void fk52ecl(dtheta, dphi, epoch) double *dtheta;
double *dphi;
double epoch;
{
  int i, j;
  double t, eps0, rphi, rtheta;
  double v1[3], v2[3], r;
  double rmat[9], *rmati;
  void rotmat(), v2s3(), s2v3(), fk5prec();
  if (epoch != 2000.0)
    fk5prec(2000.0, epoch, dtheta, dphi);
  rtheta = degrad(*dtheta);
  rphi = degrad(*dphi);
  r = 1.0;
  s2v3(rtheta, rphi, r, v1);
  t = (epoch - 2000.0) * 0.01;
  eps0 = secrad((84381.448 + (-46.8150 + (-0.00059 + 0.001813 * t) * t) * t));
  rotmat(1, eps0, 0.0, 0.0, rmat);
  rmati = rmat;
  for (i = 0; i < 3; i++) {
    v2[i] = 0;
    for (j = 0; j < 3; j++)
      v2[i] = v2[i] + (*rmati++ * v1[j]);
  }
  v2s3(v2, &rtheta, &rphi, &r);
  *dtheta = raddeg(rtheta);
  *dphi = raddeg(rphi);
}


x86 assembly (clang, -O0):
<fk52ecl>:
push   %rbp
mov    %rsp,%rbp
sub    $0xe0,%rsp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movsd  %xmm0,-0x18(%rbp)
movsd  -0x18(%rbp),%xmm0
movsd  0xe6b(%rip),%xmm1
ucomisd %xmm1,%xmm0
jne    11aa <fk52ecl+0x3a>
jp     11aa <fk52ecl+0x3a>
jmp    11c6 <fk52ecl+0x56>
movsd  -0x18(%rbp),%xmm1
mov    -0x8(%rbp),%rdi
mov    -0x10(%rbp),%rsi
movsd  0xe41(%rip),%xmm0
mov    $0x2,%al
call   1030 <fk5prec@plt>
mov    -0x8(%rbp),%rax
movsd  (%rax),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x40(%rbp)
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x38(%rbp)
movsd  0xe32(%rip),%xmm0
movsd  %xmm0,-0x88(%rbp)
ff
movsd  -0x40(%rbp),%xmm0
movsd  -0x38(%rbp),%xmm1
movsd  -0x88(%rbp),%xmm2
ff
lea    -0x60(%rbp),%rdi
mov    $0x3,%al
call   1070 <s2v3@plt>
movsd  -0x18(%rbp),%xmm0
movsd  0xdd0(%rip),%xmm1
subsd  %xmm1,%xmm0
movsd  0xdec(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x28(%rbp)
movsd  -0x28(%rbp),%xmm0
movsd  0xdc6(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xdc2(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  -0x28(%rbp),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xd9d(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  -0x28(%rbp),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xd80(%rip),%xmm1
addsd  %xmm1,%xmm0
mov    $0x1,%al
call   1080 <secrad@plt>
cvtsi2sd %eax,%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  -0x30(%rbp),%xmm0
lea    -0xd0(%rbp),%rsi
mov    $0x1,%edi
xorps  %xmm2,%xmm2
movaps %xmm2,%xmm1
mov    $0x3,%al
call   1040 <rotmat@plt>
lea    -0xd0(%rbp),%rax
mov    %rax,-0xd8(%rbp)
movl   $0x0,-0x1c(%rbp)
cmpl   $0x3,-0x1c(%rbp)
jge    1357 <fk52ecl+0x1e7>
movslq -0x1c(%rbp),%rax
xorps  %xmm0,%xmm0
movsd  %xmm0,-0x80(%rbp,%rax,8)
movl   $0x0,-0x20(%rbp)
cmpl   $0x3,-0x20(%rbp)
jge    1344 <fk52ecl+0x1d4>
movslq -0x1c(%rbp),%rax
movsd  -0x80(%rbp,%rax,8),%xmm1
mov    -0xd8(%rbp),%rax
mov    %rax,%rcx
add    $0x8,%rcx
mov    %rcx,-0xd8(%rbp)
movsd  (%rax),%xmm0
movslq -0x20(%rbp),%rax
movsd  -0x60(%rbp,%rax,8),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movslq -0x1c(%rbp),%rax
movsd  %xmm0,-0x80(%rbp,%rax,8)
mov    -0x20(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x20(%rbp)
jmp    12ed <fk52ecl+0x17d>
jmp    1349 <fk52ecl+0x1d9>
mov    -0x1c(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x1c(%rbp)
jmp    12cf <fk52ecl+0x15f>
lea    -0x80(%rbp),%rdi
lea    -0x40(%rbp),%rsi
lea    -0x38(%rbp),%rdx
lea    -0x88(%rbp),%rcx
mov    $0x0,%al
call   1090 <v2s3@plt>
movsd  -0x40(%rbp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
cvtsi2sd %eax,%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,(%rax)
movsd  -0x38(%rbp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
cvtsi2sd %eax,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,(%rax)
add    $0xe0,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<fk52ecl>:
