The LDS output queue is accessed via the OQAP register. The OQAP
register cannot be live across clauses, so if value is written to the
output queue, it must be retrieved before the end of the clause.
With the machine scheduler, we cannot statisfy this constraint, because
it lacks proper alias analysis and it will mark some LDS accesses as
having a chain dependency on vertex fetches. Since vertex fetches
require a new clauses, the dependency may end up spiltting OQAP uses and
defs so the end up in different clauses. See the lds-output-queue.ll
test for a more detailed explanation.
To work around this issue, we now combine the LDS read and the OQAP
copy into one instruction and expand it after register allocation.
This patch also adds some checks to the EmitClauseMarker pass, so that
it doesn't end a clause with a value still in the output queue and
removes AR.X and OQAP handling from the scheduler (AR.X uses and defs
were already being expanded post-RA, so the scheduler will never see
them).
Reviewed-by: Vincent Lejeune <vljn at ovi.com>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194755 91177308-0d34-0410-b5e6-96231b3b80d8
+==============================================================================+
| How to organize the lit tests |
+==============================================================================+
- If you write a test for matching a single DAG opcode or intrinsic, it should
go in a file called {opcode_name,intrinsic_name}.ll (e.g. fadd.ll)
- If you write a test that matches several DAG opcodes and checks for a single
ISA instruction, then that test should go in a file called {ISA_name}.ll (e.g.
bfi_int.ll
- For all other tests, use your best judgement for organizing tests and naming
the files.
+==============================================================================+
| Naming conventions |
+==============================================================================+
- Use dash '-' and not underscore '_' to separate words in file names, unless
the file is named after a DAG opcode or ISA instruction that has an
underscore '_' in its name.
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