[Truffle] Use faster version of String#size for single-byte optimizable Strings throughout.

Author: nirvdrum

truffle/src/main/java/org/jruby/truffle/nodes/core/StringNodes.java

@@ -622,15 +622,18 @@ public Object slice(VirtualFrame frame, RubyString string, RubyString matchStr,
     @CoreMethod(names = "[]=", required = 2, lowerFixnumParameters = 0, raiseIfFrozenSelf = true)
     public abstract static class ElementSetNode extends CoreMethodNode {
 
+        @Child private SizeNode sizeNode;
         @Child private ToStrNode toStrNode;
 
         public ElementSetNode(RubyContext context, SourceSection sourceSection) {
             super(context, sourceSection);
+            sizeNode = StringNodesFactory.SizeNodeFactory.create(context, sourceSection, new RubyNode[] { null });
             toStrNode = ToStrNodeFactory.create(context, sourceSection, null);
         }
 
         public ElementSetNode(ElementSetNode prev) {
             super(prev);
+            sizeNode = prev.sizeNode;
             toStrNode = prev.toStrNode;
         }
 
@@ -648,7 +651,7 @@ public RubyString elementSet(VirtualFrame frame, RubyString string, RubyRange.In
 
             int begin = range.getBegin();
             int end = range.getEnd();
-            final int stringLength = string.length();
+            final int stringLength = sizeNode.executeIntegerFixnum(frame, string);
 
             if (begin < 0) {
                 begin += stringLength;
@@ -801,19 +804,23 @@ public int byteSize(RubyString string) {
     @CoreMethod(names = "chop!", raiseIfFrozenSelf = true)
     public abstract static class ChopBangNode extends CoreMethodNode {
 
+        @Child private SizeNode sizeNode;
+
         public ChopBangNode(RubyContext context, SourceSection sourceSection) {
             super(context, sourceSection);
+            sizeNode = StringNodesFactory.SizeNodeFactory.create(context, sourceSection, new RubyNode[] { null });
         }
 
         public ChopBangNode(ChopBangNode prev) {
             super(prev);
+            sizeNode = prev.sizeNode;
         }
 
         @Specialization
-        public Object chopBang(RubyString string) {
+        public Object chopBang(VirtualFrame frame, RubyString string) {
             notDesignedForCompilation();
 
-            if (string.length() == 0) {
+            if (sizeNode.executeIntegerFixnum(frame, string) == 0) {
                 return nil();
             }
 
@@ -1483,38 +1490,43 @@ public RubyString replace(RubyString string, RubyString other) {
     @CoreMethod(names = "rindex", required = 1, optional = 1, lowerFixnumParameters = 1)
     public abstract static class RindexNode extends CoreMethodNode {
 
+        @Child private SizeNode sizeNode;
+
         public RindexNode(RubyContext context, SourceSection sourceSection) {
             super(context, sourceSection);
+            sizeNode = StringNodesFactory.SizeNodeFactory.create(context, sourceSection, new RubyNode[] { null });
         }
 
         public RindexNode(RindexNode prev) {
             super(prev);
+            sizeNode = prev.sizeNode;
         }
 
         @Specialization
-        public Object rindex(RubyString string, RubyString subString, @SuppressWarnings("unused") UndefinedPlaceholder endPosition) {
+        public Object rindex(VirtualFrame frame, RubyString string, RubyString subString, @SuppressWarnings("unused") UndefinedPlaceholder endPosition) {
             notDesignedForCompilation();
 
-            return rindex(string, subString, string.length());
+            return rindex(frame, string, subString, sizeNode.executeIntegerFixnum(frame, string));
         }
 
         @Specialization
-        public Object rindex(RubyString string, RubyString subString, int endPosition) {
+        public Object rindex(VirtualFrame frame, RubyString string, RubyString subString, int endPosition) {
             notDesignedForCompilation();
 
+            final int stringLength = sizeNode.executeIntegerFixnum(frame, string);
             int normalizedEndPosition = endPosition;
 
             if (endPosition < 0) {
-                normalizedEndPosition = endPosition + string.length();
+                normalizedEndPosition = endPosition + stringLength;
 
                 if (normalizedEndPosition < 0) {
                     return nil();
                 }
-            } else if (endPosition > string.length()) {
-                normalizedEndPosition = string.length();
+            } else if (endPosition > stringLength) {
+                normalizedEndPosition = stringLength;
             }
 
