[llvm-commits] [llvm] r43120 - in /llvm/trunk: lib/CodeGen/SelectionDAG/LegalizeDAG.cpp test/CodeGen/PowerPC/2007-10-18-PtrArithmetic.ll

[Bill Wendling]

Okay. Fixed. :-)

-bw

On 10/18/07, Chris Lattner <clattner at apple.com> wrote:
>
> On Oct 18, 2007, at 10:58 AM, Bill Wendling wrote:
>
> > On 10/18/07, Chris Lattner <clattner at apple.com> wrote:
> >>
> >> On Oct 18, 2007, at 1:32 AM, Bill Wendling wrote:
> >>
> >>> Author: void
> >>> Date: Thu Oct 18 03:32:37 2007
> >>> New Revision: 43120
> >>>
> >>> URL: http://llvm.org/viewvc/llvm-project?rev=43120&view=rev
> >>> Log:
> >>> Pointer arithmetic should be done with the index the same size as
> >>> the pointer.
> >>
> >> Nice catch Bill.  Should this use sign extend or zero extend if the
> >> value is too small?  It seems like zext would be more appropriate,
> >>
> > There was a similar case before with CFA_OFFSET that I tackled before.
> > I went back and forth with Anton a few times and he came up with
> > essentially the patch you saw there:
> >
> > http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-August/010424.html
> >
> > I was thinking about sign-extend vs. zero-extend afterwards and I
> > think the reason behind the sign-extend is to allow for negative
> > indexes. Does that sound reasonable?
>
> Negative indices aren't allowed in EXTRAACT_VECTOR_ELT.
>
> -Chris
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