Add a level of indirection to the register accessors used in

instruction execute methods.  Register i now means the instruction's
i'th src (or dest) operand, not architectural register i.  Current
models that use the architectural reg index can look that up easily
in the instruction object.  Future models that do register renaming
should find this much simpler to deal with.

arch/isa_parser.py:
    Generate register accessors with an extra level of indirection.
cpu/simple_cpu/simple_cpu.hh:
    Modify register accessors to use an extra level of indirection.

--HG--
extra : convert_revision : f4c7d6bfa92fb2ea6251f31ee368809c3643f08f

1 files changed, 54 insertions, 19 deletions

diff --git a/cpu/simple_cpu/simple_cpu.hh b/cpu/simple_cpu/simple_cpu.hh
index a04dcd057..0c7204fcd 100644
--- a/cpu/simple_cpu/simple_cpu.hh
+++ b/cpu/simple_cpu/simple_cpu.hh
@@ -35,6 +35,7 @@
 #include "cpu/pc_event.hh"
 #include "base/statistics.hh"
 #include "cpu/exec_context.hh"
+#include "cpu/static_inst.hh"
 
 // forward declarations
 #ifdef FULL_SYSTEM
@@ -261,37 +262,71 @@ class SimpleCPU : public BaseCPU
 
     Fault copy(Addr dest);
 
-    uint64_t readIntReg(int reg_idx) { return xc->readIntReg(reg_idx); }
+    // The register accessor methods provide the index of the
+    // instruction's operand (e.g., 0 or 1), not the architectural
+    // register index, to simplify the implementation of register
+    // renaming.  We find the architectural register index by indexing
+    // into the instruction's own operand index table.  Note that a
+    // raw pointer to the StaticInst is provided instead of a
+    // ref-counted StaticInstPtr to redice overhead.  This is fine as
+    // long as these methods don't copy the pointer into any long-term
+    // storage (which is pretty hard to imagine they would have reason
+    // to do).
+
+    uint64_t readIntReg(StaticInst<TheISA> *si, int idx)
+    {
+        return xc->readIntReg(si->srcRegIdx(idx));
+    }
 
-    float readFloatRegSingle(int reg_idx)
-    { return xc->readFloatRegSingle(reg_idx); }
+    float readFloatRegSingle(StaticInst<TheISA> *si, int idx)
+    {
+        int reg_idx = si->srcRegIdx(idx) - TheISA::FP_Base_DepTag;
+        return xc->readFloatRegSingle(reg_idx);
+    }
 
-    double readFloatRegDouble(int reg_idx)
-    { return xc->readFloatRegDouble(reg_idx); }
+    double readFloatRegDouble(StaticInst<TheISA> *si, int idx)
+    {
+        int reg_idx = si->srcRegIdx(idx) - TheISA::FP_Base_DepTag;
+        return xc->readFloatRegDouble(reg_idx);
+    }
 
-    uint64_t readFloatRegInt(int reg_idx)
-    { return xc->readFloatRegInt(reg_idx); }
+    uint64_t readFloatRegInt(StaticInst<TheISA> *si, int idx)
+    {
+        int reg_idx = si->srcRegIdx(idx) - TheISA::FP_Base_DepTag;
+        return xc->readFloatRegInt(reg_idx);
+    }
 
-    void setIntReg(int reg_idx, uint64_t val)
-    { return xc->setIntReg(reg_idx, val); }
+    void setIntReg(StaticInst<TheISA> *si, int idx, uint64_t val)
+    {
+        xc->setIntReg(si->destRegIdx(idx), val);
+    }
 
-    void setFloatRegSingle(int reg_idx, float val)
-    { return xc->setFloatRegSingle(reg_idx, val); }
+    void setFloatRegSingle(StaticInst<TheISA> *si, int idx, float val)
+    {
+        int reg_idx = si->destRegIdx(idx) - TheISA::FP_Base_DepTag;
+        xc->setFloatRegSingle(reg_idx, val);
+    }
 
-    void setFloatRegDouble(int reg_idx, double val)
-    { return xc->setFloatRegDouble(reg_idx, val); }
+    void setFloatRegDouble(StaticInst<TheISA> *si, int idx, double val)
+    {
+        int reg_idx = si->destRegIdx(idx) - TheISA::FP_Base_DepTag;
+        xc->setFloatRegDouble(reg_idx, val);
+    }
 
-    void setFloatRegInt(int reg_idx, uint64_t val)
-    { return xc->setFloatRegInt(reg_idx, val); }
+    void setFloatRegInt(StaticInst<TheISA> *si, int idx, uint64_t val)
+    {
+        int reg_idx = si->destRegIdx(idx) - TheISA::FP_Base_DepTag;
+        xc->setFloatRegInt(reg_idx, val);
+    }
 
     uint64_t readPC() { return xc->readPC(); }
-    void setNextPC(uint64_t val) { return xc->setNextPC(val); }
+    void setNextPC(uint64_t val) { xc->setNextPC(val); }
 
     uint64_t readUniq() { return xc->readUniq(); }
-    void setUniq(uint64_t val) { return xc->setUniq(val); }
+    void setUniq(uint64_t val) { xc->setUniq(val); }
 
     uint64_t readFpcr() { return xc->readFpcr(); }
-    void setFpcr(uint64_t val) { return xc->setFpcr(val); }
+    void setFpcr(uint64_t val) { xc->setFpcr(val); }
 
 #ifdef FULL_SYSTEM
     uint64_t readIpr(int idx, Fault &fault) { return xc->readIpr(idx, fault); }
@@ -300,7 +335,7 @@ class SimpleCPU : public BaseCPU
     int readIntrFlag() { return xc->readIntrFlag(); }
     void setIntrFlag(int val) { xc->setIntrFlag(val); }
     bool inPalMode() { return xc->inPalMode(); }
-    void ev5_trap(Fault fault) { return xc->ev5_trap(fault); }
+    void ev5_trap(Fault fault) { xc->ev5_trap(fault); }
     bool simPalCheck(int palFunc) { return xc->simPalCheck(palFunc); }
 #else
     void syscall() { xc->syscall(); }