JIT: Simplify internal GC tracking structures

src/coreclr/jit/emit.cpp

@@ -9983,7 +9983,6 @@ void emitter::emitStackPopLargeStk(BYTE* addr, bool isCall, unsigned char callIn
 
     unsigned argStkCnt;
     S_UINT16 argRecCnt(0); // arg count for ESP, ptr-arg count for EBP
-    unsigned gcrefRegs, byrefRegs;
 
 #ifdef JIT32_GCENCODER
     // For the general encoder, we always need to record calls, so we make this call
@@ -10025,26 +10024,19 @@ void emitter::emitStackPopLargeStk(BYTE* addr, bool isCall, unsigned char callIn
         return;
 #endif
 
-    // Do we have any interesting (i.e., callee-saved) registers live here?
+    // Do we have any interesting registers live here?
 
-    gcrefRegs = byrefRegs = 0;
+    unsigned gcrefRegs = emitThisGCrefRegs.GetIntRegSet() >> REG_INT_FIRST;
+    unsigned byrefRegs = emitThisByrefRegs.GetIntRegSet() >> REG_INT_FIRST;
 
-    // We make a bitmask whose bits correspond to callee-saved register indices (in the sequence
-    // of callee-saved registers only).
-    for (unsigned calleeSavedRegIdx = 0; calleeSavedRegIdx < CNT_CALL_GC_REGS; calleeSavedRegIdx++)
-    {
-        regMaskTP calleeSavedRbm = raRbmCalleeSaveOrder[calleeSavedRegIdx];
-        if (emitThisGCrefRegs & calleeSavedRbm)
-        {
-            gcrefRegs |= (1 << calleeSavedRegIdx);
-        }
-        if (emitThisByrefRegs & calleeSavedRbm)
-        {
-            byrefRegs |= (1 << calleeSavedRegIdx);
-        }
-    }
+    assert(regMaskTP::FromIntRegSet(SingleTypeRegSet(gcrefRegs << REG_INT_FIRST)) == emitThisGCrefRegs);
+    assert(regMaskTP::FromIntRegSet(SingleTypeRegSet(byrefRegs << REG_INT_FIRST)) == emitThisByrefRegs);
 
 #ifdef JIT32_GCENCODER
+    // x86 does not report GC refs/byrefs in return registers at call sites
+    gcrefRegs &= ~(1u << (REG_INTRET - REG_INT_FIRST));
+    byrefRegs &= ~(1u << (REG_INTRET - REG_INT_FIRST));
+
     // For the general encoder, we always have to record calls, so we don't take this early return.    /* Are there any
     // args to pop at this call site?
 

src/coreclr/jit/gcencode.cpp

@@ -3199,9 +3199,24 @@ size_t GCInfo::gcMakeRegPtrTable(BYTE* dest, int mask, const InfoHdr& header, un
 
                     callArgCnt = genRegPtrTemp->rpdPtrArg;
 
-                    unsigned gcrefRegMask = genRegPtrTemp->rpdCallGCrefRegs;
+                    unsigned gcrefRegMask = 0;
 
-                    byrefRegMask = genRegPtrTemp->rpdCallByrefRegs;
+                    byrefRegMask = 0;
+
+                    // The order here is fixed: it must agree with the order assumed in eetwain.
+                    // NB: x86 GC decoder does not report return registers at call sites.
+                    static const regNumber calleeSaveOrder[] = {REG_EDI, REG_ESI, REG_EBX, REG_EBP};
+                    for (unsigned i = 0; i < ArrLen(calleeSaveOrder); i++)
+                    {
+                        if ((genRegPtrTemp->rpdCallGCrefRegs & (1 << (calleeSaveOrder[i] - REG_INT_FIRST))) != 0)
+                        {
+                            gcrefRegMask |= 1u << i;
+                        }
+                        if ((genRegPtrTemp->rpdCallByrefRegs & (1 << (calleeSaveOrder[i] - REG_INT_FIRST))) != 0)
+                        {
+                            byrefRegMask |= 1u << i;
+                        }
+                    }
 
                     assert((gcrefRegMask & byrefRegMask) == 0);
 
