[XRay] Merge instrumentation point table emission code into AsmPrinter.

Summary:
No need to have this per-architecture.  While there, unify 32-bit ARM's
behaviour with what changed elsewhere and start function names lowercase
as per the coding standards.  Individual entry emission code goes to the
entry's own class.

Fully tested on amd64, cross-builds on both ARMs and PowerPC.

Reviewers: dberris

Subscribers: aemerson, llvm-commits

Differential Revision: https://reviews.llvm.org/D28209

llvm-svn: 290858

6 files changed, 2 insertions, 150 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index b2d96a32fd3..efc22189378 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -76,7 +76,6 @@ public:
   void LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI);
   void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI);
 
-  void EmitXRayTable();
   void EmitSled(const MachineInstr &MI, SledKind Kind);
 
   /// \brief tblgen'erated driver function for lowering simple MI->MC
@@ -95,7 +94,7 @@ public:
     AArch64FI = F.getInfo<AArch64FunctionInfo>();
     STI = static_cast<const AArch64Subtarget*>(&F.getSubtarget());
     bool Result = AsmPrinter::runOnMachineFunction(F);
-    EmitXRayTable();
+    emitXRayTable();
     return Result;
   }
 
@@ -150,59 +149,6 @@ void AArch64AsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI)
   EmitSled(MI, SledKind::TAIL_CALL);
 }
 
-void AArch64AsmPrinter::EmitXRayTable()
-{
-  //TODO: merge the logic for ELF XRay sleds at a higher level, so to avoid
-  // code duplication as it is now for x86_64, ARM32 and AArch64.
-  if (Sleds.empty())
-    return;
-
-  auto PrevSection = OutStreamer->getCurrentSectionOnly();
-  auto Fn = MF->getFunction();
-  MCSection *Section;
-
-  if (STI->isTargetELF()) {
-    if (Fn->hasComdat())
-      Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
-        ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
-        Fn->getComdat()->getName());
-    else
-      Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
-        ELF::SHF_ALLOC);
-  } else if (STI->isTargetMachO()) {
-    Section = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
-                                         SectionKind::getReadOnlyWithRel());
-  } else {
-    llvm_unreachable("Unsupported target");
-  }
-
-  // Before we switch over, we force a reference to a label inside the
-  // xray_instr_map section. Since EmitXRayTable() is always called just
-  // before the function's end, we assume that this is happening after the
-  // last return instruction.
-  //
-  // We then align the reference to 16 byte boundaries, which we determined
-  // experimentally to be beneficial to avoid causing decoder stalls.
-  MCSymbol *Tmp = OutContext.createTempSymbol("xray_synthetic_", true);
-  OutStreamer->EmitCodeAlignment(16);
-  OutStreamer->EmitSymbolValue(Tmp, 8, false);
-  OutStreamer->SwitchSection(Section);
-  OutStreamer->EmitLabel(Tmp);
-  for (const auto &Sled : Sleds) {
-    OutStreamer->EmitSymbolValue(Sled.Sled, 8);
-    OutStreamer->EmitSymbolValue(CurrentFnSym, 8);
-    auto Kind = static_cast<uint8_t>(Sled.Kind);
-    OutStreamer->EmitBytes(
-      StringRef(reinterpret_cast<const char *>(&Kind), 1));
-    OutStreamer->EmitBytes(
-      StringRef(reinterpret_cast<const char *>(&Sled.AlwaysInstrument), 1));
-    OutStreamer->EmitZeros(14);
-  }
-  OutStreamer->SwitchSection(PrevSection);
-
-  Sleds.clear();
-}
-
 void AArch64AsmPrinter::EmitSled(const MachineInstr &MI, SledKind Kind)
 {
   static const int8_t NoopsInSledCount = 7;
diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
index f20768ab77a..8ec9cb02813 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.cpp
@@ -164,9 +164,6 @@ bool ARMAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
   // Emit the rest of the function body.
   EmitFunctionBody();
 
-  // Emit the XRay table for this function.
-  EmitXRayTable();
-
   // If we need V4T thumb mode Register Indirect Jump pads, emit them.
   // These are created per function, rather than per TU, since it's
   // relatively easy to exceed the thumb branch range within a TU.
diff --git a/llvm/lib/Target/ARM/ARMAsmPrinter.h b/llvm/lib/Target/ARM/ARMAsmPrinter.h
index ce0b04d56d9..93fed10eb2d 100644
--- a/llvm/lib/Target/ARM/ARMAsmPrinter.h
+++ b/llvm/lib/Target/ARM/ARMAsmPrinter.h
@@ -113,9 +113,6 @@ public:
   void LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI);
   void LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI);
   void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI);
-  // Helper function that emits the XRay sleds we've collected for a particular
-  // function.
-  void EmitXRayTable();
 
