Section symbols exist as an optimization: instead of having multiple relocations
point to different symbols, many of them can point to a single section symbol.
When that optimization is unused, a section symbol is also unused and adds no
extra information to the object file.
This saves a bit of space on the object files and makes the output of
llvm-objdump -t easier to read and consequently some tests get quite a bit
simpler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239045 91177308-0d34-0410-b5e6-96231b3b80d8
The fix is just that getOther had not been updated for packing the st_other
values in fewer bits and could return spurious values:
- unsigned Other = (getFlags() & (0x3f << ELF_STO_Shift)) >> ELF_STO_Shift;
+ unsigned Other = (getFlags() & (0x7 << ELF_STO_Shift)) >> ELF_STO_Shift;
Original message:
Pack the MCSymbolELF bit fields into MCSymbol's Flags.
This reduces MCSymolfELF from 64 bytes to 56 bytes on x86_64.
While at it, also make getOther/setOther easier to use by accepting unshifted
STO_* values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239012 91177308-0d34-0410-b5e6-96231b3b80d8
This reduces MCSymolfELF from 64 bytes to 56 bytes on x86_64.
While at it, also make getOther/setOther easier to use by accepting unshifted
STO_* values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239006 91177308-0d34-0410-b5e6-96231b3b80d8
This avoids yet another last minute patching of the binding.
While at it, also simplify the weakref implementation a bit by not walking
past it in the expression evaluation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238982 91177308-0d34-0410-b5e6-96231b3b80d8
With this getBinging can now return the correct answer for all cases not
involving a .symver and the elf writer doesn't need to patch it last minute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238980 91177308-0d34-0410-b5e6-96231b3b80d8
_GLOBAL_OFFSET_TABLE_ is not magical and we can now directly check for a
symbol never getting an explicit binding.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238978 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we have a dedicated type for ELF symbol, these helper functions can
become member function of MCSymbolELF.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238864 91177308-0d34-0410-b5e6-96231b3b80d8
This create a MCSymbolELF class and moves SymbolSize since only ELF
needs a size expression.
This reduces the size of MCSymbol from 56 to 48 bytes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238801 91177308-0d34-0410-b5e6-96231b3b80d8
And with that simplify the logic for inserting them in ExternalSymbolData or
LocalSymbolData.
No functionality change overall since the old code avoided the isLocal bug.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238555 91177308-0d34-0410-b5e6-96231b3b80d8
ELF has no restrictions on where undefined symbols go relative to other defined
symbols. In fact, gas just sorts them together. Do the same.
This was there since r111174 probably just because the MachO writer has it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238513 91177308-0d34-0410-b5e6-96231b3b80d8
This was a bug for bug compatibility with gas that is completely unnecessary.
If a _GLOBAL_OFFSET_TABLE_ symbol is used, it will already be created by
the time we get to the ELF writer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238432 91177308-0d34-0410-b5e6-96231b3b80d8
Both MCStreamer and MCObjectStreamer were maintaining a current section
variable and they were slightly out of sync. I don't think this was observable,
but was inefficient and error prone.
Changing this requires a few cascading changes:
* SwitchSection has to call ChangeSection earlier for ChangeSection to see
the old section.
* With that change, ChangeSection cannot call EmitLabel, since during
ChangeSection we are still in the old section.
* When the object streamer requires a begin label, just reused the existing
generic support for begin labels instead of calling EmitLabel directly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238357 91177308-0d34-0410-b5e6-96231b3b80d8
Normally an ELF .o has two string tables, one for symbols, one for section
names.
With the scheme of naming sections like ".text.foo" where foo is a symbol,
there is a big potential saving in using a single one.
Building llvm+clang+lld with master and with this patch the results were:
master: 193,267,008 bytes
patch: 186,107,952 bytes
master non unique section names: 183,260,192 bytes
patch non unique section names: 183,118,632 bytes
So using non usique saves 10,006,816 bytes, and the patch saves 7,159,056 while
still using distinct names for the sections.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238073 91177308-0d34-0410-b5e6-96231b3b80d8
Lift `MCSymbolData::Index` up a level to `MCSymbol`, as preparation for
packing it into the bitfield in `MCSymbol`.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238001 91177308-0d34-0410-b5e6-96231b3b80d8
