When decided whether to generate a post-inc load/store, look at the
other memory nodes that use the same base address and, if any proceed
the current node, then don't do the combine.
The change only seems to be affecting the Arm backend, which I was
surprised at, but it appears to fix a lot of our issues around MVE
masked load/stores having to store a temporary address after an early
post-increment on a shared base address.
Differential Revision: https://reviews.llvm.org/D75847
Check that no Q-regs are live out of the loop, unless the instruction
within the loop is predicated on the vctp.
Differential Revision: https://reviews.llvm.org/D72713
This patch uses helper function rewriteLoopExitValues that is refactored in
D72602 to rematerialise the iteration count in exit blocks, so that we can
clean-up loop update expressions inside the hardware-loops later in
ARMLowOverheadLoops, which is necessary to get actual performance gains for
tail-predicated loops.
Differential Revision: https://reviews.llvm.org/D72714
This adds ICmp to the list of instructions that we sink a splat to in a
loop, allowing the register forms of instructions to be selected more
often. It does not add FCmp yet as the results look a little odd, trying
to keep the register in an float reg and having to move it back to a GPR.
Differential Revision: https://reviews.llvm.org/D70997
Record the discovered VPT blocks while checking for validity and, for
now, only handle blocks that begin with VPST and not VPT. We're now
allowing more than one instruction to define vpr, but each block must
somehow be predicated using the vctp. This leaves us with several
scenarios which need fixing up:
1) A VPT block with is only predicated by the vctp and has no
internal vpr defs.
2) A VPT block which is only predicated by the vctp but has an
internal vpr def.
3) A VPT block which is predicated upon the vctp as well as another
vpr def.
4) A VPT block which is not predicated upon a vctp, but contains it
and all instructions within the block are predicated upon in.
The changes needed are, for:
1) The easy one, just remove the vpst and unpredicate the
instructions in the block.
2) Remove the vpst and unpredicate the instructions up to the
internal vpr def. Need insert a new vpst to predicate the
remaining instructions.
3) No nothing.
4) The vctp will be inside a vpt and the instruction will be removed,
so adjust the size of the mask on the vpst.
Differential Revision: https://reviews.llvm.org/D71107
With the extra optimisations we have done, these should now be fine to
enable by default. Which is what this patch does.
Differential Revision: https://reviews.llvm.org/D70968
MVE has a basic symmetry between it's normal loads/store operations and
the masked variants. This means that masked loads and stores can use
pre-inc and post-inc addressing modes, just like the standard loads and
stores already do.
To enable that, this patch adds all the relevant infrastructure for
treating masked loads/stores addressing modes in the same way as normal
loads/stores.
This involves:
- Adding an AddressingMode to MaskedLoadStoreSDNode, along with an extra
Offset operand that is added after the PtrBase.
- Extending the IndexedModeActions from 8bits to 16bits to store the
legality of masked operations as well as normal ones. This array is
fairly small, so doubling the size still won't make it very large.
Offset masked loads can then be controlled with
setIndexedMaskedLoadAction, similar to standard loads.
- The same methods that combine to indexed loads, such as
CombineToPostIndexedLoadStore, are adjusted to handle masked loads in
the same way.
- The ARM backend is then adjusted to make use of these indexed masked
loads/stores.
- The X86 backend is adjusted to hopefully be no functional changes.
Differential Revision: https://reviews.llvm.org/D70176
The VCTP instruction will calculate the predicate masked based upon
the number of elements that need to be processed. I had inserted the
sub before the vctp intrinsic and supplied it as the operand, but
this is incorrect as the phi should directly feed the vctp. The sub
is calculating the value for the next iteration.
Differential Revision: https://reviews.llvm.org/D67921
llvm-svn: 373188
Remove any predicate that we replace with a vctp intrinsic, and try
to remove their operands too. Also look into the exit block to see if
there's any duplicates of the predicates that we've replaced and
clone the vctp to be used there instead.
Differential Revision: https://reviews.llvm.org/D67709
llvm-svn: 372567
Sam Parker