8349721: Add aarch64 intrinsics for ML-KEM

src/hotspot/cpu/aarch64/register_aarch64.cpp

@@ -58,23 +58,3 @@ const char* PRegister::PRegisterImpl::name() const {
   };
   return is_valid() ? names[encoding()] : "pnoreg";
 }
-
-// convenience methods for splitting 8-way vector register sequences
-// in half -- needed because vector operations can normally only be
-// benefit from 4-way instruction parallelism
-
-VSeq<4> vs_front(const VSeq<8>& v) {
-  return VSeq<4>(v.base(), v.delta());
-}
-
-VSeq<4> vs_back(const VSeq<8>& v) {
-  return VSeq<4>(v.base() + 4 * v.delta(), v.delta());
-}
-
-VSeq<4> vs_even(const VSeq<8>& v) {
-  return VSeq<4>(v.base(), v.delta() * 2);
-}
-
-VSeq<4> vs_odd(const VSeq<8>& v) {
-  return VSeq<4>(v.base() + 1, v.delta() * 2);
-}

src/hotspot/cpu/aarch64/register_aarch64.hpp

@@ -436,19 +436,20 @@ enum RC { rc_bad, rc_int, rc_float, rc_predicate, rc_stack };
 // inputs into front and back halves or odd and even halves (see
 // convenience methods below).
 
+// helper macro for computing register masks
+#define VS_MASK_BIT(base, delta, i) (1 << (base + delta * i))
+
 template<int N> class VSeq {
   static_assert(N >= 2, "vector sequence length must be greater than 1");
-  static_assert(N <= 8, "vector sequence length must not exceed 8");
-  static_assert((N & (N - 1)) == 0, "vector sequence length must be power of two");
 private:
   int _base;  // index of first register in sequence
   int _delta; // increment to derive successive indices
 public:
   VSeq(FloatRegister base_reg, int delta = 1) : VSeq(base_reg->encoding(), delta) { }
   VSeq(int base, int delta = 1) : _base(base), _delta(delta) {
-    assert (_base >= 0, "invalid base register");
-    assert (_delta >= 0, "invalid register delta");
-    assert ((_base + (N - 1) * _delta) < 32, "range exceeded");
+    assert (_base >= 0 && _base <= 31, "invalid base register");
+    assert ((_base + (N - 1) * _delta) >= 0, "register range underflow");
+    assert ((_base + (N - 1) * _delta) < 32, "register range overflow");
   }
   // indexed access to sequence
   FloatRegister operator [](int i) const {
@@ -457,27 +458,89 @@ template<int N> class VSeq {
   }
   int mask() const {
     int m = 0;
-    int bit = 1 << _base;
     for (int i = 0; i < N; i++) {
-      m |= bit << (i * _delta);
+      m |= VS_MASK_BIT(_base, _delta, i);
     }
     return m;
   }
   int base() const { return _base; }
   int delta() const { return _delta; }
+  bool is_constant() const { return _delta == 0; }
 };
 
-// declare convenience methods for splitting vector register sequences
-
-VSeq<4> vs_front(const VSeq<8>& v);
-VSeq<4> vs_back(const VSeq<8>& v);
-VSeq<4> vs_even(const VSeq<8>& v);
-VSeq<4> vs_odd(const VSeq<8>& v);
-
-// methods for use in asserts to check VSeq inputs and oupts are
+// methods for use in asserts to check VSeq inputs and outputs are
 // either disjoint or equal
 
 template<int N, int M> bool vs_disjoint(const VSeq<N>& n, const VSeq<M>& m) { return (n.mask() & m.mask()) == 0; }
 template<int N> bool vs_same(const VSeq<N>& n, const VSeq<N>& m) { return n.mask() == m.mask(); }
 
+// method for use in asserts to check whether registers appearing in
+// an output sequence will be written before they are read from an
+// input sequence.
+
+template<int N> bool vs_write_before_read(const VSeq<N>& vout, const VSeq<N>& vin) {
+  int b_in = vin.base();
+  int d_in = vin.delta();
+  int b_out = vout.base();
+  int d_out = vout.delta();
+  int bit_in = 1 << b_in;
+  int bit_out = 1 << b_out;
+  int mask_read = vin.mask();   // all pending reads
+  int mask_write = 0;         // no writes as yet
+
+
+  for (int i = 0; i < N - 1; i++) {
+    // check whether a pending read clashes with a write
+    if ((mask_write & mask_read) != 0) {
+      return true;
+    }
+    // remove the pending input (so long as this is a constant
+    // sequence)
+    if (d_in != 0) {
+      mask_read ^= VS_MASK_BIT(b_in, d_in, i);
+    }
+    // record the next write
+    mask_write |= VS_MASK_BIT(b_out, d_out, i);
+  }
+  // no write before read
+  return false;
+}
+
+// convenience methods for splitting 8-way of 4-way vector register
+// sequences in half -- needed because vector operations can normally
+// benefit from 4-way instruction parallelism or, occasionally, 2-way
+// parallelism
+
+template<int N>
+VSeq<N/2> vs_front(const VSeq<N>& v) {
+  static_assert(N > 0 && ((N & 1) == 0), "sequence length must be even");
+  return VSeq<N/2>(v.base(), v.delta());
+}
+
+template<int N>
+VSeq<N/2> vs_back(const VSeq<N>& v) {
+  static_assert(N > 0 && ((N & 1) == 0), "sequence length must be even");
+  return VSeq<N/2>(v.base() + N / 2 * v.delta(), v.delta());
+}
+
+template<int N>
+VSeq<N/2> vs_even(const VSeq<N>& v) {
+  static_assert(N > 0 && ((N & 1) == 0), "sequence length must be even");
+  return VSeq<N/2>(v.base(), v.delta() * 2);
+}
+
+template<int N>
+VSeq<N/2> vs_odd(const VSeq<N>& v) {
+  static_assert(N > 0 && ((N & 1) == 0), "sequence length must be even");
+  return VSeq<N/2>(v.base() + v.delta(), v.delta() * 2);
+}
+
+// convenience method to construct a vector register sequence that
+// indexes its elements in reverse order to the original
+
+template<int N>
+VSeq<N> vs_reverse(const VSeq<N>& v) {
+  return VSeq<N>(v.base() + (N - 1) * v.delta(), -v.delta());
+}
+
 #endif // CPU_AARCH64_REGISTER_AARCH64_HPP