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| author | Xavier Leroy <xavier.leroy@inria.fr> | 2015-03-15 17:07:36 +0100 |
|---|---|---|
| committer | Xavier Leroy <xavier.leroy@inria.fr> | 2015-03-15 17:07:36 +0100 |
| commit | 57d3627c69a812a037d2d4161941ce25d15082d1 (patch) | |
| tree | 02f375b130eb6cdab00796fc3580d56684f95a70 /cfrontend/Cshmgenproof.v | |
| parent | b3294fbaf50539f254ff3bb7145e848b3f902f73 (diff) | |
| download | compcert-kvx-57d3627c69a812a037d2d4161941ce25d15082d1.tar.gz compcert-kvx-57d3627c69a812a037d2d4161941ce25d15082d1.zip | |
Revised semantics of comparisons between a pointer and 0.
It used to be that a pointer value (Vptr) always compare unequal to the
null pointer (Vint Int.zero). However, this may not be true in the
final machine code when pointer addition overflows and wraps around
to the bit pattern 0. This patch checks the validity of the pointer
being compared with 0, and makes the comparison undefined if the
pointer is out of bounds.
Note: only the IA32 back-end was updated, ARM and PowerPC need updating.
Diffstat (limited to 'cfrontend/Cshmgenproof.v')
| -rw-r--r-- | cfrontend/Cshmgenproof.v | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/cfrontend/Cshmgenproof.v b/cfrontend/Cshmgenproof.v index 7f61c657..847e4856 100644 --- a/cfrontend/Cshmgenproof.v +++ b/cfrontend/Cshmgenproof.v @@ -333,7 +333,6 @@ Proof. econstructor; split. econstructor; eauto with cshm. simpl. eauto. unfold Val.cmpu, Val.cmpu_bool. simpl. destruct (Int.eq i Int.zero); simpl; constructor. - exists Vtrue; split. econstructor; eauto with cshm. constructor. (* long *) econstructor; split. econstructor; eauto with cshm. simpl. unfold Val.cmpl. simpl. eauto. destruct (Int64.eq i Int64.zero); simpl; constructor. |