# HG changeset patch

# User mdoerr

# Date 1507750779 -3600

#      Wed Oct 11 20:39:39 2017 +0100

# Node ID 92f0dbe76a13992cc27188e0f68e4b1771c7004a

# Parent  542c122b1d7d30c29189565248074aa28f21ae58

8145913, PR3466, RH1498309: PPC64: add Montgomery multiply intrinsic

Reviewed-by: aph, goetz

diff --git a/src/cpu/ppc/vm/assembler_ppc.hpp b/src/cpu/ppc/vm/assembler_ppc.hpp

--- openjdk/hotspot/src/cpu/ppc/vm/assembler_ppc.hpp

+++ openjdk/hotspot/src/cpu/ppc/vm/assembler_ppc.hpp

@@ -1179,6 +1179,8 @@

   inline void mullw_( Register d, Register a, Register b);

   inline void mulhw(  Register d, Register a, Register b);

   inline void mulhw_( Register d, Register a, Register b);

+  inline void mulhwu( Register d, Register a, Register b);

+  inline void mulhwu_(Register d, Register a, Register b);

   inline void mulhd(  Register d, Register a, Register b);

   inline void mulhd_( Register d, Register a, Register b);

   inline void mulhdu( Register d, Register a, Register b);

diff --git a/src/cpu/ppc/vm/assembler_ppc.inline.hpp b/src/cpu/ppc/vm/assembler_ppc.inline.hpp

--- openjdk/hotspot/src/cpu/ppc/vm/assembler_ppc.inline.hpp

+++ openjdk/hotspot/src/cpu/ppc/vm/assembler_ppc.inline.hpp

@@ -109,6 +109,8 @@

 inline void Assembler::mullw_( Register d, Register a, Register b) { emit_int32(MULLW_OPCODE  | rt(d) | ra(a) | rb(b) | oe(0) | rc(1)); }

 inline void Assembler::mulhw(  Register d, Register a, Register b) { emit_int32(MULHW_OPCODE  | rt(d) | ra(a) | rb(b) | rc(0)); }

 inline void Assembler::mulhw_( Register d, Register a, Register b) { emit_int32(MULHW_OPCODE  | rt(d) | ra(a) | rb(b) | rc(1)); }

+inline void Assembler::mulhwu( Register d, Register a, Register b) { emit_int32(MULHWU_OPCODE | rt(d) | ra(a) | rb(b) | rc(0)); }

+inline void Assembler::mulhwu_(Register d, Register a, Register b) { emit_int32(MULHWU_OPCODE | rt(d) | ra(a) | rb(b) | rc(1)); }

 inline void Assembler::mulhd(  Register d, Register a, Register b) { emit_int32(MULHD_OPCODE  | rt(d) | ra(a) | rb(b) | rc(0)); }

 inline void Assembler::mulhd_( Register d, Register a, Register b) { emit_int32(MULHD_OPCODE  | rt(d) | ra(a) | rb(b) | rc(1)); }

 inline void Assembler::mulhdu( Register d, Register a, Register b) { emit_int32(MULHDU_OPCODE | rt(d) | ra(a) | rb(b) | rc(0)); }

diff --git a/src/cpu/ppc/vm/c2_init_ppc.cpp b/src/cpu/ppc/vm/c2_init_ppc.cpp

--- openjdk/hotspot/src/cpu/ppc/vm/c2_init_ppc.cpp

+++ openjdk/hotspot/src/cpu/ppc/vm/c2_init_ppc.cpp

@@ -45,4 +45,10 @@

       FLAG_SET_ERGO(bool, InsertEndGroupPPC64, true);

     }

   }

+

+  if (OptimizeFill) {

+    warning("OptimizeFill is not supported on this CPU.");

+    FLAG_SET_DEFAULT(OptimizeFill, false);

+  }

+

 }

diff --git a/src/cpu/ppc/vm/sharedRuntime_ppc.cpp b/src/cpu/ppc/vm/sharedRuntime_ppc.cpp

