src/hotspot/share/opto/regmask.cpp
changeset 47216 71c04702a3d5
parent 38022 342a29d198d8
child 53443 675d857f5ee3
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/opto/regmask.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,454 @@
+/*
+ * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "opto/ad.hpp"
+#include "opto/compile.hpp"
+#include "opto/matcher.hpp"
+#include "opto/node.hpp"
+#include "opto/regmask.hpp"
+
+#define RM_SIZE _RM_SIZE /* a constant private to the class RegMask */
+
+//-------------Non-zero bit search methods used by RegMask---------------------
+// Find lowest 1, or return 32 if empty
+int find_lowest_bit( uint32_t mask ) {
+  int n = 0;
+  if( (mask & 0xffff) == 0 ) {
+    mask >>= 16;
+    n += 16;
+  }
+  if( (mask & 0xff) == 0 ) {
+    mask >>= 8;
+    n += 8;
+  }
+  if( (mask & 0xf) == 0 ) {
+    mask >>= 4;
+    n += 4;
+  }
+  if( (mask & 0x3) == 0 ) {
+    mask >>= 2;
+    n += 2;
+  }
+  if( (mask & 0x1) == 0 ) {
+    mask >>= 1;
+     n += 1;
+  }
+  if( mask == 0 ) {
+    n = 32;
+  }
+  return n;
+}
+
+// Find highest 1, or return 32 if empty
+int find_hihghest_bit( uint32_t mask ) {
+  int n = 0;
+  if( mask > 0xffff ) {
+    mask >>= 16;
+    n += 16;
+  }
+  if( mask > 0xff ) {
+    mask >>= 8;
+    n += 8;
+  }
+  if( mask > 0xf ) {
+    mask >>= 4;
+    n += 4;
+  }
+  if( mask > 0x3 ) {
+    mask >>= 2;
+    n += 2;
+  }
+  if( mask > 0x1 ) {
+    mask >>= 1;
+    n += 1;
+  }
+  if( mask == 0 ) {
+    n = 32;
+  }
+  return n;
+}
+
+//------------------------------dump-------------------------------------------
+
+#ifndef PRODUCT
+void OptoReg::dump(int r, outputStream *st) {
+  switch (r) {
+  case Special: st->print("r---"); break;
+  case Bad:     st->print("rBAD"); break;
+  default:
+    if (r < _last_Mach_Reg) st->print("%s", Matcher::regName[r]);
+    else st->print("rS%d",r);
+    break;
+  }
+}
+#endif
+
+
+//=============================================================================
+const RegMask RegMask::Empty(
+# define BODY(I) 0,
+  FORALL_BODY
+# undef BODY
+  0
+);
+
+//=============================================================================
+bool RegMask::is_vector(uint ireg) {
+  return (ireg == Op_VecS || ireg == Op_VecD ||
+          ireg == Op_VecX || ireg == Op_VecY || ireg == Op_VecZ );
+}
+
+int RegMask::num_registers(uint ireg) {
+    switch(ireg) {
+      case Op_VecZ:
+        return 16;
+      case Op_VecY:
+        return 8;
+      case Op_VecX:
+        return 4;
+      case Op_VecD:
+      case Op_RegD:
+      case Op_RegL:
+#ifdef _LP64
+      case Op_RegP:
+#endif
+        return 2;
+    }
+    // Op_VecS and the rest ideal registers.
+    return 1;
+}
+
+//------------------------------find_first_pair--------------------------------
+// Find the lowest-numbered register pair in the mask.  Return the
+// HIGHEST register number in the pair, or BAD if no pairs.
