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riscv-gcc-1
Commit 967fb65e by Arnaud Charlet
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[multiple changes] 

2012-10-05  Robert Dewar  <dewar@adacore.com>

	* sem_util.adb (Has_One_Matching_Field): Handle case of lone
	discriminant.

2012-10-05  Yannick Moy  <moy@adacore.com>

	* checks.adb (Minimize_Eliminate_Overflow_Checks): Correct code
	for the division operation and exponent operation. Adjust bound
	for the mod and rem operations.

From-SVN: r192126
parent 60b68e56
Showing with 90 additions and 139 deletions
gcc/ada/ChangeLog
2012-10-05 Robert Dewar <dewar@adacore.com>
* sem_util.adb (Has_One_Matching_Field): Handle case of lone
discriminant.
2012-10-05 Yannick Moy <moy@adacore.com>
* checks.adb (Minimize_Eliminate_Overflow_Checks): Correct code
for the division operation and exponent operation. Adjust bound
for the mod and rem operations.
2012-10-05 Robert Dewar <dewar@adacore.com>
* checks.adb, checks.ads, s-tassta.adb, s-stposu.adb, s-spsufi.adb,
s-spsufi.ads, exp_ch4.adb: Minor reformatting.
......
gcc/ada/checks.adb
......@@ -1209,7 +1209,7 @@ package body Checks is
-- Here we know the result is Long_Long_Integer'Base, of that it has
-- been rewritten because the parent operation is a conversion. See
-- Conversion_Optimization.Apply_Arithmetic_Overflow_Checked_Suppressed.
-- Apply_Arithmetic_Overflow_Checked_Suppressed.Conversion_Optimization.
else
pragma Assert
......@@ -7087,147 +7087,80 @@ package body Checks is
when N_Op_Divide =>
-- Following seems awfully complex, can it be simplified ???
-- If the right operand can only be zero, set 0..0
Hi := No_Uint;
Lo := No_Uint;
declare
S : Uint;
begin
-- First work on finding big absolute result values. These
-- come from dividing large numbers (which we have in Llo
-- and Lhi) by small values, which we need to figure out.
-- Case where right operand can be positive
if Rhi > 0 then
-- Find smallest positive divisor
if Rlo > 0 then
S := Rlo;
else
S := Uint_1;
end if;
-- Big negative value divided by small positive value
-- generates a candidate for lowest possible result.
if Llo < 0 then
Min (Lo, Llo / S);
end if;
-- Big positive value divided by small positive value
-- generates a candidate for highest possible result.
if Lhi > 0 then
Max (Hi, Lhi / S);
end if;
end if;
-- Case where right operand can be negative
if Rlo < 0 then
-- Find smallest absolute value negative divisor
if Rhi < 0 then
S := Rhi;
else
S := -Uint_1;
end if;
-- Big negative value divided by small negative value
-- generates a candidate for largest possible result.
if Llo < 0 then
Max (Hi, Llo / S);
end if;
-- Big positive value divided by small negative value
-- generates a candidate for lowest possible result.
if Lhi > 0 then
Min (Lo, Lhi / S);
end if;
end if;
-- Now work on finding small absolute result values. These
-- come from dividing small numbers, which we need to figure
-- out, by large values (which we have in Rlo, Rhi).
-- Case where left operand can be positive
if Rlo = 0 and then Rhi = 0 then
Lo := Uint_0;
Hi := Uint_0;
if Lhi > 0 then
-- Possible bounds of division must come from dividing end
-- values of the input ranges (four possibilities), provided
-- zero is not included in the possible values of the right
-- operand.
-- Otherwise, we just consider two intervals of values for
-- the right operand: the interval of negative values (up to
-- -1) and the interval of positive values (starting at 1).
-- Since division by 1 is the identity, and division by -1
-- is negation, we get all possible bounds of division in that
-- case by considering:
-- - all values from the division of end values of input
-- ranges;
-- - the end values of the left operand;
-- - the negation of the end values of the left operand.
-- Find smallest positive dividend
else
declare
Mrk : constant Uintp.Save_Mark := Mark;
-- Mark so we can release the RR and Ev values
if Llo > 0 then
S := Llo;
else
S := Uint_1;
end if;
Ev1 : Uint;
Ev2 : Uint;
Ev3 : Uint;
Ev4 : Uint;
-- Small positive values divided by large negative values
-- generate candidates for low results.
begin
-- Discard extreme values of zero for the divisor, since
-- they will simply result in an exception in any case.
if Rlo < 0 then
Min (Lo, S / Rlo);
if Rlo = 0 then
Rlo := Uint_1;
