void bot_vector_interpolate_3d(const double ta[3], const double tb[3],
                               double weight_b, double result[3]) {
  result[0] = ta[0] * (1 - weight_b) + tb[0] * weight_b;
  result[1] = ta[1] * (1 - weight_b) + tb[1] * weight_b;
  result[2] = ta[2] * (1 - weight_b) + tb[2] * weight_b;
}


x86 assembly (clang, -O0):
<bot_vector_interpolate_3d>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
movsd  %xmm0,-0x18(%rbp)
mov    %rdx,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movsd  (%rax),%xmm0
movsd  0xedb(%rip),%xmm2
subsd  -0x18(%rbp),%xmm2
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm1
mulsd  -0x18(%rbp),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x20(%rbp),%rax
movsd  %xmm0,(%rax)
mov    -0x8(%rbp),%rax
movsd  0x8(%rax),%xmm0
movsd  0xea8(%rip),%xmm2
subsd  -0x18(%rbp),%xmm2
mov    -0x10(%rbp),%rax
movsd  0x8(%rax),%xmm1
mulsd  -0x18(%rbp),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x20(%rbp),%rax
movsd  %xmm0,0x8(%rax)
mov    -0x8(%rbp),%rax
movsd  0x10(%rax),%xmm0
movsd  0xe73(%rip),%xmm2
subsd  -0x18(%rbp),%xmm2
mov    -0x10(%rbp),%rax
movsd  0x10(%rax),%xmm1
mulsd  -0x18(%rbp),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x20(%rbp),%rax
movsd  %xmm0,0x10(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<bot_vector_interpolate_3d>:
movsd  0xef8(%rip),%xmm1
subsd  %xmm0,%xmm1
movsd  (%rsi),%xmm2
mulsd  %xmm0,%xmm2
movsd  (%rdi),%xmm3
mulsd  %xmm1,%xmm3
addsd  %xmm2,%xmm3
movsd  %xmm3,(%rdx)
movsd  0x8(%rsi),%xmm2
mulsd  %xmm0,%xmm2
movsd  0x8(%rdi),%xmm3
mulsd  %xmm1,%xmm3
addsd  %xmm2,%xmm3
movsd  %xmm3,0x8(%rdx)
mulsd  0x10(%rsi),%xmm0
mulsd  0x10(%rdi),%xmm1
addsd  %xmm0,%xmm1
movsd  %xmm1,0x10(%rdx)
ret

LLVM IR (-O0):
define void @bot_vector_interpolate_3d(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 = load double, double* %7
%13 = fsub double 1.000000e+00, %12
%14 = load double*, double** %6
%15 = getelementptr inbounds double, double* %14, i64 0
%16 = load double, double* %15
%17 = load double, double* %7
%18 = fmul double %16, %17
%19 = call double @llvm.fmuladd.f64(double %11, double %13, double %18)
%20 = load double*, double** %8
%21 = getelementptr inbounds double, double* %20, i64 0
store double %19, double* %21
%22 = load double*, double** %5
%23 = getelementptr inbounds double, double* %22, i64 1
%24 = load double, double* %23
%25 = load double, double* %7
%26 = fsub double 1.000000e+00, %25
%27 = load double*, double** %6
%28 = getelementptr inbounds double, double* %27, i64 1
%29 = load double, double* %28
%30 = load double, double* %7
%31 = fmul double %29, %30
%32 = call double @llvm.fmuladd.f64(double %24, double %26, double %31)
%33 = load double*, double** %8
%34 = getelementptr inbounds double, double* %33, i64 1
store double %32, double* %34
%35 = load double*, double** %5
%36 = getelementptr inbounds double, double* %35, i64 2
%37 = load double, double* %36
%38 = load double, double* %7
%39 = fsub double 1.000000e+00, %38
%40 = load double*, double** %6
%41 = getelementptr inbounds double, double* %40, i64 2
%42 = load double, double* %41
%43 = load double, double* %7
%44 = fmul double %42, %43
%45 = call double @llvm.fmuladd.f64(double %37, double %39, double %44)
%46 = load double*, double** %8
%47 = getelementptr inbounds double, double* %46, i64 2
store double %45, double* %47
ret void
}

LLVM IR (-O2):
define void @bot_vector_interpolate_3d(double* nocapture %0, double* nocapture %1, double %2, double* nocapture writeonly %3) {
%5 = load double, double* %0
%6 = fsub double 1.000000e+00, %2
%7 = load double, double* %1
%8 = fmul double %7, %2
%9 = tail call double @llvm.fmuladd.f64(double %5, double %6, double %8)
store double %9, double* %3
%10 = getelementptr inbounds double, double* %0, i64 1
%11 = load double, double* %10
%12 = getelementptr inbounds double, double* %1, i64 1
%13 = load double, double* %12
%14 = fmul double %13, %2
%15 = tail call double @llvm.fmuladd.f64(double %11, double %6, double %14)
%16 = getelementptr inbounds double, double* %3, i64 1
store double %15, double* %16
%17 = getelementptr inbounds double, double* %0, i64 2
%18 = load double, double* %17
%19 = getelementptr inbounds double, double* %1, i64 2
%20 = load double, double* %19
%21 = fmul double %20, %2
%22 = tail call double @llvm.fmuladd.f64(double %18, double %6, double %21)
%23 = getelementptr inbounds double, double* %3, i64 2
store double %22, double* %23
ret void
}