#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 */
int /*<<< orphan*/ c_drev(int, double *, int);
int /*<<< orphan*/ printf(char *);
double rand_double();
double tic();
double benchmark(int iterations, int len) {
  double elapsed;
  double x[len];
  double t;
  int i;
  for (i = 0; i < len; i++) {
    x[i] = (rand_double() * 200.0) - 100.0;
  }
  t = tic();
  for (i = 0; i < iterations; i++) {
    c_drev(len, x, 1);
    if (x[0] != x[0]) {
      printf("should not return NaN\n");
      break;
    }
  }
  elapsed = tic() - t;
  if (x[0] != x[0]) {
    printf("should not return NaN\n");
  }
  return elapsed;
}


x86 assembly (clang, -O0):
<benchmark>:
push   %rbp
mov    %rsp,%rbp
sub    $0x40,%rsp
mov    %edi,-0x4(%rbp)
mov    %esi,-0x8(%rbp)
mov    -0x8(%rbp),%eax
mov    %rsp,%rcx
mov    %rcx,-0x18(%rbp)
lea    0xf(,%rax,8),%rdx
and    $0xfffffffffffffff0,%rdx
mov    %rsp,%rcx
sub    %rdx,%rcx
mov    %rcx,-0x38(%rbp)
mov    %rcx,%rsp
mov    %rax,-0x20(%rbp)
movl   $0x0,-0x2c(%rbp)
mov    -0x2c(%rbp),%eax
cmp    -0x8(%rbp),%eax
jge    11c2 <benchmark+0x82>
mov    $0x0,%al
call   1060 <rand_double@plt>
mov    -0x38(%rbp),%rax
movsd  0xe65(%rip),%xmm1
mulsd  %xmm1,%xmm0
movsd  0xe61(%rip),%xmm1
addsd  %xmm1,%xmm0
movslq -0x2c(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x2c(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x2c(%rbp)
jmp    117c <benchmark+0x3c>
mov    $0x0,%al
call   1050 <tic@plt>
movsd  %xmm0,-0x28(%rbp)
movl   $0x0,-0x2c(%rbp)
mov    -0x2c(%rbp),%eax
cmp    -0x4(%rbp),%eax
jge    1233 <benchmark+0xf3>
mov    -0x38(%rbp),%rsi
mov    -0x8(%rbp),%edi
mov    $0x1,%edx
call   1030 <c_drev@plt>
mov    -0x38(%rbp),%rax
movsd  (%rax),%xmm0
ucomisd (%rax),%xmm0
jne    120f <benchmark+0xcf>
jp     120f <benchmark+0xcf>
jmp    1220 <benchmark+0xe0>
lea    0xdfa(%rip),%rdi
call   1040 <printf@plt>
jmp    1233 <benchmark+0xf3>
jmp    1225 <benchmark+0xe5>
mov    -0x2c(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x2c(%rbp)
jmp    11d5 <benchmark+0x95>
mov    $0x0,%al
call   1050 <tic@plt>
mov    -0x38(%rbp),%rax
subsd  -0x28(%rbp),%xmm0
movsd  %xmm0,-0x10(%rbp)
movsd  (%rax),%xmm0
ucomisd (%rax),%xmm0
jne    1261 <benchmark+0x121>
jp     1261 <benchmark+0x121>
jmp    126d <benchmark+0x12d>
lea    0xda8(%rip),%rdi
call   1040 <printf@plt>
movsd  -0x10(%rbp),%xmm0
mov    -0x18(%rbp),%rax
mov    %rax,%rsp
mov    %rbp,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<benchmark>:
push   %rbp
mov    %rsp,%rbp
push   %r15
push   %r14
push   %r13
push   %r12
push   %rbx
sub    $0x18,%rsp
mov    %esi,%r14d
mov    %edi,%r13d
mov    %esi,%r12d
mov    %rsp,%r15
lea    0xf(,%r12,8),%rax
and    $0xfffffffffffffff0,%rax
sub    %rax,%r15
mov    %r15,%rsp
test   %esi,%esi
jle    11a6 <benchmark+0x66>
xor    %ebx,%ebx
cs nopw 0x0(%rax,%rax,1)
nop
xor    %eax,%eax
call   1060 <rand_double@plt>
mulsd  0xe71(%rip),%xmm0
addsd  0xe71(%rip),%xmm0
movsd  %xmm0,(%r15,%rbx,8)
add    $0x1,%rbx
cmp    %rbx,%r12
jne    1180 <benchmark+0x40>
xor    %eax,%eax
call   1050 <tic@plt>
movsd  %xmm0,-0x38(%rbp)
test   %r13d,%r13d
jle    11ef <benchmark+0xaf>
nopw   0x0(%rax,%rax,1)
mov    %r14d,%edi
mov    %r15,%rsi
mov    $0x1,%edx
call   1030 <c_drev@plt>
movsd  (%r15),%xmm0
ucomisd %xmm0,%xmm0
jp     11e3 <benchmark+0xa3>
add    $0xffffffff,%r13d
jne    11c0 <benchmark+0x80>
jmp    11ef <benchmark+0xaf>
lea    0xe26(%rip),%rdi
call   1040 <puts@plt>
xor    %eax,%eax
call   1050 <tic@plt>
movsd  (%r15),%xmm1
ucomisd %xmm1,%xmm1
jp     1215 <benchmark+0xd5>
subsd  -0x38(%rbp),%xmm0
lea    -0x28(%rbp),%rsp
pop    %rbx
pop    %r12
pop    %r13
pop    %r14
pop    %r15
pop    %rbp
ret
lea    0xdf4(%rip),%rdi
movsd  %xmm0,-0x30(%rbp)
call   1040 <puts@plt>
movsd  -0x30(%rbp),%xmm0
jmp    1201 <benchmark+0xc1>

