| Message ID | 542C8168.4030409@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Wed, 2014-10-01 at 16:34 -0600, Jeff Law wrote: > This was inspired by a discussion with Felix who was making changes in > this area. > > Basically this promotes the "init_insns" field within struct equivalence > from an rtx to an rtx_insn_list. > > The only thing that's really interesting here is the old code exploits > the fact that we could put any RTX in the list by shoving const0_rtx > into the init_insns list as a marker to indicate we've already > determined the relevant pseudo must not have an equivalence. > > Thus we could have the following objects in the init_insns field: > > NULL > const0_rtx > INSN_LIST ... > > This patch uses INSN_LIST (NULL_RTX, NULL) as the special marker. Thus > the only two things that would exist in the init_insns field would be > NULL or an INSN_LIST. Goodness. > > Rather than stash away the special marker INSN_LIST into a global > variable or something similar, we instead to do a two step check for the > marker. First verify that the insn_list field is non-NULL, then look at > the first insn in the list and see if that is NULL. > > Bootstrapped and regression tested on i686-unknown-linux-gnu and > x86_64-unknown-linux-gnu. > > Ok for the trunk? > [...] > * ira.c (struct equivalence): Promote INIT_INSNs field to > an rtx_insn_list. Add comments. > (no_equiv): Promote LIST to an rtx_insn_list. Update > testing for and creating the special marker. Use methods > to extract the insn and next pointers. > (update_equiv_regs): Update test for special marker in the > INIT_INSNs list. > > diff --git a/gcc/ira.c b/gcc/ira.c [...] > @@ -3258,9 +3266,9 @@ no_equiv (rtx reg, const_rtx store ATTRIBUTE_UNUSED, > return; > ira_reg_equiv[regno].defined_p = false; > ira_reg_equiv[regno].init_insns = NULL; > - for (; list; list = XEXP (list, 1)) > + for (; list; list = list->next ()) > { > - rtx insn = XEXP (list, 0); > + rtx insn = list->insn (); > remove_note (insn, find_reg_note (insn, REG_EQUIV, NULL_RTX)); FWIW, presumably "insn" here also can now be an rtx_insn *? (I'd like to eventually strengthen the params to the note-handling functions, so fixing this up now would help with that). > } [...]
On 10/01/14 17:27, David Malcolm wrote: > On Wed, 2014-10-01 at 16:34 -0600, Jeff Law wrote: >> This was inspired by a discussion with Felix who was making changes in >> this area. >> >> Basically this promotes the "init_insns" field within struct equivalence >> from an rtx to an rtx_insn_list. >> >> The only thing that's really interesting here is the old code exploits >> the fact that we could put any RTX in the list by shoving const0_rtx >> into the init_insns list as a marker to indicate we've already >> determined the relevant pseudo must not have an equivalence. >> >> Thus we could have the following objects in the init_insns field: >> >> NULL >> const0_rtx >> INSN_LIST ... >> >> This patch uses INSN_LIST (NULL_RTX, NULL) as the special marker. Thus >> the only two things that would exist in the init_insns field would be >> NULL or an INSN_LIST. Goodness. >> >> Rather than stash away the special marker INSN_LIST into a global >> variable or something similar, we instead to do a two step check for the >> marker. First verify that the insn_list field is non-NULL, then look at >> the first insn in the list and see if that is NULL. >> >> Bootstrapped and regression tested on i686-unknown-linux-gnu and >> x86_64-unknown-linux-gnu. >> >> Ok for the trunk? >> > > [...] > >> * ira.c (struct equivalence): Promote INIT_INSNs field to >> an rtx_insn_list. Add comments. >> (no_equiv): Promote LIST to an rtx_insn_list. Update >> testing for and creating the special marker. Use methods >> to extract the insn and next pointers. >> (update_equiv_regs): Update test for special marker in the >> INIT_INSNs list. >> >> diff --git a/gcc/ira.c b/gcc/ira.c > [...] > >> @@ -3258,9 +3266,9 @@ no_equiv (rtx reg, const_rtx store ATTRIBUTE_UNUSED, >> return; >> ira_reg_equiv[regno].defined_p = false; >> ira_reg_equiv[regno].init_insns = NULL; >> - for (; list; list = XEXP (list, 1)) >> + for (; list; list = list->next ()) >> { >> - rtx insn = XEXP (list, 0); >> + rtx insn = list->insn (); >> remove_note (insn, find_reg_note (insn, REG_EQUIV, NULL_RTX)); > > FWIW, presumably "insn" here also can now be an rtx_insn *? Yes. I'll update that. Thanks. Jeff
diff --git a/gcc/ira.c b/gcc/ira.c index ad0e463..231cfc5 100644 --- a/gcc/ira.c +++ b/gcc/ira.c @@ -2890,8 +2890,16 @@ struct equivalence e.g. by reload. */ rtx replacement; rtx *src_p; - /* The list of each instruction which initializes this register. */ - rtx init_insns; + + /* The list of each instruction which initializes this register. + + NULL indicates we know nothing about this register's equivalence + properties. + + An INSN_LIST with a NULL insn indicates this pseudo is already + known to not have a valid equivalence. */ + rtx_insn_list *init_insns; + /* Loop depth is used to recognize equivalences which appear to be present within the same loop (or in an inner loop). */ int loop_depth; @@ -3242,15 +3250,15 @@ no_equiv (rtx reg, const_rtx store ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) { int regno; - rtx list; + rtx_insn_list *list; if (!REG_P (reg)) return; regno = REGNO (reg); list = reg_equiv[regno].init_insns; - if (list == const0_rtx) + if (list && list->insn () == NULL) return; - reg_equiv[regno].init_insns = const0_rtx; + reg_equiv[regno].init_insns = gen_rtx_INSN_LIST (VOIDmode, NULL_RTX, NULL); reg_equiv[regno].replacement = NULL_RTX; /* This doesn't matter for equivalences made for argument registers, we should keep their initialization insns. */ @@ -3258,9 +3266,9 @@ no_equiv (rtx reg, const_rtx store ATTRIBUTE_UNUSED, return; ira_reg_equiv[regno].defined_p = false; ira_reg_equiv[regno].init_insns = NULL; - for (; list; list = XEXP (list, 1)) + for (; list; list = list->next ()) { - rtx insn = XEXP (list, 0); + rtx insn = list->insn (); remove_note (insn, find_reg_note (insn, REG_EQUIV, NULL_RTX)); } } @@ -3437,7 +3445,8 @@ update_equiv_regs (void) if (!REG_P (dest) || (regno = REGNO (dest)) < FIRST_PSEUDO_REGISTER - || reg_equiv[regno].init_insns == const0_rtx + || (reg_equiv[regno].init_insns + && reg_equiv[regno].init_insns->insn () == NULL) || (targetm.class_likely_spilled_p (reg_preferred_class (regno)) && MEM_P (src) && ! reg_equiv[regno].is_arg_equivalence)) { @@ -3608,8 +3617,8 @@ update_equiv_regs (void) && (regno = REGNO (src)) >= FIRST_PSEUDO_REGISTER && REG_BASIC_BLOCK (regno) >= NUM_FIXED_BLOCKS && DF_REG_DEF_COUNT (regno) == 1 - && reg_equiv[regno].init_insns != 0 - && reg_equiv[regno].init_insns != const0_rtx + && reg_equiv[regno].init_insns != NULL + && reg_equiv[regno].init_insns->insn () != NULL && ! find_reg_note (XEXP (reg_equiv[regno].init_insns, 0), REG_EQUIV, NULL_RTX) && ! contains_replace_regs (XEXP (dest, 0)) @@ -3728,7 +3737,7 @@ update_equiv_regs (void) delete_insn (equiv_insn); reg_equiv[regno].init_insns - = XEXP (reg_equiv[regno].init_insns, 1); + = reg_equiv[regno].init_insns->next (); ira_reg_equiv[regno].init_insns = NULL; bitmap_set_bit (cleared_regs, regno);