3 Commits

Author SHA1 Message Date
Qiu Chaofan
b922a36211 [PowerPC] Define SchedModel for Power8
PowerPC subtargets prior to Power9 use the 'legacy' itinerary way to
provide scheduling information. This patch re-writes the tablegen file
to define the scheduling information in the new SchedModel way, which
can bring improvements to some benchmarks.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D154488
2023-09-08 15:43:21 +08:00
Kai Luo
f6515b0520 [PowerPC] Do not fold cmp(d|w) and subf instruction to subf. if nsw is not present
In `PPCInstrInfo::optimizeCompareInstr` we seek opportunities to fold `cmp(d|w)` and `subf` as an `subf.`. However, if `subf.` gets overflow, `cr0` can't reflect the correct order, violating the semantics of `cmp(d|w)`.

Fixed https://bugs.llvm.org/show_bug.cgi?id=47830.

Reviewed By: #powerpc, nemanjai

Differential Revision: https://reviews.llvm.org/D90156
2021-01-04 07:54:15 +00:00
Kai Luo
82150dae86 [PowerPC] Add test case for pr47830. NFC. 2020-10-26 09:11:33 +00:00