Don't allocate instrDescDebugInfo when JitDisasm is not set

src/coreclr/jit/emit.cpp

@@ -1506,18 +1506,19 @@ void* emitter::emitAllocAnyInstr(size_t sz, emitAttr opsz)
 
     emitInsCount++;
 
-    instrDescDebugInfo* info = (instrDescDebugInfo*)emitGetMem(sizeof(*info));
-
-    info->idNum         = emitInsCount;
-    info->idSize        = sz;
-    info->idVarRefOffs  = 0;
-    info->idMemCookie   = 0;
-    info->idFlags       = GTF_EMPTY;
-    info->idFinallyCall = false;
-    info->idCatchRet    = false;
-    info->idCallSig     = nullptr;
-
-    id->idDebugOnlyInfo(info);
+    if (emitComp->opts.disAsm)
+    {
+        instrDescDebugInfo* info = (instrDescDebugInfo*)emitGetMem(sizeof(*info));
+        info->idNum = emitInsCount;
+        info->idSize = sz;
+        info->idVarRefOffs = 0;
+        info->idMemCookie = 0;
+        info->idFlags = GTF_EMPTY;
+        info->idFinallyCall = false;
+        info->idCatchRet = false;
+        info->idCallSig = nullptr;
+        id->idDebugOnlyInfo(info);
+    }
 
     /* Store the size and handle the two special values
        that indicate GCref and ByRef */
@@ -4259,12 +4260,12 @@ void emitter::emitRemoveJumpToNextInst()
                     emitDispIG(targetGroup, nullptr, false);
                     assert(jmp == id);
                 }
-#endif // DEBUG
 
                 JITDUMP("IG%02u IN%04x is the last instruction in the group and jumps to the next instruction group "
                         "IG%02u %s, removing.\n",
                         jmpGroup->igNum, jmp->idDebugOnlyInfo()->idNum, targetGroup->igNum,
                         emitLabelString(targetGroup));
+#endif // DEBUG
 
                 // Unlink the jump from emitJumpList while keeping the previousJmp the same.
                 if (previousJmp != nullptr)

src/coreclr/jit/emit.h

@@ -822,28 +822,19 @@ class emitter
         CLANG_FORMAT_COMMENT_ANCHOR;
 
 //
-// This is the end of the 'small' instrDesc which is the same on all
-//   platforms (except 64-bit DEBUG which is a little bigger).
-// Non-DEBUG sizes:
-//   x86/amd64/arm/arm64: 64 bits
-// DEBUG sizes (includes one pointer):
+// This is the end of the 'small' instrDesc which is the same on all platforms
+// Sizes (includes one pointer):
 //   x86:   2 DWORDs, 96 bits
 //   amd64: 4 DWORDs, 128 bits
 //   arm:   3 DWORDs, 96 bits
 //   arm64: 4 DWORDs, 128 bits
-// There should no padding or alignment issues on any platform or
-//   configuration (including DEBUG which has 1 extra pointer).
+// There should no padding or alignment issues on any platform or configuration.
 //
+// If you add lots more fields that need to be cleared (such
+// as various flags), you might need to update the body of
+// emitter::emitAllocInstr() to clear them.
 
-/*
-    If you add lots more fields that need to be cleared (such
-    as various flags), you might need to update the body of
-    emitter::emitAllocInstr() to clear them.
- */
-
-#define SMALL_IDSC_DEBUG_EXTRA (sizeof(void*))
-
-#define SMALL_IDSC_SIZE (8 + SMALL_IDSC_DEBUG_EXTRA)
+#define SMALL_IDSC_SIZE (8 + sizeof(void*))
 
         void checkSizes();
 
@@ -2688,10 +2679,7 @@ class emitter
 
 inline void emitter::instrDesc::checkSizes()
 {
-#ifdef DEBUG
     C_ASSERT(SMALL_IDSC_SIZE == (offsetof(instrDesc, _idDebugOnlyInfo) + sizeof(instrDescDebugInfo*)));
-#endif
-    C_ASSERT(SMALL_IDSC_SIZE == offsetof(instrDesc, _idAddrUnion));
 }
 
 /*****************************************************************************

src/coreclr/jit/emitarm.cpp

@@ -4837,8 +4837,14 @@ void emitter::emitIns_Call(EmitCallType          callType,
         }
     }
     id->idDebugOnlyInfo()->idCallSig = sigInfo;
-#endif
     id->idDebugOnlyInfo()->idMemCookie = (size_t)methHnd; // method token
+#else
+    if (emitComp->opts.disAsm)
+    {
+        id->idDebugOnlyInfo()->idMemCookie = (size_t)methHnd; // method token
+    }
+#endif
+
 
 #ifdef LATE_DISASM
     if (addr != nullptr)

src/coreclr/jit/emitarm64.cpp

@@ -8701,8 +8701,13 @@ void emitter::emitIns_Call(EmitCallType          callType,
         }
     }
     id->idDebugOnlyInfo()->idCallSig = sigInfo;
-#endif
     id->idDebugOnlyInfo()->idMemCookie = (size_t)methHnd; // method token
+#else
+    if (emitComp->opts.disAsm)
+    {
+        id->idDebugOnlyInfo()->idMemCookie = (size_t)methHnd; // method token
+    }
+#endif
 
 #ifdef LATE_DISASM
     if (addr != nullptr)

src/coreclr/jit/emitxarch.cpp

@@ -4367,7 +4367,15 @@ void emitter::emitIns_IJ(emitAttr attr, regNumber reg, unsigned base)
     id->idAddr()->iiaAddrMode.amBaseReg = REG_NA;
     id->idAddr()->iiaAddrMode.amIndxReg = reg;
     id->idAddr()->iiaAddrMode.amScale   = emitter::OPSZP;
+
+#ifdef DEBUG 
     id->idDebugOnlyInfo()->idMemCookie  = base;
+#else
+    if (emitComp->opts.disAsm)
+    {
+        id->idDebugOnlyInfo()->idMemCookie = base;
+    }
+#endif
 
     id->idCodeSize(sz);
 
@@ -7989,8 +7997,13 @@ void emitter::emitIns_Call(EmitCallType          callType,
 
 #ifdef DEBUG
     id->idDebugOnlyInfo()->idCallSig = sigInfo;
-#endif
     id->idDebugOnlyInfo()->idMemCookie = (size_t)methHnd; // method token
+#else
+    if (emitComp->opts.disAsm)
+    {
+        id->idDebugOnlyInfo()->idMemCookie = (size_t)methHnd; // method token
+    }
+#endif
 
 #ifdef LATE_DISASM
     if (addr != nullptr)