-            int result = StringSupport.rindex(string.getBytes(), string.length(), subString.length(),
+            int result = StringSupport.rindex(string.getBytes(), stringLength, subString.length(),
                     normalizedEndPosition, subString, string.getBytes().getEncoding()
             );
 
@@ -1770,6 +1782,8 @@ public SizeNode(SizeNode prev) {
             super(prev);
         }
 
+        public abstract int executeIntegerFixnum(VirtualFrame frame, RubyString string);
+
         @Specialization(guards = "isSingleByteOptimizable")
         public int sizeSingleByte(RubyString string) {
             return string.getByteList().getRealSize();
@@ -1819,7 +1833,7 @@ public SuccBangNode(SuccBangNode prev) {
         public RubyString succBang(RubyString string) {
             notDesignedForCompilation();
 
-            if (string.length() > 0) {
+            if (string.getByteList().getRealSize() > 0) {
                 string.set(StringSupport.succCommon(getContext().getRuntime(), string.getBytes()));
             }
 

truffle/src/main/java/org/jruby/truffle/nodes/rubinius/StringPrimitiveNodes.java

@@ -363,23 +363,30 @@ public static abstract class StringCompareSubstringPrimitiveNode extends Rubiniu
         private final ConditionProfile startTooLargeProfile = ConditionProfile.createBinaryProfile();
         private final ConditionProfile startTooSmallProfile = ConditionProfile.createBinaryProfile();
 
+        @Child private StringNodes.SizeNode sizeNode;
+
         public StringCompareSubstringPrimitiveNode(RubyContext context, SourceSection sourceSection) {
             super(context, sourceSection);
+            sizeNode = StringNodesFactory.SizeNodeFactory.create(context, sourceSection, new RubyNode[] { null });
         }
 
         public StringCompareSubstringPrimitiveNode(StringCompareSubstringPrimitiveNode prev) {
             super(prev);
+            sizeNode = prev.sizeNode;
         }
 
         @Specialization
-        public int stringCompareSubstring(RubyString string, RubyString other, int start, int size) {
+        public int stringCompareSubstring(VirtualFrame frame, RubyString string, RubyString other, int start, int size) {
             // Transliterated from Rubinius C++.
 
+            final int stringLength = sizeNode.executeIntegerFixnum(frame, string);
+            final int otherLength = sizeNode.executeIntegerFixnum(frame, other);
+
             if (start < 0) {
-                start += other.length();
+                start += otherLength;
             }
 
-            if (startTooLargeProfile.profile(start > other.length())) {
+            if (startTooLargeProfile.profile(start > otherLength)) {
                 CompilerDirectives.transferToInterpreter();
 
                 throw new RaiseException(
@@ -399,12 +406,12 @@ public int stringCompareSubstring(RubyString string, RubyString other, int start
                         ));
             }
 
-            if (start + size > other.length()) {
-                size = other.length() - start;
+            if (start + size > otherLength) {
+                size = otherLength - start;
             }
 
-            if (size > string.length()) {
-                size = string.length();
+            if (size > stringLength) {
+                size = stringLength;
             }
 
             final ByteList bytes = string.getByteList();

truffle/src/main/java/org/jruby/truffle/runtime/core/RubyString.java

@@ -9,6 +9,7 @@
  */
 package org.jruby.truffle.runtime.core;
 
+import com.oracle.truffle.api.CompilerDirectives;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.nodes.Node;
 import org.jcodings.Encoding;
@@ -134,7 +135,15 @@ public String toString() {
     }
 
     public int length() {
-        return StringSupport.strLengthFromRubyString(this);
+        if (CompilerDirectives.injectBranchProbability(
+                CompilerDirectives.FASTPATH_PROBABILITY,
+                StringSupport.isSingleByteOptimizable(this, getByteList().getEncoding()))) {
+
+            return getByteList().getRealSize();
+
+        } else {
+            return StringSupport.strLengthFromRubyString(this);
+        }
     }
 
     public int normalizeIndex(int index) {