JIT: Enable CSE for CLS/STR const handles (#70580)

dotnet · Jun 13, 2022 · 76d3224 · 76d3224
1 parent e4aba62
commit 76d3224
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Showing 3 changed files with 15 additions and 8 deletions.
diff --git a/src/coreclr/jit/gentree.cpp b/src/coreclr/jit/gentree.cpp
@@ -4401,6 +4401,11 @@ unsigned Compiler::gtSetEvalOrder(GenTree* tree)
                 {
                     costSz = 10;
                     costEx = 2;
+                    if (con->IsIconHandle())
+                    {
+                        // A sort of a hint for CSE to try harder for class handles
+                        costEx += 1;
+                    }
                 }
 #endif // TARGET_AMD64
                 else

diff --git a/src/coreclr/jit/jitconfigvalues.h b/src/coreclr/jit/jitconfigvalues.h
@@ -354,9 +354,9 @@ CONFIG_INTEGER(JitDisableSimdVN, W("JitDisableSimdVN"), 0) // Default 0, ValueNu
 //
 CONFIG_INTEGER(JitConstCSE, W("JitConstCSE"), 0)
 
-#define CONST_CSE_ENABLE_ARM64 0
+#define CONST_CSE_ENABLE_ARM 0
 #define CONST_CSE_DISABLE_ALL 1
-#define CONST_CSE_ENABLE_ARM64_NO_SHARING 2
+#define CONST_CSE_ENABLE_ARM_NO_SHARING 2
 #define CONST_CSE_ENABLE_ALL 3
 #define CONST_CSE_ENABLE_ALL_NO_SHARING 4
 

diff --git a/src/coreclr/jit/optcse.cpp b/src/coreclr/jit/optcse.cpp
@@ -385,13 +385,13 @@ unsigned Compiler::optValnumCSE_Index(GenTree* tree, Statement* stmt)
     bool     isSharedConst        = false;
     int      configValue          = JitConfig.JitConstCSE();
 
-#if defined(TARGET_ARM64)
-    // ARM64 - allow to combine with nearby offsets, when config is not 2 or 4
-    if ((configValue != CONST_CSE_ENABLE_ARM64_NO_SHARING) && (configValue != CONST_CSE_ENABLE_ALL_NO_SHARING))
+#if defined(TARGET_ARMARCH)
+    // ARMARCH - allow to combine with nearby offsets, when config is not 2 or 4
+    if ((configValue != CONST_CSE_ENABLE_ARM_NO_SHARING) && (configValue != CONST_CSE_ENABLE_ALL_NO_SHARING))
     {
         enableSharedConstCSE = true;
     }
-#endif // TARGET_ARM64
+#endif // TARGET_ARMARCH
 
     // All Platforms - also allow to combine with nearby offsets, when config is 3
     if (configValue == CONST_CSE_ENABLE_ALL)
@@ -785,10 +785,12 @@ bool Compiler::optValnumCSE_Locate()
                 }
 
                 // Don't allow CSE of constants if it is disabled
-                //
                 if (tree->IsIntegralConst())
                 {
-                    if (!enableConstCSE)
+                    if (!enableConstCSE &&
+                        // Unconditionally allow these constant handles to be CSE'd
+                        !tree->IsIconHandle(GTF_ICON_STATIC_HDL) && !tree->IsIconHandle(GTF_ICON_CLASS_HDL) &&
+                        !tree->IsIconHandle(GTF_ICON_STR_HDL))
                     {
                         continue;
                     }