[AArch64][SVE] Asm: Predicate patterns

Summary:
This patch adds support for parsing/printing of named or unnamed
patterns that are used in SVE's PTRUE instruction, amongst others.

The pattern can be specified as a named pattern to initialize the predicate
vector or it can be specified as an immediate in the range 0-31.

Reviewers: fhahn, rengolin, evandro, mcrosier, t.p.northover

Reviewed By: fhahn

Subscribers: aemerson, javed.absar, tschuett, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D41818

llvm-svn: 323098

llvm/lib/Target/AArch64/AArch64SystemOperands.td

@@ -174,6 +174,37 @@ def : PRFM<"pstl2strm", 0x13>;
 def : PRFM<"pstl3keep", 0x14>;
 def : PRFM<"pstl3strm", 0x15>;
 
+//===----------------------------------------------------------------------===//
+// SVE Predicate patterns
+//===----------------------------------------------------------------------===//
+
+class SVEPREDPAT<string name, bits<5> encoding> : SearchableTable {
+  let SearchableFields = ["Name", "Encoding"];
+  let EnumValueField = "Encoding";
+
+  string Name = name;
+  bits<5> Encoding;
+  let Encoding = encoding;
+}
+
+def : SVEPREDPAT<"pow2",  0x00>;
+def : SVEPREDPAT<"vl1",   0x01>;
+def : SVEPREDPAT<"vl2",   0x02>;
+def : SVEPREDPAT<"vl3",   0x03>;
+def : SVEPREDPAT<"vl4",   0x04>;
+def : SVEPREDPAT<"vl5",   0x05>;
+def : SVEPREDPAT<"vl6",   0x06>;
+def : SVEPREDPAT<"vl7",   0x07>;
+def : SVEPREDPAT<"vl8",   0x08>;
+def : SVEPREDPAT<"vl16",  0x09>;
+def : SVEPREDPAT<"vl32",  0x0a>;
+def : SVEPREDPAT<"vl64",  0x0b>;
+def : SVEPREDPAT<"vl128", 0x0c>;
+def : SVEPREDPAT<"vl256", 0x0d>;
+def : SVEPREDPAT<"mul4",  0x1d>;
+def : SVEPREDPAT<"mul3",  0x1e>;
+def : SVEPREDPAT<"all",   0x1f>;
+
 //===----------------------------------------------------------------------===//
 // PState instruction options.
 //===----------------------------------------------------------------------===//

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -140,6 +140,8 @@ class AArch64AsmParser : public MCTargetAsmParser {
   template <bool ParseSuffix>
   OperandMatchResultTy tryParseSVEDataVector(OperandVector &Operands);
   OperandMatchResultTy tryParseSVEPredicateVector(OperandVector &Operands);
+  LLVM_ATTRIBUTE_UNUSED OperandMatchResultTy
+  tryParseSVEPattern(OperandVector &Operands);
 
 public:
   enum AArch64MatchResultTy {
@@ -488,6 +490,16 @@ class AArch64Operand : public MCParsedAsmOperand {
     return Val >= MinVal && Val <= MaxVal && (Val % Scale) == 0;
   }
 
+  bool isSVEPattern() const {
+    if (!isImm())
+      return false;
+    auto *MCE = dyn_cast<MCConstantExpr>(getImm());
+    if (!MCE)
+      return false;
+    int64_t Val = MCE->getValue();
+    return Val >= 0 && Val < 32;
+  }
+
   bool isSymbolicUImm12Offset(const MCExpr *Expr, unsigned Scale) const {
     AArch64MCExpr::VariantKind ELFRefKind;
     MCSymbolRefExpr::VariantKind DarwinRefKind;
@@ -4725,3 +4737,47 @@ AArch64AsmParser::tryParseSVEDataVector(OperandVector &Operands) {
 
