[llvm] r357470 - [RISCV] Support assembling @plt symbol operands

Alex Bradbury via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 2 05:47:21 PDT 2019


Author: asb
Date: Tue Apr  2 05:47:20 2019
New Revision: 357470

URL: http://llvm.org/viewvc/llvm-project?rev=357470&view=rev
Log:
[RISCV] Support assembling @plt symbol operands

This patch allows symbols appended with @plt to parse and assemble with the
R_RISCV_CALL_PLT relocation.

Differential Revision: https://reviews.llvm.org/D55335
Patch by Lewis Revill.


Modified:
    llvm/trunk/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
    llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
    llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h
    llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
    llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVFixupKinds.h
    llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp
    llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
    llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.h
    llvm/trunk/test/MC/RISCV/function-call.s
    llvm/trunk/test/MC/RISCV/lla-invalid.s
    llvm/trunk/test/MC/RISCV/tail-call.s

Modified: llvm/trunk/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp Tue Apr  2 05:47:20 2019
@@ -291,7 +291,8 @@ public:
     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
       return false;
     return RISCVAsmParser::classifySymbolRef(getImm(), VK, Imm) &&
-           VK == RISCVMCExpr::VK_RISCV_CALL;
+           (VK == RISCVMCExpr::VK_RISCV_CALL ||
+            VK == RISCVMCExpr::VK_RISCV_CALL_PLT);
   }
 
   bool isCSRSystemRegister() const { return isSystemRegister(); }
@@ -1142,6 +1143,11 @@ OperandMatchResultTy RISCVAsmParser::par
   if (getParser().parseIdentifier(Identifier))
     return MatchOperand_ParseFail;
 
+  if (Identifier.consume_back("@plt")) {
+    Error(getLoc(), "'@plt' operand not valid for instruction");
+    return MatchOperand_ParseFail;
+  }
+
   MCSymbol *Sym = getContext().getOrCreateSymbol(Identifier);
 
   if (Sym->isVariable()) {
@@ -1169,9 +1175,13 @@ OperandMatchResultTy RISCVAsmParser::par
   if (getParser().parseIdentifier(Identifier))
     return MatchOperand_ParseFail;
 
+  RISCVMCExpr::VariantKind Kind = RISCVMCExpr::VK_RISCV_CALL;
+  if (Identifier.consume_back("@plt"))
+    Kind = RISCVMCExpr::VK_RISCV_CALL_PLT;
+
   MCSymbol *Sym = getContext().getOrCreateSymbol(Identifier);
   Res = MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, getContext());
-  Res = RISCVMCExpr::create(Res, RISCVMCExpr::VK_RISCV_CALL, getContext());
+  Res = RISCVMCExpr::create(Res, Kind, getContext());
   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
   return MatchOperand_Success;
 }

Modified: llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp (original)
+++ llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp Tue Apr  2 05:47:20 2019
@@ -230,7 +230,8 @@ static uint64_t adjustFixupValue(const M
     Value = (Sbit << 31) | (Mid6 << 25) | (Lo4 << 8) | (Hi1 << 7);
     return Value;
   }
-  case RISCV::fixup_riscv_call: {
+  case RISCV::fixup_riscv_call:
+  case RISCV::fixup_riscv_call_plt: {
     // Jalr will add UpperImm with the sign-extended 12-bit LowerImm,
     // we need to add 0x800ULL before extract upper bits to reflect the
     // effect of the sign extension.

Modified: llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h (original)
+++ llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h Tue Apr  2 05:47:20 2019
@@ -110,6 +110,7 @@ public:
       { "fixup_riscv_rvc_jump",      2,     11,  MCFixupKindInfo::FKF_IsPCRel },
       { "fixup_riscv_rvc_branch",    0,     16,  MCFixupKindInfo::FKF_IsPCRel },
       { "fixup_riscv_call",          0,     64,  MCFixupKindInfo::FKF_IsPCRel },
+      { "fixup_riscv_call_plt",      0,     64,  MCFixupKindInfo::FKF_IsPCRel },
       { "fixup_riscv_relax",         0,      0,  0 },
       { "fixup_riscv_align",         0,      0,  0 }
     };

Modified: llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp (original)
+++ llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp Tue Apr  2 05:47:20 2019
@@ -95,6 +95,8 @@ unsigned RISCVELFObjectWriter::getRelocT
     return ELF::R_RISCV_RVC_BRANCH;
   case RISCV::fixup_riscv_call:
     return ELF::R_RISCV_CALL;
+  case RISCV::fixup_riscv_call_plt:
+    return ELF::R_RISCV_CALL_PLT;
   case RISCV::fixup_riscv_relax:
     return ELF::R_RISCV_RELAX;
   case RISCV::fixup_riscv_align:

Modified: llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVFixupKinds.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVFixupKinds.h?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVFixupKinds.h (original)
+++ llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVFixupKinds.h Tue Apr  2 05:47:20 2019
@@ -52,6 +52,10 @@ enum Fixups {
   // fixup_riscv_call - A fixup representing a call attached to the auipc
   // instruction in a pair composed of adjacent auipc+jalr instructions.
   fixup_riscv_call,
+  // fixup_riscv_call_plt - A fixup representing a procedure linkage table call
+  // attached to the auipc instruction in a pair composed of adjacent auipc+jalr
+  // instructions.
+  fixup_riscv_call_plt,
   // fixup_riscv_relax - Used to generate an R_RISCV_RELAX relocation type,
   // which indicates the linker may relax the instruction pair.
   fixup_riscv_relax,