@@ -4465,8 +4480,8 @@ void GCInfo::gcMakeRegPtrTable(
             assert(call->u1.cdArgMask == 0 && call->cdArgCnt == 0);
 
             // Other than that, we just have to deal with the regmasks.
-            regMaskSmall gcrefRegMask = call->cdGCrefRegs & RBM_CALL_GC_REGS.GetIntRegSet();
-            regMaskSmall byrefRegMask = call->cdByrefRegs & RBM_CALL_GC_REGS.GetIntRegSet();
+            regMaskSmall gcrefRegMask = call->cdGCrefRegs;
+            regMaskSmall byrefRegMask = call->cdByrefRegs;
 
             assert((gcrefRegMask & byrefRegMask) == 0);
 
@@ -4552,11 +4567,8 @@ void GCInfo::gcMakeRegPtrTable(
                 {
                     // This is a true call site.
 
-                    regMaskSmall gcrefRegMask =
-                        genRegMaskFromCalleeSavedMask(genRegPtrTemp->rpdCallGCrefRegs).GetIntRegSet();
-
-                    regMaskSmall byrefRegMask =
-                        genRegMaskFromCalleeSavedMask(genRegPtrTemp->rpdCallByrefRegs).GetIntRegSet();
+                    regMaskSmall gcrefRegMask = regMaskSmall(genRegPtrTemp->rpdCallGCrefRegs << REG_INT_FIRST);
+                    regMaskSmall byrefRegMask = regMaskSmall(genRegPtrTemp->rpdCallByrefRegs << REG_INT_FIRST);
 
                     assert((gcrefRegMask & byrefRegMask) == 0);
 

src/coreclr/jit/jitgcinfo.h

@@ -162,7 +162,13 @@ class GCInfo
                 regMaskSmall rpdDel; // regptr bitset being removed
             } rpdCompiler;
 
-            unsigned short rpdPtrArg; // arg offset or popped arg count
+            struct
+            {
+                // Registers after call containing GC/byref (index 0 = REG_INT_FIRST)
+                unsigned int   rpdCallGCrefRegs;
+                unsigned int   rpdCallByrefRegs;
+                unsigned short rpdPtrArg; // arg offset or popped arg count
+            };
         };
 
 #ifndef JIT32_GCENCODER
@@ -182,11 +188,8 @@ class GCInfo
             return (GCtype)rpdGCtype;
         }
 
-        unsigned short rpdIsThis : 1;                       // is it the 'this' pointer
-        unsigned short rpdCall   : 1;                       // is this a true call site?
-        unsigned short           : 1;                       // Padding bit, so next two start on a byte boundary
-        unsigned short rpdCallGCrefRegs : CNT_CALL_GC_REGS; // Callee-saved and return registers containing GC pointers.
-        unsigned short rpdCallByrefRegs : CNT_CALL_GC_REGS; // Callee-saved and return registers containing byrefs.
+        unsigned short rpdIsThis : 1; // is it the 'this' pointer
+        unsigned short rpdCall   : 1; // is this a true call site?
 
 #ifndef JIT32_GCENCODER
         bool rpdIsCallInstr()

src/coreclr/jit/regset.cpp

@@ -944,27 +944,6 @@ regNumber genRegArgNext(regNumber argReg)
     }
 }
 
-/*****************************************************************************
- *
- *  The following table determines the order in which callee registers
- *  are encoded in GC information at call sites.
- */
-
-const regMaskTP raRbmCalleeSaveOrder[] = {RBM_CALL_GC_REGS_ORDER};
-
-regMaskTP genRegMaskFromCalleeSavedMask(unsigned short calleeSaveMask)
-{
-    regMaskTP res = 0;
-    for (int i = 0; i < CNT_CALL_GC_REGS; i++)
-    {
-        if ((calleeSaveMask & (1 << i)) != 0)
-        {
-            res |= raRbmCalleeSaveOrder[i];
-        }
-    }
-    return res;
-}
-
 /*****************************************************************************
  *
  *  Initializes the spill code. Should be called once per function compiled.

