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Re: PATCH: PR target/35657: TDmode isn't aligned at 128bit when passing to a function


On Thu, Mar 27, 2008 at 2:33 PM, H.J. Lu <hjl.tools@gmail.com> wrote:

>  Decimal floating point isn't covered by the ia32 psABI. Gcc is the
>  first compiler
>  which implements DFP on ia32 and is defining the de facto DFP psABI. I don't
>  see a reason not to align them to their natural boundary when passing them
>  on stack. I'd like to install it on trunk and 4.3.1.

I assume that DFP passing will be specified in the next revision of psABI.

The patch is OK for mainline, but please revert runtime part of my
previous patch [1][2] that forced unaligned moves when TDmode (TImode)
values were moved to/from the stack. There is no need for this
functionality, once TDmode values are aligned to their natural
boundaries.

Also, please re-test your change (with my patch reverted) with
"--with-arch=core2" configured compiler, to check if problems [3]
resurfaced.

Regarding 4.3.1 support - since this is an ABI change w.r.t released
compiler, RMs should have their last word. IMO, at least a notice in
release notes is needed

Thanks,
Uros.

[1] http://gcc.gnu.org/ml/gcc-patches/2007-05/msg01716.html
[2] http://gcc.gnu.org/ml/gcc-patches/2007-05/msg01863.html
[3] http://gcc.gnu.org/ml/gcc-testresults/2007-05/msg01171.html


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