#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 RAND_MAX;
scalar_t__ random();
void generate_randvec(double *vec, int n) {
  int i = 0;
  for (i = 0; i < n; i++) {
    vec[i] = (double)random() / (RAND_MAX + 1.0);
  }
}


x86 assembly (clang, -O0):
<generate_randvec>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    %esi,-0xc(%rbp)
movl   $0x0,-0x10(%rbp)
movl   $0x0,-0x10(%rbp)
mov    -0x10(%rbp),%eax
cmp    -0xc(%rbp),%eax
jge    1177 <generate_randvec+0x67>
mov    $0x0,%al
call   1030 <random@plt>
cvtsi2sd %rax,%xmm0
movsd  0xeb3(%rip),%xmm1
mov    0x2e94(%rip),%rax
addsd  (%rax),%xmm1
divsd  %xmm1,%xmm0
mov    -0x8(%rbp),%rax
movslq -0x10(%rbp),%rcx
movsd  %xmm0,(%rax,%rcx,8)
mov    -0x10(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x10(%rbp)
jmp    112d <generate_randvec+0x1d>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<generate_randvec>:
push   %r15
push   %r14
push   %r12
push   %rbx
push   %rax
test   %esi,%esi
jle    115f <generate_randvec+0x4f>
mov    %rdi,%r14
mov    %esi,%r12d
mov    0x2ebf(%rip),%r15
xor    %ebx,%ebx
nopl   0x0(%rax,%rax,1)
xor    %eax,%eax
call   1030 <random@plt>
xorps  %xmm0,%xmm0
cvtsi2sd %rax,%xmm0
movsd  (%r15),%xmm1
addsd  0xeb4(%rip),%xmm1
divsd  %xmm1,%xmm0
movsd  %xmm0,(%r14,%rbx,8)
add    $0x1,%rbx
cmp    %rbx,%r12
jne    1130 <generate_randvec+0x20>
add    $0x8,%rsp
pop    %rbx
pop    %r12
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@RAND_MAX = global double 0.000000e+00
define void @generate_randvec(double* %0, i32 %1) {
%3 = alloca double*
%4 = alloca i32
%5 = alloca i32
store double* %0, double** %3
store i32 %1, i32* %4
store i32 0, i32* %5
store i32 0, i32* %5
br label %6
6: ; preds = %20, %2
%7 = load i32, i32* %5
%8 = load i32, i32* %4
%9 = icmp slt i32 %7, %8
br i1 %9, label %10, label %23
10: ; preds = %6
%11 = call i64 (...) @random()
%12 = sitofp i64 %11 to double
%13 = load double, double* @RAND_MAX
%14 = fadd double %13, 1.000000e+00
%15 = fdiv double %12, %14
%16 = load double*, double** %3
%17 = load i32, i32* %5
%18 = sext i32 %17 to i64
%19 = getelementptr inbounds double, double* %16, i64 %18
store double %15, double* %19
br label %20
20: ; preds = %10
%21 = load i32, i32* %5
%22 = add nsw i32 %21, 1
store i32 %22, i32* %5
br label %6
23: ; preds = %6
ret void
}

LLVM IR (-O2):
@RAND_MAX = global double 0.000000e+00
define void @generate_randvec(double* nocapture writeonly %0, i32 %1) {
%3 = icmp sgt i32 %1, 0
br i1 %3, label %4, label %16
4: ; preds = %2
%5 = zext i32 %1 to i64
br label %6
6: ; preds = %4, %6
%7 = phi i64 [ 0, %4 ], [ %14, %6 ]
%8 = tail call i64 (...) @random()
%9 = sitofp i64 %8 to double
%10 = load double, double* @RAND_MAX
%11 = fadd double %10, 1.000000e+00
%12 = fdiv double %9, %11
%13 = getelementptr inbounds double, double* %0, i64 %7
store double %12, double* %13
%14 = add nuw nsw i64 %7, 1
%15 = icmp eq i64 %14, %5
br i1 %15, label %16, label %6
16: ; preds = %6, %2
ret void
}