From 39ce8da5e02a08db5f25440a65196df369b0ffe7 Mon Sep 17 00:00:00 2001
From: Fei Peng <fei.peng@intel.com>
Date: Fri, 15 Dec 2017 16:51:21 -0800
Subject: [PATCH] Enable Vector256<T> with AVX

---
 src/jit/compiler.h    | 21 ++++++++++++++++++++-
 src/jit/ee_il_dll.cpp |  6 +++++-
 src/jit/morph.cpp     |  2 +-
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/jit/compiler.h b/src/jit/compiler.h
index 5b47689..d397239 100644
--- a/src/jit/compiler.h
+++ b/src/jit/compiler.h
@@ -7705,7 +7705,8 @@ private:
     // Get preferred alignment of SIMD type.
     int getSIMDTypeAlignment(var_types simdType);
 
-    // Get the number of bytes in a SIMD Vector for the current compilation.
+    // Get the number of bytes in a System.Numeric.Vector<T> for the current compilation.
+    // Note - cannot be used for System.Runtime.Intrinsic 
     unsigned getSIMDVectorRegisterByteLength()
     {
 #if defined(_TARGET_XARCH_) && !defined(LEGACY_BACKEND)
@@ -7727,9 +7728,27 @@ private:
     }
 
     // The minimum and maximum possible number of bytes in a SIMD vector.
+
+    // maxSIMDStructBytes
+    // The minimum SIMD size supported by System.Numeric.Vectors or System.Runtime.Intrinsic
+    // SSE:  16-byte Vector<T> and Vector128<T>
+    // AVX:  32-byte Vector256<T> (Vector<T> is 16-byte)
+    // AVX2: 32-byte Vector<T> and Vector256<T>
     unsigned int maxSIMDStructBytes()
     {
+#if FEATURE_HW_INTRINSICS && defined(_TARGET_XARCH_)
+        if (compSupports(InstructionSet_AVX))
+        {
+            return YMM_REGSIZE_BYTES;
+        }
+        else
+        {
+            assert(getSIMDSupportLevel() >= SIMD_SSE2_Supported);
+            return XMM_REGSIZE_BYTES;
+        }
+#else
         return getSIMDVectorRegisterByteLength();
+#endif
     }
     unsigned int minSIMDStructBytes()
     {
diff --git a/src/jit/ee_il_dll.cpp b/src/jit/ee_il_dll.cpp
index 45df939..8707376 100644
--- a/src/jit/ee_il_dll.cpp
+++ b/src/jit/ee_il_dll.cpp
@@ -386,7 +386,11 @@ unsigned CILJit::getMaxIntrinsicSIMDVectorLength(CORJIT_FLAGS cpuCompileFlags)
     if (!jitFlags.IsSet(JitFlags::JIT_FLAG_PREJIT) && jitFlags.IsSet(JitFlags::JIT_FLAG_FEATURE_SIMD) &&
         jitFlags.IsSet(JitFlags::JIT_FLAG_USE_AVX2))
     {
-        if (JitConfig.EnableAVX() != 0)
+        if (JitConfig.EnableAVX() != 0
+#ifdef DEBUG
+            && JitConfig.EnableAVX2() != 0
+#endif
+            )
         {
             if (GetJitTls() != nullptr && JitTls::GetCompiler() != nullptr)
             {
diff --git a/src/jit/morph.cpp b/src/jit/morph.cpp
index 4265289..88d382b 100644
--- a/src/jit/morph.cpp
+++ b/src/jit/morph.cpp
@@ -5944,7 +5944,7 @@ GenTreePtr Compiler::fgMorphArrayIndex(GenTreePtr tree)
     noway_assert(elemTyp != TYP_STRUCT || elemStructType != nullptr);
 
 #ifdef FEATURE_SIMD
-    if (featureSIMD && varTypeIsStruct(elemTyp) && elemSize <= getSIMDVectorRegisterByteLength())
+    if (featureSIMD && varTypeIsStruct(elemTyp) && elemSize <= maxSIMDStructBytes())
     {
         // If this is a SIMD type, this is the point at which we lose the type information,
         // so we need to set the correct type on the GT_IND.
-- 
2.7.4