--- openjdk/hotspot/src/cpu/ppc/vm/sharedRuntime_ppc.cpp

+++ openjdk/hotspot/src/cpu/ppc/vm/sharedRuntime_ppc.cpp

@@ -42,6 +42,8 @@

 #include "opto/runtime.hpp"

 #endif

+#include <alloca.h>

+

 #define __ masm->

 #ifdef PRODUCT

@@ -3269,3 +3271,245 @@

   return RuntimeStub::new_runtime_stub(name, &buffer, frame_complete, frame_size_in_bytes/wordSize,

                                        oop_maps, true);

 }

+

+

+//------------------------------Montgomery multiplication------------------------

+//

+

+// Subtract 0:b from carry:a. Return carry.

+static unsigned long

+sub(unsigned long a[], unsigned long b[], unsigned long carry, long len) {

+  long i = 0;

+  unsigned long tmp, tmp2;

+  __asm__ __volatile__ (

+    "subfc  %[tmp], %[tmp], %[tmp]   \n" // pre-set CA

+    "mtctr  %[len]                   \n"

+    "0:                              \n"

+    "ldx    %[tmp], %[i], %[a]       \n"

+    "ldx    %[tmp2], %[i], %[b]      \n"

+    "subfe  %[tmp], %[tmp2], %[tmp]  \n" // subtract extended

+    "stdx   %[tmp], %[i], %[a]       \n"

+    "addi   %[i], %[i], 8            \n"

+    "bdnz   0b                       \n"

+    "addme  %[tmp], %[carry]         \n" // carry + CA - 1

+    : [i]"+b"(i), [tmp]"=&r"(tmp), [tmp2]"=&r"(tmp2)

+    : [a]"r"(a), [b]"r"(b), [carry]"r"(carry), [len]"r"(len)

+    : "ctr", "xer", "memory"

+  );

+  return tmp;

+}

+

+// Multiply (unsigned) Long A by Long B, accumulating the double-

+// length result into the accumulator formed of T0, T1, and T2.

+inline void MACC(unsigned long A, unsigned long B, unsigned long &T0, unsigned long &T1, unsigned long &T2) {

+  unsigned long hi, lo;

+  __asm__ __volatile__ (

+    "mulld  %[lo], %[A], %[B]    \n"

+    "mulhdu %[hi], %[A], %[B]    \n"

+    "addc   %[T0], %[T0], %[lo]  \n"

+    "adde   %[T1], %[T1], %[hi]  \n"

+    "addze  %[T2], %[T2]         \n"

+    : [hi]"=&r"(hi), [lo]"=&r"(lo), [T0]"+r"(T0), [T1]"+r"(T1), [T2]"+r"(T2)

+    : [A]"r"(A), [B]"r"(B)

+    : "xer"

+  );

+}

+

+// As above, but add twice the double-length result into the

+// accumulator.

+inline void MACC2(unsigned long A, unsigned long B, unsigned long &T0, unsigned long &T1, unsigned long &T2) {

+  unsigned long hi, lo;

+  __asm__ __volatile__ (

+    "mulld  %[lo], %[A], %[B]    \n"

+    "mulhdu %[hi], %[A], %[B]    \n"

+    "addc   %[T0], %[T0], %[lo]  \n"

+    "adde   %[T1], %[T1], %[hi]  \n"

+    "addze  %[T2], %[T2]         \n"

+    "addc   %[T0], %[T0], %[lo]  \n"

+    "adde   %[T1], %[T1], %[hi]  \n"

+    "addze  %[T2], %[T2]         \n"

+    : [hi]"=&r"(hi), [lo]"=&r"(lo), [T0]"+r"(T0), [T1]"+r"(T1), [T2]"+r"(T2)

+    : [A]"r"(A), [B]"r"(B)

+    : "xer"

+  );

+}

+

+// Fast Montgomery multiplication. The derivation of the algorithm is

+// in "A Cryptographic Library for the Motorola DSP56000,

+// Dusse and Kaliski, Proc. EUROCRYPT 90, pp. 230-237".