push   %r14
push   %rbx
sub    $0xb8,%rsp
mov    %rsi,%r14
mov    %rdi,%rbx
movsd  %xmm0,0x8(%rsp)
ucomisd 0xe72(%rip),%xmm0
jne    1192 <fk52ecl+0x22>
jnp    11ad <fk52ecl+0x3d>
movsd  0xe66(%rip),%xmm0
movsd  0x8(%rsp),%xmm1
mov    %rbx,%rdi
mov    %r14,%rsi
mov    $0x2,%al
call   1030 <fk5prec@plt>
movsd  (%rbx),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  %xmm0,0x20(%rsp)
movsd  %xmm0,0x10(%rsp)
movsd  (%r14),%xmm0
mov    $0x1,%al
call   1060 <degrad@plt>
xorps  %xmm1,%xmm1
cvtsi2sd %eax,%xmm1
movsd  %xmm1,0x18(%rsp)
movabs $0x3ff0000000000000,%rax
mov    %rax,0x28(%rsp)
movsd  0xe0d(%rip),%xmm2
lea    0x30(%rsp),%rdi
movsd  0x20(%rsp),%xmm0
mov    $0x3,%al
call   1070 <s2v3@plt>
movsd  0x8(%rsp),%xmm1
addsd  0xdf5(%rip),%xmm1
mulsd  0xdf5(%rip),%xmm1
movsd  0xdf5(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xdf1(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xded(%rip),%xmm0
mulsd  %xmm1,%xmm0
addsd  0xde9(%rip),%xmm0
mov    $0x1,%al
call   1080 <secrad@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
lea    0x50(%rsp),%rsi
xorpd  %xmm1,%xmm1
xorps  %xmm2,%xmm2
mov    $0x1,%edi
mov    $0x3,%al
call   1040 <rotmat@plt>
movapd 0x50(%rsp),%xmm3
movupd 0x58(%rsp),%xmm4
movsd  0x30(%rsp),%xmm2
movsd  0x38(%rsp),%xmm0
movapd 0x60(%rsp),%xmm5
movsd  0x40(%rsp),%xmm1
movhpd 0x68(%rsp),%xmm3
movapd %xmm2,%xmm6
unpcklpd %xmm2,%xmm6
mulpd  %xmm3,%xmm6
xorpd  %xmm3,%xmm3
movhpd 0x70(%rsp),%xmm4
addpd  %xmm6,%xmm3
movapd %xmm0,%xmm6
unpcklpd %xmm0,%xmm6
mulpd  %xmm4,%xmm6
addpd  %xmm3,%xmm6
movhpd 0x78(%rsp),%xmm5
movapd %xmm1,%xmm3
unpcklpd %xmm1,%xmm3
mulpd  %xmm5,%xmm3
addpd  %xmm6,%xmm3
movapd %xmm3,0xa0(%rsp)
mulsd  0x80(%rsp),%xmm2
addsd  0xd47(%rip),%xmm2
mulsd  0x88(%rsp),%xmm0
addsd  %xmm2,%xmm0
mulsd  0x90(%rsp),%xmm1
addsd  %xmm0,%xmm1
movsd  %xmm1,0xb0(%rsp)
lea    0xa0(%rsp),%rdi
lea    0x10(%rsp),%rsi
lea    0x18(%rsp),%rdx
lea    0x28(%rsp),%rcx
xor    %eax,%eax
call   1090 <v2s3@plt>
movsd  0x10(%rsp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  %xmm0,(%rbx)
movsd  0x18(%rsp),%xmm0
mov    $0x1,%al
call   1050 <raddeg@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %eax,%xmm0
movsd  %xmm0,(%r14)
add    $0xb8,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
define void @fk52ecl(double* %0, double* %1, double %2) {
%4 = alloca double*
%5 = alloca double*
%6 = alloca double
%7 = alloca i32
%8 = alloca i32
%9 = alloca double
%10 = alloca double
%11 = alloca double
%12 = alloca double
%13 = alloca [3 x double]
%14 = alloca [3 x double]
%15 = alloca double
%16 = alloca [9 x double]
%17 = alloca double*
store double* %0, double** %4
store double* %1, double** %5
store double %2, double* %6
%18 = load double, double* %6
%19 = fcmp une double %18, 2.000000e+03
br i1 %19, label %20, label %24
20: ; preds = %3
%21 = load double, double* %6
%22 = load double*, double** %4
%23 = load double*, double** %5
br label %24
24: ; preds = %20, %3
%25 = load double*, double** %4
%26 = load double, double* %25
%27 = call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %26)
%28 = sitofp i32 %27 to double
store double %28, double* %12
%29 = load double*, double** %5
%30 = load double, double* %29
%31 = call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %30)
%32 = sitofp i32 %31 to double
store double %32, double* %11
store double 1.000000e+00, double* %15
%33 = load double, double* %12
%34 = load double, double* %11
%35 = load double, double* %15
%36 = getelementptr inbounds [3 x double], [3 x double]* %13, i64 0, i64 0
%37 = load double, double* %6
%38 = fsub double %37, 2.000000e+03
%39 = fmul double %38, 1.000000e-02
