Fewer AddressExposedReason::TOO_CONSERVATIVE (#59429)

Delete some too_conservative addrExposed reasons.

src/coreclr/jit/codegencommon.cpp

@@ -7469,14 +7469,8 @@ void CodeGen::genFnProlog()
 
     if (compiler->info.compPublishStubParam)
     {
-#if CPU_LOAD_STORE_ARCH
         GetEmitter()->emitIns_S_R(ins_Store(TYP_I_IMPL), EA_PTRSIZE, REG_SECRET_STUB_PARAM,
                                   compiler->lvaStubArgumentVar, 0);
-#else
-        // mov [lvaStubArgumentVar], EAX
-        GetEmitter()->emitIns_AR_R(ins_Store(TYP_I_IMPL), EA_PTRSIZE, REG_SECRET_STUB_PARAM, genFramePointerReg(),
-                                   compiler->lvaTable[compiler->lvaStubArgumentVar].GetStackOffset());
-#endif
         assert(intRegState.rsCalleeRegArgMaskLiveIn & RBM_SECRET_STUB_PARAM);
 
         // It's no longer live; clear it out so it can be used after this in the prolog

src/coreclr/jit/compiler.cpp

@@ -4476,6 +4476,11 @@ void Compiler::compCompile(void** methodCodePtr, uint32_t* methodCodeSize, JitFl
             assert(lvaStubArgumentVar == BAD_VAR_NUM);
             lvaStubArgumentVar                  = lvaGrabTempWithImplicitUse(false DEBUGARG("stub argument"));
             lvaTable[lvaStubArgumentVar].lvType = TYP_I_IMPL;
+            // TODO-CQ: there is no need to mark it as doNotEnreg. There are no stores for this local
+            // before codegen so liveness and LSRA mark it as "liveIn" and always allocate a stack slot for it.
+            // However, it would be better to process it like other argument locals and keep it in
+            // a reg for the whole method without spilling to the stack when possible.
+            lvaSetVarDoNotEnregister(lvaStubArgumentVar DEBUGARG(DoNotEnregisterReason::VMNeedsStackAddr));
         }
     };
     DoPhase(this, PHASE_PRE_IMPORT, preImportPhase);

src/coreclr/jit/compiler.hpp

@@ -1758,11 +1758,6 @@ inline unsigned Compiler::lvaGrabTempWithImplicitUse(bool shortLifetime DEBUGARG
 
     LclVarDsc* varDsc = &lvaTable[lclNum];
 
-    // This will prevent it from being optimized away
-    // TODO-CQ: We shouldn't have to go as far as to declare these
-    // address-exposed -- DoNotEnregister should suffice?
-    lvaSetVarAddrExposed(lclNum DEBUGARG(AddressExposedReason::TOO_CONSERVATIVE));
-
     // Note the implicit use
     varDsc->lvImplicitlyReferenced = 1;
 

src/coreclr/jit/fginline.cpp

@@ -1404,8 +1404,11 @@ void Compiler::fgInsertInlineeBlocks(InlineInfo* pInlineInfo)
     if (!getNeedsGSSecurityCookie() && InlineeCompiler->getNeedsGSSecurityCookie())
     {
         setNeedsGSSecurityCookie();
-        const unsigned dummy   = lvaGrabTempWithImplicitUse(false DEBUGARG("GSCookie dummy for inlinee"));
-        lvaTable[dummy].lvType = TYP_INT;
+        const unsigned dummy         = lvaGrabTempWithImplicitUse(false DEBUGARG("GSCookie dummy for inlinee"));
+        LclVarDsc*     gsCookieDummy = lvaGetDesc(dummy);
+        gsCookieDummy->lvType        = TYP_INT;
+        gsCookieDummy->lvIsTemp      = true; // It is not alive at all, set the flag to prevent zero-init.
+        lvaSetVarDoNotEnregister(dummy DEBUGARG(DoNotEnregisterReason::VMNeedsStackAddr));
     }
 
     // If there is non-NULL return, replace the GT_CALL with its return value expression,

src/coreclr/jit/flowgraph.cpp

@@ -2757,6 +2757,9 @@ void Compiler::fgAddInternal()
 
         lvaInlinedPInvokeFrameVar = lvaGrabTempWithImplicitUse(false DEBUGARG("Pinvoke FrameVar"));
 
+        // Lowering::InsertPInvokeMethodProlog will create a call with this local addr as an argument.
+        lvaSetVarAddrExposed(lvaInlinedPInvokeFrameVar DEBUGARG(AddressExposedReason::ESCAPE_ADDRESS));
+
         LclVarDsc* varDsc = &lvaTable[lvaInlinedPInvokeFrameVar];
         varDsc->lvType    = TYP_BLK;
         // Make room for the inlined frame.

