Re: [Patch, PR 88253, combine] Prevent combine simplification to zero if side_effects_p

Hi! On Fri, Dec 14, 2018 at 09:21:26AM +, senthilkumar.selva...@microchip.com wrote: > This patch fixes PR 88253 by preventing combine_simplify_rtx from > folding an rtx with side_effects_p to const0_rtx. > 2018-12-14 Senthil Kumar Selvaraj > > PR 88253.c > * combine.c (combi

[Patch, PR 88253, combine] Prevent combine simplification to zero if side_effects_p

Hi, This patch fixes PR 88253 by preventing combine_simplify_rtx from folding an rtx with side_effects_p to const0_rtx. Without the patch, combine deletes volatile loads from memory in certain cases. When combine_simplify_rtx is called with op0_mode = E_HImode and rtx like (subreg:QI (ashift:HI