Some files still contained the old University of Illinois Open Source
Licence header. This patch replaces that with the Apache 2 with LLVM
Exception licence.
Differential Revision: https://reviews.llvm.org/D107528
A linker optimization is available on PowerPC for GOT indirect PCRelative loads.
The idea is that we can mark a usual GOT indirect load:
pld 3, vec@got@pcrel(0), 1
lwa 3, 4(3)
With a relocation to say that if we don't need to go through the GOT we can let
the linker further optimize this and replace a load with a nop.
pld 3, vec@got@pcrel(0), 1
.Lpcrel1:
.reloc .Lpcrel1-8,R_PPC64_PCREL_OPT,.-(.Lpcrel1-8)
lwa 3, 4(3)
This patch adds the logic that allows the compiler to add the R_PPC64_PCREL_OPT.
Reviewers: nemanjai, lei, hfinkel, sfertile, efriedma, tstellar, grosbach
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D79864
A known limitation for Future CPU is that the new prefixed instructions may
not cross 64 Byte boundaries.
All instructions are already 4 byte aligned so the only situation where this
can occur is when the prefix is in one 64 byte block and the instruction that
is prefixed is at the top of the next 64 byte block. To fix this case
PPCELFStreamer was added to intercept EmitInstruction. When a prefixed
instruction is emitted we try to align it to 64 Bytes by adding a maximum of
4 bytes. If the prefixed instruction crosses the 64 Byte boundary then the
alignment would trigger and a 4 byte nop would be added to push the
instruction into the next 64 byte block.
Differential Revision: https://reviews.llvm.org/D72570
Christopher Di Bella