It's IMO never a good idea to call leaf_function_p in port-specific
code. Sooner or later, you'll need that information in a context
where calling leaf_function_p is either a bad idea (it does a linear
walk over all emitted insns in a function) or invalid (called when
global context is within a sequence), like here. I kind of knew that,
just bad judgement. :) Better find out leaffunctionness some other
way, and/or stash it in a field in cfun->machine.
There's one more patch needed for PR85666, to bring back
mmix-knuth-mmixware to a buildable state.
gcc:
PR target/85666
* config/mmix/mmix.c (MMIX_CFUN_NEEDS_SAVED_EH_RETURN_ADDRESS): Don't
call leaf_function_p, instead use has_hard_reg_initial_val.
Index: gcc/config/mmix/mmix.c
===================================================================
--- gcc/config/mmix/mmix.c (revision 264163)
+++ gcc/config/mmix/mmix.c (working copy)
@@ -60,19 +60,16 @@
/* We have no means to tell DWARF 2 about the register stack, so we need
to store the return address on the stack if an exception can get into
- this function. FIXME: Narrow condition. Before any whole-function
- analysis, df_regs_ever_live_p () isn't initialized. We know it's up-to-date
- after reload_completed; it may contain incorrect information some time
- before that. Within a RTL sequence (after a call to start_sequence,
- such as in RTL expanders), leaf_function_p doesn't see all insns
- (perhaps any insn). But regs_ever_live is up-to-date when
- leaf_function_p () isn't, so we "or" them together to get accurate
- information. FIXME: Some tweak to leaf_function_p might be
- preferable. */
+ this function. We'll have an "initial value" recorded for the
+ return-register if we've seen a call instruction emitted. This note
+ will be inaccurate before instructions are emitted, but the only caller
+ at that time is looking for modulo from stack-boundary, to which the
+ return-address does not contribute, and which is always 0 for MMIX
+ anyway. Beware of calling leaf_function_p here, as it'll abort if
+ called within a sequence. */
#define MMIX_CFUN_NEEDS_SAVED_EH_RETURN_ADDRESS \
(flag_exceptions \
- && ((reload_completed && df_regs_ever_live_p (MMIX_rJ_REGNUM)) \
- || !leaf_function_p ()))
+ && has_hard_reg_initial_val (Pmode, MMIX_INCOMING_RETURN_ADDRESS_REGNUM))
#define IS_MMIX_EH_RETURN_DATA_REG(REGNO) \
(crtl->calls_eh_return \
brgds, H-P
