bsdjhb added a comment.
Hmmm, so I was somewhat mistaken as DwarfInstructions.hpp::stepWithDwarf() does
use the Register class's setFloatRegister(), however, it assumes that the
floating point register is always a double
(DwarfInstructions.hpp::getSavedFloatRegister() uses AddressSpace::getDouble()
to read a double from memory). So I think that means that the NEWABI cases
work as-is. O32 with 64-bit FP registers should also work as-is. However, O32
with 32-bit FP registers will not quite work. The DWARF info for O32 with
32-bit registers does save/restore individual 32-bit registers:
000006dc 00000034 000006e0 FDE cie=00000000 pc=0000d384..0000d46c
DW_CFA_advance_loc4: 16 to 0000d394
DW_CFA_def_cfa_offset: 56
DW_CFA_advance_loc4: 20 to 0000d3a8
DW_CFA_offset: r31 at cfa-12
DW_CFA_offset: r17 at cfa-16
DW_CFA_offset: r16 at cfa-20
DW_CFA_offset: r52 at cfa-4
DW_CFA_offset: r53 at cfa-8
...
If the compiler happens to always save and restore them in pairs then the
current approach will work. If we don't want to assume that they are saved and
restored in pairs, then we could instead perhaps claim that 32-bit FP registers
aren't really floating point but are just plain 32-bit registers. This would
make unwinding work (I believe), but would mean that one would need to use
unw_get_reg() instead of unw_get_fpreg() to fetch individual 32-bit FP
registers.
https://reviews.llvm.org/D41968
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
