[llvm] 1fcf49a - MC: Replace FT_PseudoProbe with FT_LEB

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2025-07-19T10:15:25-07:00
New Revision: 1fcf49a35c4ffce2c0a8baf8a045c031f783ccff

URL: https://github.com/llvm/llvm-project/commit/1fcf49a35c4ffce2c0a8baf8a045c031f783ccff
DIFF: https://github.com/llvm/llvm-project/commit/1fcf49a35c4ffce2c0a8baf8a045c031f783ccff.diff

LOG: MC: Replace FT_PseudoProbe with FT_LEB

The fragment type introduced by https://reviews.llvm.org/D91878 is
unnecessary and can be replaced with FT_LEB.

Added: 
    

Modified: 
    llvm/include/llvm/MC/MCAssembler.h
    llvm/include/llvm/MC/MCSection.h
    llvm/lib/MC/MCAssembler.cpp
    llvm/lib/MC/MCFragment.cpp
    llvm/lib/MC/MCPseudoProbe.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/MC/MCAssembler.h b/llvm/include/llvm/MC/MCAssembler.h
index ade9ee6fa56e0..467ad4eabd3b0 100644
--- a/llvm/include/llvm/MC/MCAssembler.h
+++ b/llvm/include/llvm/MC/MCAssembler.h
@@ -36,8 +36,6 @@ class MCCVDefRangeFragment;
 class MCCVInlineLineTableFragment;
 class MCFragment;
 class MCFixup;
-class MCLEBFragment;
-class MCPseudoProbeAddrFragment;
 class MCSymbolRefExpr;
 class raw_ostream;
 class MCAsmBackend;
@@ -123,7 +121,6 @@ class MCAssembler {
   bool relaxCVInlineLineTable(MCCVInlineLineTableFragment &DF);
   bool relaxCVDefRange(MCCVDefRangeFragment &DF);
   bool relaxFill(MCFillFragment &F);
-  bool relaxPseudoProbeAddr(MCPseudoProbeAddrFragment &DF);
 
 public:
   /// Construct a new assembler instance.

diff  --git a/llvm/include/llvm/MC/MCSection.h b/llvm/include/llvm/MC/MCSection.h
index 63a23b1eb034d..66ea8f8620940 100644
--- a/llvm/include/llvm/MC/MCSection.h
+++ b/llvm/include/llvm/MC/MCSection.h
@@ -207,7 +207,6 @@ class MCFragment {
     FT_SymbolId,
     FT_CVInlineLines,
     FT_CVDefRange,
-    FT_PseudoProbe,
   };
 
 private:
@@ -287,7 +286,6 @@ class MCFragment {
     case MCFragment::FT_Dwarf:
     case MCFragment::FT_DwarfFrame:
     case MCFragment::FT_LEB:
-    case MCFragment::FT_PseudoProbe:
     case MCFragment::FT_CVInlineLines:
     case MCFragment::FT_CVDefRange:
       return true;
@@ -732,22 +730,6 @@ class MCBoundaryAlignFragment : public MCFragment {
   }
 };
 
-class MCPseudoProbeAddrFragment : public MCEncodedFragment {
-  /// The expression for the 
diff erence of the two symbols that
-  /// make up the address delta between two .pseudoprobe directives.
-  const MCExpr *AddrDelta;
-
-public:
-  MCPseudoProbeAddrFragment(const MCExpr *AddrDelta)
-      : MCEncodedFragment(FT_PseudoProbe, false), AddrDelta(AddrDelta) {}
-
-  const MCExpr &getAddrDelta() const { return *AddrDelta; }
-
-  static bool classof(const MCFragment *F) {
-    return F->getKind() == MCFragment::FT_PseudoProbe;
-  }
-};
-
 inline MCSection::iterator &MCSection::iterator::operator++() {
   F = F->Next;
   return *this;

