Optimize call indirect for R2R, Arm and Arm64 scenarios (#35675)

* Use a different approach to optimize the indirect calls for R2R During lowering, don't create a controlExpr for indirect call. Instead use temp register for such calls and during codegen, load the indirect from x11 into that temp register before calling the address in that temp register.
dotnet · May 20, 2020 · 3fda6ef · 3fda6ef
1 parent e9c272c
commit 3fda6ef
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Showing 3 changed files with 40 additions and 5 deletions.
diff --git a/src/coreclr/src/jit/codegenarmarch.cpp b/src/coreclr/src/jit/codegenarmarch.cpp
@@ -2523,6 +2523,27 @@ void CodeGen::genCallInstruction(GenTreeCall* call)
                     INDEBUG_LDISASM_COMMA(sigInfo) nullptr, // addr
                     retSize MULTIREG_HAS_SECOND_GC_RET_ONLY_ARG(secondRetSize), ilOffset, target->GetRegNum());
     }
+#if defined(FEATURE_READYTORUN_COMPILER) && defined(TARGET_ARMARCH)
+    else if (call->IsR2RRelativeIndir())
+    {
+        // Generate a direct call to a non-virtual user defined or helper method
+        assert(callType == CT_HELPER || callType == CT_USER_FUNC);
+        assert(call->gtEntryPoint.accessType == IAT_PVALUE);
+        assert(call->gtControlExpr == nullptr);
+
+        regNumber tmpReg = call->GetSingleTempReg();
+        GetEmitter()->emitIns_R_R(ins_Load(TYP_I_IMPL), emitActualTypeSize(TYP_I_IMPL), tmpReg, REG_R2R_INDIRECT_PARAM);
+
+        // We have now generated code for gtControlExpr evaluating it into `tmpReg`.
+        // We just need to emit "call tmpReg" in this case.
+        //
+        assert(genIsValidIntReg(tmpReg));
+
+        genEmitCall(emitter::EC_INDIR_R, methHnd,
+                    INDEBUG_LDISASM_COMMA(sigInfo) nullptr, // addr
+                    retSize MULTIREG_HAS_SECOND_GC_RET_ONLY_ARG(secondRetSize), ilOffset, tmpReg);
+    }
+#endif // FEATURE_READYTORUN_COMPILER && TARGET_ARMARCH
     else
     {
         // Generate a direct call to a non-virtual user defined or helper method

diff --git a/src/coreclr/src/jit/lower.cpp b/src/coreclr/src/jit/lower.cpp
@@ -3287,11 +3287,19 @@ GenTree* Lowering::LowerDirectCall(GenTreeCall* call)
 
         case IAT_PVALUE:
         {
-            // Non-virtual direct calls to addresses accessed by
-            // a single indirection.
-            GenTree* cellAddr = AddrGen(addr);
-            GenTree* indir    = Ind(cellAddr);
-            result            = indir;
+            bool isR2RRelativeIndir = false;
+#if defined(FEATURE_READYTORUN_COMPILER) && defined(TARGET_ARMARCH)
+            isR2RRelativeIndir = call->IsR2RRelativeIndir();
+#endif // FEATURE_READYTORUN_COMPILER && TARGET_ARMARCH
+
+            if (!isR2RRelativeIndir)
+            {
+                // Non-virtual direct calls to addresses accessed by
+                // a single indirection.
+                GenTree* cellAddr = AddrGen(addr);
+                GenTree* indir    = Ind(cellAddr);
+                result            = indir;
+            }
             break;
         }
 

diff --git a/src/coreclr/src/jit/lsraarmarch.cpp b/src/coreclr/src/jit/lsraarmarch.cpp
@@ -182,6 +182,12 @@ int LinearScan::BuildCall(GenTreeCall* call)
             ctrlExprCandidates = RBM_FASTTAILCALL_TARGET;
         }
     }
+#if defined(FEATURE_READYTORUN_COMPILER) && defined(TARGET_ARMARCH)
+    else if (call->IsR2RRelativeIndir())
+    {
+        buildInternalIntRegisterDefForNode(call);
+    }
+#endif // FEATURE_READYTORUN_COMPILER && TARGET_ARMARCH
 #ifdef TARGET_ARM
     else
     {