store double %39, double* %9
%40 = load double, double* %9
%41 = call double @llvm.fmuladd.f64(double 1.813000e-03, double %40, double -5.900000e-04)
%42 = load double, double* %9
%43 = call double @llvm.fmuladd.f64(double %41, double %42, double -4.681500e+01)
%44 = load double, double* %9
%45 = call double @llvm.fmuladd.f64(double %43, double %44, double 0x40F499D72B020C4A)
%46 = call i32 (double, ...) bitcast (i32 (...)* @secrad to i32 (double, ...)*)(double %45)
%47 = sitofp i32 %46 to double
store double %47, double* %10
%48 = load double, double* %10
%49 = getelementptr inbounds [9 x double], [9 x double]* %16, i64 0, i64 0
%50 = getelementptr inbounds [9 x double], [9 x double]* %16, i64 0, i64 0
store double* %50, double** %17
store i32 0, i32* %7
br label %51
51: ; preds = %81, %24
%52 = load i32, i32* %7
%53 = icmp slt i32 %52, 3
br i1 %53, label %54, label %84
54: ; preds = %51
%55 = load i32, i32* %7
%56 = sext i32 %55 to i64
%57 = getelementptr inbounds [3 x double], [3 x double]* %14, i64 0, i64 %56
store double 0.000000e+00, double* %57
store i32 0, i32* %8
br label %58
58: ; preds = %77, %54
%59 = load i32, i32* %8
%60 = icmp slt i32 %59, 3
br i1 %60, label %61, label %80
61: ; preds = %58
%62 = load i32, i32* %7
%63 = sext i32 %62 to i64
%64 = getelementptr inbounds [3 x double], [3 x double]* %14, i64 0, i64 %63
%65 = load double, double* %64
%66 = load double*, double** %17
%67 = getelementptr inbounds double, double* %66, i32 1
store double* %67, double** %17
%68 = load double, double* %66
%69 = load i32, i32* %8
%70 = sext i32 %69 to i64
%71 = getelementptr inbounds [3 x double], [3 x double]* %13, i64 0, i64 %70
%72 = load double, double* %71
%73 = call double @llvm.fmuladd.f64(double %68, double %72, double %65)
%74 = load i32, i32* %7
%75 = sext i32 %74 to i64
%76 = getelementptr inbounds [3 x double], [3 x double]* %14, i64 0, i64 %75
store double %73, double* %76
br label %77
77: ; preds = %61
%78 = load i32, i32* %8
%79 = add nsw i32 %78, 1
store i32 %79, i32* %8
br label %58
80: ; preds = %58
br label %81
81: ; preds = %80
%82 = load i32, i32* %7
%83 = add nsw i32 %82, 1
store i32 %83, i32* %7
br label %51
84: ; preds = %51
%85 = getelementptr inbounds [3 x double], [3 x double]* %14, i64 0, i64 0
%86 = load double, double* %12
%87 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %86)
%88 = sitofp i32 %87 to double
%89 = load double*, double** %4
store double %88, double* %89
%90 = load double, double* %11
%91 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %90)
%92 = sitofp i32 %91 to double
%93 = load double*, double** %5
store double %92, double* %93
ret void
}

LLVM IR (-O2):
define void @fk52ecl(double* %0, double* %1, double %2) {
%4 = alloca double
%5 = alloca double
%6 = alloca [3 x double]
%7 = alloca [3 x double]
%8 = alloca double
%9 = alloca [9 x double]
%10 = bitcast double* %4 to i8*
%11 = bitcast double* %5 to i8*
%12 = bitcast [3 x double]* %6 to i8*
%13 = bitcast [3 x double]* %7 to i8*
%14 = bitcast double* %8 to i8*
%15 = bitcast [9 x double]* %9 to i8*
%16 = fcmp une double %2, 2.000000e+03
br i1 %16, label %17, label %18
17: ; preds = %3
tail call void (double, double, double*, double*, ...) bitcast (void (...)* @fk5prec to void (double, double, double*, double*, ...)*)(double 2.000000e+03, double %2, double* %0, double* %1)
br label %18
18: ; preds = %17, %3
%19 = load double, double* %0
%20 = tail call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %19)
%21 = sitofp i32 %20 to double
store double %21, double* %5
%22 = load double, double* %1
%23 = tail call i32 (double, ...) bitcast (i32 (...)* @degrad to i32 (double, ...)*)(double %22)
