void amsp_interpolate_getBesselCoeff(double v, double *out) {
  out[0] = v - 0.5;
  out[1] = v * (v - 1) / 4.;
  out[2] = v * (0.5 + v * (-1.5 + v)) / 6.;
  out[3] = v * (2. + v * (-1 + v * (-1 + v))) / 48.;
  out[4] = v * (-1. + v * (2.5 + v * v * (-2.5 + v))) / 120;
}


x86 assembly (clang, -O0):
<amsp_interpolate_getBesselCoeff>:
push   %rbp
mov    %rsp,%rbp
movsd  %xmm0,-0x8(%rbp)
mov    %rdi,-0x10(%rbp)
movsd  -0x8(%rbp),%xmm0
movsd  0xf1e(%rip),%xmm1
subsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,(%rax)
movsd  -0x8(%rbp),%xmm0
movsd  -0x8(%rbp),%xmm1
movsd  0xf18(%rip),%xmm2
subsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
movsd  0xf00(%rip),%xmm1
divsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,0x8(%rax)
movsd  -0x8(%rbp),%xmm0
movsd  -0x8(%rbp),%xmm1
movsd  0xed9(%rip),%xmm2
addsd  -0x8(%rbp),%xmm2
mulsd  %xmm2,%xmm1
movsd  0xec0(%rip),%xmm2
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
movsd  0xea8(%rip),%xmm1
divsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,0x10(%rax)
movsd  -0x8(%rbp),%xmm0
movsd  -0x8(%rbp),%xmm1
movsd  -0x8(%rbp),%xmm2
movsd  0xe5c(%rip),%xmm3
addsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xe4b(%rip),%xmm3
addsd  %xmm3,%xmm2
mulsd  %xmm2,%xmm1
movsd  0xe5b(%rip),%xmm2
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
movsd  0xe43(%rip),%xmm1
divsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,0x18(%rax)
movsd  -0x8(%rbp),%xmm0
movsd  -0x8(%rbp),%xmm1
movsd  -0x8(%rbp),%xmm2
mulsd  -0x8(%rbp),%xmm2
movsd  0xe12(%rip),%xmm3
addsd  -0x8(%rbp),%xmm3
mulsd  %xmm3,%xmm2
movsd  0xdf9(%rip),%xmm3
addsd  %xmm3,%xmm2
mulsd  %xmm2,%xmm1
movsd  0xde1(%rip),%xmm2
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
movsd  0xdc9(%rip),%xmm1
divsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,0x20(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<amsp_interpolate_getBesselCoeff>:
movsd  0xef8(%rip),%xmm1
addsd  %xmm0,%xmm1
movsd  %xmm1,(%rdi)
movsd  0xef0(%rip),%xmm1
movapd %xmm0,%xmm3
addsd  %xmm1,%xmm3
mulsd  %xmm0,%xmm3
movsd  0xee4(%rip),%xmm2
mulsd  %xmm3,%xmm2
movapd %xmm0,%xmm4
mulsd  %xmm0,%xmm4
movsd  0xee0(%rip),%xmm5
addsd  %xmm0,%xmm5
mulsd  %xmm4,%xmm5
movsd  0xec8(%rip),%xmm4
addsd  %xmm0,%xmm4
addsd  %xmm1,%xmm3
addsd  0xec8(%rip),%xmm5
unpcklpd %xmm3,%xmm4
mulsd  %xmm0,%xmm5
addsd  %xmm1,%xmm5
mulsd  %xmm0,%xmm5
unpcklpd %xmm0,%xmm0
mulpd  %xmm0,%xmm4
addpd  0xec0(%rip),%xmm4
movsd  %xmm2,0x8(%rdi)
mulpd  %xmm0,%xmm4
divpd  0xebf(%rip),%xmm4
movupd %xmm4,0x10(%rdi)
divsd  0xe92(%rip),%xmm5
movsd  %xmm5,0x20(%rdi)
ret

