arch: Templatize the BasicDecodeCache.

While the arch/generic directory is in arch/, it still shouldn't assume
any particular ISA. This change templatizes away the ISA specific types
so it can be used in multiple ISAs at a time.

Change-Id: I1abb4f5081a0a25f743be786ad8e7e3d55cfc67a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40097
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/arm/decoder.cc

@@ -50,7 +50,7 @@
 namespace ArmISA
 {
 
-GenericISA::BasicDecodeCache Decoder::defaultCache;
+GenericISA::BasicDecodeCache<Decoder, ExtMachInst> Decoder::defaultCache;
 
 Decoder::Decoder(ISA* isa)
     : data(0), fpscrLen(0), fpscrStride(0),

src/arch/arm/decoder.hh

@@ -80,7 +80,7 @@ class Decoder : public InstDecoder
     Enums::DecoderFlavor decoderFlavor;
 
     /// A cache of decoded instruction objects.
-    static GenericISA::BasicDecodeCache defaultCache;
+    static GenericISA::BasicDecodeCache<Decoder, ExtMachInst> defaultCache;
 
     /**
      * Pre-decode an instruction from the current state of the

src/arch/generic/SConscript

@@ -52,5 +52,4 @@ DebugFlag('TLB')
 if env['TARGET_ISA'] == 'null':
     Return()
 
-Source('decode_cache.cc')
 Source('decoder.cc')

src/arch/generic/decode_cache.cc

@@ -1,58 +0,0 @@
-/*
- * Copyright (c) 2011-2012 Google
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "arch/generic/decode_cache.hh"
-
-#include "arch/decoder.hh"
-#include "arch/types.hh"
-#include "config/the_isa.hh"
-#include "cpu/static_inst.hh"
-
-namespace GenericISA
-{
-
-StaticInstPtr
-BasicDecodeCache::decode(TheISA::Decoder *decoder,
-        TheISA::ExtMachInst mach_inst, Addr addr)
-{
-    StaticInstPtr &si = decodePages.lookup(addr);
-    if (si && (si->machInst == mach_inst))
-        return si;
-
-    auto iter = instMap.find(mach_inst);
-    if (iter != instMap.end()) {
-        si = iter->second;
-        return si;
-    }
-
-    si = decoder->decodeInst(mach_inst);
-    instMap[mach_inst] = si;
-    return si;
-}
-
-} // namespace GenericISA

src/arch/generic/decode_cache.hh

@@ -29,31 +29,48 @@
 #ifndef __ARCH_GENERIC_DECODE_CACHE_HH__
 #define __ARCH_GENERIC_DECODE_CACHE_HH__
 
-#include "arch/types.hh"
-#include "config/the_isa.hh"
+#include "base/types.hh"
 #include "cpu/decode_cache.hh"
 #include "cpu/static_inst_fwd.hh"
 
-namespace TheISA
-{
-    class Decoder;
-}
-
 namespace GenericISA
 {
 
+template <typename Decoder, typename EMI>
 class BasicDecodeCache
 {
   private:
-    DecodeCache::InstMap<TheISA::ExtMachInst> instMap;
-    DecodeCache::AddrMap<StaticInstPtr> decodePages;
+    DecodeCache::InstMap<EMI> instMap;
+    struct AddrMapEntry
+    {
+        StaticInstPtr inst;
+        EMI machInst;
+    };
+    DecodeCache::AddrMap<AddrMapEntry> decodePages;
 
   public:
     /// Decode a machine instruction.
     /// @param mach_inst The binary instruction to decode.
     /// @retval A pointer to the corresponding StaticInst object.
-    StaticInstPtr decode(TheISA::Decoder * const decoder,
-            TheISA::ExtMachInst mach_inst, Addr addr);
+    StaticInstPtr
+    decode(Decoder *const decoder, EMI mach_inst, Addr addr)
+    {
+        auto &entry = decodePages.lookup(addr);
+        if (entry.inst && (entry.machInst == mach_inst))
+            return entry.inst;
+
+        entry.machInst = mach_inst;
+
+        auto iter = instMap.find(mach_inst);
+        if (iter != instMap.end()) {
+            entry.inst = iter->second;
+            return entry.inst;
+        }
+
+        entry.inst = decoder->decodeInst(mach_inst);
+        instMap[mach_inst] = entry.inst;
+        return entry.inst;
+    }
 };
 
 } // namespace GenericISA

src/arch/mips/decoder.cc

@@ -31,6 +31,6 @@
 namespace MipsISA
 {
 
-GenericISA::BasicDecodeCache Decoder::defaultCache;
+GenericISA::BasicDecodeCache<Decoder, ExtMachInst> Decoder::defaultCache;
 
 }

src/arch/mips/decoder.hh

@@ -87,7 +87,7 @@ class Decoder : public InstDecoder
 
   protected:
     /// A cache of decoded instruction objects.
-    static GenericISA::BasicDecodeCache defaultCache;
+    static GenericISA::BasicDecodeCache<Decoder, ExtMachInst> defaultCache;
 
   public:
     StaticInstPtr decodeInst(ExtMachInst mach_inst);

src/arch/power/decoder.cc

@@ -31,6 +31,6 @@
 namespace PowerISA
 {
 
-GenericISA::BasicDecodeCache Decoder::defaultCache;
+GenericISA::BasicDecodeCache<Decoder, ExtMachInst> Decoder::defaultCache;
 
 }

src/arch/power/decoder.hh

@@ -94,7 +94,7 @@ class Decoder : public InstDecoder
 
   protected:
     /// A cache of decoded instruction objects.
-    static GenericISA::BasicDecodeCache defaultCache;
+    static GenericISA::BasicDecodeCache<Decoder, ExtMachInst> defaultCache;
 
   public:
     StaticInstPtr decodeInst(ExtMachInst mach_inst);

src/arch/sparc/decoder.cc

@@ -31,6 +31,6 @@
 namespace SparcISA
 {
 
-GenericISA::BasicDecodeCache Decoder::defaultCache;
+GenericISA::BasicDecodeCache<Decoder, ExtMachInst> Decoder::defaultCache;
 
 }

src/arch/sparc/decoder.hh

@@ -101,7 +101,7 @@ class Decoder : public InstDecoder
 
   protected:
     /// A cache of decoded instruction objects.
-    static GenericISA::BasicDecodeCache defaultCache;
+    static GenericISA::BasicDecodeCache<Decoder, ExtMachInst> defaultCache;
 
   public:
     StaticInstPtr decodeInst(ExtMachInst mach_inst);