elsif Rhi = 0 then
Rhi := -Uint_1;
end if;
-- Small positive values divided by large positive values
-- generate candidates for high results.
-- Compute possible bounds coming from dividing end
-- values of the input ranges.
if Rhi > 0 then
Max (Hi, S / Rhi);
end if;
end if;
Ev1 := Llo / Rlo;
Ev2 := Llo / Rhi;
Ev3 := Lhi / Rlo;
Ev4 := Lhi / Rhi;
-- Case where left operand can be negative
Lo := UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4));
Hi := UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4));
if Llo < 0 then
-- If the right operand can be both negative or positive,
-- include the end values of the left operand in the
-- extreme values, as well as their negation.
-- Find smallest absolute value negative dividend
if Rlo < 0 and then Rhi > 0 then
Ev1 := Llo;
Ev2 := -Llo;
Ev3 := Lhi;
Ev4 := -Lhi;
if Lhi < 0 then
S := Lhi;
else
S := -Uint_1;
Min (Lo,
UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4)));
Max (Hi,
UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4)));
end if;
-- Small negative value divided by large negative value
-- generates a candidate for highest possible result.
if Rlo < 0 then
Max (Hi, Rlo / S);
end if;
-- Release the RR and Ev values
-- Small negative value divided by large positive value
-- generates a candidate for lowest possible result.
if Rhi > 0 then
Min (Lo, Rhi / S);
end if;
end if;
-- Finally, if neither Lo or Hi set (happens if the right
-- operand is always zero for example), then set 0 .. 0.
if Lo = No_Uint and then Hi = No_Uint then
Lo := Uint_0;
Hi := Uint_0;
-- If one bound set and not the other copy
elsif Lo = No_Uint then
Lo := Hi;
elsif Hi = No_Uint then
Hi := Lo;
end if;
end;
Release_And_Save (Mrk, Lo, Hi);
end;
end if;
-- Exponentiation
......@@ -7264,14 +7197,15 @@ package body Checks is
else
-- High bound comes either from exponentiation of largest
-- positive value to largest exponent value, or from the
-- exponentiation of most negative value to an odd exponent.
-- positive value to largest exponent value, or from
-- the exponentiation of most negative value to an
-- even exponent.
declare
Hi1, Hi2 : Uint;
begin
if Lhi >= 0 then
if Lhi > 0 then
Hi1 := Lhi ** Rhi;
else
Hi1 := Uint_0;
......@@ -7279,9 +7213,9 @@ package body Checks is
if Llo < 0 then
if Rhi mod 2 = 0 then
Hi2 := Llo ** (Rhi - 1);
else
Hi2 := Llo ** Rhi;
else
Hi2 := Llo ** (Rhi - 1);
end if;
else
Hi2 := Uint_0;
......@@ -7316,7 +7250,7 @@ package body Checks is
when N_Op_Mod =>
declare
Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi);
Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1;
-- This is the maximum absolute value of the result
begin
......@@ -7371,9 +7305,10 @@ package body Checks is
when N_Op_Rem =>
declare
Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi);
Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1;
-- This is the maximum absolute value of the result. Note
-- that the result range does not depend on the sign of B.
-- that the result range does not depend on the sign of the
-- right operand.
begin
Lo := Uint_0;
......
gcc/ada/sem_util.adb
......@@ -13622,7 +13622,9 @@ package body Sem_Util is
function Has_One_Matching_Field return Boolean;
-- Determines if Expec_Type is a record type with a single component or
-- discriminant whose type matches the found type or is one dimensional
-- array whose component type matches the found type.
-- array whose component type matches the found type. In the case of
-- one discriminant, we ignore the variant parts. That's not accurate,
-- but good enough for the warning.
----------------------------
-- Has_One_Matching_Field --
......@@ -13664,10 +13666,10 @@ package body Sem_Util is
if No (E) then
return False;
elsif (Ekind (E) /= E_Discriminant
and then Ekind (E) /= E_Component)
elsif not Ekind_In (E, E_Discriminant, E_Component)
or else (Chars (E) = Name_uTag
or else Chars (E) = Name_uParent)
or else
Chars (E) = Name_uParent)
then
Next_Entity (E);
......@@ -13679,7 +13681,10 @@ package body Sem_Util is
if not Covers (Etype (E), Found_Type) then
return False;
elsif Present (Next_Entity (E)) then
elsif Present (Next_Entity (E))
and then (Ekind (E) = E_Component
or else Ekind (Next_Entity (E)) = E_Discriminant)
then
return False;
else
......
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