LLVM IR (-O0):
define void @amsp_interpolate_getBesselCoeff(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 = fsub double %5, 5.000000e-01
%7 = load double*, double** %4
%8 = getelementptr inbounds double, double* %7, i64 0
store double %6, double* %8
%9 = load double, double* %3
%10 = load double, double* %3
%11 = fsub double %10, 1.000000e+00
%12 = fmul double %9, %11
%13 = fdiv double %12, 4.000000e+00
%14 = load double*, double** %4
%15 = getelementptr inbounds double, double* %14, i64 1
store double %13, double* %15
%16 = load double, double* %3
%17 = load double, double* %3
%18 = load double, double* %3
%19 = fadd double -1.500000e+00, %18
%20 = call double @llvm.fmuladd.f64(double %17, double %19, double 5.000000e-01)
%21 = fmul double %16, %20
%22 = fdiv double %21, 6.000000e+00
%23 = load double*, double** %4
%24 = getelementptr inbounds double, double* %23, i64 2
store double %22, double* %24
%25 = load double, double* %3
%26 = load double, double* %3
%27 = load double, double* %3
%28 = load double, double* %3
%29 = fadd double -1.000000e+00, %28
%30 = call double @llvm.fmuladd.f64(double %27, double %29, double -1.000000e+00)
%31 = call double @llvm.fmuladd.f64(double %26, double %30, double 2.000000e+00)
%32 = fmul double %25, %31
%33 = fdiv double %32, 4.800000e+01
%34 = load double*, double** %4
%35 = getelementptr inbounds double, double* %34, i64 3
store double %33, double* %35
%36 = load double, double* %3
%37 = load double, double* %3
%38 = load double, double* %3
%39 = load double, double* %3
%40 = fmul double %38, %39
%41 = load double, double* %3
%42 = fadd double -2.500000e+00, %41
%43 = call double @llvm.fmuladd.f64(double %40, double %42, double 2.500000e+00)
%44 = call double @llvm.fmuladd.f64(double %37, double %43, double -1.000000e+00)
%45 = fmul double %36, %44
%46 = fdiv double %45, 1.200000e+02
%47 = load double*, double** %4
%48 = getelementptr inbounds double, double* %47, i64 4
store double %46, double* %48
ret void
}

LLVM IR (-O2):
define void @amsp_interpolate_getBesselCoeff(double %0, double* nocapture writeonly %1) {
%3 = fadd double %0, -5.000000e-01
store double %3, double* %1
%4 = fadd double %0, -1.000000e+00
%5 = fmul double %4, %0
%6 = fmul double %5, 2.500000e-01
%7 = getelementptr inbounds double, double* %1, i64 1
store double %6, double* %7
%8 = fadd double %0, -1.500000e+00
%9 = getelementptr inbounds double, double* %1, i64 2
%10 = tail call double @llvm.fmuladd.f64(double %0, double %4, double -1.000000e+00)
%11 = insertelement <2 x double> poison, double %0, i64 0
%12 = shufflevector <2 x double> %11, <2 x double> poison, <2 x i32> zeroinitializer
%13 = insertelement <2 x double> poison, double %8, i64 0
%14 = insertelement <2 x double> %13, double %10, i64 1
%15 = call <2 x double> @llvm.fmuladd.v2f64(<2 x double> %12, <2 x double> %14, <2 x double> <double 5.000000e-01, double 2.000000e+00>)
%16 = fmul <2 x double> %15, %12
%17 = fdiv <2 x double> %16, <double 6.000000e+00, double 4.800000e+01>
%18 = bitcast double* %9 to <2 x double>*
store <2 x double> %17, <2 x double>* %18
%19 = fmul double %0, %0
%20 = fadd double %0, -2.500000e+00
%21 = tail call double @llvm.fmuladd.f64(double %19, double %20, double 2.500000e+00)
%22 = tail call double @llvm.fmuladd.f64(double %0, double %21, double -1.000000e+00)
%23 = fmul double %22, %0
%24 = fdiv double %23, 1.200000e+02
%25 = getelementptr inbounds double, double* %1, i64 4
store double %24, double* %25
ret void
}