epoch) {
  double t, eps0, rphi, rtheta;
  double rmat[3][3];
  double das2r = 4.8481368110953599358991410235794797595635330237270e-6;
  double v1[3], v2[3];
  void fk5prec();
  rtheta = ((*dtheta) * 3.141592653589793238462643 / 180.);
  rphi = ((*dphi) * 3.141592653589793238462643 / 180.);
  if (epoch != 2000.0)
    fk5prec(2000.0, epoch, &rtheta, &rphi);
  slaDcs2c(rtheta, rphi, v1);
  t = (epoch - 2000.0) * 0.01;
  eps0 = das2r * (84381.448 + (-46.8150 + (-0.00059 + 0.001813 * t) * t) * t);
  slaDeuler("X", eps0, 0.0, 0.0, rmat);
  slaDmxv(rmat, v1, v2);
  slaDcc2s(v2, &rtheta, &rphi);
  rtheta = slaDranrm(rtheta);
  rphi = slaDrange(rphi);
  *dtheta = ((rtheta)*180. / 3.141592653589793238462643);
  *dphi = ((rphi)*180. / 3.141592653589793238462643);
}


x86 assembly (clang, -O0):
<fk52ecl>:
push   %rbp
mov    %rsp,%rbp
sub    $0xc0,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movsd  %xmm0,-0x18(%rbp)
movsd  0xe88(%rip),%xmm0
movsd  %xmm0,-0x88(%rbp)
ff
mov    -0x8(%rbp),%rax
movsd  0xe6c(%rip),%xmm0
mulsd  (%rax),%xmm0
movsd  0xe58(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x38(%rbp)
mov    -0x10(%rbp),%rax
movsd  0xe4b(%rip),%xmm0
mulsd  (%rax),%xmm0
movsd  0xe37(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  -0x18(%rbp),%xmm0
movsd  0xe19(%rip),%xmm1
ucomisd %xmm1,%xmm0
jne    11fc <fk52ecl+0x8c>
jp     11fc <fk52ecl+0x8c>
jmp    1218 <fk52ecl+0xa8>
movsd  -0x18(%rbp),%xmm1
movsd  0xdf7(%rip),%xmm0
lea    -0x38(%rbp),%rdi
lea    -0x30(%rbp),%rsi
mov    $0x2,%al
call   1070 <fk5prec@plt>
movsd  -0x38(%rbp),%xmm0
movsd  -0x30(%rbp),%xmm1
lea    -0xa0(%rbp),%rdi
mov    $0x2,%al
call   1050 <slaDcs2c@plt>
movsd  -0x18(%rbp),%xmm0
movsd  0xdc3(%rip),%xmm1
subsd  %xmm1,%xmm0
movsd  0xdf7(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x88(%rbp),%xmm0
ff
movsd  -0x20(%rbp),%xmm1
movsd  0xdc9(%rip),%xmm2
mulsd  %xmm2,%xmm1
movsd  0xdc5(%rip),%xmm2
addsd  %xmm2,%xmm1
movsd  -0x20(%rbp),%xmm2
mulsd  %xmm2,%xmm1
movsd  0xda0(%rip),%xmm2
addsd  %xmm2,%xmm1
movsd  -0x20(%rbp),%xmm2
mulsd  %xmm2,%xmm1
movsd  0xd83(%rip),%xmm2
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x28(%rbp)
movsd  -0x28(%rbp),%xmm0
lea    -0x80(%rbp),%rsi
lea    0xd8e(%rip),%rdi
xorps  %xmm2,%xmm2
movaps %xmm2,%xmm1
mov    $0x3,%al
call   1080 <slaDeuler@plt>
lea    -0x80(%rbp),%rdi
lea    -0xa0(%rbp),%rsi
lea    -0xc0(%rbp),%rdx
mov    $0x0,%al
call   1090 <slaDmxv@plt>
lea    -0xc0(%rbp),%rdi
lea    -0x38(%rbp),%rsi
lea    -0x30(%rbp),%rdx
mov    $0x0,%al
call   1030 <slaDcc2s@plt>
movsd  -0x38(%rbp),%xmm0
mov    $0x1,%al
call   1060 <slaDranrm@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x38(%rbp)
movsd  -0x30(%rbp),%xmm0
mov    $0x1,%al
call   1040 <slaDrange@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  0xce0(%rip),%xmm0
mulsd  -0x38(%rbp),%xmm0
movsd  0xcdb(%rip),%xmm1
divsd  %xmm1,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,(%rax)
movsd  0xcbf(%rip),%xmm0
mulsd  -0x30(%rbp),%xmm0
