void izh_f(double *vars, double *ret, double *params, double syn) {
  ret[0] =
      0.04 * vars[0] * vars[0] + 5 * vars[0] + 140 - vars[1] + params[0] - syn;
  ret[1] = params[1] * (params[2] * vars[0] - vars[1]);
  return;
}


x86 assembly (clang, -O0):
<izh_f>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
movsd  %xmm0,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movsd  0xeef(%rip),%xmm0
mulsd  (%rax),%xmm0
mov    -0x8(%rbp),%rax
movsd  (%rax),%xmm2
mov    -0x8(%rbp),%rax
movsd  0xecf(%rip),%xmm1
mulsd  (%rax),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  0xeb3(%rip),%xmm1
addsd  %xmm1,%xmm0
mov    -0x8(%rbp),%rax
subsd  0x8(%rax),%xmm0
mov    -0x18(%rbp),%rax
addsd  (%rax),%xmm0
subsd  -0x20(%rbp),%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,(%rax)
mov    -0x18(%rbp),%rax
movsd  0x8(%rax),%xmm0
mov    -0x18(%rbp),%rax
movsd  0x10(%rax),%xmm1
mov    -0x8(%rbp),%rax
movsd  (%rax),%xmm3
mov    -0x8(%rbp),%rax
movsd  0x8(%rax),%xmm2
movq   %xmm2,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm2
mulsd  %xmm3,%xmm1
addsd  %xmm2,%xmm1
mulsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
movsd  %xmm0,0x8(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<izh_f>:
movsd  (%rdi),%xmm1
movsd  0xef4(%rip),%xmm2
mulsd  %xmm1,%xmm2
mulsd  %xmm1,%xmm2
mulsd  0xeec(%rip),%xmm1
addsd  %xmm2,%xmm1
addsd  0xee8(%rip),%xmm1
subsd  0x8(%rdi),%xmm1
addsd  (%rdx),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,(%rsi)
movsd  0x10(%rdx),%xmm0
mulsd  (%rdi),%xmm0
subsd  0x8(%rdi),%xmm0
mulsd  0x8(%rdx),%xmm0
movsd  %xmm0,0x8(%rsi)
ret

LLVM IR (-O0):
define void @izh_f(double* %0, double* %1, double* %2, double %3) {
%5 = alloca double*
%6 = alloca double*
%7 = alloca double*
%8 = alloca double
store double* %0, double** %5
store double* %1, double** %6
store double* %2, double** %7
store double %3, double* %8
%9 = load double*, double** %5
%10 = getelementptr inbounds double, double* %9, i64 0
%11 = load double, double* %10
%12 = fmul double 4.000000e-02, %11
%13 = load double*, double** %5
%14 = getelementptr inbounds double, double* %13, i64 0
%15 = load double, double* %14
%16 = load double*, double** %5
%17 = getelementptr inbounds double, double* %16, i64 0
%18 = load double, double* %17
%19 = fmul double 5.000000e+00, %18
%20 = call double @llvm.fmuladd.f64(double %12, double %15, double %19)
%21 = fadd double %20, 1.400000e+02
%22 = load double*, double** %5
%23 = getelementptr inbounds double, double* %22, i64 1
%24 = load double, double* %23
%25 = fsub double %21, %24
%26 = load double*, double** %7
%27 = getelementptr inbounds double, double* %26, i64 0
%28 = load double, double* %27
%29 = fadd double %25, %28
%30 = load double, double* %8
%31 = fsub double %29, %30
%32 = load double*, double** %6
%33 = getelementptr inbounds double, double* %32, i64 0
store double %31, double* %33
%34 = load double*, double** %7
%35 = getelementptr inbounds double, double* %34, i64 1
%36 = load double, double* %35
%37 = load double*, double** %7
%38 = getelementptr inbounds double, double* %37, i64 2
%39 = load double, double* %38
%40 = load double*, double** %5
%41 = getelementptr inbounds double, double* %40, i64 0
%42 = load double, double* %41
%43 = load double*, double** %5
%44 = getelementptr inbounds double, double* %43, i64 1
%45 = load double, double* %44
%46 = fneg double %45
%47 = call double @llvm.fmuladd.f64(double %39, double %42, double %46)
%48 = fmul double %36, %47
%49 = load double*, double** %6
%50 = getelementptr inbounds double, double* %49, i64 1
store double %48, double* %50
ret void
}

LLVM IR (-O2):
define void @izh_f(double* nocapture %0, double* nocapture writeonly %1, double* nocapture %2, double %3) {
%5 = load double, double* %0
%6 = fmul double %5, 4.000000e-02
%7 = fmul double %5, 5.000000e+00
%8 = tail call double @llvm.fmuladd.f64(double %6, double %5, double %7)
%9 = fadd double %8, 1.400000e+02
%10 = getelementptr inbounds double, double* %0, i64 1
%11 = load double, double* %10
%12 = fsub double %9, %11
%13 = load double, double* %2
%14 = fadd double %13, %12
%15 = fsub double %14, %3
store double %15, double* %1
%16 = getelementptr inbounds double, double* %2, i64 1
%17 = load double, double* %16
%18 = getelementptr inbounds double, double* %2, i64 2
%19 = load double, double* %18
%20 = load double, double* %0
%21 = load double, double* %10
%22 = fneg double %21
%23 = tail call double @llvm.fmuladd.f64(double %19, double %20, double %22)
%24 = fmul double %17, %23
%25 = getelementptr inbounds double, double* %1, i64 1
store double %24, double* %25
ret void
}