void epipolar_line(double L[3], double F[9], double x[2]) {
  L[0] = x[0] * F[0] + x[1] * F[3] + F[6];
  L[1] = x[0] * F[1] + x[1] * F[4] + F[7];
  L[2] = x[0] * F[2] + x[1] * F[5] + F[8];
}


x86 assembly (clang, -O0):
<epipolar_line>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    -0x18(%rbp),%rax
movsd  (%rax),%xmm0
mov    -0x10(%rbp),%rax
movsd  (%rax),%xmm2
mov    -0x18(%rbp),%rax
movsd  0x8(%rax),%xmm1
mov    -0x10(%rbp),%rax
mulsd  0x18(%rax),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
addsd  0x30(%rax),%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,(%rax)
mov    -0x18(%rbp),%rax
movsd  (%rax),%xmm0
mov    -0x10(%rbp),%rax
movsd  0x8(%rax),%xmm2
mov    -0x18(%rbp),%rax
movsd  0x8(%rax),%xmm1
mov    -0x10(%rbp),%rax
mulsd  0x20(%rax),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
addsd  0x38(%rax),%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,0x8(%rax)
mov    -0x18(%rbp),%rax
movsd  (%rax),%xmm0
mov    -0x10(%rbp),%rax
movsd  0x10(%rax),%xmm2
mov    -0x18(%rbp),%rax
movsd  0x8(%rax),%xmm1
mov    -0x10(%rbp),%rax
mulsd  0x28(%rax),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
addsd  0x40(%rax),%xmm0
mov    -0x8(%rbp),%rax
movsd  %xmm0,0x10(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<epipolar_line>:
movsd  (%rdx),%xmm0
movsd  0x8(%rdx),%xmm1
mulsd  0x18(%rsi),%xmm1
mulsd  (%rsi),%xmm0
addsd  %xmm1,%xmm0
addsd  0x30(%rsi),%xmm0
movsd  %xmm0,(%rdi)
movsd  (%rdx),%xmm0
movsd  0x8(%rdx),%xmm1
mulsd  0x20(%rsi),%xmm1
mulsd  0x8(%rsi),%xmm0
addsd  %xmm1,%xmm0
addsd  0x38(%rsi),%xmm0
movsd  %xmm0,0x8(%rdi)
movsd  (%rdx),%xmm0
movsd  0x8(%rdx),%xmm1
mulsd  0x28(%rsi),%xmm1
mulsd  0x10(%rsi),%xmm0
addsd  %xmm1,%xmm0
addsd  0x40(%rsi),%xmm0
movsd  %xmm0,0x10(%rdi)
ret

LLVM IR (-O0):
define void @epipolar_line(double* %0, double* %1, double* %2) {
%4 = alloca double*
%5 = alloca double*
%6 = alloca double*
store double* %0, double** %4
store double* %1, double** %5
store double* %2, double** %6
%7 = load double*, double** %6
%8 = getelementptr inbounds double, double* %7, i64 0
%9 = load double, double* %8
%10 = load double*, double** %5
%11 = getelementptr inbounds double, double* %10, i64 0
%12 = load double, double* %11
%13 = load double*, double** %6
%14 = getelementptr inbounds double, double* %13, i64 1
%15 = load double, double* %14
%16 = load double*, double** %5
%17 = getelementptr inbounds double, double* %16, i64 3
%18 = load double, double* %17
%19 = fmul double %15, %18
%20 = call double @llvm.fmuladd.f64(double %9, double %12, double %19)
%21 = load double*, double** %5
%22 = getelementptr inbounds double, double* %21, i64 6
%23 = load double, double* %22
%24 = fadd double %20, %23
%25 = load double*, double** %4
%26 = getelementptr inbounds double, double* %25, i64 0
store double %24, double* %26
%27 = load double*, double** %6
%28 = getelementptr inbounds double, double* %27, i64 0
%29 = load double, double* %28
%30 = load double*, double** %5
%31 = getelementptr inbounds double, double* %30, i64 1
%32 = load double, double* %31
%33 = load double*, double** %6
%34 = getelementptr inbounds double, double* %33, i64 1
%35 = load double, double* %34
%36 = load double*, double** %5
%37 = getelementptr inbounds double, double* %36, i64 4
%38 = load double, double* %37
%39 = fmul double %35, %38
%40 = call double @llvm.fmuladd.f64(double %29, double %32, double %39)
%41 = load double*, double** %5
%42 = getelementptr inbounds double, double* %41, i64 7
%43 = load double, double* %42
%44 = fadd double %40, %43
%45 = load double*, double** %4
%46 = getelementptr inbounds double, double* %45, i64 1
store double %44, double* %46
%47 = load double*, double** %6
%48 = getelementptr inbounds double, double* %47, i64 0
%49 = load double, double* %48
%50 = load double*, double** %5
%51 = getelementptr inbounds double, double* %50, i64 2
%52 = load double, double* %51
%53 = load double*, double** %6
%54 = getelementptr inbounds double, double* %53, i64 1
%55 = load double, double* %54
%56 = load double*, double** %5
%57 = getelementptr inbounds double, double* %56, i64 5
%58 = load double, double* %57
%59 = fmul double %55, %58
%60 = call double @llvm.fmuladd.f64(double %49, double %52, double %59)
%61 = load double*, double** %5
%62 = getelementptr inbounds double, double* %61, i64 8
%63 = load double, double* %62
%64 = fadd double %60, %63
%65 = load double*, double** %4
%66 = getelementptr inbounds double, double* %65, i64 2
store double %64, double* %66
ret void
}

LLVM IR (-O2):
define void @epipolar_line(double* nocapture writeonly %0, double* nocapture %1, double* nocapture %2) {
%4 = load double, double* %2
%5 = load double, double* %1
%6 = getelementptr inbounds double, double* %2, i64 1
%7 = load double, double* %6
%8 = getelementptr inbounds double, double* %1, i64 3
%9 = load double, double* %8
%10 = fmul double %7, %9
%11 = tail call double @llvm.fmuladd.f64(double %4, double %5, double %10)
%12 = getelementptr inbounds double, double* %1, i64 6
%13 = load double, double* %12
%14 = fadd double %13, %11
store double %14, double* %0
%15 = load double, double* %2
%16 = getelementptr inbounds double, double* %1, i64 1
%17 = load double, double* %16
%18 = load double, double* %6
%19 = getelementptr inbounds double, double* %1, i64 4
%20 = load double, double* %19
%21 = fmul double %18, %20
%22 = tail call double @llvm.fmuladd.f64(double %15, double %17, double %21)
%23 = getelementptr inbounds double, double* %1, i64 7
%24 = load double, double* %23
%25 = fadd double %24, %22
%26 = getelementptr inbounds double, double* %0, i64 1
store double %25, double* %26
%27 = load double, double* %2
%28 = getelementptr inbounds double, double* %1, i64 2
%29 = load double, double* %28
%30 = load double, double* %6
%31 = getelementptr inbounds double, double* %1, i64 5
%32 = load double, double* %31
%33 = fmul double %30, %32
%34 = tail call double @llvm.fmuladd.f64(double %27, double %29, double %33)
%35 = getelementptr inbounds double, double* %1, i64 8
%36 = load double, double* %35
%37 = fadd double %36, %34
%38 = getelementptr inbounds double, double* %0, i64 2
store double %37, double* %38
ret void
}