Displaying 5 results from an estimated 5 matches for "expandshiftbyconstant".
2009 Dec 01
2
[LLVMdev] Possible bug in ExpandShiftWithUnknownAmountBit
Duncan,
It seems that the code you pasted came from the function
ExpandShiftByConstant and indeed it looks correct. In my example I used 6
as the shift amount but forgot to mention that it's stored in a register.
Otherwise ExpandShiftWithUnknownAmountBit wouldn't get called. Below is the
execution of DAGTypeLegalizer::ExpandIntRes_Shift() using my example
showing how ExpandSh...
2009 Dec 01
0
[LLVMdev] Possible bug in ExpandShiftWithUnknownAmountBit
Hi Javier,
> It seems that the code you pasted came from the function
> ExpandShiftByConstant and indeed it looks correct. In my example I used 6
> as the shift amount but forgot to mention that it's stored in a register.
I see, sorry I didn't read your email more carefully. It does look like
ExpandShiftWithUnknownAmountBit is bogus - at a glance it looks like the
Cmp condition...
2009 Dec 03
2
[LLVMdev] Possible bug in ExpandShiftWithUnknownAmountBit
Hi Duncan,
Just wondering if you had a chance to look at the expansion.
Thanks,
Javier
On Tue, 01 Dec 2009 20:20:14 +0100, Duncan Sands <baldrick at free.fr> wrote:
> Hi Javier,
>
>> It seems that the code you pasted came from the function
>> ExpandShiftByConstant and indeed it looks correct. In my example I used
6
>> as the shift amount but forgot to mention that it's stored in a
register.
>
> I see, sorry I didn't read your email more carefully. It does look like
> ExpandShiftWithUnknownAmountBit is bogus - at a glance it looks lik...
2009 Dec 01
0
[LLVMdev] Possible bug in ExpandShiftWithUnknownAmountBit
Hi Javier,
> The problem is the implementation of the expansion. Perhaps an example
> can help illustrate better. Take the case of a 64-bit integer shifted
> left by say 6 bits and is decomposed using 32-bit registers. Because 6
> is less than the 32 (the register size) the resulting low part should be
> equal to the source low part shifted left by 6 bits. The current
>
2009 Dec 01
2
[LLVMdev] Possible bug in ExpandShiftWithUnknownAmountBit
Hi Duncan,
The problem is the implementation of the expansion. Perhaps an example
can help illustrate better. Take the case of a 64-bit integer shifted
left by say 6 bits and is decomposed using 32-bit registers. Because 6
is less than the 32 (the register size) the resulting low part should be
equal to the source low part shifted left by 6 bits. The current
implementation places a zero