From 783288d052bbcf75e250dff5018443d109c6101c Mon Sep 17 00:00:00 2001 From: xleroy Date: Wed, 23 Jul 2014 13:14:02 +0000 Subject: Merge the various $(ARCH)/$(VARIANT)/xxx.v files into $(ARCH)/xxx.v. The only platform where we have two variants is ARM, and it's easier to share the callling convention code between the two than to maintain both variants separately. git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@2540 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e --- powerpc/Stacklayout.v | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 powerpc/Stacklayout.v (limited to 'powerpc/Stacklayout.v') diff --git a/powerpc/Stacklayout.v b/powerpc/Stacklayout.v new file mode 100644 index 0000000..be823c1 --- /dev/null +++ b/powerpc/Stacklayout.v @@ -0,0 +1,134 @@ +(* *********************************************************************) +(* *) +(* The Compcert verified compiler *) +(* *) +(* Xavier Leroy, INRIA Paris-Rocquencourt *) +(* *) +(* Copyright Institut National de Recherche en Informatique et en *) +(* Automatique. All rights reserved. This file is distributed *) +(* under the terms of the INRIA Non-Commercial License Agreement. *) +(* *) +(* *********************************************************************) + +(** Machine- and ABI-dependent layout information for activation records. *) + +Require Import Coqlib. +Require Import Bounds. + +(** In the PowerPC/EABI application binary interface, + the general shape of activation records is as follows, + from bottom (lowest offsets) to top: +- 8 reserved bytes. The first 4 bytes hold the back pointer to the + activation record of the caller. The next 4 bytes are reserved + for called functions to store their return addresses. + Since we would rather store our return address in our own + frame, we will not use these 4 bytes, and just reserve them. +- Space for outgoing arguments to function calls. +- Local stack slots. +- Saved values of integer callee-save registers used by the function. +- Saved values of float callee-save registers used by the function. +- Space for the stack-allocated data declared in Cminor. + +The [frame_env] compilation environment records the positions of +the boundaries between areas in the frame part. +*) + +Definition fe_ofs_arg := 8. + +Record frame_env : Type := mk_frame_env { + fe_size: Z; + fe_ofs_link: Z; + fe_ofs_retaddr: Z; + fe_ofs_local: Z; + fe_ofs_int_callee_save: Z; + fe_num_int_callee_save: Z; + fe_ofs_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 + function. *) + +Definition make_env (b: bounds) := + let ol := align (8 + 4 * b.(bound_outgoing)) 8 in (* locals *) + let ora := ol + 4 * b.(bound_local) in (* saved return address *) + let oics := ora + 4 in (* integer callee-saves *) + let oendi := oics + 4 * b.(bound_int_callee_save) in + let ofcs := align oendi 8 in (* float callee-saves *) + let ostkdata := ofcs + 8 * b.(bound_float_callee_save) in (* stack data *) + let sz := align (ostkdata + b.(bound_stack_data)) 16 in + mk_frame_env sz 0 ora + ol + oics b.(bound_int_callee_save) + ofcs b.(bound_float_callee_save) + ostkdata. + +(** Separation property *) + +Remark frame_env_separated: + forall b, + let fe := make_env b in + 0 <= fe.(fe_ofs_link) + /\ fe.(fe_ofs_link) + 4 <= fe_ofs_arg + /\ fe_ofs_arg + 4 * b.(bound_outgoing) <= fe.(fe_ofs_local) + /\ fe.(fe_ofs_local) + 4 * b.(bound_local) <= fe.(fe_ofs_retaddr) + /\ fe.(fe_ofs_retaddr) + 4 <= fe.(fe_ofs_int_callee_save) + /\ fe.(fe_ofs_int_callee_save) + 4 * b.(bound_int_callee_save) <= fe.(fe_ofs_float_callee_save) + /\ fe.(fe_ofs_float_callee_save) + 8 * b.(bound_float_callee_save) <= fe.(fe_stack_data) + /\ fe.(fe_stack_data) + b.(bound_stack_data) <= fe.(fe_size) + /\ fe.(fe_ofs_retaddr) + 4 <= fe.(fe_size). +Proof. + intros. + generalize (align_le (8 + 4 * b.(bound_outgoing)) 8 (refl_equal _)). + 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)) 16 (refl_equal _)). + unfold fe, make_env, fe_size, fe_ofs_link, fe_ofs_retaddr, + fe_ofs_local, fe_ofs_int_callee_save, + fe_num_int_callee_save, + fe_ofs_float_callee_save, fe_num_float_callee_save, + fe_stack_data, fe_ofs_arg. + intros. + generalize (bound_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)) + /\ (8 | fe.(fe_ofs_local)) + /\ (4 | fe.(fe_ofs_int_callee_save)) + /\ (8 | fe.(fe_ofs_float_callee_save)) + /\ (4 | fe.(fe_ofs_retaddr)) + /\ (8 | fe.(fe_stack_data)) + /\ (16 | fe.(fe_size)). +Proof. + intros. + unfold fe, make_env, fe_size, fe_ofs_link, fe_ofs_retaddr, + fe_ofs_local, fe_ofs_int_callee_save, + fe_num_int_callee_save, + fe_ofs_float_callee_save, fe_num_float_callee_save, + fe_stack_data. + set (x1 := align (8 + 4 * bound_outgoing b) 8). + assert (8 | x1). unfold x1; apply align_divides. omega. + set (x2 := x1 + 4 * bound_local b). + assert (4 | x2). unfold x2; apply Zdivide_plus_r; auto. + apply Zdivides_trans with 8. exists 2; auto. auto. + exists (bound_local b); ring. + set (x3 := x2 + 4). + assert (4 | x3). unfold x3; apply Zdivide_plus_r; auto. exists 1; auto. + set (x4 := align (x3 + 4 * bound_int_callee_save b) 8). + assert (8 | x4). unfold x4. apply align_divides. omega. + set (x5 := x4 + 8 * bound_float_callee_save b). + assert (8 | x5). unfold x5. apply Zdivide_plus_r; auto. exists (bound_float_callee_save b); ring. + set (x6 := align (x5 + bound_stack_data b) 16). + assert (16 | x6). unfold x6; apply align_divides. omega. + intuition. +Qed. -- cgit v1.2.3