tryLatency compares two sched candidates. For the top zone it prefers
the one with lesser depth, but only if that depth is greater than the
total latency of the instructions we've already scheduled -- otherwise
its latency would be hidden and there would be no stall.
Unfortunately it only tests the depth of one of the candidates. This can
lead to situations where the TopDepthReduce heuristic does not kick in,
but a lower priority heuristic chooses the other candidate, whose depth
*is* greater than the already scheduled latency, which causes a stall.
The fix is to apply the heuristic if the depth of *either* candidate is
greater than the already scheduled latency.
All this also applies to the BotHeightReduce heuristic in the bottom
zone.
Differential Revision: https://reviews.llvm.org/D72392
Summary:
When doing the conversion: MachineInst -> MCInst, we should ignore the
implicit operands, it will expose more opportunity for InstiAlias.
Reviewed By: steven.zhang
Differential Revision: https://reviews.llvm.org/D77118
This adds AA to Post-RA Machine Scheduling, allowing the pass more
freedom when handling memory operations.
My understanding is that this was just never done, not that it is
inherently incorrect to do so. The older PostRA List scheduler already
makes use of AA, it's just that the MI PostRA Scheduler was never taught
to use it.
Differential Revision: https://reviews.llvm.org/D69814
If the instruction have match pattern, llvm-tblgen will infer the sideeffect bit from the match pattern and it works well.
If not, the tblgen will set it as true that hurt the scheduling.
PowerPC has some instructions that didn't specify the match pattern(i.e. LXSD etc), which is manually selected post-ra according
to the register pressure. We need to clear the sideeffect flag for these instructions.
Differential Revision: https://reviews.llvm.org/D69232
After implemented this hook, we will model the memory dependency in the scheduling dependency graph more precise,
and will have more opportunity to reorder the load/stores, as they didn't have the dependency at some condition
Differential Revision: https://reviews.llvm.org/D63804
llvm-svn: 364886
NFC commit of a test case in order for the subsequent review to show differences
in codegen.
Differential revision: https://reviews.llvm.org/D62843
llvm-svn: 362573
This patch exploits the instructions that store a single element from a vector
to preform a (store (extract_elt)). We already have code that does this with
ISA 3.0 instructions that were added to handle i8/i16 types. However, we had
never exploited the existing ones that handle f32/f64/i32/i64 types.
Differential revision: https://reviews.llvm.org/D56175
llvm-svn: 352131
An upcoming patch will change the codegen for these patterns. This test case is
added now so that the patch can show the differences in codegen.
llvm-svn: 344112
Jay Foad