On Jan 3, 2017, Jeff Law <l...@redhat.com> wrote: > What if REGNO is 2147483648 (assume 32 bit host). That will get us > into the else block in df_ref_record as it's >= FIRST_PSEUDO_REGISTER.
> In df_ref_create_structure, we use the same expression to compute > REGNO, but this time it's interpreted as a signed integer, so > -2147483648. That gets us into the path where we call > TEST_HARD_REG_BIT and thus the oob array index. > Right? Yup, that's exactly how VRP goes about in concluding that there is something to warn about. If we get a pseudo count overflow, I guess we'll have bigger problems than this one, but VRP doesn't know it ;-) -- Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/ You must be the change you wish to see in the world. -- Gandhi Be Free! -- http://FSFLA.org/ FSF Latin America board member Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer
