fastmodel: Implement CC reg accessors.

Change-Id: I4d8a7eaa097446b6aa3483880c2a7ed1a2e0d97c
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23790
Reviewed-by: Chun-Chen TK Hsu <chunchenhsu@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/arch/arm/fastmodel/CortexA76/thread_context.cc

@@ -93,9 +93,51 @@ CortexA76TC::initFromIrisInstance(const ResourceMap &resources)
     extractResourceMap(intReg32Ids, resources, intReg32IdxNameMap);
     extractResourceMap(intReg64Ids, resources, intReg64IdxNameMap);
 
+    extractResourceMap(ccRegIds, resources, ccRegIdxNameMap);
+
     extractResourceMap(vecRegIds, resources, vecRegIdxNameMap);
 }
 
+RegVal
+CortexA76TC::readCCRegFlat(RegIndex idx) const
+{
+    RegVal result = Iris::ThreadContext::readCCRegFlat(idx);
+    switch (idx) {
+      case ArmISA::CCREG_NZ:
+        result = ((CPSR)result).nz;
+        break;
+      case ArmISA::CCREG_FP:
+        result = bits(result, 31, 28);
+        break;
+      default:
+        break;
+    }
+    return result;
+}
+
+void
+CortexA76TC::setCCRegFlat(RegIndex idx, RegVal val)
+{
+    switch (idx) {
+      case ArmISA::CCREG_NZ:
+        {
+            CPSR cpsr = readMiscRegNoEffect(ArmISA::MISCREG_CPSR);
+            cpsr.nz = val;
+            val = cpsr;
+        }
+        break;
+      case ArmISA::CCREG_FP:
+        {
+            FPSCR fpscr = readMiscRegNoEffect(ArmISA::MISCREG_FPSCR);
+            val = insertBits(fpscr, 31, 28, val);
+        }
+        break;
+      default:
+        break;
+    }
+    Iris::ThreadContext::setCCRegFlat(idx, val);
+}
+
 iris::MemorySpaceId
 CortexA76TC::getBpSpaceId(Addr pc) const
 {
@@ -798,6 +840,14 @@ Iris::ThreadContext::IdxNameMap CortexA76TC::intReg64IdxNameMap({
         { ArmISA::INTREG_SPX, "SP" },
 });
 
+Iris::ThreadContext::IdxNameMap CortexA76TC::ccRegIdxNameMap({
+        { ArmISA::CCREG_NZ, "CPSR" },
+        { ArmISA::CCREG_C, "CPSR.C" },
+        { ArmISA::CCREG_V, "CPSR.V" },
+        { ArmISA::CCREG_GE, "CPSR.GE" },
+        { ArmISA::CCREG_FP, "FPSCR" },
+});
+
 Iris::ThreadContext::IdxNameMap CortexA76TC::vecRegIdxNameMap({
         { 0, "V0" }, { 1, "V1" }, { 2, "V2" }, { 3, "V3" },
         { 4, "V4" }, { 5, "V5" }, { 6, "V6" }, { 7, "V7" },

src/arch/arm/fastmodel/CortexA76/thread_context.hh

@@ -43,6 +43,7 @@ class CortexA76TC : public Iris::ThreadContext
     static IdxNameMap miscRegIdxNameMap;
     static IdxNameMap intReg32IdxNameMap;
     static IdxNameMap intReg64IdxNameMap;
+    static IdxNameMap ccRegIdxNameMap;
     static IdxNameMap vecRegIdxNameMap;
     static iris::MemorySpaceId bpSpaceId;
 
@@ -56,6 +57,9 @@ class CortexA76TC : public Iris::ThreadContext
 
     void initFromIrisInstance(const ResourceMap &resources) override;
 
+    RegVal readCCRegFlat(RegIndex idx) const override;
+    void setCCRegFlat(RegIndex idx, RegVal val) override;
+
     iris::MemorySpaceId getBpSpaceId(Addr pc) const override;
 };
 

src/arch/arm/fastmodel/iris/thread_context.cc

@@ -520,6 +520,25 @@ ThreadContext::setIntReg(RegIndex reg_idx, RegVal val)
         call().resource_write(_instId, result, intReg64Ids.at(reg_idx), val);
 }
 
+RegVal
+ThreadContext::readCCRegFlat(RegIndex idx) const
+{
+    if (idx >= ccRegIds.size())
+        return 0;
+    iris::ResourceReadResult result;
+    call().resource_read(_instId, result, ccRegIds.at(idx));
+    return result.data.at(0);
+}
+
+void
+ThreadContext::setCCRegFlat(RegIndex idx, RegVal val)
+{
+    panic_if(idx >= ccRegIds.size(),
+            "CC reg %d is not supported by fast model.", idx);
+    iris::ResourceWriteResult result;
+    call().resource_write(_instId, result, ccRegIds.at(idx), val);
+}
+
 const ArmISA::VecRegContainer &
 ThreadContext::readVecReg(const RegId &reg_id) const
 {

src/arch/arm/fastmodel/iris/thread_context.hh

@@ -83,6 +83,7 @@ class ThreadContext : public ::ThreadContext
     ResourceIds miscRegIds;
     ResourceIds intReg32Ids;
     ResourceIds intReg64Ids;
+    ResourceIds ccRegIds;
 
     iris::ResourceId pcRscId = iris::IRIS_UINT64_MAX;
     iris::ResourceId icountRscId;
@@ -386,7 +387,7 @@ class ThreadContext : public ::ThreadContext
     RegVal
     readCCReg(RegIndex reg_idx) const override
     {
-        panic("%s not implemented.", __FUNCTION__);
+        return readCCRegFlat(reg_idx);
     }
 
     void setIntReg(RegIndex reg_idx, RegVal val) override;
@@ -419,7 +420,7 @@ class ThreadContext : public ::ThreadContext
     void
     setCCReg(RegIndex reg_idx, RegVal val) override
     {
-        panic("%s not implemented.", __FUNCTION__);
+        setCCRegFlat(reg_idx, val);
     }
 
     void pcStateNoRecord(const ArmISA::PCState &val) override { pcState(val); }
@@ -547,16 +548,8 @@ class ThreadContext : public ::ThreadContext
         panic("%s not implemented.", __FUNCTION__);
     }
 
-    RegVal
-    readCCRegFlat(RegIndex idx) const override
-    {
-        panic("%s not implemented.", __FUNCTION__);
-    }
-    void
-    setCCRegFlat(RegIndex idx, RegVal val) override
-    {
-        panic("%s not implemented.", __FUNCTION__);
-    }
+    RegVal readCCRegFlat(RegIndex idx) const override;
+    void setCCRegFlat(RegIndex idx, RegVal val) override;
     /** @} */
 
 };