src/coreclr/jit/importer.cpp

@@ -12206,7 +12206,6 @@ void Compiler::impImportBlockCode(BasicBlock* block)
                 /* The ARGLIST cookie is a hidden 'last' parameter, we have already
                    adjusted the arg count cos this is like fetching the last param */
                 assertImp(0 < numArgs);
-                assert(lvaTable[lvaVarargsHandleArg].IsAddressExposed());
                 lclNum = lvaVarargsHandleArg;
                 op1    = gtNewLclvNode(lclNum, TYP_I_IMPL DEBUGARG(opcodeOffs + sz + 1));
                 op1    = gtNewOperNode(GT_ADDR, TYP_BYREF, op1);

src/coreclr/jit/lclvars.cpp

@@ -339,8 +339,11 @@ void Compiler::lvaInitTypeRef()
     {
         // Ensure that there will be at least one stack variable since
         // we require that the GSCookie does not have a 0 stack offset.
-        unsigned dummy         = lvaGrabTempWithImplicitUse(false DEBUGARG("GSCookie dummy"));
-        lvaTable[dummy].lvType = TYP_INT;
+        unsigned   dummy         = lvaGrabTempWithImplicitUse(false DEBUGARG("GSCookie dummy"));
+        LclVarDsc* gsCookieDummy = lvaGetDesc(dummy);
+        gsCookieDummy->lvType    = TYP_INT;
+        gsCookieDummy->lvIsTemp  = true; // It is not alive at all, set the flag to prevent zero-init.
+        lvaSetVarDoNotEnregister(dummy DEBUGARG(DoNotEnregisterReason::VMNeedsStackAddr));
     }
 
     // Allocate the lvaOutgoingArgSpaceVar now because we can run into problems in the
@@ -1228,14 +1231,17 @@ void Compiler::lvaInitVarArgsHandle(InitVarDscInfo* varDscInfo)
         LclVarDsc* varDsc = varDscInfo->varDsc;
         varDsc->lvType    = TYP_I_IMPL;
         varDsc->lvIsParam = 1;
-        // Make sure this lives in the stack -- address may be reported to the VM.
-        // TODO-CQ: This should probably be:
-        //   lvaSetVarDoNotEnregister(varDscInfo->varNum DEBUGARG(VMNeedsStackAddr));
-        // But that causes problems, so, for expedience, I switched back to this heavyweight
-        // hammer.  But I think it should be possible to switch; it may just work now
-        // that other problems are fixed.
-        lvaSetVarAddrExposed(varDscInfo->varNum DEBUGARG(AddressExposedReason::TOO_CONSERVATIVE));
+#if defined(TARGET_X86)
+        // Codegen will need it for x86 scope info.
+        varDsc->lvImplicitlyReferenced = 1;
+#endif // TARGET_X86
+
+        lvaSetVarDoNotEnregister(lvaVarargsHandleArg DEBUGARG(DoNotEnregisterReason::VMNeedsStackAddr));
 
+        assert(mostRecentlyActivePhase == PHASE_PRE_IMPORT);
+
+        // TODO-Cleanup: this is preImportation phase, why do we try to work with regs here?
+        // Should it be just deleted?
         if (varDscInfo->canEnreg(TYP_I_IMPL))
         {
             /* Another register argument */
@@ -4323,6 +4329,7 @@ void Compiler::lvaMarkLocalVars()
             lvaPSPSym            = lvaGrabTempWithImplicitUse(false DEBUGARG("PSPSym"));
             LclVarDsc* lclPSPSym = &lvaTable[lvaPSPSym];
             lclPSPSym->lvType    = TYP_I_IMPL;
+            lvaSetVarDoNotEnregister(lvaPSPSym DEBUGARG(DoNotEnregisterReason::VMNeedsStackAddr));
         }
 #endif // FEATURE_EH_FUNCLETS
 
@@ -7360,7 +7367,7 @@ void Compiler::lvaDumpEntry(unsigned lclNum, FrameLayoutState curState, size_t r
         }
 
         // The register or stack location field is 11 characters wide.
-        if (varDsc->lvRefCnt() == 0)
+        if ((varDsc->lvRefCnt() == 0) && !varDsc->lvImplicitlyReferenced)
         {
             printf("zero-ref   ");
         }

src/coreclr/jit/lower.cpp

@@ -4066,8 +4066,11 @@ void Lowering::InsertPInvokeMethodProlog()
     const CORINFO_EE_INFO*                       pInfo         = comp->eeGetEEInfo();
     const CORINFO_EE_INFO::InlinedCallFrameInfo& callFrameInfo = pInfo->inlinedCallFrameInfo;
 
