#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 log(double);
double rand0_1();
double sqrt(double);
double rand_gauss() {
  double v1, v2, R, fac;
  static double gset;
  static int iset;
  if (iset == 0) {
    do {
      v1 = 2.0 * rand0_1() - 1.0;
      v2 = 2.0 * rand0_1() - 1.0;
      R = v1 * v1 + v2 * v2;
    } while (R >= 1.0 || R == 0.0);
    fac = sqrt(-2.0 * log(R) / R);
    gset = v1 * fac;
    iset = 1;
    return (v2 * fac);
  } else {
    iset = 0;
    return gset;
  }
}


x86 assembly (clang, -O0):
<rand_gauss>:
push   %rbp
mov    %rsp,%rbp
sub    $0x30,%rsp
cmpl   $0x0,0x2f09(%rip)
jne    1239 <rand_gauss+0x109>
jmp    114a <rand_gauss+0x1a>
mov    $0x0,%al
call   1030 <rand0_1@plt>
addsd  %xmm0,%xmm0
movsd  0xea3(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x10(%rbp)
mov    $0x0,%al
call   1030 <rand0_1@plt>
addsd  %xmm0,%xmm0
movsd  0xe87(%rip),%xmm1
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x18(%rbp)
movsd  -0x10(%rbp),%xmm0
movsd  -0x10(%rbp),%xmm2
movsd  -0x18(%rbp),%xmm1
mulsd  -0x18(%rbp),%xmm1
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
movsd  %xmm0,-0x20(%rbp)
movsd  -0x20(%rbp),%xmm0
mov    $0x1,%al
movsd  0xe56(%rip),%xmm1
ucomisd %xmm1,%xmm0
mov    %al,-0x29(%rbp)
jae    11d6 <rand_gauss+0xa6>
movsd  -0x20(%rbp),%xmm0
xorps  %xmm1,%xmm1
ucomisd %xmm1,%xmm0
sete   %al
setnp  %cl
and    %cl,%al
mov    %al,-0x29(%rbp)
mov    -0x29(%rbp),%al
test   $0x1,%al
jne    114a <rand_gauss+0x1a>
movsd  -0x20(%rbp),%xmm0
call   1040 <log@plt>
movaps %xmm0,%xmm1
movsd  0xe1a(%rip),%xmm0
mulsd  %xmm1,%xmm0
divsd  -0x20(%rbp),%xmm0
call   1050 <sqrt@plt>
movsd  %xmm0,-0x28(%rbp)
movsd  -0x10(%rbp),%xmm0
mulsd  -0x28(%rbp),%xmm0
movsd  %xmm0,0x2e25(%rip)
movl   $0x1,0x2e23(%rip)
movsd  -0x18(%rbp),%xmm0
mulsd  -0x28(%rbp),%xmm0
movsd  %xmm0,-0x8(%rbp)
jmp    1250 <rand_gauss+0x120>
movl   $0x0,0x2e05(%rip)
movsd  0x2df5(%rip),%xmm0
movsd  %xmm0,-0x8(%rbp)
movsd  -0x8(%rbp),%xmm0
add    $0x30,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<rand_gauss>:
sub    $0x18,%rsp
cmpb   $0x0,0x2f0d(%rip)
je     1160 <rand_gauss+0x30>
movb   $0x0,0x2f04(%rip)
movsd  0x2ef4(%rip),%xmm1
jmp    1218 <rand_gauss+0xe8>
cs nopw 0x0(%rax,%rax,1)
nopl   0x0(%rax,%rax,1)
xor    %eax,%eax
call   1030 <rand0_1@plt>
movapd %xmm0,%xmm1
addsd  %xmm0,%xmm1
movsd  0xe89(%rip),%xmm0
addsd  %xmm0,%xmm1
movsd  %xmm1,(%rsp)
xor    %eax,%eax
call   1030 <rand0_1@plt>
addsd  %xmm0,%xmm0
addsd  0xe6d(%rip),%xmm0
movapd %xmm0,%xmm1
mulsd  %xmm0,%xmm1
movsd  (%rsp),%xmm2
mulsd  %xmm2,%xmm2
addsd  %xmm1,%xmm2
ucomisd 0xe58(%rip),%xmm2
jae    1160 <rand_gauss+0x30>
ucomisd 0xe5e(%rip),%xmm2
jne    11be <rand_gauss+0x8e>
jnp    1160 <rand_gauss+0x30>
movsd  %xmm0,0x10(%rsp)
movapd %xmm2,%xmm0
movsd  %xmm2,0x8(%rsp)
call   1040 <log@plt>
mulsd  0xe35(%rip),%xmm0
divsd  0x8(%rsp),%xmm0
xorpd  %xmm1,%xmm1
ucomisd %xmm1,%xmm0
jb     11f1 <rand_gauss+0xc1>
sqrtsd %xmm0,%xmm0
jmp    11f6 <rand_gauss+0xc6>
call   1050 <sqrt@plt>
movsd  (%rsp),%xmm1
mulsd  %xmm0,%xmm1
movsd  %xmm1,0x2e39(%rip)
movb   $0x1,0x2e3a(%rip)
movsd  0x10(%rsp),%xmm1
mulsd  %xmm0,%xmm1
movapd %xmm1,%xmm0
add    $0x18,%rsp
ret