LLVM IR (-O0):
@.str = [23 x i8] c"should not return NaN\0A\00"
define double @benchmark(i32 %0, i32 %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca double
%6 = alloca i8*
%7 = alloca i64
%8 = alloca double
%9 = alloca i32
store i32 %0, i32* %3
store i32 %1, i32* %4
%10 = load i32, i32* %4
%11 = zext i32 %10 to i64
%12 = call i8* @llvm.stacksave()
store i8* %12, i8** %6
%13 = alloca double, i64 %11
store i64 %11, i64* %7
store i32 0, i32* %9
br label %14
14: ; preds = %24, %2
%15 = load i32, i32* %9
%16 = load i32, i32* %4
%17 = icmp slt i32 %15, %16
br i1 %17, label %18, label %27
18: ; preds = %14
%19 = call double (...) @rand_double()
%20 = call double @llvm.fmuladd.f64(double %19, double 2.000000e+02, double -1.000000e+02)
%21 = load i32, i32* %9
%22 = sext i32 %21 to i64
%23 = getelementptr inbounds double, double* %13, i64 %22
store double %20, double* %23
br label %24
24: ; preds = %18
%25 = load i32, i32* %9
%26 = add nsw i32 %25, 1
store i32 %26, i32* %9
br label %14
27: ; preds = %14
%28 = call double (...) @tic()
store double %28, double* %8
store i32 0, i32* %9
br label %29
29: ; preds = %44, %27
%30 = load i32, i32* %9
%31 = load i32, i32* %3
%32 = icmp slt i32 %30, %31
br i1 %32, label %33, label %47
33: ; preds = %29
%34 = load i32, i32* %4
%35 = call i32 @c_drev(i32 %34, double* %13, i32 1)
%36 = getelementptr inbounds double, double* %13, i64 0
%37 = load double, double* %36
%38 = getelementptr inbounds double, double* %13, i64 0
%39 = load double, double* %38
%40 = fcmp une double %37, %39
br i1 %40, label %41, label %43
41: ; preds = %33
%42 = call i32 @printf(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0))
br label %47
43: ; preds = %33
br label %44
44: ; preds = %43
%45 = load i32, i32* %9
%46 = add nsw i32 %45, 1
store i32 %46, i32* %9
br label %29
47: ; preds = %41, %29
%48 = call double (...) @tic()
%49 = load double, double* %8
%50 = fsub double %48, %49
store double %50, double* %5
%51 = getelementptr inbounds double, double* %13, i64 0
%52 = load double, double* %51
%53 = getelementptr inbounds double, double* %13, i64 0
%54 = load double, double* %53
%55 = fcmp une double %52, %54
br i1 %55, label %56, label %58
56: ; preds = %47
%57 = call i32 @printf(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0))
br label %58
58: ; preds = %56, %47
%59 = load double, double* %5
%60 = load i8*, i8** %6
ret double %59
}

LLVM IR (-O2):
@str.1 = [22 x i8] c"should not return NaN\00"
define double @benchmark(i32 %0, i32 %1) {
%3 = zext i32 %1 to i64
%4 = alloca double, i64 %3
%5 = icmp sgt i32 %1, 0
br i1 %5, label %6, label %13
6: ; preds = %2, %6
%7 = phi i64 [ %11, %6 ], [ 0, %2 ]
%8 = tail call double (...) @rand_double()
%9 = tail call double @llvm.fmuladd.f64(double %8, double 2.000000e+02, double -1.000000e+02)
%10 = getelementptr inbounds double, double* %4, i64 %7
store double %9, double* %10
%11 = add nuw nsw i64 %7, 1
%12 = icmp eq i64 %11, %3
br i1 %12, label %13, label %6
13: ; preds = %6, %2
%14 = tail call double (...) @tic()
%15 = icmp sgt i32 %0, 0
br i1 %15, label %18, label %26
16: ; preds = %18
%17 = icmp eq i32 %23, %0
br i1 %17, label %26, label %18
18: ; preds = %13, %16
%19 = phi i32 [ %23, %16 ], [ 0, %13 ]
%20 = call i32 @c_drev(i32 %1, double* %4, i32 1)
%21 = load double, double* %4
%22 = fcmp uno double %21, 0.000000e+00
%23 = add nuw nsw i32 %19, 1
br i1 %22, label %24, label %16
24: ; preds = %18
%25 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([22 x i8], [22 x i8]* @str.1, i64 0, i64 0))
br label %26
26: ; preds = %16, %13, %24
%27 = call double (...) @tic()
%28 = load double, double* %4
%29 = fcmp uno double %28, 0.000000e+00
br i1 %29, label %30, label %32
30: ; preds = %26
%31 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([22 x i8], [22 x i8]* @str.1, i64 0, i64 0))
br label %32
32: ; preds = %30, %26
%33 = fsub double %27, %14
ret double %33
}