From: Geert Bosch Date: Wed, 27 Oct 2004 13:01:02 +0000 (+0200) Subject: eval_fat.adb (Eps_Model,Eps_Denorm): Remove, no longer used. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=057742339839a36409a581887adc9cb529656ba4;p=gcc.git eval_fat.adb (Eps_Model,Eps_Denorm): Remove, no longer used. 2004-10-26 Geert Bosch * eval_fat.adb (Eps_Model,Eps_Denorm): Remove, no longer used. (Succ): Re-implement using Scaling, Exponent and Ceiling attributes. (Pred): Implement in terms of Succ. From-SVN: r89648 --- diff --git a/gcc/ada/eval_fat.adb b/gcc/ada/eval_fat.adb index 00a131dd623..9221e919cdc 100644 --- a/gcc/ada/eval_fat.adb +++ b/gcc/ada/eval_fat.adb @@ -38,14 +38,14 @@ package body Eval_Fat is -- case of anyone ever having to adjust this code for another value, -- and for documentation purposes. + -- Another assumption is that the range of the floating-point type + -- is symmetric around zero. + type Radix_Power_Table is array (Int range 1 .. 4) of Int; Radix_Powers : constant Radix_Power_Table := (Radix ** 1, Radix ** 2, Radix ** 3, Radix ** 4); - function Float_Radix return T renames Ureal_2; - -- Radix expressed in real form - ----------------------- -- Local Subprograms -- ----------------------- @@ -74,12 +74,6 @@ package body Eval_Fat is -- even, a floor operation or a ceiling operation depending on the setting -- of Mode (see corresponding descriptions in Urealp). - function Eps_Model (RT : R) return T; - -- Return the smallest model number of R. - - function Eps_Denorm (RT : R) return T; - -- Return the smallest denormal of type R. - function Machine_Emin (RT : R) return Int; -- Return value of the Machine_Emin attribute @@ -91,10 +85,8 @@ package body Eval_Fat is begin if Towards = X then return X; - elsif Towards > X then return Succ (RT, X); - else return Pred (RT, X); end if; @@ -106,14 +98,11 @@ package body Eval_Fat is function Ceiling (RT : R; X : T) return T is XT : constant T := Truncation (RT, X); - begin if UR_Is_Negative (X) then return XT; - elsif X = XT then return X; - else return XT + Ureal_1; end if; @@ -382,10 +371,10 @@ package body Eval_Fat is Calculate_Fraction_And_Exponent : begin Uintp_Mark := Mark; - -- Determine correct rounding based on the remainder - -- which is in N and the divisor D. The rounding is - -- performed on the absolute value of X, so Ceiling - -- and Floor need to check for the sign of X explicitly. + -- Determine correct rounding based on the remainder which is in + -- N and the divisor D. The rounding is performed on the absolute + -- value of X, so Ceiling and Floor need to check for the sign of + -- X explicitly. case Mode is when Round_Even => @@ -440,25 +429,6 @@ package body Eval_Fat is end Calculate_Fraction_And_Exponent; end Decompose_Int; - ---------------- - -- Eps_Denorm -- - ---------------- - - function Eps_Denorm (RT : R) return T is - begin - return Float_Radix ** UI_From_Int - (Machine_Emin (RT) - Machine_Mantissa (RT)); - end Eps_Denorm; - - --------------- - -- Eps_Model -- - --------------- - - function Eps_Model (RT : R) return T is - begin - return Float_Radix ** UI_From_Int (Machine_Emin (RT)); - end Eps_Model; - -------------- -- Exponent -- -------------- @@ -735,37 +705,8 @@ package body Eval_Fat is ---------- function Pred (RT : R; X : T) return T is - Result_F : UI; - Result_X : UI; - begin - if abs X < Eps_Model (RT) then - if Denorm_On_Target then - return X - Eps_Denorm (RT); - - elsif X > Ureal_0 then - - -- Target does not support denorms, so predecessor is 0.0 - - return Ureal_0; - - else - -- Target does not support denorms, and X is 0.0 - -- or at least bigger than -Eps_Model (RT) - - return -Eps_Model (RT); - end if; - - else - Decompose_Int (RT, X, Result_F, Result_X, Ceiling); - return UR_From_Components - (Num => Result_F - 1, - Den => Machine_Mantissa (RT) - Result_X, - Rbase => Radix, - Negative => False); - -- Result_F may be false, but this is OK as UR_From_Components - -- handles that situation. - end if; + return -Succ (RT, -X); end Pred; --------------- @@ -892,35 +833,38 @@ package body Eval_Fat is ---------- function Succ (RT : R; X : T) return T is - Result_F : UI; - Result_X : UI; + Emin : constant UI := UI_From_Int (Machine_Emin (RT)); + Mantissa : constant UI := UI_From_Int (Machine_Mantissa (RT)); + Exp : UI := UI_Max (Emin, Exponent (RT, X)); + Frac : T; + New_Frac : T; begin - if abs X < Eps_Model (RT) then - if Denorm_On_Target then - return X + Eps_Denorm (RT); + if UR_Is_Zero (X) then + Exp := Emin; + end if; - elsif X < Ureal_0 then - -- Target does not support denorms, so successor is 0.0 - return Ureal_0; + -- Set exponent such that the radix point will be directly + -- following the mantissa after scaling - else - -- Target does not support denorms, and X is 0.0 - -- or at least smaller than Eps_Model (RT) + if Denorm_On_Target or Exp /= Emin then + Exp := Exp - Mantissa; + else + Exp := Exp - 1; + end if; - return Eps_Model (RT); - end if; + Frac := Scaling (RT, X, -Exp); + New_Frac := Ceiling (RT, Frac); - else - Decompose_Int (RT, X, Result_F, Result_X, Floor); - return UR_From_Components - (Num => Result_F + 1, - Den => Machine_Mantissa (RT) - Result_X, - Rbase => Radix, - Negative => False); - -- Result_F may be false, but this is OK as UR_From_Components - -- handles that situation. + if New_Frac = Frac then + if New_Frac = Scaling (RT, -Ureal_1, Mantissa - 1) then + New_Frac := New_Frac + Scaling (RT, Ureal_1, Uint_Minus_1); + else + New_Frac := New_Frac + Ureal_1; + end if; end if; + + return Scaling (RT, New_Frac, Exp); end Succ; ---------------- @@ -929,7 +873,6 @@ package body Eval_Fat is function Truncation (RT : R; X : T) return T is pragma Warnings (Off, RT); - begin return UR_From_Uint (UR_Trunc (X)); end Truncation;