diff  --git a/llvm/lib/MC/MCAssembler.cpp b/llvm/lib/MC/MCAssembler.cpp
index 3e96bdf5169d8..942092457c452 100644
--- a/llvm/lib/MC/MCAssembler.cpp
+++ b/llvm/lib/MC/MCAssembler.cpp
@@ -201,7 +201,6 @@ uint64_t MCAssembler::computeFragmentSize(const MCFragment &F) const {
   case MCFragment::FT_DwarfFrame:
   case MCFragment::FT_CVInlineLines:
   case MCFragment::FT_CVDefRange:
-  case MCFragment::FT_PseudoProbe:
     return F.getSize();
   case MCFragment::FT_Fill: {
     auto &FF = cast<MCFillFragment>(F);
@@ -424,8 +423,7 @@ static void writeFragment(raw_ostream &OS, const MCAssembler &Asm,
   case MCFragment::FT_Dwarf:
   case MCFragment::FT_DwarfFrame:
   case MCFragment::FT_CVInlineLines:
-  case MCFragment::FT_CVDefRange:
-  case MCFragment::FT_PseudoProbe: {
+  case MCFragment::FT_CVDefRange: {
     if (F.getKind() == MCFragment::FT_Data)
       ++stats::EmittedDataFragments;
     else if (F.getKind() == MCFragment::FT_Relaxable)
@@ -974,22 +972,6 @@ bool MCAssembler::relaxFill(MCFillFragment &F) {
   return true;
 }
 
-bool MCAssembler::relaxPseudoProbeAddr(MCPseudoProbeAddrFragment &PF) {
-  uint64_t OldSize = PF.getContents().size();
-  int64_t AddrDelta;
-  bool Abs = PF.getAddrDelta().evaluateKnownAbsolute(AddrDelta, *this);
-  assert(Abs && "We created a pseudo probe with an invalid expression");
-  (void)Abs;
-  SmallVector<char, 8> Data;
-  raw_svector_ostream OSE(Data);
-
-  // AddrDelta is a signed integer
-  encodeSLEB128(AddrDelta, OSE, OldSize);
-  PF.setContents(Data);
-  PF.clearFixups();
-  return OldSize != Data.size();
-}
-
 bool MCAssembler::relaxFragment(MCFragment &F) {
   switch(F.getKind()) {
   default:
@@ -1011,8 +993,6 @@ bool MCAssembler::relaxFragment(MCFragment &F) {
     return relaxCVDefRange(cast<MCCVDefRangeFragment>(F));
   case MCFragment::FT_Fill:
     return relaxFill(cast<MCFillFragment>(F));
-  case MCFragment::FT_PseudoProbe:
-    return relaxPseudoProbeAddr(cast<MCPseudoProbeAddrFragment>(F));
   }
 }
 

diff  --git a/llvm/lib/MC/MCFragment.cpp b/llvm/lib/MC/MCFragment.cpp
index bfe045abe6e53..fe7afd4b41378 100644
--- a/llvm/lib/MC/MCFragment.cpp
+++ b/llvm/lib/MC/MCFragment.cpp
@@ -58,7 +58,6 @@ LLVM_DUMP_METHOD void MCFragment::dump() const {
   case MCFragment::FT_SymbolId:      OS << "SymbolId"; break;
   case MCFragment::FT_CVInlineLines: OS << "CVInlineLineTable"; break;
   case MCFragment::FT_CVDefRange:    OS << "CVDefRangeTable"; break;
-  case MCFragment::FT_PseudoProbe:   OS << "PseudoProbe"; break;
     // clang-format on
   }
 
@@ -182,12 +181,6 @@ LLVM_DUMP_METHOD void MCFragment::dump() const {
     }
     break;
   }
-  case MCFragment::FT_PseudoProbe: {
-    const auto *OF = cast<MCPseudoProbeAddrFragment>(this);
-    OS << " AddrDelta:";
-    OF->getAddrDelta().print(OS, nullptr);
-    break;
-  }
   }
 }
 #endif

diff  --git a/llvm/lib/MC/MCPseudoProbe.cpp b/llvm/lib/MC/MCPseudoProbe.cpp
index f87d27f4adcc5..b493337b39317 100644
--- a/llvm/lib/MC/MCPseudoProbe.cpp
+++ b/llvm/lib/MC/MCPseudoProbe.cpp
@@ -81,8 +81,9 @@ void MCPseudoProbe::emit(MCObjectStreamer *MCOS,
     if (AddrDelta->evaluateAsAbsolute(Delta, MCOS->getAssemblerPtr())) {
       MCOS->emitSLEB128IntValue(Delta);
     } else {
-      MCOS->insert(MCOS->getContext().allocFragment<MCPseudoProbeAddrFragment>(
-          AddrDelta));
+      auto *F = MCOS->getCurrentFragment();
+      F->makeLEB(true, AddrDelta);
+      MCOS->newFragment();
     }
   } else {
     // Emit the GUID of the split function that the sentinel probe represents.