From: Arnaud Charlet Date: Thu, 11 Jun 2020 12:49:58 +0000 (-0400) Subject: [Ada] Wrong execution of Tan on large argument X-Git-Tag: upstream/12.2.0~14788 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0b043c8fea135de32a751c97fa412f5610699fbc;p=platform%2Fupstream%2Fgcc.git [Ada] Wrong execution of Tan on large argument gcc/ada/ * Makefile.rtl: replace a-numaux__x86.ads by a-numaux__libc-x86.ads and a-numaux__x86.adb by a-numaux__dummy.adb. * libgnat/a-numaux__x86.ads, libgnat/a-numaux__x86.adb: Removed. * libgnat/a-numaux__dummy.adb: New. --- diff --git a/gcc/ada/Makefile.rtl b/gcc/ada/Makefile.rtl index 73109a2..d7f2bde 100644 --- a/gcc/ada/Makefile.rtl +++ b/gcc/ada/Makefile.rtl @@ -834,13 +834,13 @@ ATOMICS_BUILTINS_TARGET_PAIRS = \ # Special version of units for x86 and x86-64 platforms. X86_TARGET_PAIRS = \ - a-numaux.ads. -- --- -- --- GNAT was originally developed by the GNAT team at New York University. -- --- Extensive contributions were provided by Ada Core Technologies Inc. -- --- -- ------------------------------------------------------------------------------- - -with System.Machine_Code; use System.Machine_Code; - -package body Ada.Numerics.Aux is - - NL : constant String := ASCII.LF & ASCII.HT; - - ----------------------- - -- Local subprograms -- - ----------------------- - - function Is_Nan (X : Double) return Boolean; - -- Return True iff X is a IEEE NaN value - - function Logarithmic_Pow (X, Y : Double) return Double; - -- Implementation of X**Y using Exp and Log functions (binary base) - -- to calculate the exponentiation. This is used by Pow for values - -- for values of Y in the open interval (-0.25, 0.25) - - procedure Reduce (X : in out Double; Q : out Natural); - -- Implement reduction of X by Pi/2. Q is the quadrant of the final - -- result in the range 0..3. The absolute value of X is at most Pi/4. - -- It is needed to avoid a loss of accuracy for sin near Pi and cos - -- near Pi/2 due to the use of an insufficiently precise value of Pi - -- in the range reduction. - - pragma Inline (Is_Nan); - pragma Inline (Reduce); - - -------------------------------- - -- Basic Elementary Functions -- - -------------------------------- - - -- This section implements a few elementary functions that are used to - -- build the more complex ones. This ordering enables better inlining. - - ---------- - -- Atan -- - ---------- - - function Atan (X : Double) return Double is - Result : Double; - - begin - Asm (Template => - "fld1" & NL - & "fpatan", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", X)); - - -- The result value is NaN iff input was invalid - - if not (Result = Result) then - raise Argument_Error; - end if; - - return Result; - end Atan; - - --------- - -- Exp -- - --------- - - function Exp (X : Double) return Double is - Result : Double; - begin - Asm (Template => - "fldl2e " & NL - & "fmulp %%st, %%st(1)" & NL -- X * log2 (E) - & "fld %%st(0) " & NL - & "frndint " & NL -- Integer (X * Log2 (E)) - & "fsubr %%st, %%st(1)" & NL -- Fraction (X * Log2 (E)) - & "fxch " & NL - & "f2xm1 " & NL -- 2**(...) - 1 - & "fld1 " & NL - & "faddp %%st, %%st(1)" & NL -- 2**(Fraction (X * Log2 (E))) - & "fscale " & NL -- E ** X - & "fstp %%st(1) ", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", X)); - return Result; - end Exp; - - ------------ - -- Is_Nan -- - ------------ - - function Is_Nan (X : Double) return Boolean is - begin - -- The IEEE NaN values are the only ones that do not equal themselves - - return X /= X; - end Is_Nan; - - --------- - -- Log -- - --------- - - function Log (X : Double) return Double is - Result : Double; - - begin - Asm (Template => - "fldln2 " & NL - & "fxch " & NL - & "fyl2x " & NL, - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", X)); - return Result; - end Log; - - ------------ - -- Reduce -- - ------------ - - procedure Reduce (X : in out Double; Q : out Natural) is - Half_Pi : constant := Pi / 2.0; - Two_Over_Pi : constant := 2.0 / Pi; - - HM : constant := Integer'Min (Double'Machine_Mantissa / 2, Natural'Size); - M : constant Double := 0.5 + 2.0**(1 - HM); -- Splitting constant - P1 : constant Double := Double'Leading_Part (Half_Pi, HM); - P2 : constant Double := Double'Leading_Part (Half_Pi - P1, HM); - P3 : constant Double := Double'Leading_Part (Half_Pi - P1 - P2, HM); - P4 : constant Double := Double'Leading_Part (Half_Pi - P1 - P2 - P3, HM); - P5 : constant Double := Double'Leading_Part (Half_Pi - P1 - P2 - P3 - - P4, HM); - P6 : constant Double := Double'Model (Half_Pi - P1 - P2 - P3 - P4 - P5); - K : Double; - R : Integer; - - begin - -- For X < 2.0**HM, all products below are computed exactly. - -- Due to cancellation effects all subtractions are exact as well. - -- As no double extended floating-point number has more than 75 - -- zeros after the binary point, the result will be the correctly - -- rounded result of X - K * (Pi / 2.0). - - K := X * Two_Over_Pi; - while abs K >= 2.0**HM loop - K := K * M - (K * M - K); - X := - (((((X - K * P1) - K * P2) - K * P3) - K * P4) - K * P5) - K * P6; - K := X * Two_Over_Pi; - end loop; - - -- If K is not a number (because X was not finite) raise exception - - if Is_Nan (K) then - raise Constraint_Error; - end if; - - -- Go through an integer temporary so as to use machine instructions - - R := Integer (Double'Rounding (K)); - Q := R mod 4; - K := Double (R); - X := (((((X - K * P1) - K * P2) - K * P3) - K * P4) - K * P5) - K * P6; - end Reduce; - - ---------- - -- Sqrt -- - ---------- - - function Sqrt (X : Double) return Double is - Result : Double; - - begin - if X < 0.0 then - raise Argument_Error; - end if; - - Asm (Template => "fsqrt", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", X)); - - return Result; - end Sqrt; - - -------------------------------- - -- Other Elementary Functions -- - -------------------------------- - - -- These are built using the previously implemented basic functions - - ---------- - -- Acos -- - ---------- - - function Acos (X : Double) return Double is - Result : Double; - - begin - Result := 2.0 * Atan (Sqrt ((1.0 - X) / (1.0 + X))); - - -- The result value is NaN iff input was invalid - - if Is_Nan (Result) then - raise Argument_Error; - end if; - - return Result; - end Acos; - - ---------- - -- Asin -- - ---------- - - function Asin (X : Double) return Double is - Result : Double; - - begin - Result := Atan (X / Sqrt ((1.0 - X) * (1.0 + X))); - - -- The result value is NaN iff input was invalid - - if Is_Nan (Result) then - raise Argument_Error; - end if; - - return Result; - end Asin; - - --------- - -- Cos -- - --------- - - function Cos (X : Double) return Double is - Reduced_X : Double := abs X; - Result : Double; - Quadrant : Natural range 0 .. 3; - - begin - if Reduced_X > Pi / 4.0 then - Reduce (Reduced_X, Quadrant); - - case Quadrant is - when 0 => - Asm (Template => "fcos", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - - when 1 => - Asm (Template => "fsin", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", -Reduced_X)); - - when 2 => - Asm (Template => "fcos ; fchs", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - - when 3 => - Asm (Template => "fsin", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - end case; - - else - Asm (Template => "fcos", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - end if; - - return Result; - end Cos; - - --------------------- - -- Logarithmic_Pow -- - --------------------- - - function Logarithmic_Pow (X, Y : Double) return Double is - Result : Double; - begin - Asm (Template => "" -- X : Y - & "fyl2x " & NL -- Y * Log2 (X) - & "fld %%st(0) " & NL -- Y * Log2 (X) : Y * Log2 (X) - & "frndint " & NL -- Int (...) : Y * Log2 (X) - & "fsubr %%st, %%st(1)" & NL -- Int (...) : Fract (...) - & "fxch " & NL -- Fract (...) : Int (...) - & "f2xm1 " & NL -- 2**Fract (...) - 1 : Int (...) - & "fld1 " & NL -- 1 : 2**Fract (...) - 1 : Int (...) - & "faddp %%st, %%st(1)" & NL -- 2**Fract (...) : Int (...) - & "fscale ", -- 2**(Fract (...) + Int (...)) - Outputs => Double'Asm_Output ("=t", Result), - Inputs => - (Double'Asm_Input ("0", X), - Double'Asm_Input ("u", Y))); - return Result; - end Logarithmic_Pow; - - --------- - -- Pow -- - --------- - - function Pow (X, Y : Double) return Double is - type Mantissa_Type is mod 2**Double'Machine_Mantissa; - -- Modular type that can hold all bits of the mantissa of Double - - -- For negative exponents, do divide at the end of the processing - - Negative_Y : constant Boolean := Y < 0.0; - Abs_Y : constant Double := abs Y; - - -- During this function the following invariant is kept: - -- X ** (abs Y) = Base**(Exp_High + Exp_Mid + Exp_Low) * Factor - - Base : Double := X; - - Exp_High : Double := Double'Floor (Abs_Y); - Exp_Mid : Double; - Exp_Low : Double; - Exp_Int : Mantissa_Type; - - Factor : Double := 1.0; - - begin - -- Select algorithm for calculating Pow (integer cases fall through) - - if Exp_High >= 2.0**Double'Machine_Mantissa then - - -- In case of Y that is IEEE infinity, just raise constraint error - - if Exp_High > Double'Safe_Last then - raise Constraint_Error; - end if; - - -- Large values of Y are even integers and will stay integer - -- after division by two. - - loop - -- Exp_Mid and Exp_Low are zero, so - -- X**(abs Y) = Base ** Exp_High = (Base**2) ** (Exp_High / 2) - - Exp_High := Exp_High / 2.0; - Base := Base * Base; - exit when Exp_High < 2.0**Double'Machine_Mantissa; - end loop; - - elsif Exp_High /= Abs_Y then - Exp_Low := Abs_Y - Exp_High; - Factor := 1.0; - - if Exp_Low /= 0.0 then - - -- Exp_Low now is in interval (0.0, 1.0) - -- Exp_Mid := Double'Floor (Exp_Low * 4.0) / 4.0; - - Exp_Mid := 0.0; - Exp_Low := Exp_Low - Exp_Mid; - - if Exp_Low >= 0.5 then - Factor := Sqrt (X); - Exp_Low := Exp_Low - 0.5; -- exact - - if Exp_Low >= 0.25 then - Factor := Factor * Sqrt (Factor); - Exp_Low := Exp_Low - 0.25; -- exact - end if; - - elsif Exp_Low >= 0.25 then - Factor := Sqrt (Sqrt (X)); - Exp_Low := Exp_Low - 0.25; -- exact - end if; - - -- Exp_Low now is in interval (0.0, 0.25) - - -- This means it is safe to call Logarithmic_Pow - -- for the remaining part. - - Factor := Factor * Logarithmic_Pow (X, Exp_Low); - end if; - - elsif X = 0.0 then - return 0.0; - end if; - - -- Exp_High is non-zero integer smaller than 2**Double'Machine_Mantissa - - Exp_Int := Mantissa_Type (Exp_High); - - -- Standard way for processing integer powers > 0 - - while Exp_Int > 1 loop - if (Exp_Int and 1) = 1 then - - -- Base**Y = Base**(Exp_Int - 1) * Exp_Int for Exp_Int > 0 - - Factor := Factor * Base; - end if; - - -- Exp_Int is even and Exp_Int > 0, so - -- Base**Y = (Base**2)**(Exp_Int / 2) - - Base := Base * Base; - Exp_Int := Exp_Int / 2; - end loop; - - -- Exp_Int = 1 or Exp_Int = 0 - - if Exp_Int = 1 then - Factor := Base * Factor; - end if; - - if Negative_Y then - Factor := 1.0 / Factor; - end if; - - return Factor; - end Pow; - - --------- - -- Sin -- - --------- - - function Sin (X : Double) return Double is - Reduced_X : Double := X; - Result : Double; - Quadrant : Natural range 0 .. 3; - - begin - if abs X > Pi / 4.0 then - Reduce (Reduced_X, Quadrant); - - case Quadrant is - when 0 => - Asm (Template => "fsin", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - - when 1 => - Asm (Template => "fcos", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - - when 2 => - Asm (Template => "fsin", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", -Reduced_X)); - - when 3 => - Asm (Template => "fcos ; fchs", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - end case; - - else - Asm (Template => "fsin", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - end if; - - return Result; - end Sin; - - --------- - -- Tan -- - --------- - - function Tan (X : Double) return Double is - Reduced_X : Double := X; - Result : Double; - Quadrant : Natural range 0 .. 3; - - begin - if abs X > Pi / 4.0 then - Reduce (Reduced_X, Quadrant); - - if Quadrant mod 2 = 0 then - Asm (Template => "fptan" & NL - & "ffree %%st(0)" & NL - & "fincstp", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - else - Asm (Template => "fsincos" & NL - & "fdivp %%st, %%st(1)" & NL - & "fchs", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - end if; - - else - Asm (Template => - "fptan " & NL - & "ffree %%st(0) " & NL - & "fincstp ", - Outputs => Double'Asm_Output ("=t", Result), - Inputs => Double'Asm_Input ("0", Reduced_X)); - end if; - - return Result; - end Tan; - - ---------- - -- Sinh -- - ---------- - - function Sinh (X : Double) return Double is - begin - -- Mathematically Sinh (x) is defined to be (Exp (X) - Exp (-X)) / 2.0 - - if abs X < 25.0 then - return (Exp (X) - Exp (-X)) / 2.0; - else - return Exp (X) / 2.0; - end if; - end Sinh; - - ---------- - -- Cosh -- - ---------- - - function Cosh (X : Double) return Double is - begin - -- Mathematically Cosh (X) is defined to be (Exp (X) + Exp (-X)) / 2.0 - - if abs X < 22.0 then - return (Exp (X) + Exp (-X)) / 2.0; - else - return Exp (X) / 2.0; - end if; - end Cosh; - - ---------- - -- Tanh -- - ---------- - - function Tanh (X : Double) return Double is - begin - -- Return the Hyperbolic Tangent of x - - -- x -x - -- e - e Sinh (X) - -- Tanh (X) is defined to be ----------- = -------- - -- x -x Cosh (X) - -- e + e - - if abs X > 23.0 then - return Double'Copy_Sign (1.0, X); - end if; - - return 1.0 / (1.0 + Exp (-(2.0 * X))) - 1.0 / (1.0 + Exp (2.0 * X)); - end Tanh; - -end Ada.Numerics.Aux;