+static void

+montgomery_multiply(unsigned long a[], unsigned long b[], unsigned long n[],

+                    unsigned long m[], unsigned long inv, int len) {

+  unsigned long t0 = 0, t1 = 0, t2 = 0; // Triple-precision accumulator

+  int i;

+

+  assert(inv * n[0] == -1UL, "broken inverse in Montgomery multiply");

+

+  for (i = 0; i < len; i++) {

+    int j;

+    for (j = 0; j < i; j++) {

+      MACC(a[j], b[i-j], t0, t1, t2);

+      MACC(m[j], n[i-j], t0, t1, t2);

+    }

+    MACC(a[i], b[0], t0, t1, t2);

+    m[i] = t0 * inv;

+    MACC(m[i], n[0], t0, t1, t2);

+

+    assert(t0 == 0, "broken Montgomery multiply");

+

+    t0 = t1; t1 = t2; t2 = 0;

+  }

+

+  for (i = len; i < 2*len; i++) {

+    int j;

+    for (j = i-len+1; j < len; j++) {

+      MACC(a[j], b[i-j], t0, t1, t2);

+      MACC(m[j], n[i-j], t0, t1, t2);

+    }

+    m[i-len] = t0;

+    t0 = t1; t1 = t2; t2 = 0;

+  }

+

+  while (t0) {

+    t0 = sub(m, n, t0, len);

+  }

+}

+

+// Fast Montgomery squaring. This uses asymptotically 25% fewer

+// multiplies so it should be up to 25% faster than Montgomery

+// multiplication. However, its loop control is more complex and it

+// may actually run slower on some machines.

+static void

+montgomery_square(unsigned long a[], unsigned long n[],

+                  unsigned long m[], unsigned long inv, int len) {

+  unsigned long t0 = 0, t1 = 0, t2 = 0; // Triple-precision accumulator

+  int i;

+

+  assert(inv * n[0] == -1UL, "broken inverse in Montgomery multiply");

+

+  for (i = 0; i < len; i++) {

+    int j;

+    int end = (i+1)/2;

+    for (j = 0; j < end; j++) {

+      MACC2(a[j], a[i-j], t0, t1, t2);

+      MACC(m[j], n[i-j], t0, t1, t2);

+    }

+    if ((i & 1) == 0) {

+      MACC(a[j], a[j], t0, t1, t2);

+    }

+    for (; j < i; j++) {

+      MACC(m[j], n[i-j], t0, t1, t2);

+    }

+    m[i] = t0 * inv;

+    MACC(m[i], n[0], t0, t1, t2);

+

+    assert(t0 == 0, "broken Montgomery square");

+

+    t0 = t1; t1 = t2; t2 = 0;

+  }

+

+  for (i = len; i < 2*len; i++) {

+    int start = i-len+1;

+    int end = start + (len - start)/2;

+    int j;

+    for (j = start; j < end; j++) {

+      MACC2(a[j], a[i-j], t0, t1, t2);

+      MACC(m[j], n[i-j], t0, t1, t2);

+    }

+    if ((i & 1) == 0) {

+      MACC(a[j], a[j], t0, t1, t2);

+    }

+    for (; j < len; j++) {

+      MACC(m[j], n[i-j], t0, t1, t2);

+    }

+    m[i-len] = t0;

+    t0 = t1; t1 = t2; t2 = 0;

+  }

+

+  while (t0) {

+    t0 = sub(m, n, t0, len);

+  }

+}

+

+// The threshold at which squaring is advantageous was determined

+// experimentally on an i7-3930K (Ivy Bridge) CPU @ 3.5GHz.

+// Doesn't seem to be relevant for Power8 so we use the same value.

+#define MONTGOMERY_SQUARING_THRESHOLD 64

+

+// Copy len longwords from s to d, word-swapping as we go. The

+// destination array is reversed.

