hotspot/src/share/vm/opto/regmask.cpp
changeset 1 489c9b5090e2
child 5547 f4b087cbb361
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/opto/regmask.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,288 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_regmask.cpp.incl"
+
+#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 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 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 ) {
+  switch( r ) {
+  case Special: tty->print("r---");   break;
+  case Bad:     tty->print("rBAD");   break;
+  default:
+    if( r < _last_Mach_Reg ) tty->print(Matcher::regName[r]);
+    else tty->print("rS%d",r);
+    break;
+  }
+}
+#endif
+
+
+//=============================================================================
+const RegMask RegMask::Empty(
+# define BODY(I) 0,
+  FORALL_BODY
+# undef BODY
+  0
+);
+
+//------------------------------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 {
+  VerifyPairs();
+  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::ClearToPairs() {
+  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;
+  }
+  VerifyPairs();
+}
+
+//------------------------------SmearToPairs-----------------------------------
+// Smear out partial bits; leave only bit pairs
+void RegMask::SmearToPairs() {
+  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;
+  }
+  VerifyPairs();
+}
+
+//------------------------------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_bound2() 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( _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;
+}
+
+//------------------------------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 bitsInByte[256];
+  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( ) const {
+  tty->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);       // 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 ) {
+          tty->print(",");      // 2-register run; print as "rX,rY"
+          OptoReg::dump(last);
+        } else {                // Multi-register run; print as "rX-rZ"
+          tty->print("-");
+          OptoReg::dump(last);
+        }
+        tty->print(",");        // Seperate start of new run
+        start = last = reg;     // Start a new register run
+        OptoReg::dump(start); // 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 ) {
+      tty->print(",");          // 2-register run; print as "rX,rY"
+      OptoReg::dump(last);
+    } else {                    // Multi-register run; print as "rX-rZ"
+      tty->print("-");
+      OptoReg::dump(last);
+    }
+    if( rm.is_AllStack() ) tty->print("...");
+  }
+  tty->print("]");
+}
+#endif