movsd  0xcba(%rip),%xmm1
divsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,(%rax)
add    $0xc0,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<fk52ecl>:
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
sub    $0xb0,%rsp
mov    %rsi,%r14
mov    %rdi,%r15
movsd  (%rsi),%xmm1
movhpd (%rdi),%xmm1
mulpd  0xe6a(%rip),%xmm1
divpd  0xe72(%rip),%xmm1
movhpd %xmm1,0x8(%rsp)
movlpd %xmm1,0x10(%rsp)
movsd  %xmm0,0x18(%rsp)
ucomisd 0xe68(%rip),%xmm0
jne    11bc <fk52ecl+0x4c>
jnp    11e7 <fk52ecl+0x77>
movsd  0xe5c(%rip),%xmm0
lea    0x8(%rsp),%rdi
lea    0x10(%rsp),%rsi
movsd  0x18(%rsp),%xmm1
mov    $0x2,%al
call   1070 <fk5prec@plt>
movsd  0x10(%rsp),%xmm1
movhpd 0x8(%rsp),%xmm1
movapd %xmm1,%xmm0
unpckhpd %xmm1,%xmm0
lea    0x40(%rsp),%r12
mov    %r12,%rdi
mov    $0x2,%al
call   1050 <slaDcs2c@plt>
movsd  0x18(%rsp),%xmm1
addsd  0xe1c(%rip),%xmm1
mulsd  0xe1c(%rip),%xmm1
movsd  0xe1c(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xe18(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xe14(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xe10(%rip),%xmm0
mulsd  0xe10(%rip),%xmm0
lea    0xe21(%rip),%rdi
lea    0x60(%rsp),%r13
xorpd  %xmm1,%xmm1
xorps  %xmm2,%xmm2
mov    %r13,%rsi
mov    $0x3,%al
call   1080 <slaDeuler@plt>
lea    0x20(%rsp),%rbx
mov    %r13,%rdi
mov    %r12,%rsi
mov    %rbx,%rdx
xor    %eax,%eax
call   1090 <slaDmxv@plt>
lea    0x8(%rsp),%rsi
lea    0x10(%rsp),%rdx
mov    %rbx,%rdi
xor    %eax,%eax
call   1030 <slaDcc2s@plt>
movsd  0x8(%rsp),%xmm0
mov    $0x1,%al
call   1060 <slaDranrm@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  %xmm0,0x8(%rsp)
movsd  0x10(%rsp),%xmm0
mov    $0x1,%al
call   1040 <slaDrange@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  0xd9c(%rip),%xmm1
movsd  0x8(%rsp),%xmm2
mulsd  %xmm1,%xmm2
movsd  0xd92(%rip),%xmm3
divsd  %xmm3,%xmm2
movsd  %xmm2,(%r15)
mulsd  %xmm1,%xmm0
divsd  %xmm3,%xmm0
movsd  %xmm0,(%r14)
add    $0xb0,%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [2 x i8] c"X\00"
define void @fk52ecl(double* %0, double* %1, double %2) {
%4 = alloca double*
%5 = alloca double*
%6 = alloca double
%7 = alloca double
%8 = alloca double
%9 = alloca double
%10 = alloca double
%11 = alloca [3 x [3 x double]]
%12 = alloca double
%13 = alloca [3 x double]
%14 = alloca [3 x double]
store double* %0, double** %4
store double* %1, double** %5
store double %2, double* %6
store double 0x3ED455A5B2FF8F9D, double* %12
%15 = load double*, double** %4
%16 = load double, double* %15
%17 = fmul double %16, 0x400921FB54442D18
%18 = fdiv double %17, 1.800000e+02
store double %18, double* %10
%19 = load double*, double** %5
%20 = load double, double* %19
%21 = fmul double %20, 0x400921FB54442D18
%22 = fdiv double %21, 1.800000e+02
store double %22, double* %9
%23 = load double, double* %6
%24 = fcmp une double %23, 2.000000e+03
br i1 %24, label %25, label %27
25: ; preds = %3
%26 = load double, double* %6
br label %27
27: ; preds = %25, %3
