#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 */
struct timeval *tvsub(struct timeval *a, struct timeval *b, struct timeval *c) {
  c->tv_sec = a->tv_sec - b->tv_sec;
  c->tv_usec = a->tv_usec - b->tv_usec;
  if (c->tv_usec < 0) {
    c->tv_sec -= 1;
    c->tv_usec += 1000000;
  }
  return c;
}


x86 assembly (clang, -O0):
<tvsub>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
mov    %rdx,-0x18(%rbp)
mov    -0x8(%rbp),%rax
mov    0x8(%rax),%rcx
mov    -0x10(%rbp),%rax
sub    0x8(%rax),%rcx
mov    -0x18(%rbp),%rax
mov    %rcx,0x8(%rax)
mov    -0x8(%rbp),%rax
mov    (%rax),%rcx
mov    -0x10(%rbp),%rax
sub    (%rax),%rcx
mov    -0x18(%rbp),%rax
mov    %rcx,(%rax)
mov    -0x18(%rbp),%rax
cmpq   $0x0,(%rax)
jge    116c <tvsub+0x6c>
mov    -0x18(%rbp),%rax
mov    0x8(%rax),%rcx
sub    $0x1,%rcx
mov    %rcx,0x8(%rax)
mov    -0x18(%rbp),%rax
mov    (%rax),%rcx
add    $0xf4240,%rcx
mov    %rcx,(%rax)
mov    -0x18(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<tvsub>:
mov    %rdx,%rax
movdqu (%rdi),%xmm0
movdqu (%rsi),%xmm1
psubq  %xmm1,%xmm0
movdqu %xmm0,(%rdx)
movq   %xmm0,%rcx
test   %rcx,%rcx
js     111e <tvsub+0x1e>
ret
paddq  0xeda(%rip),%xmm0
movdqu %xmm0,(%rax)
ret

LLVM IR (-O0):
%struct.timeval = type { i64, i64 }
define %struct.timeval* @tvsub(%struct.timeval* %0, %struct.timeval* %1, %struct.timeval* %2) {
%4 = alloca %struct.timeval*
%5 = alloca %struct.timeval*
%6 = alloca %struct.timeval*
store %struct.timeval* %0, %struct.timeval** %4
store %struct.timeval* %1, %struct.timeval** %5
store %struct.timeval* %2, %struct.timeval** %6
%7 = load %struct.timeval*, %struct.timeval** %4
%8 = getelementptr inbounds %struct.timeval, %struct.timeval* %7, i32 0, i32 1
%9 = load i64, i64* %8
%10 = load %struct.timeval*, %struct.timeval** %5
%11 = getelementptr inbounds %struct.timeval, %struct.timeval* %10, i32 0, i32 1
%12 = load i64, i64* %11
%13 = sub nsw i64 %9, %12
%14 = load %struct.timeval*, %struct.timeval** %6
%15 = getelementptr inbounds %struct.timeval, %struct.timeval* %14, i32 0, i32 1
store i64 %13, i64* %15
%16 = load %struct.timeval*, %struct.timeval** %4
%17 = getelementptr inbounds %struct.timeval, %struct.timeval* %16, i32 0, i32 0
%18 = load i64, i64* %17
%19 = load %struct.timeval*, %struct.timeval** %5
%20 = getelementptr inbounds %struct.timeval, %struct.timeval* %19, i32 0, i32 0
%21 = load i64, i64* %20
%22 = sub nsw i64 %18, %21
%23 = load %struct.timeval*, %struct.timeval** %6
%24 = getelementptr inbounds %struct.timeval, %struct.timeval* %23, i32 0, i32 0
store i64 %22, i64* %24
%25 = load %struct.timeval*, %struct.timeval** %6
%26 = getelementptr inbounds %struct.timeval, %struct.timeval* %25, i32 0, i32 0
%27 = load i64, i64* %26
%28 = icmp slt i64 %27, 0
br i1 %28, label %29, label %38
29: ; preds = %3
%30 = load %struct.timeval*, %struct.timeval** %6
%31 = getelementptr inbounds %struct.timeval, %struct.timeval* %30, i32 0, i32 1
%32 = load i64, i64* %31
%33 = sub nsw i64 %32, 1
store i64 %33, i64* %31
%34 = load %struct.timeval*, %struct.timeval** %6
%35 = getelementptr inbounds %struct.timeval, %struct.timeval* %34, i32 0, i32 0
%36 = load i64, i64* %35
%37 = add nsw i64 %36, 1000000
store i64 %37, i64* %35
br label %38
38: ; preds = %29, %3
%39 = load %struct.timeval*, %struct.timeval** %6
ret %struct.timeval* %39
}

LLVM IR (-O2):
%struct.timeval = type { i64, i64 }
define %struct.timeval* @tvsub(%struct.timeval* nocapture %0, %struct.timeval* nocapture %1, %struct.timeval* returned %2) {
%4 = bitcast %struct.timeval* %0 to <2 x i64>*
%5 = load <2 x i64>, <2 x i64>* %4
%6 = bitcast %struct.timeval* %1 to <2 x i64>*
%7 = load <2 x i64>, <2 x i64>* %6
%8 = sub nsw <2 x i64> %5, %7
%9 = bitcast %struct.timeval* %2 to <2 x i64>*
store <2 x i64> %8, <2 x i64>* %9
%10 = extractelement <2 x i64> %8, i64 0
%11 = icmp slt i64 %10, 0
br i1 %11, label %12, label %15
12: ; preds = %3
%13 = add nsw <2 x i64> %8, <i64 1000000, i64 -1>
%14 = bitcast %struct.timeval* %2 to <2 x i64>*
store <2 x i64> %13, <2 x i64>* %14
br label %15
15: ; preds = %12, %3
ret %struct.timeval* %2
}