src/cpu/x86/vm/icache_x86.hpp

Tue, 14 Oct 2008 15:10:26 -0700

author
kvn
date
Tue, 14 Oct 2008 15:10:26 -0700
changeset 840
2649e5276dd7
parent 435
a61af66fc99e
child 1907
c18cbe5936b8
permissions
-rw-r--r--

6532536: Optimize arraycopy stubs for Intel cpus
Summary: Use SSE2 movdqu in arraycopy stubs on newest Intel's cpus
Reviewed-by: rasbold

     1 /*
     2  * Copyright 1997-2004 Sun Microsystems, Inc.  All Rights Reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
    20  * CA 95054 USA or visit www.sun.com if you need additional information or
    21  * have any questions.
    22  *
    23  */
    25 // Interface for updating the instruction cache.  Whenever the VM modifies
    26 // code, part of the processor instruction cache potentially has to be flushed.
    28 // On the x86, this is a no-op -- the I-cache is guaranteed to be consistent
    29 // after the next jump, and the VM never modifies instructions directly ahead
    30 // of the instruction fetch path.
    32 // [phh] It's not clear that the above comment is correct, because on an MP
    33 // system where the dcaches are not snooped, only the thread doing the invalidate
    34 // will see the update.  Even in the snooped case, a memory fence would be
    35 // necessary if stores weren't ordered.  Fortunately, they are on all known
    36 // x86 implementations.
    38 class ICache : public AbstractICache {
    39  public:
    40 #ifdef AMD64
    41   enum {
    42     stub_size      = 64, // Size of the icache flush stub in bytes
    43     line_size      = 32, // Icache line size in bytes
    44     log2_line_size = 5   // log2(line_size)
    45   };
    47   // Use default implementation
    48 #else
    49   enum {
    50     stub_size      = 16,                 // Size of the icache flush stub in bytes
    51     line_size      = BytesPerWord,      // conservative
    52     log2_line_size = LogBytesPerWord    // log2(line_size)
    53   };
    54 #endif // AMD64
    55 };

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