diff options
Diffstat (limited to 'gcc/ada/s-valrea.adb')
| -rw-r--r-- | gcc/ada/s-valrea.adb | 78 |
1 files changed, 67 insertions, 11 deletions
diff --git a/gcc/ada/s-valrea.adb b/gcc/ada/s-valrea.adb index 7d93472a538..28f687e8ca2 100644 --- a/gcc/ada/s-valrea.adb +++ b/gcc/ada/s-valrea.adb @@ -6,7 +6,7 @@ -- -- -- S p e c -- -- -- --- Copyright (C) 1992-2000 Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2003 Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- @@ -81,6 +81,17 @@ package body System.Val_Real is After_Point : Natural := 0; -- Set to 1 after the point + Num_Saved_Zeroes : Natural := 0; + -- This counts zeroes after the decimal point. A non-zero value means + -- that this number of previously scanned digits are zero. if the end + -- of the number is reached, these zeroes are simply discarded, which + -- ensures that trailing zeroes after the point never affect the value + -- (which might otherwise happen as a result of rounding). With this + -- processing in place, we can ensure that, for example, we get the + -- same exact result from 1.0E+49 and 1.0000000E+49. This is not + -- necessarily required in a case like this where the result is not + -- a machine number, but it is certainly a desirable behavior. + procedure Scanf; -- Scans integer literal value starting at current character position. -- For each digit encountered, Uval is multiplied by 10.0, and the new @@ -96,9 +107,36 @@ package body System.Val_Real is begin loop Digit := Character'Pos (Str (P)) - Character'Pos ('0'); - Uval := Uval * 10.0 + Long_Long_Float (Digit); P := P + 1; - Scale := Scale - After_Point; + + -- Save up trailing zeroes after the decimal point + + if Digit = 0 and After_Point = 1 then + Num_Saved_Zeroes := Num_Saved_Zeroes + 1; + + -- Here for a non-zero digit + + else + -- First deal with any previously saved zeroes + + if Num_Saved_Zeroes /= 0 then + while Num_Saved_Zeroes > Maxpow loop + Uval := Uval * Powten (Maxpow); + Num_Saved_Zeroes := Num_Saved_Zeroes - Maxpow; + Scale := Scale - Maxpow; + end loop; + + Uval := Uval * Powten (Num_Saved_Zeroes); + Scale := Scale - Num_Saved_Zeroes; + + Num_Saved_Zeroes := 0; + end if; + + -- Accumulate new digit + + Uval := Uval * 10.0 + Long_Long_Float (Digit); + Scale := Scale - After_Point; + end if; -- Done if end of input field @@ -197,16 +235,36 @@ package body System.Val_Real is raise Constraint_Error; end if; - P := P + 1; - Fdigit := Long_Long_Float (Digit); + -- Save up trailing zeroes after the decimal point + + if Digit = 0 and After_Point = 1 then + Num_Saved_Zeroes := Num_Saved_Zeroes + 1; + + -- Here for a non-zero digit - if Fdigit >= Base then - Bad_Base := True; else - Scale := Scale - After_Point; - Uval := Uval * Base + Fdigit; + -- First deal with any previously saved zeroes + + if Num_Saved_Zeroes /= 0 then + Uval := Uval * Base ** Num_Saved_Zeroes; + Scale := Scale - Num_Saved_Zeroes; + Num_Saved_Zeroes := 0; + end if; + + -- Now accumulate the new digit + + Fdigit := Long_Long_Float (Digit); + + if Fdigit >= Base then + Bad_Base := True; + else + Scale := Scale - After_Point; + Uval := Uval * Base + Fdigit; + end if; end if; + P := P + 1; + if P > Max then raise Constraint_Error; @@ -276,7 +334,6 @@ package body System.Val_Real is -- For base 10, use power of ten table, repeatedly if necessary. elsif Scale > 0 then - while Scale > Maxpow loop Uval := Uval * Powten (Maxpow); Scale := Scale - Maxpow; @@ -287,7 +344,6 @@ package body System.Val_Real is end if; elsif Scale < 0 then - while (-Scale) > Maxpow loop Uval := Uval / Powten (Maxpow); Scale := Scale + Maxpow; |