That does the trick. Thanks,
steve -----Original Message----- From: Ian Lance Taylor [mailto:i...@google.com] Sent: 21 August 2010 19:50 To: Kilbane, Stephen Cc: gcc@gcc.gnu.org Subject: Re: CLEAR_INSN_CACHE "Kilbane, Stephen" <stephen.kilb...@analog.com> writes: > I'm trying to add support to 4.3 for cache flushing when setting up a > trampoline. > Reading around, it looks like I should be defining CLEAR_INSN_CACHE: > > To clear the instruction cache when a trampoline is initialized, define the > following macro. > CLEAR_INSN_CACHE (beg, end) > > but I can't see anywhere that this macro gets used during trampoline > creation. I can see > that it provides an implementation for __clear_cache() in libgcc, but nothing > that would > invoke that routine, either, short of an explicit call in the source file > being compiled. > > Am I missing something? No. You do need to arrange to flush the cache yourself, typically by generating the appropriate instructions in the TARGET_TRAMPOLINE_INIT target hook. On targets which need to clear the cache, that hook will often emit a call to __clear_cache, as in emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__clear_cache"), LCT_NORMAL, VOIDmode, 2, a_tramp, Pmode, plus_constant (a_tramp, TRAMPOLINE_SIZE), Pmode); where a_tramp is the address of the trampoline. The CLEAR_INSN_CACHE macro will then provide the body of the __clear_cache function. Of course, if clearing the cache is reasonably simple, the instructions can be emitted inline by TARGET_TRAMPOLINE_INIT; e.g., that's what the MIPS target does. Ian
