* [Ada] Fix interaction of 128-bit integer types and -gnato2 mode
@ 2021-04-29 8:03 Pierre-Marie de Rodat
0 siblings, 0 replies; only message in thread
From: Pierre-Marie de Rodat @ 2021-04-29 8:03 UTC (permalink / raw)
To: gcc-patches; +Cc: Eric Botcazou
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The -gnato2 mode of overflow checking, aka Minimized overflow checking,
cannot work for 128-bit integer types because it is implemented using
64-bit integer types.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* exp_ch4.adb (Expand_Compare_Minimize_Eliminate_Overflow): Remove
entry condition.
(Expand_N_In): Call Minimized_Eliminated_Overflow_Check on the left
operand before doing the special overflow expansion.
(Expand_N_Op_Eq): Likewise.
(Expand_N_Op_Ge): Likewise.
(Expand_N_Op_Gt): Likewise.
(Expand_N_Op_Le): Likewise.
(Expand_N_Op_Lt): Likewise.
(Expand_N_Op_Ne): Likewise.
(Minimized_Eliminated_Overflow_Check): Return False for Minimized
if the size of the type is greater than that of Long_Long_Integer.
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diff --git a/gcc/ada/exp_ch4.adb b/gcc/ada/exp_ch4.adb
--- a/gcc/ada/exp_ch4.adb
+++ b/gcc/ada/exp_ch4.adb
@@ -2253,9 +2253,6 @@ package body Exp_Ch4 is
LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer);
-- Entity for Long_Long_Integer'Base
- Check : constant Overflow_Mode_Type := Overflow_Check_Mode;
- -- Current overflow checking mode
-
procedure Set_True;
procedure Set_False;
-- These procedures rewrite N with an occurrence of Standard_True or
@@ -2284,17 +2281,6 @@ package body Exp_Ch4 is
-- Start of processing for Expand_Compare_Minimize_Eliminate_Overflow
begin
- -- Nothing to do unless we have a comparison operator with operands
- -- that are signed integer types, and we are operating in either
- -- MINIMIZED or ELIMINATED overflow checking mode.
-
- if Nkind (N) not in N_Op_Compare
- or else Check not in Minimized_Or_Eliminated
- or else not Is_Signed_Integer_Type (Etype (Left_Opnd (N)))
- then
- return;
- end if;
-
-- OK, this is the case we are interested in. First step is to process
-- our operands using the Minimize_Eliminate circuitry which applies
-- this processing to the two operand subtrees.
@@ -6425,8 +6411,7 @@ 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 in Minimized_Or_Eliminated
- and then Is_Signed_Integer_Type (Ltyp)
+ if Minimized_Eliminated_Overflow_Check (Left_Opnd (N))
and then not No_Minimize_Eliminate (N)
then
Expand_Membership_Minimize_Eliminate_Overflow (N);
@@ -8343,7 +8328,9 @@ package body Exp_Ch4 is
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
- Expand_Compare_Minimize_Eliminate_Overflow (N);
+ if Minimized_Eliminated_Overflow_Check (Left_Opnd (N)) then
+ Expand_Compare_Minimize_Eliminate_Overflow (N);
+ end if;
if Nkind (N) /= N_Op_Eq then
return;
@@ -9201,7 +9188,9 @@ package body Exp_Ch4 is
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
- Expand_Compare_Minimize_Eliminate_Overflow (N);
+ if Minimized_Eliminated_Overflow_Check (Op1) then
+ Expand_Compare_Minimize_Eliminate_Overflow (N);
+ end if;
if Nkind (N) /= N_Op_Ge then
return;
@@ -9250,7 +9239,9 @@ package body Exp_Ch4 is
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
- Expand_Compare_Minimize_Eliminate_Overflow (N);
+ if Minimized_Eliminated_Overflow_Check (Op1) then
+ Expand_Compare_Minimize_Eliminate_Overflow (N);
+ end if;
if Nkind (N) /= N_Op_Gt then
return;
@@ -9299,7 +9290,9 @@ package body Exp_Ch4 is
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
- Expand_Compare_Minimize_Eliminate_Overflow (N);
+ if Minimized_Eliminated_Overflow_Check (Op1) then
+ Expand_Compare_Minimize_Eliminate_Overflow (N);
+ end if;
if Nkind (N) /= N_Op_Le then
return;
@@ -9348,7 +9341,9 @@ package body Exp_Ch4 is
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
-- means we no longer have a comparison operation, we are all done.
- Expand_Compare_Minimize_Eliminate_Overflow (N);
+ if Minimized_Eliminated_Overflow_Check (Op1) then
+ Expand_Compare_Minimize_Eliminate_Overflow (N);
+ end if;
if Nkind (N) /= N_Op_Lt then
return;
@@ -9942,7 +9937,9 @@ package body Exp_Ch4 is
-- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if
-- means we no longer have a /= operation, we are all done.
- Expand_Compare_Minimize_Eliminate_Overflow (N);
+ if Minimized_Eliminated_Overflow_Check (Left_Opnd (N)) then
+ Expand_Compare_Minimize_Eliminate_Overflow (N);
+ end if;
if Nkind (N) /= N_Op_Ne then
return;
@@ -14114,9 +14111,15 @@ package body Exp_Ch4 is
function Minimized_Eliminated_Overflow_Check (N : Node_Id) return Boolean is
begin
+ -- The MINIMIZED mode operates in Long_Long_Integer so we cannot use it
+ -- if the type of the expression is already larger.
+
return
Is_Signed_Integer_Type (Etype (N))
- and then Overflow_Check_Mode in Minimized_Or_Eliminated;
+ and then Overflow_Check_Mode in Minimized_Or_Eliminated
+ and then not (Overflow_Check_Mode = Minimized
+ and then
+ Esize (Etype (N)) > Standard_Long_Long_Integer_Size);
end Minimized_Eliminated_Overflow_Check;
----------------------------
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2021-04-29 8:03 [Ada] Fix interaction of 128-bit integer types and -gnato2 mode Pierre-Marie de Rodat
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