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Re: Bug in x86-64 psABI or in gcc?
On Wed, Dec 9, 2009 at 7:15 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Wed, Dec 9, 2009 at 7:10 AM, Michael Matz <matz@suse.de> wrote:
>> Hi,
>>
>> On Wed, 9 Dec 2009, H. Peter Anvin wrote:
>>
>>> On 12/09/2009 06:56 AM, Michael Matz wrote:
>>> >>
>>> >> Aren't bits in the _Bool byte of"bar" specified by the psABI
>>> >
>>> > Right now they are specified in the psABI, you suggested to remove that
>>> > specification.
>>> >
>>>
>>> The intent of H.J.'s proposal is to require bits <7:1> == 0 in all cases
>>> (and higher bits as don't cares, the same way a char is passed),
>>
>> Or bits <31:1> . ?But he also repeatedly suggests to remove the whole
>> sentence about the bit clearing. ?That's what I'm opposing. ?I'm not
>> against limiting the bit range that must be zero.
>
> I just want _Bool to have the same specification for parameter pass
> and function return, ideally memory object.
>
>>> opposed to the current text which requires <63:1> == 0 when passed as
>>> registers or on the stack (and <7:1> == 0 when stored in a memory
>>> object.) ?Furthermore, the current psABI text is inconsistent for
>>> arguments are return values; this is a bug in the wordsmithing of the
>>> text rather than intentional, if I remember the original discussions
>>> correctly.
>>
>> Right, I remember the same.
>>
>
> Then fix the psABI.
>
Don't we need to specify passing and returning char, short and int since
they are smaller than the integer class, which is eightbytes?
--
H.J.