Multi-piece values and GDB values

[Jim Blandy]

Jim Blandy <jimb@codesourcery.com> writes:
> There is one special multi-piece case that GDB could support without
> much trouble: variables allocated to consecutive registers (in GDB's
> register numbering).  GDB register lvalues simply refer to the value's
> starting offset in the register cache; if the value's type is larger
> than the register, later bytes simply refer to the next register.
> This accomodated GCC's long-standing treatment of 'long long' values
> described above.  dwarf2_evaluate_loc_desc could recognize this case.
> But this is still not a general solution.

For the record: it's not so that register lvalues use a starting
offset into the register cache.  Hasn't been so for years.  Sorry.
Instead, we use a register number, and an offset from the start of
that register.  But the overall point of the paragraph is still
correct, I think.