#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
double _f(double);
double difm8(double x, double h) {
  double f1, f2, f3, f4, f5, f6, f7, f8;
  f1 = _f(x + h) - _f(x - h);
  f2 = _f(x + 2. * h) - _f(x - 2. * h);
  f3 = _f(x + 3. * h) - _f(x - 3. * h);
  f4 = _f(x + 4. * h) - _f(x - 4. * h);
  f5 = _f(x + 5. * h) - _f(x - 5. * h);
  f6 = _f(x + 6. * h) - _f(x - 6. * h);
  f7 = _f(x + 7. * h) - _f(x - 7. * h);
  f8 = _f(x + 8. * h) - _f(x - 8. * h);
  return (1921920. * f1 - 672672. * f2 + 244608. * f3 - 76440. * f4 +
          18816. * f5 - 3360. * f6 + 384. * f7 - 21. * f8) /
         2162160. / h;
}


x86 assembly (clang, -O0):
<difm8>:
push   %rbp
mov    %rsp,%rbp
sub    $0x90,%rsp
movsd  %xmm0,-0x8(%rbp)
movsd  %xmm1,-0x10(%rbp)
movsd  -0x8(%rbp),%xmm0
addsd  -0x10(%rbp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x90(%rbp)
ff
movsd  -0x8(%rbp),%xmm0
subsd  -0x10(%rbp),%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x90(%rbp),%xmm0
ff
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
addsd  %xmm0,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x88(%rbp)
ff
movsd  -0x8(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm1
addsd  %xmm1,%xmm1
subsd  %xmm1,%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x88(%rbp),%xmm0
ff
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xee5(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x80(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xeb9(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x80(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x28(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xe81(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x78(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xe55(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x78(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x30(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xe1d(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x70(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xdf1(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x70(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x38(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xdb9(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x68(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xd8d(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x68(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x40(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xd55(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x60(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xd29(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x60(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x48(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xcf1(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,-0x58(%rbp)
movsd  -0x8(%rbp),%xmm1
movsd  -0x10(%rbp),%xmm0
movsd  0xcc5(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movaps %xmm0,%xmm1
movsd  -0x58(%rbp),%xmm0
subsd  %xmm1,%xmm0
movsd  %xmm0,-0x50(%rbp)
movsd  -0x18(%rbp),%xmm0
movsd  0xc92(%rip),%xmm1
mulsd  -0x20(%rbp),%xmm1
movq   %xmm1,%rax
movabs $0x8000000000000000,%rcx
xor    %rcx,%rax
movq   %rax,%xmm1
movsd  0xc66(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  -0x28(%rbp),%xmm1
movsd  0xc49(%rip),%xmm2
mulsd  %xmm2,%xmm1
addsd  %xmm0,%xmm1
movsd  -0x30(%rbp),%xmm0
movsd  0xc2c(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  -0x38(%rbp),%xmm1
movsd  0xc0f(%rip),%xmm2
mulsd  %xmm2,%xmm1
addsd  %xmm0,%xmm1
movsd  -0x40(%rbp),%xmm0
movsd  0xbf2(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  -0x48(%rbp),%xmm1
movsd  0xbd5(%rip),%xmm2
mulsd  %xmm2,%xmm1
addsd  %xmm0,%xmm1
movsd  -0x50(%rbp),%xmm0
movsd  0xbb8(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  0xba0(%rip),%xmm1
divsd  %xmm1,%xmm0
divsd  -0x10(%rbp),%xmm0
add    $0x90,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<difm8>:
sub    $0x58,%rsp
movsd  %xmm1,0x10(%rsp)
movsd  %xmm0,0x8(%rsp)
addsd  %xmm1,%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x48(%rsp)
movsd  0x8(%rsp),%xmm0
subsd  0x10(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x48(%rsp),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,0x48(%rsp)
movsd  0x10(%rsp),%xmm0
addsd  %xmm0,%xmm0
movsd  %xmm0,0x18(%rsp)
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x40(%rsp)
movsd  0x8(%rsp),%xmm0
subsd  0x18(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x40(%rsp),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,0x40(%rsp)
movsd  0xe66(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x18(%rsp)
