for small >= 4096 && stdcall3(_VirtualFree, uintptr(v), small, _MEM_DECOMMIT) == 0 {
			small /= 2
			small &^= 4096 - 1
		}
		if small < 4096 {
			print("runtime: VirtualFree of ", small, " bytes failed with errno=", getlasterror(), "\n")
			throw("runtime: failed to decommit pages")
		}
		v = add(v, small)
		n -= small
	}
}

func sysUsedOS(v unsafe.Pointer, n uintptr) {

                // when pid is not attached to console, GetLastError(pid) returns:
                // ERROR_GEN_FAILURE on Win7
                // ERROR_INVALID_HANDLE on Win10
                if (!AttachConsole(pid)) {
                    if (GetLastError() == ERROR_GEN_FAILURE || GetLastError() == ERROR_INVALID_HANDLE) {
                        printf("none\\n");
                        exit(0);

		throw("runtime: netpollinit failed")
	}
}

func netpollIsPollDescriptor(fd uintptr) bool {
	return fd == iocphandle
}

func netpollopen(fd uintptr, pd *pollDesc) int32 {
	key := packNetpollKey(netpollSourceReady, pd)
	if stdcall4(_CreateIoCompletionPort, fd, iocphandle, key, 0) == 0 {
		return int32(getlasterror())
	}
	return 0
}

        [DllImport("kernel32.dll")]
        public static extern uint GetLastError();
    }

    public static class Profile
    {
        public static uint Delete(string sidString)
        { //Profile path and computer name are optional
            if (!UserEnv.DeleteProfile(sidString, null, null))
            {
                return UserEnv.GetLastError();
            }

            return 0;
        }
    }

		if m32 == 0 {
			print("runtime: LoadLibraryExW failed; errno=", getlasterror(), "\n")
			throw("winmm.dll not found")
		}
		_timeBeginPeriod = windowsFindfunc(m32, []byte("timeBeginPeriod\000"))
		_timeEndPeriod = windowsFindfunc(m32, []byte("timeEndPeriod\000"))
		if _timeBeginPeriod == nil || _timeEndPeriod == nil {
			print("runtime: GetProcAddress failed; errno=", getlasterror(), "\n")
			throw("timeBegin/EndPeriod not found")
		}
	}

	if ret == 0 {
		// AdjustTokenPrivileges call failed
		return err
	}
	// AdjustTokenPrivileges call succeeded
	if err == syscall.EINVAL {
		// GetLastError returned ERROR_SUCCESS
		return nil
	}
	return err
}

}

//go:uintptrescapes

// Call executes procedure p with arguments a. It will panic, if more than 15 arguments
// are supplied.
//
// The returned error is always non-nil, constructed from the result of GetLastError.
// Callers must inspect the primary return value to decide whether an error occurred
// (according to the semantics of the specific function being called) before consulting

	// DI SI BP BX are preserved, SP is not
	CALL	libcall_fn(BX)
	MOVL	BP, SP

	// Return result.
	MOVL	fn+0(FP), BX
	MOVL	AX, libcall_r1(BX)
	MOVL	DX, libcall_r2(BX)

	// GetLastError().
	MOVL	0x34(FS), AX
	MOVL	AX, libcall_err(BX)

	RET

// faster get/set last error
TEXT runtime·getlasterror(SB),NOSPLIT,$0
	MOVL	0x34(FS), AX
	MOVL	AX, ret+0(FP)
	RET

	BL	(R12)

	MOVD	R20, RSP			// free stack space
	MOVD	R0, libcall_r1(R19)		// save return value to libcall->r1
	// TODO(rsc) floating point like amd64 in libcall->r2?

	// GetLastError
	MOVD	TEB_error(R18_PLATFORM), R0
	MOVD	R0, libcall_err(R19)

	// Restore callee-saved registers.
	LDP	16(RSP), (R19, R20)
	RET

TEXT runtime·getlasterror(SB),NOSPLIT,$0

	BIC	$0x7, R13		// alignment for ABI
	MOVW	0(R4), R12		// branch to libcall->fn
	BL	(R12)

	MOVW	R5, R13			// free stack space
	MOVW	R0, 12(R4)		// save return value to libcall->r1
	MOVW	R1, 16(R4)

	// GetLastError
	MRC	15, 0, R1, C13, C0, 2
	MOVW	0x34(R1), R0
	MOVW	R0, 20(R4)		// store in libcall->err

	MOVM.IA.W (R13), [R4, R5, R15]

TEXT runtime·getlasterror(SB),NOSPLIT,$0
	MRC	15, 0, R0, C13, C0, 2