Add support for clmul (#1318)

Author: dtcxzyw

ir/instr.cpp

@@ -186,6 +186,7 @@ void BinOp::print(ostream &os) const {
   case Abs:           str = "abs "; break;
   case UCmp:          str = "ucmp "; break;
   case SCmp:          str = "scmp "; break;
+  case Clmul:         str = "clmul "; break;
   }
 
   os << getName() << " = " << str;
@@ -473,6 +474,11 @@ StateValue BinOp::toSMT(State &s) const {
               ap && bp};
     };
     break;
+  case Clmul:
+    fn = [&](auto &a, auto &ap, auto &b, auto &bp) -> StateValue {
+      return {a.clmul(b), ap && bp};
+    };
+    break;
   }
 
   function<pair<StateValue,StateValue>(const expr&, const expr&, const expr&,

ir/instr.h

@@ -41,7 +41,7 @@ class BinOp final : public Instr {
             SAdd_Overflow, UAdd_Overflow, SSub_Overflow, USub_Overflow,
             SMul_Overflow, UMul_Overflow,
             And, Or, Xor, Cttz, Ctlz, UMin, UMax, SMin, SMax, Abs,
-            UCmp, SCmp };
+            UCmp, SCmp, Clmul };
   enum Flags { None = 0, NSW = 1 << 0, NUW = 1 << 1, Exact = 1 << 2, Disjoint = 1 << 3 };
 
 private:

llvm_util/llvm2alive.cpp

@@ -840,7 +840,8 @@ class llvm2alive_ : public llvm::InstVisitor<llvm2alive_, unique_ptr<Instr>> {
     case llvm::Intrinsic::smax:
     case llvm::Intrinsic::abs:
     case llvm::Intrinsic::ucmp:
-    case llvm::Intrinsic::scmp: {
+    case llvm::Intrinsic::scmp:
+    case llvm::Intrinsic::clmul: {
       PARSE_BINOP();
       addNoundefAssumes(i, {a, b});
       BinOp::Op op;
@@ -866,6 +867,7 @@ class llvm2alive_ : public llvm::InstVisitor<llvm2alive_, unique_ptr<Instr>> {
       case llvm::Intrinsic::abs:      op = BinOp::Abs; break;
       case llvm::Intrinsic::ucmp:     op = BinOp::UCmp; break;
       case llvm::Intrinsic::scmp:     op = BinOp::SCmp; break;
+      case llvm::Intrinsic::clmul:    op = BinOp::Clmul; break;
       default: UNREACHABLE();
       }
       ret = make_unique<BinOp>(*ty, value_name(i), *a, *b, op);

smt/expr.cpp

@@ -1124,6 +1124,18 @@ expr expr::ctpop() const {
   return res;
 }
 
+expr expr::clmul(const expr &rhs) const {
+  C(rhs);
+  auto nbits = bits();
+
+  auto res = mkUInt(0, sort());
+  for (unsigned i = 0; i < nbits; ++i) {
+    res = res ^ (extract(i, i).sext(nbits - 1) & (rhs << mkUInt(i, sort())));
+  }
+
+  return res;
+}
+
 expr expr::umin(const expr &rhs) const {
   return mkIf(ule(rhs), *this, rhs);
 }

smt/expr.h

@@ -217,6 +217,7 @@ class expr {
   expr cttz(const expr &val_zero) const;
   expr ctlz() const;
   expr ctpop() const;
+  expr clmul(const expr &rhs) const;
 
   expr umin(const expr &rhs) const;
   expr umax(const expr &rhs) const;

tests/alive-tv/clmul.srctgt.ll

@@ -0,0 +1,20 @@
+; clmulr(x, y)
+; = clmul(zext(x, 2 * BW), zext(y, 2 * BW)) >> (BW - 1)
+; = bitreverse(clmul(bitreverse(x)))
+
+define i8 @src(i8 %x, i8 %y) {
+  %extx = zext i8 %x to i16
+  %exty = zext i8 %y to i16
+  %clmul = call i16 @llvm.clmul.i16(i16 %extx, i16 %exty)
+  %clmulr = lshr i16 %clmul, 7
+  %trunc = trunc i16 %clmulr to i8
+  ret i8 %trunc
+}
+
+define i8 @tgt(i8 %x, i8 %y) {
+  %rx = call i8 @llvm.bitreverse.i8(i8 %x)
+  %ry = call i8 @llvm.bitreverse.i8(i8 %y)
+  %clmul = call i8 @llvm.clmul.i8(i8 %rx, i8 %ry)
+  %clmulr = call i8 @llvm.bitreverse.i8(i8 %clmul)
+  ret i8 %clmulr
+}

tests/unit/clmul.opt

@@ -0,0 +1,39 @@
+Name: clmul constant1
+%r = clmul i4 1, i4 2
+  =>
+%r = 2
+
+Name: clmul constant2
+%r = clmul i4 5, i4 6
+  =>
+%r = 14
+
+Name: clmul constant3
+%r = clmul i4 -4, i4 2
+  =>
+%r = -8
+
+Name: clmul constant4
+%r = clmul i4 -4, i4 -5
+  =>
+%r = 4
+
+Name: clmul constant5
+%r = clmul i8 0, i8 255
+  =>
+%r = 0
+
+Name: clmul constant6
+%r = clmul i8 15, i8 15
+  =>
+%r = 85
+
+Name: clmul constant7
+%r = clmul i8 1, i8 2
+  =>
+%r = 2
+
+Name: clmul constant8
+%r = clmul i16 -1, i16 -2
+  =>
+%r = -21846

tools/alive_lexer.re

@@ -286,6 +286,7 @@ space+ {
 "abs" { return ABS; }
 "ucmp" { return UCMP; }
 "scmp" { return SCMP; }
+"clmul" { return CLMUL; }
 "oeq" { return OEQ; }
 "ogt" { return OGT; }
 "oge" { return OGE; }

tools/alive_parser.cpp

@@ -710,6 +710,7 @@ static unsigned parse_binop_flags(token op_token) {
   case ABS:
   case UCMP:
   case SCMP:
+  case CLMUL:
     return BinOp::None;
   default:
     UNREACHABLE();
@@ -782,6 +783,7 @@ static unique_ptr<Instr> parse_binop(string_view name, token op_token) {
   case ABS:  op = BinOp::Abs; break;
   case UCMP: op = BinOp::UCmp; break;
   case SCMP: op = BinOp::SCmp; break;
+  case CLMUL: op = BinOp::Clmul; break;
   default:
     UNREACHABLE();
   }
@@ -1273,6 +1275,7 @@ static unique_ptr<Instr> parse_instr(string_view name) {
   case ABS:
   case UCMP:
   case SCMP:
+  case CLMUL:
     return parse_binop(name, t);
   case FADD:
   case FSUB:

tools/tokens.h

@@ -15,6 +15,7 @@ TOKEN(BITREVERSE)
 TOKEN(BSWAP)
 TOKEN(BOR)
 TOKEN(CALL)
+TOKEN(CLMUL)
 TOKEN(COMMA)
 TOKEN(CONSTANT)
 TOKEN(CEQ)