The result must be the Small instead of the Tiny in this case.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* libgnat/s-fatgen.adb: Add use clause for Interfaces.Unsigned_16
and Interfaces.Unsigned_32.
(Small16): New constant.
(Small32): Likewise.
(Small64): Likewise.
(Small80): Likewise.
(Pred): Declare a local overlay for Small and return it negated
for zero if the type does not support denormalized numbers.
(Succ): Likewise, but return it directly.diff --git a/gcc/ada/libgnat/s-fatgen.adb b/gcc/ada/libgnat/s-fatgen.adb
--- a/gcc/ada/libgnat/s-fatgen.adb
+++ b/gcc/ada/libgnat/s-fatgen.adb
@@ -42,6 +42,8 @@ pragma Warnings (Off, "non-static constant in preelaborated unit");
-- Every constant is static given our instantiation model
package body System.Fat_Gen is
+ use type Interfaces.Unsigned_16;
+ use type Interfaces.Unsigned_32;
use type Interfaces.Unsigned_64;
pragma Assert (T'Machine_Radix = 2);
@@ -59,6 +61,18 @@ package body System.Fat_Gen is
-- Small : constant T := Rad ** (T'Machine_Emin - 1);
-- Smallest positive normalized number
+ Small16 : constant Interfaces.Unsigned_16 := 2**(Mantissa - 1);
+ Small32 : constant Interfaces.Unsigned_32 := 2**(Mantissa - 1);
+ Small64 : constant Interfaces.Unsigned_64 := 2**(Mantissa - 1);
+ Small80 : constant array (1 .. 2) of Interfaces.Unsigned_64 :=
+ (2**48 * (1 - Standard'Default_Bit_Order),
+ 1 * Standard'Default_Bit_Order);
+ for Small80'Alignment use Standard'Maximum_Alignment;
+ -- We cannot use the direct declaration because it cannot be translated
+ -- into C90, as the hexadecimal floating constants were introduced in C99.
+ -- So we work around this by using an overlay of the integer constant.
+ -- ??? Revisit this when the new CCG technoloy is in production
+
-- Tiny : constant T := Rad ** (T'Machine_Emin - Mantissa);
-- Smallest positive denormalized number
@@ -72,6 +86,7 @@ package body System.Fat_Gen is
-- We cannot use the direct declaration because it cannot be translated
-- into C90, as the hexadecimal floating constants were introduced in C99.
-- So we work around this by using an overlay of the integer constant.
+ -- ??? Revisit this when the new CCG technoloy is in production
RM1 : constant T := Rad ** (Mantissa - 1);
-- Smallest positive member of the large consecutive integers. It is equal
@@ -424,6 +439,13 @@ package body System.Fat_Gen is
----------
function Pred (X : T) return T is
+ Small : constant T;
+ pragma Import (Ada, Small);
+ for Small'Address use (if T'Size = 16 then Small16'Address
+ elsif T'Size = 32 then Small32'Address
+ elsif T'Size = 64 then Small64'Address
+ elsif Mantissa = 64 then Small80'Address
+ else raise Program_Error);
Tiny : constant T;
pragma Import (Ada, Tiny);
for Tiny'Address use (if T'Size = 16 then Tiny16'Address
@@ -438,7 +460,7 @@ package body System.Fat_Gen is
-- Zero has to be treated specially, since its exponent is zero
if X = 0.0 then
- return -Tiny;
+ return -(if T'Denorm then Tiny else Small);
-- Special treatment for largest negative number: raise Constraint_Error
@@ -700,6 +722,13 @@ package body System.Fat_Gen is
----------
function Succ (X : T) return T is
+ Small : constant T;
+ pragma Import (Ada, Small);
+ for Small'Address use (if T'Size = 16 then Small16'Address
+ elsif T'Size = 32 then Small32'Address
+ elsif T'Size = 64 then Small64'Address
+ elsif Mantissa = 64 then Small80'Address
+ else raise Program_Error);
Tiny : constant T;
pragma Import (Ada, Tiny);
for Tiny'Address use (if T'Size = 16 then Tiny16'Address
@@ -714,7 +743,7 @@ package body System.Fat_Gen is
-- Treat zero specially since it has a zero exponent
if X = 0.0 then
- return Tiny;
+ return (if T'Denorm then Tiny else Small);
-- Special treatment for largest positive number: raise Constraint_Error