+static void reverse_words(unsigned long *s, unsigned long *d, int len) {

+  d += len;

+  while(len-- > 0) {

+    d--;

+    unsigned long s_val = *s;

+    // Swap words in a longword on little endian machines.

+#ifdef VM_LITTLE_ENDIAN

+     s_val = (s_val << 32) | (s_val >> 32);

+#endif

+    *d = s_val;

+    s++;

+  }

+}

+

+void SharedRuntime::montgomery_multiply(jint *a_ints, jint *b_ints, jint *n_ints,

+                                        jint len, jlong inv,

+                                        jint *m_ints) {

+  assert(len % 2 == 0, "array length in montgomery_multiply must be even");

+  int longwords = len/2;

+  assert(longwords > 0, "unsupported");

+

+  // Make very sure we don't use so much space that the stack might

+  // overflow. 512 jints corresponds to an 16384-bit integer and

+  // will use here a total of 8k bytes of stack space.

+  int total_allocation = longwords * sizeof (unsigned long) * 4;

+  guarantee(total_allocation <= 8192, "must be");

+  unsigned long *scratch = (unsigned long *)alloca(total_allocation);

+

+  // Local scratch arrays

+  unsigned long

+    *a = scratch + 0 * longwords,

+    *b = scratch + 1 * longwords,

+    *n = scratch + 2 * longwords,

+    *m = scratch + 3 * longwords;

+

+  reverse_words((unsigned long *)a_ints, a, longwords);

+  reverse_words((unsigned long *)b_ints, b, longwords);

+  reverse_words((unsigned long *)n_ints, n, longwords);

+

+  ::montgomery_multiply(a, b, n, m, (unsigned long)inv, longwords);

+

+  reverse_words(m, (unsigned long *)m_ints, longwords);

+}

+

+void SharedRuntime::montgomery_square(jint *a_ints, jint *n_ints,

+                                      jint len, jlong inv,

+                                      jint *m_ints) {

+  assert(len % 2 == 0, "array length in montgomery_square must be even");

+  int longwords = len/2;

+  assert(longwords > 0, "unsupported");

+

+  // Make very sure we don't use so much space that the stack might

+  // overflow. 512 jints corresponds to an 16384-bit integer and

+  // will use here a total of 6k bytes of stack space.

+  int total_allocation = longwords * sizeof (unsigned long) * 3;

+  guarantee(total_allocation <= 8192, "must be");

+  unsigned long *scratch = (unsigned long *)alloca(total_allocation);

+

+  // Local scratch arrays

+  unsigned long

+    *a = scratch + 0 * longwords,

+    *n = scratch + 1 * longwords,

+    *m = scratch + 2 * longwords;

+

+  reverse_words((unsigned long *)a_ints, a, longwords);

+  reverse_words((unsigned long *)n_ints, n, longwords);

+

+  if (len >= MONTGOMERY_SQUARING_THRESHOLD) {

+    ::montgomery_square(a, n, m, (unsigned long)inv, longwords);

+  } else {

+    ::montgomery_multiply(a, a, n, m, (unsigned long)inv, longwords);

+  }

+

+  reverse_words(m, (unsigned long *)m_ints, longwords);

+}

diff --git a/src/cpu/ppc/vm/stubGenerator_ppc.cpp b/src/cpu/ppc/vm/stubGenerator_ppc.cpp

--- openjdk/hotspot/src/cpu/ppc/vm/stubGenerator_ppc.cpp

+++ openjdk/hotspot/src/cpu/ppc/vm/stubGenerator_ppc.cpp

@@ -2094,6 +2094,14 @@

     generate_safefetch("SafeFetchN", sizeof(intptr_t), &StubRoutines::_safefetchN_entry,

                                                        &StubRoutines::_safefetchN_fault_pc,

                                                        &StubRoutines::_safefetchN_continuation_pc);

+    if (UseMontgomeryMultiplyIntrinsic) {

+      StubRoutines::_montgomeryMultiply

+        = CAST_FROM_FN_PTR(address, SharedRuntime::montgomery_multiply);

