#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 timespec {
  int tv_sec;
  scalar_t__ tv_nsec;
};

/* Variables and functions */
unsigned long long timediff_nsec(struct timespec *start_ts,
                                 struct timespec *end_ts) {
  unsigned long long nsec;
  nsec = (end_ts->tv_sec - start_ts->tv_sec) * 1000000000;
  nsec += (end_ts->tv_nsec - start_ts->tv_nsec);
  return nsec;
}


x86 assembly (clang, -O0):
<timediff_nsec>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x10(%rbp),%rax
mov    (%rax),%eax
mov    -0x8(%rbp),%rcx
sub    (%rcx),%eax
imul   $0x3b9aca00,%eax,%eax
cltq
mov    %rax,-0x18(%rbp)
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rax
mov    -0x8(%rbp),%rcx
sub    0x8(%rcx),%rax
add    -0x18(%rbp),%rax
mov    %rax,-0x18(%rbp)
mov    -0x18(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<timediff_nsec>:
movslq (%rsi),%rax
movslq (%rdi),%rcx
sub    %rcx,%rax
imul   $0x3b9aca00,%rax,%rcx
mov    0x8(%rsi),%rax
sub    0x8(%rdi),%rax
add    %rcx,%rax
ret

LLVM IR (-O0):
%struct.timespec = type { i32, i64 }
define i64 @timediff_nsec(%struct.timespec* %0, %struct.timespec* %1) {
%3 = alloca %struct.timespec*
%4 = alloca %struct.timespec*
%5 = alloca i64
store %struct.timespec* %0, %struct.timespec** %3
store %struct.timespec* %1, %struct.timespec** %4
%6 = load %struct.timespec*, %struct.timespec** %4
%7 = getelementptr inbounds %struct.timespec, %struct.timespec* %6, i32 0, i32 0
%8 = load i32, i32* %7
%9 = load %struct.timespec*, %struct.timespec** %3
%10 = getelementptr inbounds %struct.timespec, %struct.timespec* %9, i32 0, i32 0
%11 = load i32, i32* %10
%12 = sub nsw i32 %8, %11
%13 = mul nsw i32 %12, 1000000000
%14 = sext i32 %13 to i64
store i64 %14, i64* %5
%15 = load %struct.timespec*, %struct.timespec** %4
%16 = getelementptr inbounds %struct.timespec, %struct.timespec* %15, i32 0, i32 1
%17 = load i64, i64* %16
%18 = load %struct.timespec*, %struct.timespec** %3
%19 = getelementptr inbounds %struct.timespec, %struct.timespec* %18, i32 0, i32 1
%20 = load i64, i64* %19
%21 = sub nsw i64 %17, %20
%22 = load i64, i64* %5
%23 = add i64 %22, %21
store i64 %23, i64* %5
%24 = load i64, i64* %5
ret i64 %24
}

LLVM IR (-O2):
%struct.timespec = type { i32, i64 }
define i64 @timediff_nsec(%struct.timespec* nocapture %0, %struct.timespec* nocapture %1) {
%3 = getelementptr inbounds %struct.timespec, %struct.timespec* %1, i64 0, i32 0
%4 = load i32, i32* %3
%5 = getelementptr inbounds %struct.timespec, %struct.timespec* %0, i64 0, i32 0
%6 = load i32, i32* %5
%7 = sub nsw i32 %4, %6
%8 = mul nsw i32 %7, 1000000000
%9 = sext i32 %8 to i64
%10 = getelementptr inbounds %struct.timespec, %struct.timespec* %1, i64 0, i32 1
%11 = load i64, i64* %10
%12 = getelementptr inbounds %struct.timespec, %struct.timespec* %0, i64 0, i32 1
%13 = load i64, i64* %12
%14 = sub i64 %11, %13
%15 = add i64 %14, %9
ret i64 %15
}