+OptoReg::Name RegMask::find_first_pair() const {
+  verify_pairs();
+  for( int i = 0; i < RM_SIZE; i++ ) {
+    if( _A[i] ) {               // Found some bits
+      int bit = _A[i] & -_A[i]; // Extract low bit
+      // Convert to bit number, return hi bit in pair
+      return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+1);
+    }
+  }
+  return OptoReg::Bad;
+}
+
+//------------------------------ClearToPairs-----------------------------------
+// Clear out partial bits; leave only bit pairs
+void RegMask::clear_to_pairs() {
+  for( int i = 0; i < RM_SIZE; i++ ) {
+    int bits = _A[i];
+    bits &= ((bits & 0x55555555)<<1); // 1 hi-bit set for each pair
+    bits |= (bits>>1);          // Smear 1 hi-bit into a pair
+    _A[i] = bits;
+  }
+  verify_pairs();
+}
+
+//------------------------------SmearToPairs-----------------------------------
+// Smear out partial bits; leave only bit pairs
+void RegMask::smear_to_pairs() {
+  for( int i = 0; i < RM_SIZE; i++ ) {
+    int bits = _A[i];
+    bits |= ((bits & 0x55555555)<<1); // Smear lo bit hi per pair
+    bits |= ((bits & 0xAAAAAAAA)>>1); // Smear hi bit lo per pair
+    _A[i] = bits;
+  }
+  verify_pairs();
+}
+
+//------------------------------is_aligned_pairs-------------------------------
+bool RegMask::is_aligned_pairs() const {
+  // Assert that the register mask contains only bit pairs.
+  for( int i = 0; i < RM_SIZE; i++ ) {
+    int bits = _A[i];
+    while( bits ) {             // Check bits for pairing
+      int bit = bits & -bits;   // Extract low bit
+      // Low bit is not odd means its mis-aligned.
+      if( (bit & 0x55555555) == 0 ) return false;
+      bits -= bit;              // Remove bit from mask
+      // Check for aligned adjacent bit
+      if( (bits & (bit<<1)) == 0 ) return false;
+      bits -= (bit<<1);         // Remove other halve of pair
+    }
+  }
+  return true;
+}
+
+//------------------------------is_bound1--------------------------------------
+// Return TRUE if the mask contains a single bit
+int RegMask::is_bound1() const {
+  if( is_AllStack() ) return false;
+  int bit = -1;                 // Set to hold the one bit allowed
+  for( int i = 0; i < RM_SIZE; i++ ) {
+    if( _A[i] ) {               // Found some bits
+      if( bit != -1 ) return false; // Already had bits, so fail
+      bit = _A[i] & -_A[i];     // Extract 1 bit from mask
+      if( bit != _A[i] ) return false; // Found many bits, so fail
+    }
+  }
+  // True for both the empty mask and for a single bit
+  return true;
+}
+
+//------------------------------is_bound2--------------------------------------
+// Return TRUE if the mask contains an adjacent pair of bits and no other bits.
+int RegMask::is_bound_pair() const {
+  if( is_AllStack() ) return false;
+
+  int bit = -1;                 // Set to hold the one bit allowed
+  for( int i = 0; i < RM_SIZE; i++ ) {
+    if( _A[i] ) {               // Found some bits
+      if( bit != -1 ) return false; // Already had bits, so fail
+      bit = _A[i] & -(_A[i]);   // Extract 1 bit from mask
+      if( (bit << 1) != 0 ) {   // Bit pair stays in same word?
+        if( (bit | (bit<<1)) != _A[i] )
+          return false;         // Require adjacent bit pair and no more bits
+      } else {                  // Else its a split-pair case
+        if( bit != _A[i] ) return false; // Found many bits, so fail
+        i++;                    // Skip iteration forward
+        if( i >= RM_SIZE || _A[i] != 1 )
+          return false; // Require 1 lo bit in next word
+      }
+    }
+  }
+  // True for both the empty mask and for a bit pair
+  return true;
+}
+
+// only indicies of power 2 are accessed, so index 3 is only filled in for storage.
+static int low_bits[5] = { 0x55555555, 0x11111111, 0x01010101, 0x00000000, 0x00010001 };
+//------------------------------find_first_set---------------------------------
+// Find the lowest-numbered register set in the mask.  Return the
+// HIGHEST register number in the set, or BAD if no sets.
+// Works also for size 1.