 private:
   void EmitSled(const MachineInstr &MI, SledKind Kind);
diff --git a/llvm/lib/Target/ARM/ARMMCInstLower.cpp b/llvm/lib/Target/ARM/ARMMCInstLower.cpp
index 293a527b09e..07044b9697b 100644
--- a/llvm/lib/Target/ARM/ARMMCInstLower.cpp
+++ b/llvm/lib/Target/ARM/ARMMCInstLower.cpp
@@ -22,9 +22,6 @@
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/MC/MCContext.h"
-#include "llvm/MC/MCSymbolELF.h"
-#include "llvm/MC/MCSectionELF.h"
-#include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCInstBuilder.h"
 #include "llvm/MC/MCStreamer.h"
 using namespace llvm;
@@ -226,38 +223,3 @@ void ARMAsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI)
 {
   EmitSled(MI, SledKind::TAIL_CALL);
 }
-
-void ARMAsmPrinter::EmitXRayTable()
-{
-  if (Sleds.empty())
-    return;
-
-  MCSection *Section = nullptr;
-  if (Subtarget->isTargetELF()) {
-    Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
-                                       ELF::SHF_ALLOC | ELF::SHF_GROUP |
-                                           ELF::SHF_MERGE,
-                                       0, CurrentFnSym->getName());
-  } else if (Subtarget->isTargetMachO()) {
-    Section = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
-                                         SectionKind::getReadOnlyWithRel());
-  } else {
-    llvm_unreachable("Unsupported target");
-  }
-
-  auto PrevSection = OutStreamer->getCurrentSectionOnly();
-  OutStreamer->SwitchSection(Section);
-  for (const auto &Sled : Sleds) {
-    OutStreamer->EmitSymbolValue(Sled.Sled, 4);
-    OutStreamer->EmitSymbolValue(CurrentFnSym, 4);
-    auto Kind = static_cast<uint8_t>(Sled.Kind);
-    OutStreamer->EmitBytes(
-      StringRef(reinterpret_cast<const char *>(&Kind), 1));
-    OutStreamer->EmitBytes(
-      StringRef(reinterpret_cast<const char *>(&Sled.AlwaysInstrument), 1));
-    OutStreamer->EmitZeros(6);
-  }
-  OutStreamer->SwitchSection(PrevSection);
-
-  Sleds.clear();
-}
diff --git a/llvm/lib/Target/X86/X86AsmPrinter.cpp b/llvm/lib/Target/X86/X86AsmPrinter.cpp
index d42e1187ce6..e1825ca1eda 100644
--- a/llvm/lib/Target/X86/X86AsmPrinter.cpp
+++ b/llvm/lib/Target/X86/X86AsmPrinter.cpp
@@ -70,7 +70,7 @@ bool X86AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
   EmitFunctionBody();
 
   // Emit the XRay table for this function.
-  EmitXRayTable();
+  emitXRayTable();
 
   // We didn't modify anything.
   return false;
diff --git a/llvm/lib/Target/X86/X86MCInstLower.cpp b/llvm/lib/Target/X86/X86MCInstLower.cpp
index 2f69df064e7..a38a4b30b77 100644
--- a/llvm/lib/Target/X86/X86MCInstLower.cpp
+++ b/llvm/lib/Target/X86/X86MCInstLower.cpp
@@ -1115,56 +1115,6 @@ void X86AsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI, X86MCInstLo
   OutStreamer->EmitInstruction(TC, getSubtargetInfo());
 }
 
-void X86AsmPrinter::EmitXRayTable() {
-  if (Sleds.empty())
-    return;
-  
-  auto PrevSection = OutStreamer->getCurrentSectionOnly();
-  auto Fn = MF->getFunction();
-  MCSection *Section = nullptr;
-  if (Subtarget->isTargetELF()) {
-    if (Fn->hasComdat()) {
-      Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
-                                         ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
-                                         Fn->getComdat()->getName());
-    } else {
-      Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
-                                         ELF::SHF_ALLOC);
-    }
-  } else if (Subtarget->isTargetMachO()) {
-    Section = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
-                                         SectionKind::getReadOnlyWithRel());
-  } else {
-    llvm_unreachable("Unsupported target");
-  }
-
-  // Before we switch over, we force a reference to a label inside the
-  // xray_instr_map section. Since EmitXRayTable() is always called just
-  // before the function's end, we assume that this is happening after the
-  // last return instruction.
-  //
-  // We then align the reference to 16 byte boundaries, which we determined
-  // experimentally to be beneficial to avoid causing decoder stalls.
-  MCSymbol *Tmp = OutContext.createTempSymbol("xray_synthetic_", true);
-  OutStreamer->EmitCodeAlignment(16);
-  OutStreamer->EmitSymbolValue(Tmp, 8, false);
-  OutStreamer->SwitchSection(Section);
-  OutStreamer->EmitLabel(Tmp);
-  for (const auto &Sled : Sleds) {
-    OutStreamer->EmitSymbolValue(Sled.Sled, 8);
-    OutStreamer->EmitSymbolValue(CurrentFnSym, 8);
-    auto Kind = static_cast<uint8_t>(Sled.Kind);
-    OutStreamer->EmitBytes(
-        StringRef(reinterpret_cast<const char *>(&Kind), 1));
-    OutStreamer->EmitBytes(
-        StringRef(reinterpret_cast<const char *>(&Sled.AlwaysInstrument), 1));
-    OutStreamer->EmitZeros(14);
-  }
-  OutStreamer->SwitchSection(PrevSection);
-
-  Sleds.clear();
-}
-
 // Returns instruction preceding MBBI in MachineFunction.
 // If MBBI is the first instruction of the first basic block, returns null.
 static MachineBasicBlock::const_iterator