Re: [PATCH] Fix CSE CLZ/CTZ handling (PR rtl-optimization/85376, variant)

2018-04-13 Thread Richard Biener
On April 13, 2018 9:33:31 PM GMT+02:00, Eric Botcazou wrote: >> 2018-04-13 Jakub Jelinek >> >> PR rtl-optimization/85376 >> * simplify-rtx.c (simplify_const_unary_operation): For CLZ and CTZ >and >> zero op0, if

[PATCH] Fix CSE CLZ/CTZ handling (PR rtl-optimization/85376, variant)

2018-04-13 Thread Jakub Jelinek
On Fri, Apr 13, 2018 at 12:33:02AM +0200, Jakub Jelinek wrote: > The following patch let us punt in these cases. Bootstrapped/regtested on > x86_64-linux and i686-linux, ok for trunk? > > Another option would be to tweak simplify-rtx.c and instead of doing > else if (!

Re: [PATCH] Fix CSE CLZ/CTZ handling (PR rtl-optimization/85376, variant)

2018-04-13 Thread Eric Botcazou
> 2018-04-13 Jakub Jelinek > > PR rtl-optimization/85376 > * simplify-rtx.c (simplify_const_unary_operation): For CLZ and CTZ and > zero op0, if C?Z_DEFINED_VALUE_AT_ZERO is false, return NULL_RTX > instead of a specific value. > > *