From 54f97d1988f623ba7422e13a504caeb5701ba93c Mon Sep 17 00:00:00 2001 From: Xavier Leroy Date: Fri, 21 Aug 2015 11:05:36 +0200 Subject: Refactoring of builtins and annotations in the back-end. Before, the back-end languages had distinct instructions - Iannot for annotations, taking structured expressions (annot_arg) as arguments, and producing no results' - Ibuiltin for other builtins, using simple pseudoregs/locations/registers as arguments and results. This branch enriches Ibuiltin instructions so that they take structured expressions (builtin_arg and builtin_res) as arguments and results. This way, - Annotations fit the general pattern of builtin functions, so Iannot instructions are removed. - EF_vload_global and EF_vstore_global become useless, as the same optimization can be achieved by EF_vload/vstore taking a structured argument of the "address of global" kind. - Better code can be generated for builtin_memcpy between stack locations, or volatile accesses to stack locations. Finally, this commit also introduces a new kind of external function, EF_debug, which is like EF_annot but produces no observable events. It will be used later to transport debug info through the back-end, without preventing optimizations. --- backend/Registers.v | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'backend/Registers.v') diff --git a/backend/Registers.v b/backend/Registers.v index 47e10fa4..20532e8c 100644 --- a/backend/Registers.v +++ b/backend/Registers.v @@ -22,6 +22,7 @@ Require Import AST. Require Import Maps. Require Import Ordered. Require FSetAVL. +Require Import Values. Definition reg: Type := positive. @@ -53,10 +54,45 @@ Definition regmap_optset | Some r => Regmap.set r v rs end. +Definition regmap_setres + (A: Type) (res: builtin_res reg) (v: A) (rs: Regmap.t A) : Regmap.t A := + match res with + | BR r => Regmap.set r v rs + | _ => rs + end. + Notation "a # b" := (Regmap.get b a) (at level 1). Notation "a ## b" := (List.map (fun r => Regmap.get r a) b) (at level 1). Notation "a # b <- c" := (Regmap.set b c a) (at level 1, b at next level). +(** Pointwise "less defined than" relation between register maps. *) + +Definition regs_lessdef (rs1 rs2: Regmap.t val) : Prop := + forall r, Val.lessdef (rs1#r) (rs2#r). + +Lemma regs_lessdef_regs: + forall rs1 rs2, regs_lessdef rs1 rs2 -> + forall rl, Val.lessdef_list rs1##rl rs2##rl. +Proof. + induction rl; constructor; auto. +Qed. + +Lemma set_reg_lessdef: + forall r v1 v2 rs1 rs2, + Val.lessdef v1 v2 -> regs_lessdef rs1 rs2 -> regs_lessdef (rs1#r <- v1) (rs2#r <- v2). +Proof. + intros; red; intros. repeat rewrite Regmap.gsspec. + destruct (peq r0 r); auto. +Qed. + +Lemma set_res_lessdef: + forall res v1 v2 rs1 rs2, + Val.lessdef v1 v2 -> regs_lessdef rs1 rs2 -> + regs_lessdef (regmap_setres res v1 rs1) (regmap_setres res v2 rs2). +Proof. + intros. destruct res; simpl; auto. apply set_reg_lessdef; auto. +Qed. + (** Sets of registers *) Module Regset := FSetAVL.Make(OrderedPositive). -- cgit