From: Eric Botcazou Date: Wed, 3 Mar 2021 19:15:42 +0000 (+0100) Subject: [Ada] Fix floating-point exponentiation with Integer'First exponent X-Git-Tag: basepoints/gcc-13~6793 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f4fe186bfe3e74c7c9b2d49b635565ea9a4df1b2;p=thirdparty%2Fgcc.git [Ada] Fix floating-point exponentiation with Integer'First exponent gcc/ada/ * urealp.adb (Scale): Change first paramter to Uint and adjust. (Equivalent_Decimal_Exponent): Pass U.Den directly to Scale. * libgnat/s-exponr.adb (Negative): Rename to... (Safe_Negative): ...this and change its lower bound. (Exponr): Adjust to above renaming and deal with Integer'First. --- diff --git a/gcc/ada/libgnat/s-exponr.adb b/gcc/ada/libgnat/s-exponr.adb index ece53b51a39a..ad7f40188dd9 100644 --- a/gcc/ada/libgnat/s-exponr.adb +++ b/gcc/ada/libgnat/s-exponr.adb @@ -57,8 +57,8 @@ function System.Exponr (Left : Num; Right : Integer) return Num is subtype Double_T is Double_Real.Double_T; -- The double floating-point type - subtype Negative is Integer range Integer'First .. -1; - -- The range of negative exponents + subtype Safe_Negative is Integer range Integer'First + 1 .. -1; + -- The range of safe negative exponents function Expon (Left : Num; Right : Natural) return Num; -- Routine used if Right is greater than 4 @@ -113,9 +113,12 @@ begin return Num'Machine (Sqr * Sqr); end; - when Negative => + when Safe_Negative => return Num'Machine (1.0 / Exponr (Left, -Right)); + when Integer'First => + return Num'Machine (1.0 / (Exponr (Left, Integer'Last) * Left)); + when others => return Num'Machine (Expon (Left, Right)); end case; diff --git a/gcc/ada/urealp.adb b/gcc/ada/urealp.adb index 59d5c08f3228..0f57043ffcd5 100644 --- a/gcc/ada/urealp.adb +++ b/gcc/ada/urealp.adb @@ -270,23 +270,21 @@ package body Urealp is 15 => (Num => 53_385_559, Den => 45_392_361), -- 1.176091259055681 16 => (Num => 78_897_839, Den => 65_523_237)); -- 1.204119982655924 - function Scale (X : Int; R : Ratio) return Int; + function Scale (X : Uint; R : Ratio) return Int; -- Compute the value of X scaled by R ----------- -- Scale -- ----------- - function Scale (X : Int; R : Ratio) return Int is - type Wide_Int is range -2**63 .. 2**63 - 1; - + function Scale (X : Uint; R : Ratio) return Int is begin - return Int (Wide_Int (X) * Wide_Int (R.Num) / Wide_Int (R.Den)); + return UI_To_Int (X * R.Num / R.Den); end Scale; begin pragma Assert (U.Rbase /= 0); - return Scale (UI_To_Int (U.Den), Logs (U.Rbase)); + return Scale (U.Den, Logs (U.Rbase)); end Equivalent_Decimal_Exponent; ----------------