On 03/08/2016 11:49 AM, Richard Henderson wrote:
On 03/07/2016 02:49 PM, Jeff Law wrote:
On 03/07/2016 03:44 AM, Kyrill Tkachov wrote:
The RTL documentation for ASHIFT and friends says that the shift amount
must be:
"a fixed-point mode or be a constant with mode @code{VOIDmode}; which
mode is determined by the mode called for in the machine description
entry for the left-shift instruction". For example, on the VAX, the mode
of @var{c} is @code{QImode} regardless of @var{m}.
Use QImode in the named pattern/expander and use the other modes in an
unnamed/anonymous pattern.
I thought the same thing you did. But I tried it out on the aarch64
port and it didn't work. Combine kept coming back to the QImode pattern.
I didn't want to look into it any farther than that, lest I fall down a
rabbit hole, but there's more to it than just tweaking the patterns.
Strange. Probably worth some investigating for gcc-7.
jeff
