[PATCH] D49310: [llvm-mca][BtVer2] Teach how to identify dependency-breaking idioms.

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

Can you add a comment to the end of the btver sched profile, that `X86MCInstrAnalysis::isDependencyBreaking()`
is also responsible (as in, needs to be modified) in detection of dep-breaking patterns?



================
Comment at: include/llvm/MC/MCInstrAnalysis.h:93
+  ///
+  /// A dependency breaking instruction is know to always compute the same value
+  /// if input register operands are all the same register. An example of
----------------
s/know/known/?


================
Comment at: lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp:317
+                                              const MCInst &Inst) const {
+  if (STI.getCPU() == "btver2") {
+    switch (Inst.getOpcode()) {
----------------
Hmm. Hardcoding.
Are there plans on somehow generalizing this, maybe using sched profiles?


https://reviews.llvm.org/D49310