[Bug target/100216] arm: UB in arm_canonicalize_comparison (shift exponent 127 is too large for 64-bit type)

2021-04-23 Thread rearnsha at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100216

Richard Earnshaw  changed:

   What|Removed |Added

 Ever confirmed|0   |1
   Last reconfirmed||2021-04-23
 Status|UNCONFIRMED |NEW

--- Comment #2 from Richard Earnshaw  ---
Confirmed by visual inspection.  Clearly this code was written at a time when
the largest integral mode on Arm was DImode.  It won't work for wider modes and
it won't do anything for non-integral modes.

Needs an overhaul.

[Bug target/100216] arm: UB in arm_canonicalize_comparison (shift exponent 127 is too large for 64-bit type)

2021-04-22 Thread acoplan at gcc dot gnu.org via Gcc-bugs 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100216

--- Comment #1 from Alex Coplan  ---
GCC built with UBSan here, to be clear.