Modified: llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCCodeEmitter.cpp Tue Apr  2 05:47:20 2019
@@ -242,6 +242,10 @@ unsigned RISCVMCCodeEmitter::getImmOpVal
       FixupKind = RISCV::fixup_riscv_call;
       RelaxCandidate = true;
       break;
+    case RISCVMCExpr::VK_RISCV_CALL_PLT:
+      FixupKind = RISCV::fixup_riscv_call_plt;
+      RelaxCandidate = true;
+      break;
     }
   } else if (Kind == MCExpr::SymbolRef &&
              cast<MCSymbolRefExpr>(Expr)->getKind() == MCSymbolRefExpr::VK_None) {

Modified: llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp (original)
+++ llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.cpp Tue Apr  2 05:47:20 2019
@@ -33,11 +33,15 @@ const RISCVMCExpr *RISCVMCExpr::create(c
 }
 
 void RISCVMCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
-  bool HasVariant =
-      ((getKind() != VK_RISCV_None) && (getKind() != VK_RISCV_CALL));
+  VariantKind Kind = getKind();
+  bool HasVariant = ((Kind != VK_RISCV_None) && (Kind != VK_RISCV_CALL) &&
+                     (Kind != VK_RISCV_CALL_PLT));
+
   if (HasVariant)
     OS << '%' << getVariantKindName(getKind()) << '(';
   Expr->print(OS, MAI);
+  if (Kind == VK_RISCV_CALL_PLT)
+    OS << "@plt";
   if (HasVariant)
     OS << ')';
 }
@@ -200,7 +204,8 @@ bool RISCVMCExpr::evaluateAsConstant(int
   MCValue Value;
 
   if (Kind == VK_RISCV_PCREL_HI || Kind == VK_RISCV_PCREL_LO ||
-      Kind == VK_RISCV_GOT_HI || Kind == VK_RISCV_CALL)
+      Kind == VK_RISCV_GOT_HI || Kind == VK_RISCV_CALL ||
+      Kind == VK_RISCV_CALL_PLT)
     return false;
 
   if (!getSubExpr()->evaluateAsRelocatable(Value, nullptr, nullptr))

Modified: llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.h?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.h (original)
+++ llvm/trunk/lib/Target/RISCV/MCTargetDesc/RISCVMCExpr.h Tue Apr  2 05:47:20 2019
@@ -30,6 +30,7 @@ public:
     VK_RISCV_PCREL_HI,
     VK_RISCV_GOT_HI,
     VK_RISCV_CALL,
+    VK_RISCV_CALL_PLT,
     VK_RISCV_Invalid
   };
 

Modified: llvm/trunk/test/MC/RISCV/function-call.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/RISCV/function-call.s?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/test/MC/RISCV/function-call.s (original)
+++ llvm/trunk/test/MC/RISCV/function-call.s Tue Apr  2 05:47:20 2019
@@ -43,3 +43,11 @@ call mstatus
 # INSTR: auipc ra, 0
 # INSTR: jalr  ra
 # FIXUP: fixup A - offset: 0, value: mstatus, kind: fixup_riscv_call
+
+# Ensure that calls to procedure linkage table symbols work.
+
+call foo at plt
+# RELOC: R_RISCV_CALL_PLT foo 0x0
+# INSTR: auipc ra, 0
+# INSTR: jalr  ra
+# FIXUP: fixup A - offset: 0, value: foo at plt, kind: fixup_riscv_call_plt

Modified: llvm/trunk/test/MC/RISCV/lla-invalid.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/RISCV/lla-invalid.s?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/test/MC/RISCV/lla-invalid.s (original)
+++ llvm/trunk/test/MC/RISCV/lla-invalid.s Tue Apr  2 05:47:20 2019
@@ -4,3 +4,4 @@
 # Non bare symbols must be rejected
 lla a2, %lo(a_symbol) # CHECK: :[[@LINE]]:9: error: operand must be a bare symbol name
 lla a2, %hi(a_symbol) # CHECK: :[[@LINE]]:9: error: operand must be a bare symbol name
+lla a2, foo at plt # CHECK: :[[@LINE]]:17: error: '@plt' operand not valid for instruction

Modified: llvm/trunk/test/MC/RISCV/tail-call.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/RISCV/tail-call.s?rev=357470&r1=357469&r2=357470&view=diff
==============================================================================
--- llvm/trunk/test/MC/RISCV/tail-call.s (original)
+++ llvm/trunk/test/MC/RISCV/tail-call.s Tue Apr  2 05:47:20 2019
@@ -45,3 +45,9 @@ tail ra
 # INSTR: auipc t1, 0
 # INSTR: jr  t1
 # FIXUP: fixup A - offset: 0, value: ra, kind:
+
+tail foo at plt
+# RELOC: R_RISCV_CALL_PLT foo 0x0
+# INSTR: auipc t1, 0
+# INSTR: jr  t1
+# FIXUP: fixup A - offset: 0, value: foo at plt, kind:




More information about the llvm-commits mailing list