From 8fad9b58c71721ab4ae4f22b743b432aea377712 Mon Sep 17 00:00:00 2001
From: Mikhail Skvortcov <m.skvortcov@partner.samsung.com>
Date: Thu, 16 Mar 2017 16:23:05 +0300
Subject: [PATCH] RyuJIT/ARM32: Enable GT_COPY and GT_MEMORYBARRIER

Commit migrated from https://github.com/dotnet/coreclr/commit/e2a91a6d6cd7ca980ba37e906f41fb433bbe6093
---
 src/coreclr/src/jit/codegenarm.cpp | 83 +++++++++++++++++++++++++++++---------
 src/coreclr/src/jit/lsraarm.cpp    |  1 +
 2 files changed, 65 insertions(+), 19 deletions(-)

diff --git a/src/coreclr/src/jit/codegenarm.cpp b/src/coreclr/src/jit/codegenarm.cpp
index e276b71..9a931b5 100644
--- a/src/coreclr/src/jit/codegenarm.cpp
+++ b/src/coreclr/src/jit/codegenarm.cpp
@@ -1082,24 +1082,7 @@ void CodeGen::genCodeForTreeNode(GenTreePtr treeNode)
         break;
 
         case GT_COPY:
-        {
-            assert(treeNode->gtOp.gtOp1->IsLocal());
-            GenTreeLclVarCommon* lcl    = treeNode->gtOp.gtOp1->AsLclVarCommon();
-            LclVarDsc*           varDsc = &compiler->lvaTable[lcl->gtLclNum];
-            inst_RV_RV(ins_Move_Extend(targetType, true), targetReg, genConsumeReg(treeNode->gtOp.gtOp1), targetType,
-                       emitTypeSize(targetType));
-
-            // The old location is dying
-            genUpdateRegLife(varDsc, /*isBorn*/ false, /*isDying*/ true DEBUGARG(treeNode->gtOp.gtOp1));
-
-            gcInfo.gcMarkRegSetNpt(genRegMask(treeNode->gtOp.gtOp1->gtRegNum));
-
-            genUpdateVarReg(varDsc, treeNode);
-
-            // The new location is going live
-            genUpdateRegLife(varDsc, /*isBorn*/ true, /*isDying*/ false DEBUGARG(treeNode));
-        }
-            genProduceReg(treeNode);
+            // This is handled at the time we call genConsumeReg() on the GT_COPY
             break;
 
         case GT_LIST:
@@ -1138,6 +1121,10 @@ void CodeGen::genCodeForTreeNode(GenTreePtr treeNode)
             genLockedInstructions(treeNode->AsOp());
             break;
 
+        case GT_MEMORYBARRIER:
+            instGen_MemoryBarrier();
+            break;
+
         case GT_CMPXCHG:
         {
             NYI("GT_CMPXCHG");
@@ -1879,7 +1866,65 @@ void CodeGen::genCodeForShiftLong(GenTreePtr tree)
 //
 void CodeGen::genRegCopy(GenTree* treeNode)
 {
-    NYI("genRegCopy");
+    assert(treeNode->OperGet() == GT_COPY);
+
+    var_types targetType = treeNode->TypeGet();
+    regNumber targetReg  = treeNode->gtRegNum;
+    assert(targetReg != REG_NA);
+
+    GenTree* op1 = treeNode->gtOp.gtOp1;
+
+    // Check whether this node and the node from which we're copying the value have the same
+    // register type.
+    // This can happen if (currently iff) we have a SIMD vector type that fits in an integer
+    // register, in which case it is passed as an argument, or returned from a call,
+    // in an integer register and must be copied if it's in an xmm register.
+
+    if (varTypeIsFloating(treeNode) != varTypeIsFloating(op1))
+    {
+        NYI("genRegCopy floating point");
+    }
+    else
+    {
+        inst_RV_RV(ins_Copy(targetType), targetReg, genConsumeReg(op1), targetType);
+    }
+
+    if (op1->IsLocal())
+    {
+        // The lclVar will never be a def.
+        // If it is a last use, the lclVar will be killed by genConsumeReg(), as usual, and genProduceReg will
+        // appropriately set the gcInfo for the copied value.
+        // If not, there are two cases we need to handle:
+        // - If this is a TEMPORARY copy (indicated by the GTF_VAR_DEATH flag) the variable
+        //   will remain live in its original register.
+        //   genProduceReg() will appropriately set the gcInfo for the copied value,
+        //   and genConsumeReg will reset it.
+        // - Otherwise, we need to update register info for the lclVar.
+
+        GenTreeLclVarCommon* lcl = op1->AsLclVarCommon();
+        assert((lcl->gtFlags & GTF_VAR_DEF) == 0);
+
+        if ((lcl->gtFlags & GTF_VAR_DEATH) == 0 && (treeNode->gtFlags & GTF_VAR_DEATH) == 0)
+        {
+            LclVarDsc* varDsc = &compiler->lvaTable[lcl->gtLclNum];
+
+            // If we didn't just spill it (in genConsumeReg, above), then update the register info
+            if (varDsc->lvRegNum != REG_STK)
+            {
+                // The old location is dying
+                genUpdateRegLife(varDsc, /*isBorn*/ false, /*isDying*/ true DEBUGARG(op1));
+
+                gcInfo.gcMarkRegSetNpt(genRegMask(op1->gtRegNum));
+
+                genUpdateVarReg(varDsc, treeNode);
+
+                // The new location is going live
+                genUpdateRegLife(varDsc, /*isBorn*/ true, /*isDying*/ false DEBUGARG(treeNode));
+            }
+        }
+    }
+
+    genProduceReg(treeNode);
 }
 
 //------------------------------------------------------------------------
diff --git a/src/coreclr/src/jit/lsraarm.cpp b/src/coreclr/src/jit/lsraarm.cpp
index 3a2206b..9ecde34 100644
--- a/src/coreclr/src/jit/lsraarm.cpp
+++ b/src/coreclr/src/jit/lsraarm.cpp
@@ -1354,6 +1354,7 @@ void Lowering::TreeNodeInfoInit(GenTree* tree)
         case GT_LABEL:
         case GT_PINVOKE_PROLOG:
         case GT_JCC:
+        case GT_MEMORYBARRIER:
             info->dstCount = tree->IsValue() ? 1 : 0;
             if (kind & (GTK_CONST | GTK_LEAF))
             {
-- 
2.7.4