[Bug debug/49676] inefficiency: DW_AT_GNU_call_site_value calculates everything << 32

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49676

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-08 15:31:38 UTC ---
Created attachment 24716
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24716
gcc47-pr49676.patch

Attached patch saves those 2 bytes.

To answer the general question, for < DWARF2_ADDR_SIZE size types entry_value
is just untyped, and assuming whether it is signed or unsigned is error-prone,
especially if it is in another CU where we can't check it.
In some ABIs the registers in which stuff is passed are sign-extended or
zero-extended, on other ABIs they may contain garbage in the upper bits, in
other ABIs it is a mess (e.g. x86_64 unfortunately).