[AsmPrinter] Remove hidden flag -print-schedule.

This patch removes hidden codegen flag -print-schedule effectively reverting the
logic originally committed as r300311
(https://llvm.org/viewvc/llvm-project?view=revision&revision=300311).

Flag -print-schedule was originally introduced by r300311 to address PR32216
(https://bugs.llvm.org/show_bug.cgi?id=32216). That bug was about adding "Better
testing of schedule model instruction latencies/throughputs".

These days, we can use llvm-mca to test scheduling models. So there is no longer
a need for flag -print-schedule in LLVM. The main use case for PR32216 is
now addressed by llvm-mca.
Flag -print-schedule is mainly used for debugging purposes, and it is only
actually used by x86 specific tests. We already have extensive (latency and
throughput) tests under "test/tools/llvm-mca" for X86 processor models. That
means, most (if not all) existing -print-schedule tests for X86 are redundant.

When flag -print-schedule was first added to LLVM, several files had to be
modified; a few APIs gained new arguments (see for example method
MCAsmStreamer::EmitInstruction), and MCSubtargetInfo/TargetSubtargetInfo gained
a couple of getSchedInfoStr() methods.

Method getSchedInfoStr() had to originally work for both MCInst and
MachineInstr. The original implmentation of getSchedInfoStr() introduced a
subtle layering violation (reported as PR37160 and then fixed/worked-around by
r330615).
In retrospect, that new API could have been designed more optimally. We can
always query MCSchedModel to get the latency and throughput. More importantly,
the "sched-info" string should not have been generated by the subtarget.
Note, r317782 fixed an issue where "print-schedule" didn't work very well in the
presence of inline assembly. That commit is also reverted by this change.

Differential Revision: https://reviews.llvm.org/D57244


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353043 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 0 insertions, 10 deletions

diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index 4297450546a..fb12bb26b3e 100644
--- a/include/llvm/CodeGen/AsmPrinter.h
+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -121,9 +121,6 @@ public:
   using GOTEquivUsePair = std::pair<const GlobalVariable *, unsigned>;
   MapVector<const MCSymbol *, GOTEquivUsePair> GlobalGOTEquivs;
 
-  /// Enable print [latency:throughput] in output.
-  bool EnablePrintSchedInfo = false;
-
 private:
   MCSymbol *CurrentFnBegin = nullptr;
   MCSymbol *CurrentFnEnd = nullptr;
diff --git a/include/llvm/CodeGen/TargetSubtargetInfo.h b/include/llvm/CodeGen/TargetSubtargetInfo.h
index b206cf4e895..bf0e9b20833 100644
--- a/include/llvm/CodeGen/TargetSubtargetInfo.h
+++ b/include/llvm/CodeGen/TargetSubtargetInfo.h
@@ -189,9 +189,6 @@ public:
   /// TargetLowering preference). It does not yet disable the postRA scheduler.
   virtual bool enableMachineScheduler() const;
 
-  /// Support printing of [latency:throughput] comment in output .S file.
-  virtual bool supportPrintSchedInfo() const { return false; }
-
   /// True if the machine scheduler should disable the TLI preference
   /// for preRA scheduling with the source level scheduler.
   virtual bool enableMachineSchedDefaultSched() const { return true; }
@@ -285,10 +282,6 @@ public:
   /// possible.
   virtual bool enableSubRegLiveness() const { return false; }
 
-  /// Returns string representation of scheduler comment
-  std::string getSchedInfoStr(const MachineInstr &MI) const;
-  std::string getSchedInfoStr(MCInst const &MCI) const override;
-
   /// This is called after a .mir file was loaded.
   virtual void mirFileLoaded(MachineFunction &MF) const;
 };