On Thu, 2005-10-06 at 16:24, hjl at lucon dot org wrote: > -000000000000 00010000004d R_IA64_PCREL32LSB 0000000000000000 .text + 2 > +000000000000 00010000004d R_IA64_PCREL32LSB 0000000000000000 .text + 1
This seems to be an old debate reborn. When we have relocs, tags, debug info, whatever that applies to a long (2-slot) instruction, do we point at slot 1 or slot 2? old-as is pointing at slot 2. new-as is pointing at slot 1. One could argue that new-as is actually more correct in this case, because the tag should be pointing before the long instruction, and hence must be pointing at slot 1. Richard's patch broke this because he moved the tag_fixups code in emit_one_bundle before the code that increments i when required_unit == IA64_UNIT_L. So in the old code, we are setting debug info and unwind info to point to slot 1 (before we increment i), and tags and relocs to point to slot 2 (after we increment i). In the new code, we are setting debug info, unwind info, and tags to point to slot 1 (before we increment i), and relocs to point to slot 2 (after we increment i). At least we are consistently inconsistent. Questions to ask at this point are: 1) Why did Richard move the code? Did he run into some problem with the debug info not matching the tags? 2) Why does the kernel care whether we use slot 1 or slot 2 here? Maybe the kernel can be fixed? It seems wrong for the kernel to insist that a tag must point into the middle of a long instruction. 3) Will this change affect gdb? 4) What does IAS do in this case? 5) Maybe we should fix relocs to point at slot 1 and then be completely consistent? This is an ABI change unfortunately, though perhaps we can hide it by making the linker accept either one for a while. -- Jim Wilson, GNU Tools Support, http://www.specifix.com _______________________________________________ bug-binutils mailing list bug-binutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-binutils