   return MatchOperand_Success;
 }
+
+OperandMatchResultTy
+AArch64AsmParser::tryParseSVEPattern(OperandVector &Operands) {
+  MCAsmParser &Parser = getParser();
+
+  SMLoc SS = getLoc();
+  const AsmToken &TokE = Parser.getTok();
+  bool IsHash = TokE.is(AsmToken::Hash);
+
+  if (!IsHash && TokE.isNot(AsmToken::Identifier))
+    return MatchOperand_NoMatch;
+
+  int64_t Pattern;
+  if (IsHash) {
+    Parser.Lex(); // Eat hash
+
+    // Parse the immediate operand.
+    const MCExpr *ImmVal;
+    SS = getLoc();
+    if (Parser.parseExpression(ImmVal))
+      return MatchOperand_ParseFail;
+
+    auto *MCE = dyn_cast<MCConstantExpr>(ImmVal);
+    if (!MCE)
+      return MatchOperand_ParseFail;
+
+    Pattern = MCE->getValue();
+  } else {
+    // Parse the pattern
+    auto Pat = AArch64SVEPredPattern::lookupSVEPREDPATByName(TokE.getString());
+    if (!Pat)
+      return MatchOperand_NoMatch;
+
+    Parser.Lex();
+    Pattern = Pat->Encoding;
+    assert(Pattern >= 0 && Pattern < 32);
+  }
+
+  Operands.push_back(
+      AArch64Operand::CreateImm(MCConstantExpr::create(Pattern, getContext()),
+                                SS, getLoc(), getContext()));
+
+  return MatchOperand_Success;
+}

llvm/lib/Target/AArch64/InstPrinter/AArch64InstPrinter.cpp

@@ -1340,6 +1340,16 @@ void AArch64InstPrinter::printComplexRotationOp(const MCInst *MI, unsigned OpNo,
   O << "#" << (Val * Angle) + Remainder;
 }
 
+void AArch64InstPrinter::printSVEPattern(const MCInst *MI, unsigned OpNum,
+                                         const MCSubtargetInfo &STI,
+                                         raw_ostream &O) {
+  unsigned Val = MI->getOperand(OpNum).getImm();
+  if (auto Pat = AArch64SVEPredPattern::lookupSVEPREDPATByEncoding(Val))
+    O << Pat->Name;
+  else
+    O << '#' << formatImm(Val);
+}
+
 template <char suffix>
 void AArch64InstPrinter::printSVERegOp(const MCInst *MI, unsigned OpNum,
                                        const MCSubtargetInfo &STI,

llvm/lib/Target/AArch64/InstPrinter/AArch64InstPrinter.h

@@ -17,6 +17,7 @@
 #include "MCTargetDesc/AArch64MCTargetDesc.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/MC/MCInstPrinter.h"
+#include "../Utils/AArch64BaseInfo.h"
 
 namespace llvm {
 
@@ -165,6 +166,8 @@ class AArch64InstPrinter : public MCInstPrinter {
   void printGPRSeqPairsClassOperand(const MCInst *MI, unsigned OpNum,
                                     const MCSubtargetInfo &STI,
                                     raw_ostream &O);
+  void printSVEPattern(const MCInst *MI, unsigned OpNum,
+                       const MCSubtargetInfo &STI, raw_ostream &O);
   template <char = 0>
   void printSVERegOp(const MCInst *MI, unsigned OpNum,
                     const MCSubtargetInfo &STI, raw_ostream &O);

llvm/lib/Target/AArch64/Utils/AArch64BaseInfo.cpp

@@ -60,6 +60,13 @@ namespace llvm {
   }
 }
 
+namespace llvm {
+  namespace AArch64SVEPredPattern {
+#define GET_SVEPREDPAT_IMPL
+#include "AArch64GenSystemOperands.inc"
+  }
+}
+
 namespace llvm {
   namespace AArch64PState {
 #define GET_PSTATE_IMPL

llvm/lib/Target/AArch64/Utils/AArch64BaseInfo.h

@@ -335,6 +335,15 @@ namespace AArch64PRFM {
   #include "AArch64GenSystemOperands.inc"
 }
 
+namespace AArch64SVEPredPattern {
+  struct SVEPREDPAT {
+    const char *Name;
+    uint16_t Encoding;
+  };
+#define GET_SVEPREDPAT_DECL
+#include "AArch64GenSystemOperands.inc"
+}
+
 namespace AArch64PState {
   struct PState : SysAlias{
     using SysAlias::SysAlias;