LLVM IR (-O0):
@rand_gauss.gset = internal global double 0.000000e+00
@rand_gauss.iset = internal global i32 0
define double @rand_gauss() {
%1 = alloca double
%2 = alloca double
%3 = alloca double
%4 = alloca double
%5 = alloca double
%6 = load i32, i32* @rand_gauss.iset
%7 = icmp eq i32 %6, 0
br i1 %7, label %8, label %41
8: ; preds = %0
br label %9
9: ; preds = %26, %8
%10 = call double (...) @rand0_1()
%11 = call double @llvm.fmuladd.f64(double 2.000000e+00, double %10, double -1.000000e+00)
store double %11, double* %2
%12 = call double (...) @rand0_1()
%13 = call double @llvm.fmuladd.f64(double 2.000000e+00, double %12, double -1.000000e+00)
store double %13, double* %3
%14 = load double, double* %2
%15 = load double, double* %2
%16 = load double, double* %3
%17 = load double, double* %3
%18 = fmul double %16, %17
%19 = call double @llvm.fmuladd.f64(double %14, double %15, double %18)
store double %19, double* %4
br label %20
20: ; preds = %9
%21 = load double, double* %4
%22 = fcmp oge double %21, 1.000000e+00
br i1 %22, label %26, label %23
23: ; preds = %20
%24 = load double, double* %4
%25 = fcmp oeq double %24, 0.000000e+00
br label %26
26: ; preds = %23, %20
%27 = phi i1 [ true, %20 ], [ %25, %23 ]
br i1 %27, label %9, label %28
28: ; preds = %26
%29 = load double, double* %4
%30 = call double @log(double %29)
%31 = fmul double -2.000000e+00, %30
%32 = load double, double* %4
%33 = fdiv double %31, %32
%34 = call double @sqrt(double %33)
store double %34, double* %5
%35 = load double, double* %2
%36 = load double, double* %5
%37 = fmul double %35, %36
store double %37, double* @rand_gauss.gset
store i32 1, i32* @rand_gauss.iset
%38 = load double, double* %3
%39 = load double, double* %5
%40 = fmul double %38, %39
store double %40, double* %1
br label %43
41: ; preds = %0
store i32 0, i32* @rand_gauss.iset
%42 = load double, double* @rand_gauss.gset
store double %42, double* %1
br label %43
43: ; preds = %41, %28
%44 = load double, double* %1
ret double %44
}

LLVM IR (-O2):
@rand_gauss.gset = internal unnamed_addr global double 0.000000e+00
@rand_gauss.iset = internal unnamed_addr global i1 false
define double @rand_gauss() {
%1 = load i1, i1* @rand_gauss.iset
br i1 %1, label %19, label %2
2: ; preds = %0, %2
%3 = tail call double (...) @rand0_1()
%4 = tail call double @llvm.fmuladd.f64(double %3, double 2.000000e+00, double -1.000000e+00)
%5 = tail call double (...) @rand0_1()
%6 = tail call double @llvm.fmuladd.f64(double %5, double 2.000000e+00, double -1.000000e+00)
%7 = fmul double %6, %6
%8 = tail call double @llvm.fmuladd.f64(double %4, double %4, double %7)
%9 = fcmp oge double %8, 1.000000e+00
%10 = fcmp oeq double %8, 0.000000e+00
%11 = or i1 %9, %10
br i1 %11, label %2, label %12
12: ; preds = %2
%13 = tail call double @log(double %8)
%14 = fmul double %13, -2.000000e+00
%15 = fdiv double %14, %8
%16 = tail call double @sqrt(double %15)
%17 = fmul double %4, %16
store double %17, double* @rand_gauss.gset
store i1 true, i1* @rand_gauss.iset
%18 = fmul double %6, %16
br label %21
19: ; preds = %0
store i1 false, i1* @rand_gauss.iset
%20 = load double, double* @rand_gauss.gset
br label %21
21: ; preds = %19, %12
%22 = phi double [ %18, %12 ], [ %20, %19 ]
ret double %22
}