From ba66eeab4b8306ac11feb19d09c19fd2d8e5aa95 Mon Sep 17 00:00:00 2001
From: Hanjoung Lee <hanjoung.lee@samsung.com>
Date: Wed, 13 Jul 2016 19:39:21 +0900
Subject: [ARM-softfp/Linux] Get precise type for pointer-size struct

Compiler::getPrimitiveTypeForStruct may return TYP_FLOAT but is off on softfp.
So we need to check that in another way rather than `IsHfa()`.
Otherwise struct types with single float32 will make inconsistency in gentree.
Which ends up with assert failure "Bad IL: Illegal assignment of float into integer!".

Check is done in Compiler::getPrimitiveTypeForStruct, by isSingleFloat32Struct.

Fix #6051
---
 src/jit/compiler.cpp | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/jit/compiler.h   |  4 ++++
 src/jit/morph.cpp    |  4 ++++
 3 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/src/jit/compiler.cpp b/src/jit/compiler.cpp
index b7b332598f..04c90d78af 100644
--- a/src/jit/compiler.cpp
+++ b/src/jit/compiler.cpp
@@ -447,6 +447,49 @@ void Compiler::getStructGcPtrsFromOp(GenTreePtr op, BYTE *gcPtrsOut)
 }
 #endif // FEATURE_MULTIREG_ARGS
 
+#ifdef ARM_SOFTFP
+//---------------------------------------------------------------------------
+// IsSingleFloat32Struct:
+//    Check if the given struct type contains only one float32 value type
+//
+// Arguments:
+//    clsHnd     - the handle for the struct type
+//
+// Return Value:
+//    true if the given struct type contains only one float32 value type,
+//    false otherwise.
+//
+
+bool Compiler::isSingleFloat32Struct(CORINFO_CLASS_HANDLE clsHnd)
+{
+    for (;;)
+    {
+        // all of class chain must be of value type and must have only one field
+        if (!info.compCompHnd->isValueClass(clsHnd) &&
+            info.compCompHnd->getClassNumInstanceFields(clsHnd) != 1)
+        {
+            return false;
+        }
+
+        CORINFO_CLASS_HANDLE* pClsHnd = &clsHnd;
+        CORINFO_FIELD_HANDLE fldHnd = info.compCompHnd->getFieldInClass(clsHnd, 0);
+        CorInfoType fieldType = info.compCompHnd->getFieldType(fldHnd, pClsHnd);
+
+        switch (fieldType)
+        {
+        case CORINFO_TYPE_VALUECLASS:
+            clsHnd = *pClsHnd;
+            break;
+
+        case CORINFO_TYPE_FLOAT:
+            return true;
+
+        default:
+            return false;
+        }
+    }
+}
+#endif // ARM_SOFTFP
 
 //-----------------------------------------------------------------------------
 // getPrimitiveTypeForStruct: 
@@ -521,8 +564,15 @@ var_types    Compiler::getPrimitiveTypeForStruct( unsigned  structSize,
 #endif // _TARGET_XARCH_
 #endif // _TARGET_64BIT_
 
+
     case TARGET_POINTER_SIZE:
+#ifdef ARM_SOFTFP
+        // For ARM_SOFTFP, HFA is unsupported so we need to check in another way
+        // This matters only for size-4 struct cause bigger structs would be processed with RetBuf
+        if (isSingleFloat32Struct(clsHnd))
+#else // !ARM_SOFTFP
         if (IsHfa(clsHnd))
+#endif // ARM_SOFTFP
         {
 #ifdef _TARGET_64BIT_
             var_types hfaType = GetHfaType(clsHnd);
@@ -547,7 +597,7 @@ var_types    Compiler::getPrimitiveTypeForStruct( unsigned  structSize,
 #else  // a 32BIT target
             // A structSize of 4 with IsHfa, it must be an HFA of one float
             useType = TYP_FLOAT;
-#endif
+#endif // _TARGET_64BIT_
         }
         else
         {
diff --git a/src/jit/compiler.h b/src/jit/compiler.h
index 26f028508d..c96defb9a7 100644
--- a/src/jit/compiler.h
+++ b/src/jit/compiler.h
@@ -1443,6 +1443,10 @@ public:
     GenTreePtr               impAssignMultiRegTypeToVar(GenTreePtr op, CORINFO_CLASS_HANDLE hClass);
 #endif // FEATURE_MULTIREG_RET
 
+#ifdef ARM_SOFTFP
+    bool                     isSingleFloat32Struct(CORINFO_CLASS_HANDLE hClass);
+#endif // ARM_SOFTFP
+
     //-------------------------------------------------------------------------
     // Functions to handle homogeneous floating-point aggregates (HFAs) in ARM.
     // HFAs are one to four element structs where each element is the same
diff --git a/src/jit/morph.cpp b/src/jit/morph.cpp
index 12ee7791e3..c65b51b251 100644
--- a/src/jit/morph.cpp
+++ b/src/jit/morph.cpp
@@ -16010,7 +16010,11 @@ Compiler::fgWalkResult      Compiler::fgMorphLocalField(GenTreePtr tree, fgWalkD
             tree->gtLclFld.SetLclNum(fieldLclIndex);
 
             // We need to keep the types 'compatible'.  If we can switch back to a GT_LCL_VAR
+#ifdef ARM_SOFTFP
+            assert(varTypeIsIntegralOrI(tree->TypeGet()) || varTypeIsFloating(tree->TypeGet()));
+#else
             assert(varTypeIsIntegralOrI(tree->TypeGet()));
+#endif
             if (varTypeCanReg(fldVarDsc->TypeGet()))
             {
                 // If the type is integer-ish, then we can use it as-is
-- 
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