double Laplacian7_4(i, f)
int i;
double f[];
{
  double tmp;
  tmp = 5.55555555556e-3 *
        (+2.0 * f[i - 3] - 27.0 * f[i - 2] + 270.0 * f[i - 1] - 490.0 * f[i] +
         270.0 * f[i + 1] - 27.0 * f[i + 2] + 2.0 * f[i + 3]);
  return tmp;
}


x86 assembly (clang, -O0):
<Laplacian7_4>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0x4(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
sub    $0x3,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
sub    $0x2,%ecx
movslq %ecx,%rcx
movsd  0xeee(%rip),%xmm1
mulsd  (%rax,%rcx,8),%xmm1
movq   %xmm1,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm1
addsd  %xmm0,%xmm0
addsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
sub    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm1
movsd  0xea0(%rip),%xmm2
mulsd  %xmm2,%xmm1
addsd  %xmm0,%xmm1
mov    -0x10(%rbp),%rax
movslq -0x4(%rbp),%rcx
movsd  (%rax,%rcx,8),%xmm0
movsd  0xe8b(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
add    $0x1,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm1
movsd  0xe61(%rip),%xmm2
mulsd  %xmm2,%xmm1
addsd  %xmm0,%xmm1
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
add    $0x2,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm0
movsd  0xe37(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
mov    -0x10(%rbp),%rax
mov    -0x4(%rbp),%ecx
add    $0x3,%ecx
movslq %ecx,%rcx
movsd  (%rax,%rcx,8),%xmm1
addsd  %xmm1,%xmm1
addsd  %xmm0,%xmm1
movsd  0xe05(%rip),%xmm0
mulsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x18(%rbp),%xmm0
pop    %rbp
ret

x86 assembly (clang, -O2):
<Laplacian7_4>:
movslq %edi,%rax
movsd  0xef5(%rip),%xmm1
movsd  -0x10(%rsi,%rax,8),%xmm0
mulsd  %xmm1,%xmm0
movsd  -0x18(%rsi,%rax,8),%xmm2
movsd  (%rsi,%rax,8),%xmm3
addsd  %xmm2,%xmm2
addsd  %xmm0,%xmm2
movsd  0xed8(%rip),%xmm0
movsd  -0x8(%rsi,%rax,8),%xmm4
mulsd  %xmm0,%xmm4
addsd  %xmm2,%xmm4
mulsd  0xeca(%rip),%xmm3
addsd  %xmm4,%xmm3
mulsd  0x8(%rsi,%rax,8),%xmm0
addsd  %xmm3,%xmm0
mulsd  0x10(%rsi,%rax,8),%xmm1
addsd  %xmm0,%xmm1
movsd  0x18(%rsi,%rax,8),%xmm0
addsd  %xmm0,%xmm0
addsd  %xmm1,%xmm0
mulsd  0xea4(%rip),%xmm0
ret

LLVM IR (-O0):
define double @Laplacian7_4(i32 %0, double* %1) {
%3 = alloca i32
%4 = alloca double*
%5 = alloca double
store i32 %0, i32* %3
store double* %1, double** %4
%6 = load double*, double** %4
%7 = load i32, i32* %3
%8 = sub nsw i32 %7, 3
%9 = sext i32 %8 to i64
%10 = getelementptr inbounds double, double* %6, i64 %9
%11 = load double, double* %10
%12 = load double*, double** %4
%13 = load i32, i32* %3
%14 = sub nsw i32 %13, 2
%15 = sext i32 %14 to i64
%16 = getelementptr inbounds double, double* %12, i64 %15
%17 = load double, double* %16
%18 = fmul double 2.700000e+01, %17
%19 = fneg double %18
%20 = call double @llvm.fmuladd.f64(double 2.000000e+00, double %11, double %19)
%21 = load double*, double** %4
%22 = load i32, i32* %3
%23 = sub nsw i32 %22, 1
%24 = sext i32 %23 to i64
%25 = getelementptr inbounds double, double* %21, i64 %24
%26 = load double, double* %25
%27 = call double @llvm.fmuladd.f64(double 2.700000e+02, double %26, double %20)
%28 = load double*, double** %4
%29 = load i32, i32* %3
%30 = sext i32 %29 to i64
%31 = getelementptr inbounds double, double* %28, i64 %30
%32 = load double, double* %31
%33 = call double @llvm.fmuladd.f64(double -4.900000e+02, double %32, double %27)
%34 = load double*, double** %4
%35 = load i32, i32* %3
%36 = add nsw i32 %35, 1
%37 = sext i32 %36 to i64
%38 = getelementptr inbounds double, double* %34, i64 %37
%39 = load double, double* %38
%40 = call double @llvm.fmuladd.f64(double 2.700000e+02, double %39, double %33)
%41 = load double*, double** %4
%42 = load i32, i32* %3
%43 = add nsw i32 %42, 2
%44 = sext i32 %43 to i64
%45 = getelementptr inbounds double, double* %41, i64 %44
%46 = load double, double* %45
%47 = call double @llvm.fmuladd.f64(double -2.700000e+01, double %46, double %40)
%48 = load double*, double** %4
%49 = load i32, i32* %3
%50 = add nsw i32 %49, 3
%51 = sext i32 %50 to i64
%52 = getelementptr inbounds double, double* %48, i64 %51
%53 = load double, double* %52
%54 = call double @llvm.fmuladd.f64(double 2.000000e+00, double %53, double %47)
%55 = fmul double 0x3F76C16C16C1801B, %54
store double %55, double* %5
%56 = load double, double* %5
ret double %56
}

LLVM IR (-O2):
define double @Laplacian7_4(i32 %0, double* nocapture %1) {
%3 = add nsw i32 %0, -3
%4 = sext i32 %3 to i64
%5 = getelementptr inbounds double, double* %1, i64 %4
%6 = load double, double* %5
%7 = add nsw i32 %0, -2
%8 = sext i32 %7 to i64
%9 = getelementptr inbounds double, double* %1, i64 %8
%10 = load double, double* %9
%11 = fmul double %10, -2.700000e+01
%12 = tail call double @llvm.fmuladd.f64(double %6, double 2.000000e+00, double %11)
%13 = add nsw i32 %0, -1
%14 = sext i32 %13 to i64
%15 = getelementptr inbounds double, double* %1, i64 %14
%16 = load double, double* %15
%17 = tail call double @llvm.fmuladd.f64(double %16, double 2.700000e+02, double %12)
%18 = sext i32 %0 to i64
%19 = getelementptr inbounds double, double* %1, i64 %18
%20 = load double, double* %19
%21 = tail call double @llvm.fmuladd.f64(double %20, double -4.900000e+02, double %17)
%22 = add nsw i32 %0, 1
%23 = sext i32 %22 to i64
%24 = getelementptr inbounds double, double* %1, i64 %23
%25 = load double, double* %24
%26 = tail call double @llvm.fmuladd.f64(double %25, double 2.700000e+02, double %21)
%27 = add nsw i32 %0, 2
%28 = sext i32 %27 to i64
%29 = getelementptr inbounds double, double* %1, i64 %28
%30 = load double, double* %29
%31 = tail call double @llvm.fmuladd.f64(double %30, double -2.700000e+01, double %26)
%32 = add nsw i32 %0, 3
%33 = sext i32 %32 to i64
%34 = getelementptr inbounds double, double* %1, i64 %33
%35 = load double, double* %34
%36 = tail call double @llvm.fmuladd.f64(double %35, double 2.000000e+00, double %31)
%37 = fmul double %36, 0x3F76C16C16C1801B
ret double %37
}