diff options
Diffstat (limited to 'backend/RTL.v')
| -rw-r--r-- | backend/RTL.v | 55 |
1 files changed, 35 insertions, 20 deletions
diff --git a/backend/RTL.v b/backend/RTL.v index a022f55a..fe350adf 100644 --- a/backend/RTL.v +++ b/backend/RTL.v @@ -43,11 +43,12 @@ Inductive instruction: Type := (** [Iop op args dest succ] performs the arithmetic operation [op] over the values of registers [args], stores the result in [dest], and branches to [succ]. *) - | Iload: memory_chunk -> addressing -> list reg -> reg -> node -> instruction - (** [Iload chunk addr args dest succ] loads a [chunk] quantity from + | Iload: trapping_mode -> memory_chunk -> addressing -> list reg -> reg -> node -> instruction + (** [Iload trap chunk addr args dest succ] loads a [chunk] quantity from the address determined by the addressing mode [addr] and the values of the [args] registers, stores the quantity just read - into [dest], and branches to [succ]. *) + into [dest], and branches to [succ]. + If trap=NOTRAP, then failures lead to a default value written to [dest]. *) | Istore: memory_chunk -> addressing -> list reg -> reg -> node -> instruction (** [Istore chunk addr args src succ] stores the value of register [src] in the [chunk] quantity at the @@ -66,11 +67,12 @@ Inductive instruction: Type := (** [Ibuiltin ef args dest succ] calls the built-in function identified by [ef], giving it the values of [args] as arguments. It stores the return value in [dest] and branches to [succ]. *) - | Icond: condition -> list reg -> node -> node -> instruction - (** [Icond cond args ifso ifnot] evaluates the boolean condition + | Icond: condition -> list reg -> node -> node -> option bool -> instruction + (** [Icond cond args ifso ifnot info] evaluates the boolean condition [cond] over the values of registers [args]. If the condition is true, it transitions to [ifso]. If the condition is false, - it transitions to [ifnot]. *) + it transitions to [ifnot]. [info] is a ghost field there to provide + information relative to branch prediction. *) | Ijumptable: reg -> list node -> instruction (** [Ijumptable arg tbl] transitions to the node that is the [n]-th element of the list [tbl], where [n] is the unsigned integer @@ -212,12 +214,25 @@ Inductive step: state -> trace -> state -> Prop := step (State s f sp pc rs m) E0 (State s f sp pc' (rs#res <- v) m) | exec_Iload: - forall s f sp pc rs m chunk addr args dst pc' a v, - (fn_code f)!pc = Some(Iload chunk addr args dst pc') -> + forall s f sp pc rs m trap chunk addr args dst pc' a v, + (fn_code f)!pc = Some(Iload trap chunk addr args dst pc') -> eval_addressing ge sp addr rs##args = Some a -> Mem.loadv chunk m a = Some v -> step (State s f sp pc rs m) E0 (State s f sp pc' (rs#dst <- v) m) + | exec_Iload_notrap1: + forall s f sp pc rs m chunk addr args dst pc', + (fn_code f)!pc = Some(Iload NOTRAP chunk addr args dst pc') -> + eval_addressing ge sp addr rs##args = None -> + step (State s f sp pc rs m) + E0 (State s f sp pc' (rs#dst <- Vundef) m) + | exec_Iload_notrap2: + forall s f sp pc rs m chunk addr args dst pc' a, + (fn_code f)!pc = Some(Iload NOTRAP chunk addr args dst pc') -> + eval_addressing ge sp addr rs##args = Some a -> + Mem.loadv chunk m a = None-> + step (State s f sp pc rs m) + E0 (State s f sp pc' (rs#dst <- Vundef) m) | exec_Istore: forall s f sp pc rs m chunk addr args src pc' a m', (fn_code f)!pc = Some(Istore chunk addr args src pc') -> @@ -248,8 +263,8 @@ Inductive step: state -> trace -> state -> Prop := step (State s f sp pc rs m) t (State s f sp