%28 = load double, double* %10
%29 = load double, double* %9
%30 = getelementptr inbounds [3 x double], [3 x double]* %13, i64 0, i64 0
%31 = call i32 (double, double, double*, ...) bitcast (i32 (...)* @slaDcs2c to i32 (double, double, double*, ...)*)(double %28, double %29, double* %30)
%32 = load double, double* %6
%33 = fsub double %32, 2.000000e+03
%34 = fmul double %33, 1.000000e-02
store double %34, double* %7
%35 = load double, double* %12
%36 = load double, double* %7
%37 = call double @llvm.fmuladd.f64(double 1.813000e-03, double %36, double -5.900000e-04)
%38 = load double, double* %7
%39 = call double @llvm.fmuladd.f64(double %37, double %38, double -4.681500e+01)
%40 = load double, double* %7
%41 = call double @llvm.fmuladd.f64(double %39, double %40, double 0x40F499D72B020C4A)
%42 = fmul double %35, %41
store double %42, double* %8
%43 = load double, double* %8
%44 = getelementptr inbounds [3 x [3 x double]], [3 x [3 x double]]* %11, i64 0, i64 0
%45 = call i32 (i8*, double, double, double, [3 x double]*, ...) bitcast (i32 (...)* @slaDeuler to i32 (i8*, double, double, double, [3 x double]*, ...)*)(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0), double %43, double 0.000000e+00, double 0.000000e+00, [3 x double]* %44)
%46 = getelementptr inbounds [3 x [3 x double]], [3 x [3 x double]]* %11, i64 0, i64 0
%47 = getelementptr inbounds [3 x double], [3 x double]* %13, i64 0, i64 0
%48 = getelementptr inbounds [3 x double], [3 x double]* %14, i64 0, i64 0
%49 = call i32 ([3 x double]*, double*, double*, ...) bitcast (i32 (...)* @slaDmxv to i32 ([3 x double]*, double*, double*, ...)*)([3 x double]* %46, double* %47, double* %48)
%50 = getelementptr inbounds [3 x double], [3 x double]* %14, i64 0, i64 0
%51 = call i32 (double*, double*, double*, ...) bitcast (i32 (...)* @slaDcc2s to i32 (double*, double*, double*, ...)*)(double* %50, double* %10, double* %9)
%52 = load double, double* %10
%53 = call i32 (double, ...) bitcast (i32 (...)* @slaDranrm to i32 (double, ...)*)(double %52)
%54 = sitofp i32 %53 to double
store double %54, double* %10
%55 = load double, double* %9
%56 = call i32 (double, ...) bitcast (i32 (...)* @slaDrange to i32 (double, ...)*)(double %55)
%57 = sitofp i32 %56 to double
store double %57, double* %9
%58 = load double, double* %10
%59 = fmul double %58, 1.800000e+02
%60 = fdiv double %59, 0x400921FB54442D18
%61 = load double*, double** %4
store double %60, double* %61
%62 = load double, double* %9
%63 = fmul double %62, 1.800000e+02
%64 = fdiv double %63, 0x400921FB54442D18
%65 = load double*, double** %5
store double %64, double* %65
ret void
}

LLVM IR (-O2):
@.str = [2 x i8] c"X\00"
define void @fk52ecl(double* nocapture %0, double* nocapture %1, double %2) {
%4 = alloca double
%5 = alloca double
%6 = alloca [3 x [3 x double]]
%7 = alloca [3 x double]
%8 = alloca [3 x double]
%9 = bitcast double* %4 to i8*
%10 = bitcast double* %5 to i8*
%11 = bitcast [3 x [3 x double]]* %6 to i8*
