[Bug tree-optimization/71016] [6/7 Regression] Redundant sign extension with conditional __builtin_clzl

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71016

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |jakub at gcc dot gnu.org

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So shall factor_out_conditional_conversion just check for cases like these and
not try to "optimize" those?  In particular, casts of int returning unary
builtin
to an integer with the precision of the unary builtin's argument.
Affected builtins
  CASE_CFN_CLZ:
  CASE_CFN_CTZ:
  CASE_CFN_CLRSB:
  CASE_CFN_FFS:
  CASE_CFN_PARITY:
  CASE_CFN_POPCOUNT:
are of this kind, perhaps only if there is corresponding optab and thus it is
likely that it might help.