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| author | charlet <charlet@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-06-19 10:59:04 +0000 |
|---|---|---|
| committer | charlet <charlet@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-06-19 10:59:04 +0000 |
| commit | 341bd953dd179dacec3648ffc315c01ae8f6be39 (patch) | |
| tree | 007f417d2cffc875792dc7dd354090911831687c /gcc/ada/a-nudira.adb | |
| parent | d4b026c15fdd0957de6d579ec01628981ade8fdd (diff) | |
| download | gcc-341bd953dd179dacec3648ffc315c01ae8f6be39.tar.gz | |
2009-06-19 Eric Botcazou <ebotcazou@adacore.com>
* einfo.ads (Handling of Type'Size Values): Fix Object_Size values.
2009-06-19 Robert Dewar <dewar@adacore.com>
* a-nudira.adb (Need_64): Handle negative ranges and also dynamic
ranges
* checks.adb (Determine_Range): Move the test for generic types later.
* sem_eval.adb (Compile_Time_Compare): Improve circuitry to catch more
cases.
(Eval_Relational_Op): Fold more cases including string compares
* sem_util.ads, sem_util.adb (References_Generic_Formal_Type): New
function.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@148697 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/ada/a-nudira.adb')
| -rw-r--r-- | gcc/ada/a-nudira.adb | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/gcc/ada/a-nudira.adb b/gcc/ada/a-nudira.adb index 087ce56ea08..3a8819b6aaa 100644 --- a/gcc/ada/a-nudira.adb +++ b/gcc/ada/a-nudira.adb @@ -51,11 +51,24 @@ package body Ada.Numerics.Discrete_Random is type Pointer is access all State; - Need_64 : constant Boolean := Rst'Pos (Rst'Last) > Int'Last; + Need_64 : constant Boolean := Rst'Pos (Rst'Last) > 2**31 - 1 + or else + Rst'Pos (Rst'First) < 2**31; -- Set if we need more than 32 bits in the result. In practice we will -- only use the meaningful 48 bits of any 64 bit number generated, since -- if more than 48 bits are required, we split the computation into two -- separate parts, since the algorithm does not behave above 48 bits. + -- + -- Note: the right hand side used to be Int'Last, but that won't work + -- since it means that if Rst is a dynamic subtype, the comparison is + -- evaluated at run time in type Int, which is too small. In practice + -- the use of dynamic bounds is rare, and this constant will always + -- be evaluated at compile time in an instance. + -- + -- This still is not quite right for dynamic subtypes of 64-bit modular + -- types where the upper bound can exceed the upper bound of universal + -- integer. Not clear how to do this with a nice static expression ??? + -- Might have to introduce a special Type'First_In_32_Bits attribute! ----------------------- -- Local Subprograms -- |