The recently announced IBM z15 processor implements the architecture
already supported as "arch13" in LLVM. This patch adds support for
"z15" as an alternate architecture name for arch13.
The patch also uses z15 in a number of places where we used arch13
as long as the official name was not yet announced.
llvm-svn: 372435
This patch series adds support for the next-generation arch13
CPU architecture to the SystemZ backend.
This includes:
- Basic support for the new processor and its features.
- Assembler/disassembler support for new instructions.
- CodeGen for new instructions, including new LLVM intrinsics.
- Scheduler description for the new processor.
- Detection of arch13 as host processor.
Note: No currently available Z system supports the arch13
architecture. Once new systems become available, the
official system name will be added as supported -march name.
llvm-svn: 365932
This patch moves formation of LOC-type instructions from (late)
IfConversion to the early if-conversion pass, and in some cases
additionally creates them directly from select instructions
during DAG instruction selection.
To make early if-conversion work, the patch implements the
canInsertSelect / insertSelect callbacks. It also implements
the commuteInstructionImpl and FoldImmediate callbacks to
enable generation of the full range of LOC instructions.
Finally, the patch adds support for all instructions of the
load-store-on-condition-2 facility, which allows using LOC
instructions also for high registers.
Due to the use of the GRX32 register class to enable high registers,
we now also have to handle the cases where there are still no single
hardware instructions (conditional move from a low register to a high
register or vice versa). These are converted back to a branch sequence
after register allocation. Since the expandRAPseudos callback is not
allowed to create new basic blocks, this requires a simple new pass,
modelled after the ARM/AArch64 ExpandPseudos pass.
Overall, this patch causes significantly more LOC-type instructions
to be used, and results in a measurable performance improvement.
llvm-svn: 288028
System z branches have a mask to select which of the 4 CC values should
cause the branch to be taken. We can invert a branch by inverting the mask.
However, not all instructions can produce all 4 CC values, so inverting
the branch like this can lead to some oddities. For example, integer
comparisons only produce a CC of 0 (equal), 1 (less) or 2 (greater).
If an integer EQ is reversed to NE before instruction selection,
the branch will test for 1 or 2. If instead the branch is reversed
after instruction selection (by inverting the mask), it will test for
1, 2 or 3. Both are correct, but the second isn't really canonical.
This patch therefore keeps track of which CC values are possible
and uses this when inverting a mask.
Although this is mostly cosmestic, it fixes undefined behavior
for the CIJNLH in branch-08.ll. Another fix would have been
to mask out bit 0 when generating the fused compare and branch,
but the point of this patch is that we shouldn't need to do that
in the first place.
The patch also makes it easier to reuse CC results from other instructions.
llvm-svn: 187495
Ulrich Weigand