Re: [PATCH] Fix __mulv[dt]i3 and expand_mul_overflow (PR target/82274)

On Fri, Sep 22, 2017 at 6:03 AM, Jakub Jelinek wrote: > > 2017-09-22 Jakub Jelinek > > PR target/82274 > * internal-fn.c (expand_mul_overflow): If both operands have > the same highpart of -1 or 0 and the topmost bit of lowpart >

[PATCH] Fix __mulv[dt]i3 and expand_mul_overflow (PR target/82274)

Hi! An overflow isn't detected on multiplication of signed integer with all ones in the upper half of bits and all zeros in the lower half by itself, either with -ftrapv, or __builtin_mul_overflow{,_p}, or signed-integer-overflow sanitization. For libgcc, we have various cases we handle earlier