Re: [PATCH] combine: Fix up simplify_shift_const_1 for nested ROTATEs [PR97386]

2020-10-13 Thread Segher Boessenkool
On Tue, Oct 13, 2020 at 07:03:15PM +0200, Jakub Jelinek wrote: > On Tue, Oct 13, 2020 at 11:47:10AM -0500, Segher Boessenkool wrote: > > On Tue, Oct 13, 2020 at 09:44:25AM +0200, Jakub Jelinek wrote: > > > The following testcases are miscompiled (the first one since my > > > improvements > > > to

Re: [PATCH] combine: Fix up simplify_shift_const_1 for nested ROTATEs [PR97386]

2020-10-13 Thread Jakub Jelinek via Gcc-patches
On Tue, Oct 13, 2020 at 11:47:10AM -0500, Segher Boessenkool wrote: > On Tue, Oct 13, 2020 at 09:44:25AM +0200, Jakub Jelinek wrote: > > The following testcases are miscompiled (the first one since my improvements > > to rotate discovery on GIMPLE, the other one for many years) because > > combiner

Re: [PATCH] combine: Fix up simplify_shift_const_1 for nested ROTATEs [PR97386]

2020-10-13 Thread Segher Boessenkool
Hi! On Tue, Oct 13, 2020 at 09:44:25AM +0200, Jakub Jelinek wrote: > The following testcases are miscompiled (the first one since my improvements > to rotate discovery on GIMPLE, the other one for many years) because > combiner optimizes nested ROTATEs with narrowing SUBREG in between (i.e. > the

[PATCH] combine: Fix up simplify_shift_const_1 for nested ROTATEs [PR97386]

2020-10-13 Thread Jakub Jelinek via Gcc-patches
Hi! The following testcases are miscompiled (the first one since my improvements to rotate discovery on GIMPLE, the other one for many years) because combiner optimizes nested ROTATEs with narrowing SUBREG in between (i.e. the outer rotate is performed in shorter precision than the inner one) to j