movsd  0xe4f(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x18(%rsp),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,0x18(%rsp)
movsd  0xe2e(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x38(%rsp)
movsd  0xe17(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x38(%rsp),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,0x38(%rsp)
movsd  0xdf6(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x30(%rsp)
movsd  0xddf(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x30(%rsp),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,0x30(%rsp)
movsd  0xdbe(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x28(%rsp)
movsd  0xda7(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x28(%rsp),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,0x28(%rsp)
movsd  0xd86(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x20(%rsp)
movsd  0xd6f(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x20(%rsp),%xmm1
subsd  %xmm0,%xmm1
movsd  %xmm1,0x20(%rsp)
movsd  0xd4e(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  %xmm0,0x50(%rsp)
movsd  0xd37(%rip),%xmm0
mulsd  0x10(%rsp),%xmm0
addsd  0x8(%rsp),%xmm0
call   1030 <_f@plt>
movsd  0x50(%rsp),%xmm3
subsd  %xmm0,%xmm3
movsd  0x40(%rsp),%xmm1
mulsd  0xd16(%rip),%xmm1
movsd  0x48(%rsp),%xmm0
mulsd  0xd10(%rip),%xmm0
movsd  0x18(%rsp),%xmm2
mulsd  0xd0a(%rip),%xmm2
addsd  %xmm1,%xmm0
addsd  %xmm0,%xmm2
movsd  0x38(%rsp),%xmm0
mulsd  0xcfc(%rip),%xmm0
addsd  %xmm2,%xmm0
movsd  0x30(%rsp),%xmm1
mulsd  0xcf2(%rip),%xmm1
addsd  %xmm0,%xmm1
movsd  0x28(%rsp),%xmm0
mulsd  0xce8(%rip),%xmm0
movsd  0x20(%rsp),%xmm2
mulsd  0xce2(%rip),%xmm2
addsd  %xmm1,%xmm0
addsd  %xmm0,%xmm2
movapd %xmm3,%xmm0
mulsd  0xcd6(%rip),%xmm0
addsd  %xmm2,%xmm0
divsd  0xcd2(%rip),%xmm0
divsd  0x10(%rsp),%xmm0
add    $0x58,%rsp
ret

LLVM IR (-O0):
define double @difm8(double %0, double %1) {
%3 = alloca double
%4 = alloca double
%5 = alloca double
%6 = alloca double
%7 = alloca double
%8 = alloca double
%9 = alloca double
%10 = alloca double
%11 = alloca double
%12 = alloca double
store double %0, double* %3
store double %1, double* %4
%13 = load double, double* %3
%14 = load double, double* %4
%15 = fadd double %13, %14
%16 = call double @_f(double %15)
%17 = load double, double* %3
%18 = load double, double* %4
%19 = fsub double %17, %18
%20 = call double @_f(double %19)
%21 = fsub double %16, %20
store double %21, double* %5
%22 = load double, double* %3
%23 = load double, double* %4
%24 = call double @llvm.fmuladd.f64(double 2.000000e+00, double %23, double %22)
%25 = call double @_f(double %24)
%26 = load double, double* %3
%27 = load double, double* %4
%28 = call double @llvm.fmuladd.f64(double -2.000000e+00, double %27, double %26)
%29 = call double @_f(double %28)
%30 = fsub double %25, %29
store double %30, double* %6
%31 = load double, double* %3
%32 = load double, double* %4
%33 = call double @llvm.fmuladd.f64(double 3.000000e+00, double %32, double %31)
%34 = call double @_f(double %33)
%35 = load double, double* %3
%36 = load double, double* %4
%37 = call double @llvm.fmuladd.f64(double -3.000000e+00, double %36, double %35)
%38 = call double @_f(double %37)
%39 = fsub double %34, %38
store double %39, double* %7
%40 = load double, double* %3
%41 = load double, double* %4
%42 = call double @llvm.fmuladd.f64(double 4.000000e+00, double %41, double %40)
%43 = call double @_f(double %42)
%44 = load double, double* %3
%45 = load double, double* %4
%46 = call double @llvm.fmuladd.f64(double -4.000000e+00, double %45, double %44)
%47 = call double @_f(double %46)
%48 = fsub double %43, %47
store double %48, double* %8
%49 = load double, double* %3
%50 = load double, double* %4
%51 = call double @llvm.fmuladd.f64(double 5.000000e+00, double %50, double %49)
%52 = call double @_f(double %51)
%53 = load double, double* %3
%54 = load double, double* %4
%55 = call double @llvm.fmuladd.f64(double -5.000000e+00, double %54, double %53)
%56 = call double @_f(double %55)
%57 = fsub double %52, %56
store double %57, double* %9
%58 = load double, double* %3
%59 = load double, double* %4
%60 = call double @llvm.fmuladd.f64(double 6.000000e+00, double %59, double %58)
%61 = call double @_f(double %60)
%62 = load double, double* %3
%63 = load double, double* %4
%64 = call double @llvm.fmuladd.f64(double -6.000000e+00, double %63, double %62)
%65 = call double @_f(double %64)
%66 = fsub double %61, %65
store double %66, double* %10
%67 = load double, double* %3
%68 = load double, double* %4
