Disable mulshift on ARM/64

No LEAs - no point.
dotnet · Jan 28, 2022 · d3b168b · d3b168b
1 parent 6a8543e
commit d3b168b
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Showing 3 changed files with 8 additions and 23 deletions.
diff --git a/src/coreclr/jit/compiler.h b/src/coreclr/jit/compiler.h
@@ -7122,12 +7122,6 @@ class Compiler
 
     bool optNarrowTree(GenTree* tree, var_types srct, var_types dstt, ValueNumPair vnpNarrow, bool doit);
 
-    /**************************************************************************
-     *                       Optimization conditions
-     *************************************************************************/
-
-    bool optAvoidIntMult(void);
-
 protected:
     //  The following is the upper limit on how many expressions we'll keep track
     //  of for the CSE analysis.

diff --git a/src/coreclr/jit/compiler.hpp b/src/coreclr/jit/compiler.hpp
@@ -3578,22 +3578,6 @@ inline bool Compiler::LoopDsc::lpArrLenLimit(Compiler* comp, ArrIndex* index) co
     return false;
 }
 
-/*
-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
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-XX                                                                           XX
-XX                Optimization activation rules                              XX
-XX                                                                           XX
-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-*/
-
-// should we try to replace integer multiplication with lea/add/shift sequences?
-inline bool Compiler::optAvoidIntMult(void)
-{
-    return (compCodeOpt() != SMALL_CODE);
-}
-
 /*
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

diff --git a/src/coreclr/jit/morph.cpp b/src/coreclr/jit/morph.cpp
@@ -13660,6 +13660,13 @@ GenTree* Compiler::fgOptimizeMultiply(GenTreeOp* mul)
             return mul;
         }
 
+#ifdef TARGET_XARCH
+        // Should we try to replace integer multiplication with lea/add/shift sequences?
+        bool mulShiftOpt = compCodeOpt() != SMALL_CODE;
+#else  // !TARGET_XARCH
+        bool mulShiftOpt = false;
+#endif // !TARGET_XARCH
+
         size_t abs_mult      = (mult >= 0) ? mult : -mult;
         size_t lowestBit     = genFindLowestBit(abs_mult);
         bool   changeToShift = false;
@@ -13702,7 +13709,7 @@ GenTree* Compiler::fgOptimizeMultiply(GenTreeOp* mul)
             op2->AsIntConCommon()->SetIconValue(genLog2(abs_mult));
             changeToShift = true;
         }
-        else if ((lowestBit > 1) && jitIsScaleIndexMul(lowestBit) && optAvoidIntMult())
+        else if (mulShiftOpt && (lowestBit > 1) && jitIsScaleIndexMul(lowestBit))
         {
             int     shift  = genLog2(lowestBit);
             ssize_t factor = abs_mult >> shift;