pc' (regmap_setres res vres rs) m') | exec_Icond: - forall s f sp pc rs m cond args ifso ifnot b pc', - (fn_code f)!pc = Some(Icond cond args ifso ifnot) -> + forall s f sp pc rs m cond args ifso ifnot b pc' predb, + (fn_code f)!pc = Some(Icond cond args ifso ifnot predb) -> eval_condition cond rs##args m = Some b -> pc' = (if b then ifso else ifnot) -> step (State s f sp pc rs m) @@ -299,8 +314,8 @@ Proof. Qed. Lemma exec_Iload': - forall s f sp pc rs m chunk addr args dst pc' rs' a v, - (fn_code f)!pc = Some(Iload chunk addr args dst pc') -> + forall s f sp pc rs m trap chunk addr args dst pc' rs' a v, + (fn_code f)!pc = Some(Iload trap chunk addr args dst pc') -> eval_addressing ge sp addr rs##args = Some a -> Mem.loadv chunk m a = Some v -> rs' = (rs#dst <- v) -> @@ -384,12 +399,12 @@ Definition successors_instr (i: instruction) : list node := match i with | Inop s => s :: nil | Iop op args res s => s :: nil - | Iload chunk addr args dst s => s :: nil + | Iload trap chunk addr args dst s => s :: nil | Istore chunk addr args src s => s :: nil | Icall sig ros args res s => s :: nil | Itailcall sig ros args => nil | Ibuiltin ef args res s => s :: nil - | Icond cond args ifso ifnot => ifso :: ifnot :: nil + | Icond cond args ifso ifnot _ => ifso :: ifnot :: nil | Ijumptable arg tbl => tbl | Ireturn optarg => nil end. @@ -403,14 +418,14 @@ Definition instr_uses (i: instruction) : list reg := match i with | Inop s => nil | Iop op args res s => args - | Iload chunk addr args dst s => args + | Iload trap chunk addr args dst s => args | Istore chunk addr args src s => src :: args | Icall sig (inl r) args res s => r :: args | Icall sig (inr id) args res s => args | Itailcall sig (inl r) args => r :: args | Itailcall sig (inr id) args => args | Ibuiltin ef args res s => params_of_builtin_args args - | Icond cond args ifso ifnot => args + | Icond cond args ifso ifnot _ => args | Ijumptable arg tbl => arg :: nil | Ireturn None => nil | Ireturn (Some arg) => arg :: nil @@ -422,13 +437,13 @@ Definition instr_defs (i: instruction) : option reg := match i with | Inop s => None | Iop op args res s => Some res - | Iload chunk addr args dst s => Some dst + | Iload trap chunk addr args dst s => Some dst | Istore chunk addr args src s => None | Icall sig ros args res s => Some res | Itailcall sig ros args => None | Ibuiltin ef args res s => match res with BR r => Some r | _ => None end - | Icond cond args ifso ifnot => None + | Icond cond args ifso ifnot _ => None | Ijumptable arg tbl => None | Ireturn optarg => None end. @@ -462,7 +477,7 @@ Definition max_reg_instr (m: positive) (pc: node) (i: instruction) := match i with | Inop s => m | Iop op args res s => fold_left Pos.max args (Pos.max res m) - | Iload chunk addr args dst s => fold_left Pos.max args (Pos.max dst m) + | Iload trap chunk addr args dst s => fold_left Pos.max args (Pos.max dst m) | Istore chunk addr args src s => fold_left Pos.max args (Pos.max src m) | Icall sig (inl r) args res s => fold_left Pos.max args (Pos.max r (Pos.max res m)) | Icall sig (inr id) args res s => fold_left Pos.max args (Pos.max res m) @@ -471,7 +486,7 @@ Definition max_reg_instr (m: positive) (pc: node) (i: instruction) := | Ibuiltin ef args res s => fold_left Pos.max (params_of_builtin_args args) (fold_left Pos.max (params_of_builtin_res res) m) - | Icond cond args ifso ifnot => fold_left Pos.max args m + | Icond cond args ifso ifnot _ => fold_left Pos.max args m | Ijumptable arg tbl => Pos.max arg m | Ireturn None => m | Ireturn (Some arg) => Pos.max arg m |