2 * from: vector.s, 386BSD 0.1 unknown origin
3 * $FreeBSD: src/sys/i386/isa/vector.s,v 1.32 1999/08/28 00:45:04 peter Exp $
4 * $DragonFly: src/sys/i386/isa/Attic/vector.s,v 1.7 2005/10/13 00:02:47 dillon Exp $
7 #include "opt_auto_eoi.h"
9 #include <i386/isa/icu.h>
10 #include <bus/isa/i386/isa.h>
15 * Macros for interrupt interrupt entry, call to handler, and exit.
17 * XXX - the interrupt frame is set up to look like a trap frame. This is
18 * usually a waste of time. The only interrupt handlers that want a frame
19 * are the clock handler (it wants a clock frame), the npx handler (it's
20 * easier to do right all in assembler). The interrupt return routine
21 * needs a trap frame for rare AST's (it could easily convert the frame).
22 * The direct costs of setting up a trap frame are two pushl's (error
23 * code and trap number), an addl to get rid of these, and pushing and
24 * popping the call-saved regs %esi, %edi and %ebp twice, The indirect
25 * costs are making the driver interface nonuniform so unpending of
26 * interrupts is more complicated and slower (call_driver(unit) would
27 * be easier than ensuring an interrupt frame for all handlers. Finally,
28 * there are some struct copies in the npx handler and maybe in the clock
29 * handler that could be avoided by working more with pointers to frames
32 * XXX - should we do a cld on every system entry to avoid the requirement
33 * for scattered cld's?
35 * Coding notes for *.s:
37 * If possible, avoid operations that involve an operand size override.
38 * Word-sized operations might be smaller, but the operand size override
39 * makes them slower on on 486's and no faster on 386's unless perhaps
40 * the instruction pipeline is depleted. E.g.,
42 * Use movl to seg regs instead of the equivalent but more descriptive
43 * movw - gas generates an irelevant (slower) operand size override.
45 * Use movl to ordinary regs in preference to movw and especially
46 * in preference to movz[bw]l. Use unsigned (long) variables with the
47 * top bits clear instead of unsigned short variables to provide more
48 * opportunities for movl.
50 * If possible, use byte-sized operations. They are smaller and no slower.
52 * Use (%reg) instead of 0(%reg) - gas generates larger code for the latter.
54 * If the interrupt frame is made more flexible, INTR can push %eax first
55 * and decide the ipending case with less overhead, e.g., by avoiding
60 #include "i386/isa/apic_vector.s"
62 #include "i386/isa/icu_vector.s"