From abe2bb5c40260a31ce5ee27b841bcbd647ff8b88 Mon Sep 17 00:00:00 2001 From: xleroy Date: Sat, 9 Apr 2011 16:59:13 +0000 Subject: Merge of branch "unsigned-offsets": - In pointer values "Vptr b ofs", interpret "ofs" as an unsigned int. (Fixes issue with wrong comparison of pointers across 0x8000_0000) - Revised Stacking pass to not use negative SP offsets. - Add pointer validity checks to Cminor ... Mach to support the use of memory injections in Stacking. - Cleaned up Stacklayout modules. - IA32: improved code generation for Mgetparam. - ARM: improved code generation for op-immediate instructions. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1632 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e --- arm/linux/Stacklayout.v | 88 +++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 75 insertions(+), 13 deletions(-) (limited to 'arm/linux') diff --git a/arm/linux/Stacklayout.v b/arm/linux/Stacklayout.v index b374bfd9..4521114f 100644 --- a/arm/linux/Stacklayout.v +++ b/arm/linux/Stacklayout.v @@ -28,12 +28,6 @@ Require Import Bounds. - Pointer to activation record of the caller. - Space for the stack-allocated data declared in Cminor. -To facilitate some of the proofs, the Cminor stack-allocated data -starts at offset 0; the preceding areas in the activation record -therefore have negative offsets. This part (with negative offsets) -is called the ``frame'', by opposition with the ``Cminor stack data'' -which is the part with positive offsets. - The [frame_env] compilation environment records the positions of the boundaries between areas in the frame part. *) @@ -49,7 +43,8 @@ Record frame_env : Type := mk_frame_env { fe_num_int_callee_save: Z; fe_ofs_float_local: Z; fe_ofs_float_callee_save: Z; - fe_num_float_callee_save: Z + fe_num_float_callee_save: Z; + fe_stack_data: Z }. (** Computation of the frame environment from the bounds of the current @@ -63,17 +58,84 @@ Definition make_env (b: bounds) := let ofcs := ofl + 8 * b.(bound_float_local) in (* float callee-saves *) let ora := ofcs + 8 * b.(bound_float_callee_save) in (* retaddr *) let olink := ora + 4 in (* back link *) - let sz := olink + 4 in (* total frame size *) + let ostkdata := olink + 4 in (* stack data *) + let sz := align (ostkdata + b.(bound_stack_data)) 8 in mk_frame_env sz olink ora oil oics b.(bound_int_callee_save) - ofl ofcs b.(bound_float_callee_save). + ofl ofcs b.(bound_float_callee_save) + ostkdata. +(** Separation property *) -Remark align_float_part: +Remark frame_env_separated: forall b, - 4 * bound_outgoing b + 4 * bound_int_local b + 4 * bound_int_callee_save b <= - align (4 * bound_outgoing b + 4 * bound_int_local b + 4 * bound_int_callee_save b) 8. + let fe := make_env b in + 0 <= fe_ofs_arg + /\ fe_ofs_arg + 4 * b.(bound_outgoing) <= fe.(fe_ofs_int_local) + /\ fe.(fe_ofs_int_local) + 4 * b.(bound_int_local) <= fe.(fe_ofs_int_callee_save) + /\ fe.(fe_ofs_int_callee_save) + 4 * b.(bound_int_callee_save) <= fe.(fe_ofs_float_local) + /\ fe.(fe_ofs_float_local) + 8 * b.(bound_float_local) <= fe.(fe_ofs_float_callee_save) + /\ fe.(fe_ofs_float_callee_save) + 8 * b.(bound_float_callee_save) <= fe.(fe_ofs_retaddr) + /\ fe.(fe_ofs_retaddr) + 4 <= fe.(fe_ofs_link) + /\ fe.(fe_ofs_link) + 4 <= fe.(fe_stack_data) + /\ fe.(fe_stack_data) + b.(bound_stack_data) <= fe.(fe_size). Proof. - intros. apply align_le. omega. + intros. + generalize (align_le (fe.(fe_ofs_int_callee_save) + 4 * b.(bound_int_callee_save)) 8 (refl_equal _)). + generalize (align_le (fe.(fe_stack_data) + b.(bound_stack_data)) 8 (refl_equal _)). + unfold fe, make_env, fe_size, fe_ofs_link, fe_ofs_retaddr, + fe_ofs_int_local, fe_ofs_int_callee_save, + fe_num_int_callee_save, + fe_ofs_float_local, fe_ofs_float_callee_save, fe_num_float_callee_save, + fe_stack_data, fe_ofs_arg. + intros. + generalize (bound_int_local_pos b); intro; + generalize (bound_float_local_pos b); intro; + generalize (bound_int_callee_save_pos b); intro; + generalize (bound_float_callee_save_pos b); intro; + generalize (bound_outgoing_pos b); intro; + generalize (bound_stack_data_pos b); intro. + omega. Qed. +(** Alignment property *) + +Remark frame_env_aligned: + forall b, + let fe := make_env b in + (4 | fe.(fe_ofs_link)) + /\ (4 | fe.(fe_ofs_int_local)) + /\ (4 | fe.(fe_ofs_int_callee_save)) + /\ (8 | fe.(fe_ofs_float_local)) + /\ (8 | fe.(fe_ofs_float_callee_save)) + /\ (4 | fe.(fe_ofs_retaddr)) + /\ (4 | fe.(fe_stack_data)) + /\ (8 | fe.(fe_size)). +Proof. + intros. + unfold fe, make_env, fe_size, fe_ofs_link, fe_ofs_retaddr, + fe_ofs_int_local, fe_ofs_int_callee_save, + fe_num_int_callee_save, + fe_ofs_float_local, fe_ofs_float_callee_save, fe_num_float_callee_save, + fe_stack_data. + set (x1 := 4 * bound_outgoing b). + assert (4 | x1). unfold x1; exists (bound_outgoing b); ring. + set (x2 := x1 + 4 * bound_int_local b). + assert (4 | x2). unfold x2; apply Zdivide_plus_r; auto. exists (bound_int_local b); ring. + set (x3 := x2 + 4 * bound_int_callee_save b). + set (x4 := align x3 8). + assert (8 | x4). unfold x4. apply align_divides. omega. + set (x5 := x4 + 8 * bound_float_local b). + assert (8 | x5). unfold x5. apply Zdivide_plus_r; auto. exists (bound_float_local b); ring. + set (x6 := x5 + 8 * bound_float_callee_save b). + assert (4 | x6). + apply Zdivides_trans with 8. exists 2; auto. + unfold x6. apply Zdivide_plus_r; auto. exists (bound_float_callee_save b); ring. + set (x7 := x6 + 4). + assert (4 | x7). unfold x7; apply Zdivide_plus_r; auto. exists 1; auto. + set (x8 := x7 + 4). + assert (4 | x8). unfold x8; apply Zdivide_plus_r; auto. exists 1; auto. + set (x9 := align (x8 + bound_stack_data b) 8). + assert (8 | x9). unfold x9; apply align_divides. omega. + tauto. +Qed. -- cgit