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Diffstat (limited to 'theories/Floats/FloatAxioms.v')
| -rw-r--r-- | theories/Floats/FloatAxioms.v | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/theories/Floats/FloatAxioms.v b/theories/Floats/FloatAxioms.v new file mode 100644 index 0000000000..8ca64aac42 --- /dev/null +++ b/theories/Floats/FloatAxioms.v @@ -0,0 +1,58 @@ +Require Import ZArith Int63 SpecFloat PrimFloat FloatOps. + +(** * Properties of the primitive operators for the Binary64 format *) + +Notation valid_binary := (valid_binary prec emax). + +Definition SF64classify := SFclassify prec. +Definition SF64mul := SFmul prec emax. +Definition SF64add := SFadd prec emax. +Definition SF64sub := SFsub prec emax. +Definition SF64div := SFdiv prec emax. +Definition SF64sqrt := SFsqrt prec emax. +Definition SF64succ := SFsucc prec emax. +Definition SF64pred := SFpred prec emax. + +Axiom Prim2SF_valid : forall x, valid_binary (Prim2SF x) = true. +Axiom SF2Prim_Prim2SF : forall x, SF2Prim (Prim2SF x) = x. +Axiom Prim2SF_SF2Prim : forall x, valid_binary x = true -> Prim2SF (SF2Prim x) = x. + +Theorem Prim2SF_inj : forall x y, Prim2SF x = Prim2SF y -> x = y. + intros. rewrite <- SF2Prim_Prim2SF. symmetry. rewrite <- SF2Prim_Prim2SF. now rewrite H. +Qed. + +Theorem SF2Prim_inj : forall x y, SF2Prim x = SF2Prim y -> valid_binary x = true -> valid_binary y = true -> x = y. + intros. rewrite <- Prim2SF_SF2Prim by assumption. symmetry. rewrite <- Prim2SF_SF2Prim by assumption. rewrite H. reflexivity. +Qed. + +Axiom opp_spec : forall x, Prim2SF (-x)%float = SFopp (Prim2SF x). +Axiom abs_spec : forall x, Prim2SF (abs x) = SFabs (Prim2SF x). + +Axiom eqb_spec : forall x y, (x == y)%float = SFeqb (Prim2SF x) (Prim2SF y). +Axiom ltb_spec : forall x y, (x < y)%float = SFltb (Prim2SF x) (Prim2SF y). +Axiom leb_spec : forall x y, (x <= y)%float = SFleb (Prim2SF x) (Prim2SF y). + +Definition flatten_cmp_opt c := + match c with + | None => FNotComparable + | Some Eq => FEq + | Some Lt => FLt + | Some Gt => FGt + end. +Axiom compare_spec : forall x y, (x ?= y)%float = flatten_cmp_opt (SFcompare (Prim2SF x) (Prim2SF y)). + +Axiom classify_spec : forall x, classify x = SF64classify (Prim2SF x). +Axiom mul_spec : forall x y, Prim2SF (x * y)%float = SF64mul (Prim2SF x) (Prim2SF y). +Axiom add_spec : forall x y, Prim2SF (x + y)%float = SF64add (Prim2SF x) (Prim2SF y). +Axiom sub_spec : forall x y, Prim2SF (x - y)%float = SF64sub (Prim2SF x) (Prim2SF y). +Axiom div_spec : forall x y, Prim2SF (x / y)%float = SF64div (Prim2SF x) (Prim2SF y). +Axiom sqrt_spec : forall x, Prim2SF (sqrt x) = SF64sqrt (Prim2SF x). + +Axiom of_int63_spec : forall n, Prim2SF (of_int63 n) = binary_normalize prec emax (to_Z n) 0%Z false. +Axiom normfr_mantissa_spec : forall f, to_Z (normfr_mantissa f) = Z.of_N (SFnormfr_mantissa prec (Prim2SF f)). + +Axiom frshiftexp_spec : forall f, let (m,e) := frshiftexp f in (Prim2SF m, ((to_Z e) - shift)%Z) = SFfrexp prec emax (Prim2SF f). +Axiom ldshiftexp_spec : forall f e, Prim2SF (ldshiftexp f e) = SFldexp prec emax (Prim2SF f) ((to_Z e) - shift). + +Axiom next_up_spec : forall x, Prim2SF (next_up x) = SF64succ (Prim2SF x). +Axiom next_down_spec : forall x, Prim2SF (next_down x) = SF64pred (Prim2SF x). |