%69 = call double @llvm.fmuladd.f64(double 7.000000e+00, double %68, double %67)
%70 = call double @_f(double %69)
%71 = load double, double* %3
%72 = load double, double* %4
%73 = call double @llvm.fmuladd.f64(double -7.000000e+00, double %72, double %71)
%74 = call double @_f(double %73)
%75 = fsub double %70, %74
store double %75, double* %11
%76 = load double, double* %3
%77 = load double, double* %4
%78 = call double @llvm.fmuladd.f64(double 8.000000e+00, double %77, double %76)
%79 = call double @_f(double %78)
%80 = load double, double* %3
%81 = load double, double* %4
%82 = call double @llvm.fmuladd.f64(double -8.000000e+00, double %81, double %80)
%83 = call double @_f(double %82)
%84 = fsub double %79, %83
store double %84, double* %12
%85 = load double, double* %5
%86 = load double, double* %6
%87 = fmul double 6.726720e+05, %86
%88 = fneg double %87
%89 = call double @llvm.fmuladd.f64(double 1.921920e+06, double %85, double %88)
%90 = load double, double* %7
%91 = call double @llvm.fmuladd.f64(double 2.446080e+05, double %90, double %89)
%92 = load double, double* %8
%93 = call double @llvm.fmuladd.f64(double -7.644000e+04, double %92, double %91)
%94 = load double, double* %9
%95 = call double @llvm.fmuladd.f64(double 1.881600e+04, double %94, double %93)
%96 = load double, double* %10
%97 = call double @llvm.fmuladd.f64(double -3.360000e+03, double %96, double %95)
%98 = load double, double* %11
%99 = call double @llvm.fmuladd.f64(double 3.840000e+02, double %98, double %97)
%100 = load double, double* %12
%101 = call double @llvm.fmuladd.f64(double -2.100000e+01, double %100, double %99)
%102 = fdiv double %101, 2.162160e+06
%103 = load double, double* %4
%104 = fdiv double %102, %103
ret double %104
}

LLVM IR (-O2):
define double @difm8(double %0, double %1) {
%3 = fadd double %0, %1
%4 = tail call double @_f(double %3)
%5 = fsub double %0, %1
%6 = tail call double @_f(double %5)
%7 = fsub double %4, %6
%8 = tail call double @llvm.fmuladd.f64(double %1, double 2.000000e+00, double %0)
%9 = tail call double @_f(double %8)
%10 = tail call double @llvm.fmuladd.f64(double %1, double -2.000000e+00, double %0)
%11 = tail call double @_f(double %10)
%12 = fsub double %9, %11
%13 = tail call double @llvm.fmuladd.f64(double %1, double 3.000000e+00, double %0)
%14 = tail call double @_f(double %13)
%15 = tail call double @llvm.fmuladd.f64(double %1, double -3.000000e+00, double %0)
%16 = tail call double @_f(double %15)
%17 = fsub double %14, %16
%18 = tail call double @llvm.fmuladd.f64(double %1, double 4.000000e+00, double %0)
%19 = tail call double @_f(double %18)
%20 = tail call double @llvm.fmuladd.f64(double %1, double -4.000000e+00, double %0)
%21 = tail call double @_f(double %20)
%22 = fsub double %19, %21
%23 = tail call double @llvm.fmuladd.f64(double %1, double 5.000000e+00, double %0)
%24 = tail call double @_f(double %23)
%25 = tail call double @llvm.fmuladd.f64(double %1, double -5.000000e+00, double %0)
%26 = tail call double @_f(double %25)
%27 = fsub double %24, %26
%28 = tail call double @llvm.fmuladd.f64(double %1, double 6.000000e+00, double %0)
%29 = tail call double @_f(double %28)
%30 = tail call double @llvm.fmuladd.f64(double %1, double -6.000000e+00, double %0)
%31 = tail call double @_f(double %30)
%32 = fsub double %29, %31
%33 = tail call double @llvm.fmuladd.f64(double %1, double 7.000000e+00, double %0)
%34 = tail call double @_f(double %33)
%35 = tail call double @llvm.fmuladd.f64(double %1, double -7.000000e+00, double %0)
%36 = tail call double @_f(double %35)
%37 = fsub double %34, %36
%38 = tail call double @llvm.fmuladd.f64(double %1, double 8.000000e+00, double %0)
%39 = tail call double @_f(double %38)
%40 = tail call double @llvm.fmuladd.f64(double %1, double -8.000000e+00, double %0)
%41 = tail call double @_f(double %40)
%42 = fsub double %39, %41
%43 = fmul double %12, -6.726720e+05
%44 = tail call double @llvm.fmuladd.f64(double %7, double 1.921920e+06, double %43)
%45 = tail call double @llvm.fmuladd.f64(double %17, double 2.446080e+05, double %44)
%46 = tail call double @llvm.fmuladd.f64(double %22, double -7.644000e+04, double %45)
%47 = tail call double @llvm.fmuladd.f64(double %27, double 1.881600e+04, double %46)
%48 = tail call double @llvm.fmuladd.f64(double %32, double -3.360000e+03, double %47)
%49 = tail call double @llvm.fmuladd.f64(double %37, double 3.840000e+02, double %48)
%50 = tail call double @llvm.fmuladd.f64(double %42, double -2.100000e+01, double %49)
%51 = fdiv double %50, 2.162160e+06
%52 = fdiv double %51, %1
ret double %52
}