Re: [PATCH] Fix UB in dse.c (PR rtl-optimization/85431)

On 04/17/2018 02:57 PM, Jakub Jelinek wrote: > Hi! > > As mentioned, for BLKmode stores with MEM_SIZE of 0 we invoke UB, > lowpart_bitmask (0) is called and that shifts an UHWI by 64. > Zero size MEMs should only appear in inline asm and shouldn't be interesting > to DSE at all, they can't make

Re: [PATCH] Fix UB in dse.c (PR rtl-optimization/85431)

> Fixed by just ignoring them. Bootstrapped/regtested on x86_64-linux and > i686-linux, ok for trunk? > > 2018-04-17 Jakub Jelinek > > PR rtl-optimization/85431 > * dse.c (record_store): Ignore zero width stores. OK, thanks. -- Eric Botcazou

[PATCH] Fix UB in dse.c (PR rtl-optimization/85431)

Hi! As mentioned, for BLKmode stores with MEM_SIZE of 0 we invoke UB, lowpart_bitmask (0) is called and that shifts an UHWI by 64. Zero size MEMs should only appear in inline asm and shouldn't be interesting to DSE at all, they can't make other stores dead, nor can be removed as dead themselves.