[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

llvm-svn: 353043

1 files changed, 6 insertions, 24 deletions

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index b18c82309ac..f5e40f5c604 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -107,10 +107,7 @@ public:
   void AddComment(const Twine &T, bool EOL = true) override;
 
   /// Add a comment showing the encoding of an instruction.
-  /// If PrintSchedInfo is true, then the comment sched:[x:y] will be added to
-  /// the output if supported by the target.
-  void AddEncodingComment(const MCInst &Inst, const MCSubtargetInfo &,
-                          bool PrintSchedInfo);
+  void AddEncodingComment(const MCInst &Inst, const MCSubtargetInfo &);
 
   /// Return a raw_ostream that comments can be written to.
   /// Unlike AddComment, you are required to terminate comments with \n if you
@@ -311,8 +308,7 @@ public:
   void emitCGProfileEntry(const MCSymbolRefExpr *From,
                           const MCSymbolRefExpr *To, uint64_t Count) override;
 
-  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
-                       bool PrintSchedInfo) override;
+  void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI) override;
 
   void EmitBundleAlignMode(unsigned AlignPow2) override;
   void EmitBundleLock(bool AlignToEnd) override;
@@ -1739,8 +1735,7 @@ void MCAsmStreamer::emitCGProfileEntry(const MCSymbolRefExpr *From,
 }
 
 void MCAsmStreamer::AddEncodingComment(const MCInst &Inst,
-                                       const MCSubtargetInfo &STI,
-                                       bool PrintSchedInfo) {
+                                       const MCSubtargetInfo &STI) {
   raw_ostream &OS = GetCommentOS();
   SmallString<256> Code;
   SmallVector<MCFixup, 4> Fixups;
@@ -1819,11 +1814,7 @@ void MCAsmStreamer::AddEncodingComment(const MCInst &Inst,
       }
     }
   }
-  OS << "]";
-  // If we are not going to add fixup or schedule comments after this point
-  // then we have to end the current comment line with "\n".
-  if (Fixups.size() || !PrintSchedInfo)
-    OS << "\n";
+  OS << "]\n";
 
   for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
     MCFixup &F = Fixups[i];
@@ -1835,18 +1826,15 @@ void MCAsmStreamer::AddEncodingComment(const MCInst &Inst,
 }
 
 void MCAsmStreamer::EmitInstruction(const MCInst &Inst,
-                                    const MCSubtargetInfo &STI,
-                                    bool PrintSchedInfo) {
+                                    const MCSubtargetInfo &STI) {
   assert(getCurrentSectionOnly() &&
          "Cannot emit contents before setting section!");
 
   // Show the encoding in a comment if we have a code emitter.
-  AddEncodingComment(Inst, STI, PrintSchedInfo);
+  AddEncodingComment(Inst, STI);
 
   // Show the MCInst if enabled.
   if (ShowInst) {
-    if (PrintSchedInfo)
-      GetCommentOS() << "\n";
     Inst.dump_pretty(GetCommentOS(), InstPrinter.get(), "\n ");
     GetCommentOS() << "\n";
   }
@@ -1856,12 +1844,6 @@ void MCAsmStreamer::EmitInstruction(const MCInst &Inst,
   else
     InstPrinter->printInst(&Inst, OS, "", STI);
 
-  if (PrintSchedInfo) {
-    std::string SI = STI.getSchedInfoStr(Inst);
-    if (!SI.empty())
-      GetCommentOS() << SI;
-  }
-
   StringRef Comments = CommentToEmit;
   if (Comments.size() && Comments.back() != '\n')
     GetCommentOS() << "\n";