#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 */
struct timeval {
  scalar_t__ tv_usec;
  scalar_t__ tv_sec;
};

/* Variables and functions */
int /*<<< orphan*/ exit(int);
scalar_t__ gettimeofday(struct timeval *, int /*<<< orphan*/);
int /*<<< orphan*/ perror(char *);
double get_time() {
  struct timeval tv;
  if (gettimeofday(&tv, 0) != 0) {
    perror("gettimeofday");
    exit(1);
  }
  return (double)tv.tv_sec + 1.0e-6 * (double)tv.tv_usec;
}


x86 assembly (clang, -O0):
<get_time>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
lea    -0x10(%rbp),%rdi
xor    %esi,%esi
call   1030 <gettimeofday@plt>
cmp    $0x0,%rax
je     1163 <get_time+0x33>
lea    0xeb4(%rip),%rdi
call   1040 <perror@plt>
mov    $0x1,%edi
call   1050 <exit@plt>
cvtsi2sdq -0x8(%rbp),%xmm1
cvtsi2sdq -0x10(%rbp),%xmm0
movsd  0xe89(%rip),%xmm2
mulsd  %xmm2,%xmm0
addsd  %xmm1,%xmm0
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<get_time>:
sub    $0x18,%rsp
lea    0x8(%rsp),%rdi
xor    %esi,%esi
call   1030 <gettimeofday@plt>
test   %rax,%rax
jne    1164 <get_time+0x34>
cvtsi2sdq 0x10(%rsp),%xmm1
cvtsi2sdq 0x8(%rsp),%xmm0
mulsd  0xea5(%rip),%xmm0
addsd  %xmm1,%xmm0
add    $0x18,%rsp
ret
lea    0xe9d(%rip),%rdi
call   1040 <perror@plt>
mov    $0x1,%edi
call   1050 <exit@plt>

LLVM IR (-O0):
%struct.timeval = type { i64, i64 }
@.str = [13 x i8] c"gettimeofday\00"
define double @get_time() {
%1 = alloca %struct.timeval
%2 = call i64 @gettimeofday(%struct.timeval* %1, i32 0)
%3 = icmp ne i64 %2, 0
br i1 %3, label %4, label %7
4: ; preds = %0
%5 = call i32 @perror(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0))
%6 = call i32 @exit(i32 1)
unreachable
7: ; preds = %0
%8 = getelementptr inbounds %struct.timeval, %struct.timeval* %1, i32 0, i32 1
%9 = load i64, i64* %8
%10 = sitofp i64 %9 to double
%11 = getelementptr inbounds %struct.timeval, %struct.timeval* %1, i32 0, i32 0
%12 = load i64, i64* %11
%13 = sitofp i64 %12 to double
%14 = call double @llvm.fmuladd.f64(double 0x3EB0C6F7A0B5ED8D, double %13, double %10)
ret double %14
}

LLVM IR (-O2):
%struct.timeval = type { i64, i64 }
@.str = [13 x i8] c"gettimeofday\00"
define double @get_time() {
%1 = alloca %struct.timeval
%2 = bitcast %struct.timeval* %1 to i8*
%3 = call i64 @gettimeofday(%struct.timeval* %1, i32 0)
%4 = icmp eq i64 %3, 0
br i1 %4, label %8, label %5
5: ; preds = %0
%6 = call i32 @perror(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str, i64 0, i64 0))
%7 = call i32 @exit(i32 1)
unreachable
8: ; preds = %0
%9 = getelementptr inbounds %struct.timeval, %struct.timeval* %1, i64 0, i32 1
%10 = load i64, i64* %9
%11 = sitofp i64 %10 to double
%12 = getelementptr inbounds %struct.timeval, %struct.timeval* %1, i64 0, i32 0
%13 = load i64, i64* %12
%14 = sitofp i64 %13 to double
%15 = call double @llvm.fmuladd.f64(double %14, double 0x3EB0C6F7A0B5ED8D, double %11)
ret double %15
}