src/coreclr/jit/target.h

@@ -379,6 +379,11 @@ struct regMaskTP
 #endif
     }
 
+    static regMaskTP FromIntRegSet(SingleTypeRegSet intRegs)
+    {
+        return regMaskTP(intRegs);
+    }
+
     void operator|=(const regMaskTP& second)
     {
         low |= second.getLow();
@@ -1066,16 +1071,6 @@ inline SingleTypeRegSet getSingleTypeRegMask(regNumber reg, var_types regType)
     return regMask;
 }
 
-/*****************************************************************************
- *
- *  These arrays list the callee-saved register numbers (and bitmaps, respectively) for
- *  the current architecture.
- */
-extern const regMaskTP raRbmCalleeSaveOrder[CNT_CALL_GC_REGS];
-
-// This method takes a "compact" bitset of the callee-saved registers, and "expands" it to a full register mask.
-regMaskTP genRegMaskFromCalleeSavedMask(unsigned short);
-
 /*****************************************************************************
  *
  *  Assumes that "reg" is of the given "type". Return the next unused reg number after "reg"

src/coreclr/jit/targetamd64.h

@@ -300,24 +300,19 @@
 #ifdef UNIX_AMD64_ABI
   #define CNT_CALLEE_SAVED         (5 + REG_ETW_FRAMED_EBP_COUNT)
   #define CNT_CALLEE_ENREG         (CNT_CALLEE_SAVED)
-  #define CNT_CALL_GC_REGS         (CNT_CALLEE_SAVED + 2)
 
   #define CNT_CALLEE_TRASH_INT_INIT   (9)
   #define CNT_CALLEE_TRASH_HIGHINT    (8)
 
   #define CNT_CALLEE_SAVED_FLOAT   (0)
   #define CNT_CALLEE_TRASH_FLOAT_INIT (16)
   #define CNT_CALLEE_TRASH_HIGHFLOAT    (16)
-  /* NOTE: Sync with variable name defined in compiler.h */
-  #define RBM_CALL_GC_REGS_ORDER   RBM_EBX,RBM_ETW_FRAMED_EBP_LIST RBM_R12,RBM_R13,RBM_R14,RBM_R15,RBM_INTRET,RBM_INTRET_1
-  #define RBM_CALL_GC_REGS         (RBM_EBX|RBM_ETW_FRAMED_EBP|RBM_R12|RBM_R13|RBM_R14|RBM_R15|RBM_INTRET|RBM_INTRET_1)
 
   // For SysV we have more volatile registers so we do not save any callee saves for EnC.
   #define RBM_ENC_CALLEE_SAVED     0
 #else // !UNIX_AMD64_ABI
   #define CNT_CALLEE_SAVED         (7 + REG_ETW_FRAMED_EBP_COUNT)
   #define CNT_CALLEE_ENREG         (CNT_CALLEE_SAVED)
-  #define CNT_CALL_GC_REGS         (CNT_CALLEE_SAVED + 1)
 
   #define CNT_CALLEE_TRASH_INT_INIT   (7)
   #define CNT_CALLEE_TRASH_HIGHINT    (8)
@@ -326,9 +321,6 @@
   #define CNT_CALLEE_SAVED_FLOAT        (10)
   #define CNT_CALLEE_TRASH_FLOAT_INIT   (6)
   #define CNT_CALLEE_TRASH_HIGHFLOAT    (16)
-  /* NOTE: Sync with variable name defined in compiler.h */
-  #define RBM_CALL_GC_REGS_ORDER   RBM_EBX,RBM_ESI,RBM_EDI,RBM_ETW_FRAMED_EBP_LIST RBM_R12,RBM_R13,RBM_R14,RBM_R15,RBM_INTRET
-  #define RBM_CALL_GC_REGS         (RBM_EBX|RBM_ESI|RBM_EDI|RBM_ETW_FRAMED_EBP|RBM_R12|RBM_R13|RBM_R14|RBM_R15|RBM_INTRET)
 
