diff options
| author |  xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e> | 2013-05-17 11:37:39 +0000 |
|---|---|---|
| committer | xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e> | 2013-05-17 11:37:39 +0000 |
| commit | a3f1744823d6dbeaf400812de86263fb615bbbba (patch) | |
| tree | ff1ed0a68fe2dceb19bb768cec89912344ea1ef6 /backend | |
| parent | 61f6aed04b846b174126d4b1cec28f6f1da20e52 (diff) | |
Add option -fno-tailcalls to turn off tailcall elimination (causes problem with some static analysis tools).
*/PrintAsm.ml: don't cfa_adjust at Pfreeframe, as more code from the function can appear after (in case of tailcalls).
git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2256 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
Diffstat (limited to 'backend')
| -rw-r--r-- | backend/Tailcall.v | 7 | ||||
| -rw-r--r-- | backend/Tailcallproof.v | 10 |
2 files changed, 11 insertions, 6 deletions
diff --git a/backend/Tailcall.v b/backend/Tailcall.v index 917ec83..26beb34 100644 --- a/backend/Tailcall.v +++ b/backend/Tailcall.v @@ -95,10 +95,13 @@ Definition transf_instr (f: function) (pc: node) (instr: instruction) := end. (** A function is transformed only if its stack block is empty, - as explained above. *) + as explained above. Moreover, we can turn tail calls off + using a compilation option. *) + +Parameter eliminate_tailcalls: unit -> bool. Definition transf_function (f: function) : function := - if zeq f.(fn_stacksize) 0 + if zeq f.(fn_stacksize) 0 && eliminate_tailcalls tt then RTL.transf_function (transf_instr f) f else f. diff --git a/backend/Tailcallproof.v b/backend/Tailcallproof.v index 02a6ca9..77725cf 100644 --- a/backend/Tailcallproof.v +++ b/backend/Tailcallproof.v @@ -181,10 +181,12 @@ Lemma transf_instr_lookup: f.(fn_code)!pc = Some i -> exists i', (transf_function f).(fn_code)!pc = Some i' /\ transf_instr_spec f i i'. Proof. - intros. unfold transf_function. destruct (zeq (fn_stacksize f) 0). + intros. unfold transf_function. + destruct (zeq (fn_stacksize f) 0). destruct (eliminate_tailcalls tt). simpl. rewrite PTree.gmap. rewrite H. simpl. exists (transf_instr f pc i); split. auto. apply transf_instr_charact; auto. exists i; split. auto. constructor. + exists i; split. auto. constructor. Qed. (** * Semantic properties of the code transformation *) @@ -260,14 +262,14 @@ Lemma sig_preserved: forall f, funsig (transf_fundef f) = funsig f. Proof. destruct f; auto. simpl. unfold transf_function. - destruct (zeq (fn_stacksize f) 0); auto. + destruct (zeq (fn_stacksize f) 0 && eliminate_tailcalls tt); auto. Qed. Lemma stacksize_preserved: forall f, fn_stacksize (transf_function f) = fn_stacksize f. Proof. unfold transf_function. intros. - destruct (zeq (fn_stacksize f) 0); auto. + destruct (zeq (fn_stacksize f) 0 && eliminate_tailcalls tt); auto. Qed. Lemma find_function_translated: @@ -553,7 +555,7 @@ Proof. assert (fn_stacksize (transf_function f) = fn_stacksize f /\ fn_entrypoint (transf_function f) = fn_entrypoint f /\ fn_params (transf_function f) = fn_params f). - unfold transf_function. destruct (zeq (fn_stacksize f) 0); auto. + unfold transf_function. destruct (zeq (fn_stacksize f) 0 && eliminate_tailcalls tt); auto. destruct H0 as [EQ1 [EQ2 EQ3]]. left. econstructor; split. simpl. eapply exec_function_internal; eauto. rewrite EQ1; eauto. |