#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 {
  long long tv_sec;
  long long tv_nsec;
};

/* Variables and functions */
long long timespec_subtract_us(struct timespec *x, struct timespec *y) {
  long long sec, nsec;
  sec = x->tv_sec - y->tv_sec;
  nsec = x->tv_nsec - y->tv_nsec;
  if (nsec < 0) {
    nsec += 1000000000;
    sec--;
  }
  return sec * 1000000 + nsec / 1000;
}


x86 assembly (clang, -O0):
<timespec_subtract_us>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    -0x8(%rbp),%rax
mov    (%rax),%rax
mov    -0x10(%rbp),%rcx
sub    (%rcx),%rax
mov    %rax,-0x18(%rbp)
mov    -0x8(%rbp),%rax
mov    0x8(%rax),%rax
mov    -0x10(%rbp),%rcx
sub    0x8(%rcx),%rax
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jge    1157 <timespec_subtract_us+0x57>
mov    -0x20(%rbp),%rax
add    $0x3b9aca00,%rax
mov    %rax,-0x20(%rbp)
mov    -0x18(%rbp),%rax
add    $0xffffffffffffffff,%rax
mov    %rax,-0x18(%rbp)
imul   $0xf4240,-0x18(%rbp),%rax
mov    %rax,-0x28(%rbp)
mov    -0x20(%rbp),%rax
mov    $0x3e8,%ecx
cqto
idiv   %rcx
mov    %rax,%rcx
mov    -0x28(%rbp),%rax
add    %rcx,%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<timespec_subtract_us>:
mov    (%rdi),%rcx
mov    0x8(%rdi),%rdx
sub    (%rsi),%rcx
sub    0x8(%rsi),%rdx
lea    0x3b9aca00(%rdx),%rax
mov    %rdx,%rsi
sar    $0x3f,%rsi
add    %rcx,%rsi
test   %rdx,%rdx
cmovns %rdx,%rax
imul   $0xf4240,%rsi,%rcx
movabs $0x20c49ba5e353f7cf,%rdx
9b c4 20
imul   %rdx
mov    %rdx,%rax
shr    $0x3f,%rax
sar    $0x7,%rdx
add    %rdx,%rax
add    %rcx,%rax
ret

LLVM IR (-O0):
%struct.timespec = type { i64, i64 }
define i64 @timespec_subtract_us(%struct.timespec* %0, %struct.timespec* %1) {
%3 = alloca %struct.timespec*
%4 = alloca %struct.timespec*
%5 = alloca i64
%6 = alloca i64
store %struct.timespec* %0, %struct.timespec** %3
store %struct.timespec* %1, %struct.timespec** %4
%7 = load %struct.timespec*, %struct.timespec** %3
%8 = getelementptr inbounds %struct.timespec, %struct.timespec* %7, i32 0, i32 0
%9 = load i64, i64* %8
%10 = load %struct.timespec*, %struct.timespec** %4
%11 = getelementptr inbounds %struct.timespec, %struct.timespec* %10, i32 0, i32 0
%12 = load i64, i64* %11
%13 = sub nsw i64 %9, %12
store i64 %13, i64* %5
%14 = load %struct.timespec*, %struct.timespec** %3
%15 = getelementptr inbounds %struct.timespec, %struct.timespec* %14, i32 0, i32 1
%16 = load i64, i64* %15
%17 = load %struct.timespec*, %struct.timespec** %4
%18 = getelementptr inbounds %struct.timespec, %struct.timespec* %17, i32 0, i32 1
%19 = load i64, i64* %18
%20 = sub nsw i64 %16, %19
store i64 %20, i64* %6
%21 = load i64, i64* %6
%22 = icmp slt i64 %21, 0
br i1 %22, label %23, label %28
23: ; preds = %2
%24 = load i64, i64* %6
%25 = add nsw i64 %24, 1000000000
store i64 %25, i64* %6
%26 = load i64, i64* %5
%27 = add nsw i64 %26, -1
store i64 %27, i64* %5
br label %28
28: ; preds = %23, %2
%29 = load i64, i64* %5
%30 = mul nsw i64 %29, 1000000
%31 = load i64, i64* %6
%32 = sdiv i64 %31, 1000
%33 = add nsw i64 %30, %32
ret i64 %33
}

LLVM IR (-O2):
%struct.timespec = type { i64, i64 }
define i64 @timespec_subtract_us(%struct.timespec* nocapture %0, %struct.timespec* nocapture %1) {
%3 = getelementptr inbounds %struct.timespec, %struct.timespec* %0, i64 0, i32 0
%4 = load i64, i64* %3
%5 = getelementptr inbounds %struct.timespec, %struct.timespec* %1, i64 0, i32 0
%6 = load i64, i64* %5
%7 = sub i64 %4, %6
%8 = getelementptr inbounds %struct.timespec, %struct.timespec* %0, i64 0, i32 1
%9 = load i64, i64* %8
%10 = getelementptr inbounds %struct.timespec, %struct.timespec* %1, i64 0, i32 1
%11 = load i64, i64* %10
%12 = sub nsw i64 %9, %11
%13 = icmp slt i64 %12, 0
%14 = add nsw i64 %12, 1000000000
%15 = ashr i64 %12, 63
%16 = add nsw i64 %7, %15
%17 = select i1 %13, i64 %14, i64 %12
%18 = mul nsw i64 %16, 1000000
%19 = sdiv i64 %17, 1000
%20 = add nsw i64 %18, %19
ret i64 %20
}