+    }

+    if (UseMontgomerySquareIntrinsic) {

+      StubRoutines::_montgomerySquare

+        = CAST_FROM_FN_PTR(address, SharedRuntime::montgomery_square);

+    }

   }

  public:

diff --git a/src/cpu/ppc/vm/templateInterpreter_ppc.cpp b/src/cpu/ppc/vm/templateInterpreter_ppc.cpp

--- openjdk/hotspot/src/cpu/ppc/vm/templateInterpreter_ppc.cpp

+++ openjdk/hotspot/src/cpu/ppc/vm/templateInterpreter_ppc.cpp

@@ -265,7 +265,7 @@

       __ cmpdi(CCR0, Rmdo, 0);

       __ beq(CCR0, no_mdo);

-      // Increment backedge counter in the MDO.

+      // Increment invocation counter in the MDO.

       const int mdo_bc_offs = in_bytes(MethodData::backedge_counter_offset()) + in_bytes(InvocationCounter::counter_offset());

       __ lwz(Rscratch2, mdo_bc_offs, Rmdo);

       __ addi(Rscratch2, Rscratch2, increment);

@@ -277,12 +277,12 @@

     }

     // Increment counter in MethodCounters*.

-    const int mo_bc_offs = in_bytes(MethodCounters::backedge_counter_offset()) + in_bytes(InvocationCounter::counter_offset());

+    const int mo_ic_offs = in_bytes(MethodCounters::invocation_counter_offset()) + in_bytes(InvocationCounter::counter_offset());

     __ bind(no_mdo);

     __ get_method_counters(R19_method, R3_counters, done);

-    __ lwz(Rscratch2, mo_bc_offs, R3_counters);

+    __ lwz(Rscratch2, mo_ic_offs, R3_counters);

     __ addi(Rscratch2, Rscratch2, increment);

-    __ stw(Rscratch2, mo_bc_offs, R3_counters);

+    __ stw(Rscratch2, mo_ic_offs, R3_counters);

     __ load_const_optimized(Rscratch1, mask, R0);

     __ and_(Rscratch1, Rscratch2, Rscratch1);

     __ beq(CCR0, *overflow);

diff --git a/src/cpu/ppc/vm/vm_version_ppc.cpp b/src/cpu/ppc/vm/vm_version_ppc.cpp

--- openjdk/hotspot/src/cpu/ppc/vm/vm_version_ppc.cpp

+++ openjdk/hotspot/src/cpu/ppc/vm/vm_version_ppc.cpp

@@ -177,6 +177,12 @@

     FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);

   }

+  if (FLAG_IS_DEFAULT(UseMontgomeryMultiplyIntrinsic)) {

+    UseMontgomeryMultiplyIntrinsic = true;

+  }

+  if (FLAG_IS_DEFAULT(UseMontgomerySquareIntrinsic)) {

+    UseMontgomerySquareIntrinsic = true;

+  }

 }

 void VM_Version::print_features() {

diff --git a/src/share/vm/opto/library_call.cpp b/src/share/vm/opto/library_call.cpp

--- openjdk/hotspot/src/share/vm/opto/library_call.cpp

+++ openjdk/hotspot/src/share/vm/opto/library_call.cpp

@@ -6031,11 +6031,21 @@

     Node* n_start = array_element_address(n, intcon(0), n_elem);

     Node* m_start = array_element_address(m, intcon(0), m_elem);

-    Node* call = make_runtime_call(RC_LEAF,

-                                   OptoRuntime::montgomeryMultiply_Type(),

-                                   stubAddr, stubName, TypePtr::BOTTOM,

-                                   a_start, b_start, n_start, len, inv, top(),

-                                   m_start);

+    Node* call = NULL;

+    if (CCallingConventionRequiresIntsAsLongs) {

+      Node* len_I2L = ConvI2L(len);

