diff options
Diffstat (limited to 'gcc/ada/exp_ch4.adb')
| -rw-r--r-- | gcc/ada/exp_ch4.adb | 56 |
1 files changed, 29 insertions, 27 deletions
diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb index ebdbcdeb316..bf3a6479761 100644 --- a/gcc/ada/exp_ch4.adb +++ b/gcc/ada/exp_ch4.adb @@ -213,19 +213,19 @@ package body Exp_Ch4 is -- Convert_To_Actual_Subtype if necessary). function Minimized_Eliminated_Overflow_Check (N : Node_Id) return Boolean; - -- For signed arithmetic operations with Do_Overflow_Check set when the - -- current overflow mode is MINIMIZED or ELIMINATED, we need to make a - -- call to Apply_Arithmetic_Overflow_Checks as the first thing we do. We - -- then return. We count on the recursive apparatus for overflow checks - -- to call us back with an equivalent operation that does not have the - -- Do_Overflow_Check flag set, and that is when we will proceed with the - -- expansion of the operator (e.g. converting X+0 to X, or X**2 to X*X). - -- We cannot do these optimizations without first making this check, since - -- there may be operands further down the tree that are relying on the - -- recursive calls triggered by the top level nodes to properly process - -- overflow checking and remaining expansion on these nodes. Note that - -- this call back may be skipped if the operation is done in Bignum mode - -- but that's fine, since the Bignum call takes care of everything. + -- For signed arithmetic operations when the current overflow mode is + -- MINIMIZED or ELIMINATED, we must call Apply_Arithmetic_Overflow_Checks + -- as the first thing we do. We then return. We count on the recursive + -- apparatus for overflow checks to call us back with an equivalent + -- operation that is in CHECKED mode, avoiding a recursive entry into this + -- routine, and that is when we will proceed with the expansion of the + -- operator (e.g. converting X+0 to X, or X**2 to X*X). We cannot do + -- these optimizations without first making this check, since there may be + -- operands further down the tree that are relying on the recursive calls + -- triggered by the top level nodes to properly process overflow checking + -- and remaining expansion on these nodes. Note that this call back may be + -- skipped if the operation is done in Bignum mode but that's fine, since + -- the Bignum call takes care of everything. procedure Optimize_Length_Comparison (N : Node_Id); -- Given an expression, if it is of the form X'Length op N (or the other @@ -2274,8 +2274,8 @@ package body Exp_Ch4 is LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); -- Entity for Long_Long_Integer'Base - Check : constant Overflow_Check_Type := Overflow_Check_Mode (Empty); - -- Current checking mode + Check : constant Overflow_Check_Type := Overflow_Check_Mode; + -- Current overflow checking mode procedure Set_True; procedure Set_False; @@ -2320,9 +2320,9 @@ package body Exp_Ch4 is -- our operands using the Minimize_Eliminate circuitry which applies -- this processing to the two operand subtrees. - Minimize_Eliminate_Overflow_Checks + Minimize_Eliminate_Overflows (Left_Opnd (N), Llo, Lhi, Top_Level => False); - Minimize_Eliminate_Overflow_Checks + Minimize_Eliminate_Overflows (Right_Opnd (N), Rlo, Rhi, Top_Level => False); -- See if the range information decides the result of the comparison. @@ -3715,13 +3715,13 @@ package body Exp_Ch4 is -- Save result type Lo, Hi : Uint; - -- Bounds in Minimize calls, not used yet ??? + -- Bounds in Minimize calls, not used currently LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); -- Entity for Long_Long_Integer'Base (Standard should export this???) begin - Minimize_Eliminate_Overflow_Checks (Lop, Lo, Hi, Top_Level => False); + Minimize_Eliminate_Overflows (Lop, Lo, Hi, Top_Level => False); -- If right operand is a subtype name, and the subtype name has no -- predicate, then we can just replace the right operand with an @@ -3751,9 +3751,9 @@ package body Exp_Ch4 is -- have not been processed for minimized or eliminated checks. if Nkind (Rop) = N_Range then - Minimize_Eliminate_Overflow_Checks + Minimize_Eliminate_Overflows (Low_Bound (Rop), Lo, Hi, Top_Level => False); - Minimize_Eliminate_Overflow_Checks + Minimize_Eliminate_Overflows (High_Bound (Rop), Lo, Hi, Top_Level => False); -- We have A in B .. C, treated as A >= B and then A <= C @@ -5498,7 +5498,7 @@ package body Exp_Ch4 is -- in which case, this usage makes sense, and in any case, we have -- actually eliminated the danger of optimization above. - if Overflow_Check_Mode (Restyp) not in Minimized_Or_Eliminated then + if Overflow_Check_Mode not in Minimized_Or_Eliminated then Error_Msg_N ("?explicit membership test may be optimized away", N); Error_Msg_N -- CODEFIX ("\?use ''Valid attribute instead", N); @@ -5526,7 +5526,7 @@ package body Exp_Ch4 is -- type, then expand with a separate procedure. Note the use of the -- flag No_Minimize_Eliminate to prevent infinite recursion. - if Overflow_Check_Mode (Empty) in Minimized_Or_Eliminated + if Overflow_Check_Mode in Minimized_Or_Eliminated and then Is_Signed_Integer_Type (Ltyp) and then not No_Minimize_Eliminate (N) then @@ -5565,8 +5565,7 @@ package body Exp_Ch4 is -- Skip this for predicated types, where such expressions are a -- reasonable way of testing if something meets the predicate. - and then not (Is_Discrete_Type (Ltyp) - and then Present (Predicate_Function (Ltyp))) + and then not Present (Predicate_Function (Ltyp)) then Substitute_Valid_Check; return; @@ -6103,6 +6102,9 @@ package body Exp_Ch4 is -- If a predicate is present, then we do the predicate test, but we -- most certainly want to omit this if we are within the predicate -- function itself, since otherwise we have an infinite recursion! + -- The check should also not be emitted when testing against a range + -- (the check is only done when the right operand is a subtype; see + -- RM12-4.5.2 (28.1/3-30/3)). declare PFunc : constant Entity_Id := Predicate_Function (Rtyp); @@ -6110,6 +6112,7 @@ package body Exp_Ch4 is begin if Present (PFunc) and then Current_Scope /= PFunc + and then Nkind (Rop) /= N_Range then Rewrite (N, Make_And_Then (Loc, @@ -11782,8 +11785,7 @@ package body Exp_Ch4 is begin return Is_Signed_Integer_Type (Etype (N)) - and then Do_Overflow_Check (N) - and then Overflow_Check_Mode (Empty) in Minimized_Or_Eliminated; + and then Overflow_Check_Mode in Minimized_Or_Eliminated; end Minimized_Eliminated_Overflow_Check; -------------------------------- |