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authorXavier Leroy <xavier.leroy@college-de-france.fr>2020-02-18 16:57:17 +0100
committerXavier Leroy <xavierleroy@users.noreply.github.com>2020-02-21 13:29:39 +0100
commitbe0b1872bf2ad36df9b0c7a0ffa63b9e77fa769b (patch)
tree0d54cce547d12567d7e9e9f2c4d650e5a1b94b39 /cfrontend/Csem.v
parenta9eaf4897c825093aba2137ff76e56bfbf1e72d5 (diff)
downloadcompcert-kvx-be0b1872bf2ad36df9b0c7a0ffa63b9e77fa769b.tar.gz
compcert-kvx-be0b1872bf2ad36df9b0c7a0ffa63b9e77fa769b.zip
Refine the type of function results in AST.signature
Before it was "option typ". Now it is a proper inductive type that can also express small integer types (8/16-bit unsigned/signed integers). One benefit is that external functions get more precise types that control better their return values. As a consequence, the CompCert C type preservation property now holds unconditionally, without extra typing hypotheses on external functions.
Diffstat (limited to 'cfrontend/Csem.v')
-rw-r--r--cfrontend/Csem.v2
1 files changed, 1 insertions, 1 deletions
diff --git a/cfrontend/Csem.v b/cfrontend/Csem.v
index a76a14ba..6d2b470f 100644
--- a/cfrontend/Csem.v
+++ b/cfrontend/Csem.v
@@ -444,7 +444,7 @@ Lemma red_selection:
Proof.
intros. unfold Eselection.
set (t := typ_of_type ty).
- set (sg := mksignature (AST.Tint :: t :: t :: nil) (Some t) cc_default).
+ set (sg := mksignature (AST.Tint :: t :: t :: nil) t cc_default).
assert (LK: lookup_builtin_function "__builtin_sel"%string sg = Some (BI_standard (BI_select t))).
{ unfold sg, t; destruct ty as [ | ? ? ? | ? | [] ? | ? ? | ? ? ? | ? ? ? | ? ? | ? ? ];
simpl; unfold Tptr; destruct Archi.ptr64; reflexivity. }