-    // First arg:  &compiler->lvaInlinedPInvokeFrameVar + callFrameInfo.offsetOfFrameVptr
-
+// First arg:  &compiler->lvaInlinedPInvokeFrameVar + callFrameInfo.offsetOfFrameVptr
+#if defined(DEBUG)
+    const LclVarDsc* inlinedPInvokeDsc = comp->lvaGetDesc(comp->lvaInlinedPInvokeFrameVar);
+    assert(inlinedPInvokeDsc->IsAddressExposed());
+#endif // DEBUG
     GenTree* frameAddr = new (comp, GT_LCL_FLD_ADDR)
         GenTreeLclFld(GT_LCL_FLD_ADDR, TYP_BYREF, comp->lvaInlinedPInvokeFrameVar, callFrameInfo.offsetOfFrameVptr);
 
@@ -4111,7 +4114,7 @@ void Lowering::InsertPInvokeMethodProlog()
         GenTreeLclFld(GT_STORE_LCL_FLD, TYP_I_IMPL, comp->lvaInlinedPInvokeFrameVar, callFrameInfo.offsetOfCallSiteSP);
     storeSP->gtOp1 = PhysReg(REG_SPBASE);
     storeSP->gtFlags |= GTF_VAR_DEF;
-    comp->lvaSetVarDoNotEnregister(comp->lvaInlinedPInvokeFrameVar DEBUGARG(DoNotEnregisterReason::LocalField));
+    assert(inlinedPInvokeDsc->lvDoNotEnregister);
 
     firstBlockRange.InsertBefore(insertionPoint, LIR::SeqTree(comp, storeSP));
     DISPTREERANGE(firstBlockRange, storeSP);
@@ -4127,6 +4130,8 @@ void Lowering::InsertPInvokeMethodProlog()
     GenTreeLclFld* storeFP =
         new (comp, GT_STORE_LCL_FLD) GenTreeLclFld(GT_STORE_LCL_FLD, TYP_I_IMPL, comp->lvaInlinedPInvokeFrameVar,
                                                    callFrameInfo.offsetOfCalleeSavedFP);
+    assert(inlinedPInvokeDsc->lvDoNotEnregister);
+
     storeFP->gtOp1 = PhysReg(REG_FPBASE);
     storeFP->gtFlags |= GTF_VAR_DEF;
 
@@ -4408,9 +4413,12 @@ void Lowering::InsertPInvokeCallEpilog(GenTreeCall* call)
         noway_assert(comp->lvaInlinedPInvokeFrameVar != BAD_VAR_NUM);
 
         // First argument is the address of the frame variable.
-        GenTree* frameAddr =
-            new (comp, GT_LCL_VAR) GenTreeLclVar(GT_LCL_VAR, TYP_BYREF, comp->lvaInlinedPInvokeFrameVar);
-        frameAddr->SetOperRaw(GT_LCL_VAR_ADDR);
+        GenTree* frameAddr = comp->gtNewLclVarAddrNode(comp->lvaInlinedPInvokeFrameVar, TYP_BYREF);
+
+#if defined(DEBUG)
+        const LclVarDsc* inlinedPInvokeDsc = comp->lvaGetDesc(comp->lvaInlinedPInvokeFrameVar);
+        assert(inlinedPInvokeDsc->IsAddressExposed());
+#endif // DEBUG
 
         // Insert call to CORINFO_HELP_JIT_PINVOKE_END
         GenTreeCall* helperCall =

src/coreclr/jit/morph.cpp

@@ -2098,7 +2098,8 @@ GenTree* Compiler::fgMakeTmpArgNode(fgArgTabEntry* curArgTabEntry)
         {
             var_types addrType = TYP_BYREF;
             arg                = gtNewOperNode(GT_ADDR, addrType, arg);
-            addrNode           = arg;
+            lvaSetVarAddrExposed(tmpVarNum DEBUGARG(AddressExposedReason::ESCAPE_ADDRESS));
+            addrNode = arg;
 
 #if FEATURE_MULTIREG_ARGS
 #ifdef TARGET_ARM64
@@ -2137,10 +2138,6 @@ GenTree* Compiler::fgMakeTmpArgNode(fgArgTabEntry* curArgTabEntry)
     if (addrNode != nullptr)
     {
         assert(addrNode->gtOper == GT_ADDR);
-
-        // This will prevent this LclVar from being optimized away
-        lvaSetVarAddrExposed(tmpVarNum DEBUGARG(AddressExposedReason::TOO_CONSERVATIVE));
-
         // the child of a GT_ADDR is required to have this flag set
         addrNode->AsOp()->gtOp1->gtFlags |= GTF_DONT_CSE;
     }