%12 = bitcast [3 x double]* %7 to i8*
%13 = bitcast [3 x double]* %8 to i8*
%14 = load double, double* %0
%15 = load double, double* %1
%16 = insertelement <2 x double> poison, double %15, i64 0
%17 = insertelement <2 x double> %16, double %14, i64 1
%18 = fmul <2 x double> %17, <double 0x400921FB54442D18, double 0x400921FB54442D18>
%19 = fdiv <2 x double> %18, <double 1.800000e+02, double 1.800000e+02>
%20 = extractelement <2 x double> %19, i64 1
store double %20, double* %5
%21 = extractelement <2 x double> %19, i64 0
store double %21, double* %4
%22 = fcmp une double %2, 2.000000e+03
br i1 %22, label %23, label %28
23: ; preds = %3
%24 = load double, double* %5
%25 = load double, double* %4
%26 = insertelement <2 x double> poison, double %25, i64 0
%27 = insertelement <2 x double> %26, double %24, i64 1
br label %28
28: ; preds = %23, %3
%29 = phi <2 x double> [ %27, %23 ], [ %19, %3 ]
%30 = getelementptr inbounds [3 x double], [3 x double]* %7, i64 0, i64 0
%31 = extractelement <2 x double> %29, i64 0
%32 = extractelement <2 x double> %29, i64 1
%33 = call i32 (double, double, double*, ...) bitcast (i32 (...)* @slaDcs2c to i32 (double, double, double*, ...)*)(double %32, double %31, double* %30)
%34 = fadd double %2, -2.000000e+03
%35 = fmul double %34, 1.000000e-02
%36 = call double @llvm.fmuladd.f64(double %35, double 1.813000e-03, double -5.900000e-04)
%37 = call double @llvm.fmuladd.f64(double %36, double %35, double -4.681500e+01)
%38 = call double @llvm.fmuladd.f64(double %37, double %35, double 0x40F499D72B020C4A)
%39 = fmul double %38, 0x3ED455A5B2FF8F9D
%40 = getelementptr inbounds [3 x [3 x double]], [3 x [3 x double]]* %6, i64 0, i64 0
%41 = call i32 (i8*, double, double, double, [3 x double]*, ...) bitcast (i32 (...)* @slaDeuler to i32 (i8*, double, double, double, [3 x double]*, ...)*)(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0), double %39, double 0.000000e+00, double 0.000000e+00, [3 x double]* %40)
%42 = getelementptr inbounds [3 x double], [3 x double]* %8, i64 0, i64 0
%43 = call i32 ([3 x double]*, double*, double*, ...) bitcast (i32 (...)* @slaDmxv to i32 ([3 x double]*, double*, double*, ...)*)([3 x double]* %40, double* %30, double* %42)
%44 = call i32 (double*, double*, double*, ...) bitcast (i32 (...)* @slaDcc2s to i32 (double*, double*, double*, ...)*)(double* %42, double* %5, double* %4)
%45 = load double, double* %5
%46 = call i32 (double, ...) bitcast (i32 (...)* @slaDranrm to i32 (double, ...)*)(double %45)
%47 = sitofp i32 %46 to double
store double %47, double* %5
%48 = load double, double* %4
%49 = call i32 (double, ...) bitcast (i32 (...)* @slaDrange to i32 (double, ...)*)(double %48)
%50 = sitofp i32 %49 to double
%51 = load double, double* %5
%52 = fmul double %51, 1.800000e+02
%53 = fdiv double %52, 0x400921FB54442D18
store double %53, double* %0
%54 = fmul double %50, 1.800000e+02
%55 = fdiv double %54, 0x400921FB54442D18
store double %55, double* %1
ret void
}