+      call = make_runtime_call(RC_LEAF,

+                               OptoRuntime::montgomeryMultiply_Type(),

+                               stubAddr, stubName, TypePtr::BOTTOM,

+                               a_start, b_start, n_start, len_I2L XTOP, inv,

+                               top(), m_start);

+    } else {

+      call = make_runtime_call(RC_LEAF,

+                               OptoRuntime::montgomeryMultiply_Type(),

+                               stubAddr, stubName, TypePtr::BOTTOM,

+                               a_start, b_start, n_start, len, inv, top(),

+                               m_start);

+    }

     set_result(m);

   }

@@ -6085,11 +6095,22 @@

     Node* n_start = array_element_address(n, intcon(0), n_elem);

     Node* m_start = array_element_address(m, intcon(0), m_elem);

-    Node* call = make_runtime_call(RC_LEAF,

-                                   OptoRuntime::montgomerySquare_Type(),

-                                   stubAddr, stubName, TypePtr::BOTTOM,

-                                   a_start, n_start, len, inv, top(),

-                                   m_start);

+    Node* call = NULL;

+    if (CCallingConventionRequiresIntsAsLongs) {

+      Node* len_I2L = ConvI2L(len);

+      call = make_runtime_call(RC_LEAF,

+                               OptoRuntime::montgomerySquare_Type(),

+                               stubAddr, stubName, TypePtr::BOTTOM,

+                               a_start, n_start, len_I2L XTOP, inv, top(),

+                               m_start);

+    } else {

+      call = make_runtime_call(RC_LEAF,

+                               OptoRuntime::montgomerySquare_Type(),

+                               stubAddr, stubName, TypePtr::BOTTOM,

+                               a_start, n_start, len, inv, top(),

+                               m_start);

+    }

+

     set_result(m);

   }

diff --git a/src/share/vm/opto/runtime.cpp b/src/share/vm/opto/runtime.cpp

--- openjdk/hotspot/src/share/vm/opto/runtime.cpp

+++ openjdk/hotspot/src/share/vm/opto/runtime.cpp

@@ -1005,12 +1005,20 @@

   // create input type (domain)

   int num_args      = 7;

   int argcnt = num_args;

+  if (CCallingConventionRequiresIntsAsLongs) {

+    argcnt++;                           // additional placeholder

+  }

   const Type** fields = TypeTuple::fields(argcnt);

   int argp = TypeFunc::Parms;

   fields[argp++] = TypePtr::NOTNULL;    // a

   fields[argp++] = TypePtr::NOTNULL;    // b

   fields[argp++] = TypePtr::NOTNULL;    // n

-  fields[argp++] = TypeInt::INT;        // len

+  if (CCallingConventionRequiresIntsAsLongs) {

+    fields[argp++] = TypeLong::LONG;    // len

+    fields[argp++] = TypeLong::HALF;    // placeholder

+  } else {

+    fields[argp++] = TypeInt::INT;      // len

+  }

   fields[argp++] = TypeLong::LONG;      // inv

   fields[argp++] = Type::HALF;

   fields[argp++] = TypePtr::NOTNULL;    // result

@@ -1029,11 +1037,19 @@

   // create input type (domain)

   int num_args      = 6;

   int argcnt = num_args;

+  if (CCallingConventionRequiresIntsAsLongs) {

+    argcnt++;                           // additional placeholder

+  }

   const Type** fields = TypeTuple::fields(argcnt);

   int argp = TypeFunc::Parms;

   fields[argp++] = TypePtr::NOTNULL;    // a

   fields[argp++] = TypePtr::NOTNULL;    // n

-  fields[argp++] = TypeInt::INT;        // len

+  if (CCallingConventionRequiresIntsAsLongs) {

+    fields[argp++] = TypeLong::LONG;    // len

+    fields[argp++] = TypeLong::HALF;    // placeholder

+  } else {

+    fields[argp++] = TypeInt::INT;      // len

+  }

   fields[argp++] = TypeLong::LONG;      // inv

   fields[argp++] = Type::HALF;

   fields[argp++] = TypePtr::NOTNULL;    // result