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| author | Xavier Leroy <xavierleroy@users.noreply.github.com> | 2018-06-17 17:48:01 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2018-06-17 17:48:01 +0200 |
| commit | 7a5aef7aa4b669a722ecce3da6e7f7c646a392cc (patch) | |
| tree | 5f50db9ea90cc8ca55551f364d972d134c3f9177 /backend/Allocproof.v | |
| parent | 3d348f51e343ff84b8e550fbeb905e23bf2b6175 (diff) | |
| download | compcert-7a5aef7aa4b669a722ecce3da6e7f7c646a392cc.tar.gz compcert-7a5aef7aa4b669a722ecce3da6e7f7c646a392cc.zip | |
Treat Outgoing stack slots as caller-save in LTL/Linear semantics (#237)
* Outgoing stack slots are set to Vundef on return from a function call,
modeling the fact that the callee could write into those stack slots.
(CompCert-generated code does not do this, but code generated by other
compilers sometimes does.)
* Adapt Stackingproof to this new semantics. This requires tighter
reasoning on how Linear's locsets are related at call points and
at return points.
* Most of this reasoning was moved from Stackingproof to Lineartyping,
because it can be expressed purely in terms of the Linear semantics,
and tracked through the wt_state predicate.
* Factor out and into Conventions.v: the notion of callee-save
locations, the "agree_callee_save" predicate, and useful lemmas on
Locmap.setpair. Now the same "agree_callee_save" predicate is used
in Allocproof and in Stackingproof.
Diffstat (limited to 'backend/Allocproof.v')
| -rw-r--r-- | backend/Allocproof.v | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/backend/Allocproof.v b/backend/Allocproof.v index 068e0de0..1804f46b 100644 --- a/backend/Allocproof.v +++ b/backend/Allocproof.v @@ -1317,15 +1317,6 @@ Proof. eauto. Qed. -Definition callee_save_loc (l: loc) := - match l with - | R r => is_callee_save r = true - | S sl ofs ty => sl <> Outgoing - end. - -Definition agree_callee_save (ls1 ls2: locset) : Prop := - forall l, callee_save_loc l -> ls1 l = ls2 l. - Lemma return_regs_agree_callee_save: forall caller callee, agree_callee_save caller (return_regs caller callee). @@ -2476,11 +2467,10 @@ Proof. rewrite Locmap.gss. rewrite Locmap.gso by (red; auto). rewrite Locmap.gss. rewrite val_longofwords_eq_1 by auto. auto. red; intros. rewrite (AG l H0). - rewrite Locmap.gpo. - unfold undef_caller_save_regs. destruct l; auto. simpl in H0; rewrite H0; auto. - assert (X: forall r, is_callee_save r = false -> Loc.diff l (R r)). - { intros. destruct l; simpl in *. congruence. auto. } - generalize (loc_result_caller_save (ef_sig ef)). destruct (loc_result (ef_sig ef)); simpl; intuition auto. + rewrite locmap_get_set_loc_result_callee_save by auto. + unfold undef_caller_save_regs. destruct l; simpl in H0. + rewrite H0; auto. + destruct sl; auto; congruence. eapply external_call_well_typed; eauto. (* return *) |