   // Callee-preserved registers we always save and allow use of for EnC code, since there are quite few volatile registers.
   #define RBM_ENC_CALLEE_SAVED     (RBM_RSI | RBM_RDI)

src/coreclr/jit/targetarm.h

@@ -89,13 +89,9 @@
   #define RBM_LOW_REGS            (RBM_R0|RBM_R1|RBM_R2|RBM_R3|RBM_R4|RBM_R5|RBM_R6|RBM_R7)
   #define RBM_HIGH_REGS           (RBM_R8|RBM_R9|RBM_R10|RBM_R11|RBM_R12|RBM_SP|RBM_LR|RBM_PC)
 
-  #define RBM_CALL_GC_REGS_ORDER   RBM_R4,RBM_R5,RBM_R6,RBM_R7,RBM_R8,RBM_R9,RBM_R10,RBM_R11,RBM_INTRET
-  #define RBM_CALL_GC_REGS         (RBM_R4|RBM_R5|RBM_R6|RBM_R7|RBM_R8|RBM_R9|RBM_R10|RBM_R11|RBM_INTRET)
-
   #define CNT_CALLEE_SAVED        (8)
   #define CNT_CALLEE_TRASH        (6)
   #define CNT_CALLEE_ENREG        (CNT_CALLEE_SAVED-1)
-  #define CNT_CALL_GC_REGS        (CNT_CALLEE_SAVED+1)
 
   #define CNT_CALLEE_SAVED_FLOAT  (16)
   #define CNT_CALLEE_TRASH_FLOAT  (16)

src/coreclr/jit/targetarm64.h

@@ -108,13 +108,9 @@
                                    REG_V12, REG_V13, REG_V14, REG_V15, \
                                    REG_V3,  REG_V2, REG_V1,  REG_V0
 
-  #define RBM_CALL_GC_REGS_ORDER   RBM_R19,RBM_R20,RBM_R21,RBM_R22,RBM_R23,RBM_R24,RBM_R25,RBM_R26,RBM_R27,RBM_R28,RBM_INTRET,RBM_INTRET_1
-  #define RBM_CALL_GC_REGS         (RBM_R19|RBM_R20|RBM_R21|RBM_R22|RBM_R23|RBM_R24|RBM_R25|RBM_R26|RBM_R27|RBM_R28|RBM_INTRET|RBM_INTRET_1)
-
   #define CNT_CALLEE_SAVED        (11)
   #define CNT_CALLEE_TRASH        (17)
   #define CNT_CALLEE_ENREG        (CNT_CALLEE_SAVED-1)
-  #define CNT_CALL_GC_REGS        (CNT_CALLEE_SAVED+2)
 
   #define CNT_CALLEE_SAVED_FLOAT  (8)
   #define CNT_CALLEE_TRASH_FLOAT  (24)

src/coreclr/jit/targetx86.h

@@ -143,16 +143,9 @@
   #define REG_VAR_ORDER            REG_EAX,REG_EDX,REG_ECX,REG_ESI,REG_EDI,REG_EBX
   #define MAX_VAR_ORDER_SIZE       6
 
-  // The order here is fixed: it must agree with an order assumed in eetwain...
-  // NB: x86 GC decoder does not report return registers at call sites.
-  #define RBM_CALL_GC_REGS_ORDER   RBM_EDI,RBM_ESI,RBM_EBX,RBM_EBP
-  #define RBM_CALL_GC_REGS         (RBM_EDI|RBM_ESI|RBM_EBX|RBM_EBP)
-
   #define CNT_CALLEE_SAVED        (4)
   #define CNT_CALLEE_TRASH        (3)
   #define CNT_CALLEE_ENREG        (CNT_CALLEE_SAVED-1)
-  // NB: x86 GC decoder does not report return registers at call sites.
-  #define CNT_CALL_GC_REGS        (CNT_CALLEE_SAVED)
 
   #define CNT_CALLEE_SAVED_FLOAT  (0)
   #define CNT_CALLEE_TRASH_FLOAT  (6)