Wrong warnings when -fgcse is active

[Jeffrey A Law]

  In message < 199807031433.QAA05423@achibm5.chemie.uni-karlsruhe.de >you write:
  > val and variant are initialized at the point of declaration, they
  > can't possibly be used uninitialized. And if gcse changes that somehow
  > then it is broken.
Not necessarily.

First you have to realize that the compiler can't determine with 100%
reliability when something is initialized or not.  So, if it can not
provide a variable is initialized, then it will assume that it is
uninitialized.


GCSE moves things around in the flowgraph in such a way that it can make
it appear like a variable is uninitialized to the rather simplistic
warning code.  This is not a bug in gcse, but a failing in the code
to find uninitialized variables.


jeff