Re: extendqihi2 and GCC RTL type system

2016-02-22 Thread David Edelsohn
Hi, Jim On Mon, Feb 22, 2016 at 12:53 PM, Jim Wilson wrote: > On Mon, Feb 22, 2016 at 7:55 AM, David Edelsohn wrote: >> If I remove extendqihi2 (extend:HI pattern) from the PowerPC port, >> will that cause any problems for the GCC RTL type system or inhibit >> optimizations? I see that Alpha a

Re: extendqihi2 and GCC RTL type system

2016-02-22 Thread Jim Wilson
On Mon, Feb 22, 2016 at 7:55 AM, David Edelsohn wrote: > If I remove extendqihi2 (extend:HI pattern) from the PowerPC port, > will that cause any problems for the GCC RTL type system or inhibit > optimizations? I see that Alpha and SPARC define extendqihi2, but > IA-64 and AArch64 do not, so the

Re: extendqihi2 and GCC RTL type system

2016-02-22 Thread Jeff Law
On 02/22/2016 08:55 AM, David Edelsohn wrote: csmith has uncovered a latent bug in the the PowerPC port for a combiner pattern involving extendqihi2 (the alternative in the pattern has never triggered for real code in over 10 years). Basic extendqihi2 works correctly (the instructions extend to e

extendqihi2 and GCC RTL type system

2016-02-22 Thread David Edelsohn
csmith has uncovered a latent bug in the the PowerPC port for a combiner pattern involving extendqihi2 (the alternative in the pattern has never triggered for real code in over 10 years). Basic extendqihi2 works correctly (the instructions extend to entire register, but the upper bits are ignored).