[Bug debug/86406] New: [8/9 Regression][UBSAN] -fcompare-debug failure with -fsanitize=undefined

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86406

            Bug ID: 86406
           Summary: [8/9 Regression][UBSAN] -fcompare-debug failure with
                    -fsanitize=undefined
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org
  Target Milestone: ---

Created attachment 44352
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=44352&action=edit
Test case, compile with: g++ -S -fcompare-debug -fsanitize=undefined -g -O1
input.ii

Using today's trunk build and today's GCC 8 branch build:

~/gcc/gcc-8/bin/g++ -S -fcompare-debug -fsanitize=undefined -g -O1 input15b.ii
g++: error: input15b.ii: -fcompare-debug failure