+OptoReg::Name RegMask::find_first_set(const int size) const {
+  verify_sets(size);
+  for (int i = 0; i < RM_SIZE; i++) {
+    if (_A[i]) {                // Found some bits
+      int bit = _A[i] & -_A[i]; // Extract low bit
+      // Convert to bit number, return hi bit in pair
+      return OptoReg::Name((i<<_LogWordBits)+find_lowest_bit(bit)+(size-1));
+    }
+  }
+  return OptoReg::Bad;
+}
+
+//------------------------------clear_to_sets----------------------------------
+// Clear out partial bits; leave only aligned adjacent bit pairs
+void RegMask::clear_to_sets(const int size) {
+  if (size == 1) return;
+  assert(2 <= size && size <= 16, "update low bits table");
+  assert(is_power_of_2(size), "sanity");
+  int low_bits_mask = low_bits[size>>2];
+  for (int i = 0; i < RM_SIZE; i++) {
+    int bits = _A[i];
+    int sets = (bits & low_bits_mask);
+    for (int j = 1; j < size; j++) {
+      sets = (bits & (sets<<1)); // filter bits which produce whole sets
+    }
+    sets |= (sets>>1);           // Smear 1 hi-bit into a set
+    if (size > 2) {
+      sets |= (sets>>2);         // Smear 2 hi-bits into a set
+      if (size > 4) {
+        sets |= (sets>>4);       // Smear 4 hi-bits into a set
+        if (size > 8) {
+          sets |= (sets>>8);     // Smear 8 hi-bits into a set
+        }
+      }
+    }
+    _A[i] = sets;
+  }
+  verify_sets(size);
+}
+
+//------------------------------smear_to_sets----------------------------------
+// Smear out partial bits to aligned adjacent bit sets
+void RegMask::smear_to_sets(const int size) {
+  if (size == 1) return;
+  assert(2 <= size && size <= 16, "update low bits table");
+  assert(is_power_of_2(size), "sanity");
+  int low_bits_mask = low_bits[size>>2];
+  for (int i = 0; i < RM_SIZE; i++) {
+    int bits = _A[i];
+    int sets = 0;
+    for (int j = 0; j < size; j++) {
+      sets |= (bits & low_bits_mask);  // collect partial bits
+      bits  = bits>>1;
+    }
+    sets |= (sets<<1);           // Smear 1 lo-bit  into a set
+    if (size > 2) {
+      sets |= (sets<<2);         // Smear 2 lo-bits into a set
+      if (size > 4) {
+        sets |= (sets<<4);       // Smear 4 lo-bits into a set
+        if (size > 8) {
+          sets |= (sets<<8);     // Smear 8 lo-bits into a set
+        }
+      }
+    }
+    _A[i] = sets;
+  }
+  verify_sets(size);
+}
+
+//------------------------------is_aligned_set--------------------------------
+bool RegMask::is_aligned_sets(const int size) const {
+  if (size == 1) return true;
+  assert(2 <= size && size <= 16, "update low bits table");
+  assert(is_power_of_2(size), "sanity");
+  int low_bits_mask = low_bits[size>>2];
+  // Assert that the register mask contains only bit sets.
+  for (int i = 0; i < RM_SIZE; i++) {
+    int bits = _A[i];
+    while (bits) {              // Check bits for pairing
+      int bit = bits & -bits;   // Extract low bit
+      // Low bit is not odd means its mis-aligned.
+      if ((bit & low_bits_mask) == 0) return false;
+      // Do extra work since (bit << size) may overflow.
+      int hi_bit = bit << (size-1); // high bit
+      int set = hi_bit + ((hi_bit-1) & ~(bit-1));
+      // Check for aligned adjacent bits in this set
+      if ((bits & set) != set) return false;
+      bits -= set;  // Remove this set
+    }
+  }
+  return true;
+}
+
+//------------------------------is_bound_set-----------------------------------
+// Return TRUE if the mask contains one adjacent set of bits and no other bits.
+// Works also for size 1.
+int RegMask::is_bound_set(const int size) const {
+  if( is_AllStack() ) return false;
+  assert(1 <= size && size <= 16, "update low bits table");
+  int bit = -1;                 // Set to hold the one bit allowed
+  for (int i = 0; i < RM_SIZE; i++) {
+    if (_A[i] ) {               // Found some bits
+      if (bit != -1)
+       return false;            // Already had bits, so fail
+      bit = _A[i] & -_A[i];     // Extract low bit from mask
+      int hi_bit = bit << (size-1); // high bit
+      if (hi_bit != 0) {        // Bit set stays in same word?