%24 = sitofp i32 %23 to double
store double %24, double* %4
store double 1.000000e+00, double* %8
%25 = getelementptr inbounds [3 x double], [3 x double]* %6, i64 0, i64 0
%26 = fadd double %2, -2.000000e+03
%27 = fmul double %26, 1.000000e-02
%28 = call double @llvm.fmuladd.f64(double %27, double 1.813000e-03, double -5.900000e-04)
%29 = call double @llvm.fmuladd.f64(double %28, double %27, double -4.681500e+01)
%30 = call double @llvm.fmuladd.f64(double %29, double %27, double 0x40F499D72B020C4A)
%31 = call i32 (double, ...) bitcast (i32 (...)* @secrad to i32 (double, ...)*)(double %30)
%32 = sitofp i32 %31 to double
%33 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 0
%34 = getelementptr inbounds [3 x double], [3 x double]* %7, i64 0, i64 0
%35 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 1
%36 = bitcast [9 x double]* %9 to <2 x double>*
%37 = load <2 x double>, <2 x double>* %36
%38 = load double, double* %25
%39 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 2
%40 = bitcast double* %35 to <2 x double>*
%41 = load <2 x double>, <2 x double>* %40
%42 = getelementptr inbounds [3 x double], [3 x double]* %6, i64 0, i64 1
%43 = load double, double* %42
%44 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 3
%45 = bitcast double* %39 to <2 x double>*
%46 = load <2 x double>, <2 x double>* %45
%47 = getelementptr inbounds [3 x double], [3 x double]* %6, i64 0, i64 2
%48 = load double, double* %47
%49 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 4
%50 = load double, double* %44
%51 = insertelement <2 x double> %37, double %50, i64 1
%52 = insertelement <2 x double> poison, double %38, i64 0
%53 = shufflevector <2 x double> %52, <2 x double> poison, <2 x i32> zeroinitializer
%54 = call <2 x double> @llvm.fmuladd.v2f64(<2 x double> %51, <2 x double> %53, <2 x double> zeroinitializer)
%55 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 5
%56 = load double, double* %49
%57 = insertelement <2 x double> %41, double %56, i64 1
%58 = insertelement <2 x double> poison, double %43, i64 0
%59 = shufflevector <2 x double> %58, <2 x double> poison, <2 x i32> zeroinitializer
%60 = call <2 x double> @llvm.fmuladd.v2f64(<2 x double> %57, <2 x double> %59, <2 x double> %54)
%61 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 6
%62 = load double, double* %55
%63 = insertelement <2 x double> %46, double %62, i64 1
%64 = insertelement <2 x double> poison, double %48, i64 0
%65 = shufflevector <2 x double> %64, <2 x double> poison, <2 x i32> zeroinitializer
%66 = call <2 x double> @llvm.fmuladd.v2f64(<2 x double> %63, <2 x double> %65, <2 x double> %60)
%67 = bitcast [3 x double]* %7 to <2 x double>*
store <2 x double> %66, <2 x double>* %67
%68 = getelementptr inbounds [3 x double], [3 x double]* %7, i64 0, i64 2
%69 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 7
%70 = load double, double* %61
%71 = call double @llvm.fmuladd.f64(double %70, double %38, double 0.000000e+00)
%72 = getelementptr inbounds [9 x double], [9 x double]* %9, i64 0, i64 8
%73 = load double, double* %69
%74 = call double @llvm.fmuladd.f64(double %73, double %43, double %71)
%75 = load double, double* %72
%76 = call double @llvm.fmuladd.f64(double %75, double %48, double %74)
store double %76, double* %68
%77 = load double, double* %5
%78 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %77)
%79 = sitofp i32 %78 to double
store double %79, double* %0
%80 = load double, double* %4
%81 = call i32 (double, ...) bitcast (i32 (...)* @raddeg to i32 (double, ...)*)(double %80)
%82 = sitofp i32 %81 to double
store double %82, double* %1
ret void
}