Use BitOperations::PopCount() in genCountBits() (#83661)

dotnet · Mar 21, 2023 · beab6cd · beab6cd
1 parent 0c9568a
commit beab6cd
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Showing 3 changed files with 13 additions and 12 deletions.
diff --git a/src/coreclr/jit/codegenarmarch.cpp b/src/coreclr/jit/codegenarmarch.cpp
@@ -4185,7 +4185,7 @@ void CodeGen::genCreateAndStoreGCInfo(unsigned codeSize,
         //  -all callee-preserved registers in case of varargs
         //  -saved bool for synchronized methods
 
-        int preservedAreaSize = (2 + genCountBits(RBM_ENC_CALLEE_SAVED)) * REGSIZE_BYTES;
+        int preservedAreaSize = (2 + genCountBits((uint64_t)RBM_ENC_CALLEE_SAVED)) * REGSIZE_BYTES;
 
         if (compiler->info.compIsVarArgs)
         {

diff --git a/src/coreclr/jit/compiler.hpp b/src/coreclr/jit/compiler.hpp
@@ -255,18 +255,19 @@ inline regMaskTP genFindLowestReg(regMaskTP value)
  *  A rather simple routine that counts the number of bits in a given number.
  */
 
-template <typename T>
-inline unsigned genCountBits(T bits)
+inline unsigned genCountBits(uint64_t bits)
 {
-    unsigned cnt = 0;
+    return BitOperations::PopCount(bits);
+}
 
-    while (bits)
-    {
-        cnt++;
-        bits -= genFindLowestBit(bits);
-    }
+/*****************************************************************************
+ *
+ *  A rather simple routine that counts the number of bits in a given number.
+ */
 
-    return cnt;
+inline unsigned genCountBits(uint32_t bits)
+{
+    return BitOperations::PopCount(bits);
 }
 
 /*****************************************************************************

diff --git a/src/coreclr/jit/emit.cpp b/src/coreclr/jit/emit.cpp
@@ -1741,10 +1741,10 @@ void emitter::emitCheckIGList()
         }
 
         // An IG can have at most one of the prolog and epilog flags set.
-        assert(genCountBits(currIG->igFlags & (IGF_FUNCLET_PROLOG | IGF_FUNCLET_EPILOG | IGF_EPILOG)) <= 1);
+        assert(genCountBits((unsigned)currIG->igFlags & (IGF_FUNCLET_PROLOG | IGF_FUNCLET_EPILOG | IGF_EPILOG)) <= 1);
 
         // An IG can't have both IGF_HAS_ALIGN and IGF_REMOVED_ALIGN.
-        assert(genCountBits(currIG->igFlags & (IGF_HAS_ALIGN | IGF_REMOVED_ALIGN)) <= 1);
+        assert(genCountBits((unsigned)currIG->igFlags & (IGF_HAS_ALIGN | IGF_REMOVED_ALIGN)) <= 1);
 
         if (currIG->igFlags & IGF_EXTEND)
         {