+        int set = hi_bit + ((hi_bit-1) & ~(bit-1));
+        if (set != _A[i])
+          return false;         // Require adjacent bit set and no more bits
+      } else {                  // Else its a split-set case
+        if (((-1) & ~(bit-1)) != _A[i])
+          return false;         // Found many bits, so fail
+        i++;                    // Skip iteration forward and check high part
+        // The lower (32-size) bits should be 0 since it is split case.
+        int clear_bit_size = 32-size;
+        int shift_back_size = 32-clear_bit_size;
+        int set = bit>>clear_bit_size;
+        set = set & -set; // Remove sign extension.
+        set = (((set << size) - 1) >> shift_back_size);
+        if (i >= RM_SIZE || _A[i] != set)
+          return false; // Require expected low bits in next word
+      }
+    }
+  }
+  // True for both the empty mask and for a bit set
+  return true;
+}
+
+//------------------------------is_UP------------------------------------------
+// UP means register only, Register plus stack, or stack only is DOWN
+bool RegMask::is_UP() const {
+  // Quick common case check for DOWN (any stack slot is legal)
+  if( is_AllStack() )
+    return false;
+  // Slower check for any stack bits set (also DOWN)
+  if( overlap(Matcher::STACK_ONLY_mask) )
+    return false;
+  // Not DOWN, so must be UP
+  return true;
+}
+
+//------------------------------Size-------------------------------------------
+// Compute size of register mask in bits
+uint RegMask::Size() const {
+  extern uint8_t bitsInByte[BITS_IN_BYTE_ARRAY_SIZE];
+  uint sum = 0;
+  for( int i = 0; i < RM_SIZE; i++ )
+    sum +=
+      bitsInByte[(_A[i]>>24) & 0xff] +
+      bitsInByte[(_A[i]>>16) & 0xff] +
+      bitsInByte[(_A[i]>> 8) & 0xff] +
+      bitsInByte[ _A[i]      & 0xff];
+  return sum;
+}
+
+#ifndef PRODUCT
+//------------------------------print------------------------------------------
+void RegMask::dump(outputStream *st) const {
+  st->print("[");
+  RegMask rm = *this;           // Structure copy into local temp
+
+  OptoReg::Name start = rm.find_first_elem(); // Get a register
+  if (OptoReg::is_valid(start)) { // Check for empty mask
+    rm.Remove(start);           // Yank from mask
+    OptoReg::dump(start, st);   // Print register
+    OptoReg::Name last = start;
+
+    // Now I have printed an initial register.
+    // Print adjacent registers as "rX-rZ" instead of "rX,rY,rZ".
+    // Begin looping over the remaining registers.
+    while (1) {                 //
+      OptoReg::Name reg = rm.find_first_elem(); // Get a register
+      if (!OptoReg::is_valid(reg))
+        break;                  // Empty mask, end loop
+      rm.Remove(reg);           // Yank from mask
+
+      if (last+1 == reg) {      // See if they are adjacent
+        // Adjacent registers just collect into long runs, no printing.
+        last = reg;
+      } else {                  // Ending some kind of run
+        if (start == last) {    // 1-register run; no special printing
+        } else if (start+1 == last) {
+          st->print(",");       // 2-register run; print as "rX,rY"
+          OptoReg::dump(last, st);
+        } else {                // Multi-register run; print as "rX-rZ"
+          st->print("-");
+          OptoReg::dump(last, st);
+        }
+        st->print(",");         // Seperate start of new run
+        start = last = reg;     // Start a new register run
+        OptoReg::dump(start, st); // Print register
+      } // End of if ending a register run or not
+    } // End of while regmask not empty
+
+    if (start == last) {        // 1-register run; no special printing
+    } else if (start+1 == last) {
+      st->print(",");           // 2-register run; print as "rX,rY"
+      OptoReg::dump(last, st);
+    } else {                    // Multi-register run; print as "rX-rZ"
+      st->print("-");
+      OptoReg::dump(last, st);
+    }
+    if (rm.is_AllStack()) st->print("...");
+  }
+  st->print("]");
+}
+#endif