diff --git a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharArray.java b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharArray.java
index f3672d5508..f1e2a4d840 100644
--- a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharArray.java
+++ b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharArray.java
@@ -338,7 +338,7 @@ private long parseHexFloatLiteral(
         // ------------------------
         index = skipWhitespace(str, index, endIndex);
         if (illegal || index < endIndex
-                || digitCount == 0 && str[virtualIndexOfPoint] != '.'
+                || digitCount == 0
                 || !hasExponent) {
             return PARSE_ERROR;
         }
diff --git a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharSequence.java b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharSequence.java
index 0e2a27bec9..5d3ed5ca7c 100644
--- a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharSequence.java
+++ b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/AbstractFloatingPointBitsFromCharSequence.java
@@ -328,7 +328,7 @@ private long parseHexFloatLiteral(
         // ------------------------
         index = skipWhitespace(str, index, endIndex);
         if (illegal || index < endIndex
-                || digitCount == 0 && str.charAt(virtualIndexOfPoint) != '.'
+                || digitCount == 0
                 || !hasExponent) {
             return PARSE_ERROR;
         }
diff --git a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/FastDoubleSwar.java b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/FastDoubleSwar.java
index 8677643a3d..afd806421c 100644
--- a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/FastDoubleSwar.java
+++ b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/FastDoubleSwar.java
@@ -132,9 +132,9 @@ public static int tryToParseEightDigitsUtf8(long chunk) {
         }
 
         // The last 2 multiplications are independent of each other.
-        val = (val * (1 + (10 << 8))) >>> 8;
-        val = (((val & 0xff_000000ffL) * (100 + (100_0000L << 32)))
-                + (((val >>> 16) & 0xff_000000ffL) * (1 + (1_0000L << 32)))) >>> 32;
+        val = val * (1 + (10 << 8)) >>> 8;
+        val = (val & 0xff_000000ffL) * (100 + (100_0000L << 32))
+                + (val >>> 16 & 0xff_000000ffL) * (1 + (1_0000L << 32)) >>> 32;
         return (int) val;
     }
 
@@ -326,4 +326,4 @@ public static long readLongFromByteArrayBigEndian(byte[] a, int offset) {
                 | ((a[offset + 6] & 0xffL) << 8)
                 | (a[offset + 7] & 0xffL);
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/package-info.java b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/package-info.java
index 15067a0a32..742c80f19c 100644
--- a/src/main/java/com/fasterxml/jackson/core/io/doubleparser/package-info.java
+++ b/src/main/java/com/fasterxml/jackson/core/io/doubleparser/package-info.java
@@ -42,14 +42,6 @@
  * </dl>
  *
  * <dl>
- * <dt><i>HexSignificand:</i>
- * <dd><i>HexNumeral</i>
- * <dd><i>HexNumeral</i> {@code .}
- * <dd>{@code 0x} <i>[HexDigits]</i> {@code .} <i>HexDigits</i>
- * <dd>{@code 0X} <i>[HexDigits]</i> {@code .} <i>HexDigits</i>
- * </dl>
- *
- * <dl>
  * <dt><i>BinaryExponent:</i>
  * <dd><i>BinaryExponentIndicator SignedInteger</i>
  * </dl>
diff --git a/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractDoubleHandPickedTest.java b/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractDoubleHandPickedTest.java
index 23a430f0f5..f13f965484 100644
--- a/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractDoubleHandPickedTest.java
+++ b/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractDoubleHandPickedTest.java
@@ -89,6 +89,10 @@ List<DynamicNode> dynamicTestsIllegalInputs() {
                 dynamicTest("0x123.456789abcde", () -> testIllegalInput("0x123.456789abcde")),
                 dynamicTest(".", () -> testIllegalInput(".")),
                 dynamicTest("0x.", () -> testIllegalInput("0x.")),
+                dynamicTest("0x", () -> testIllegalInput("0x")),
+                dynamicTest("0x1", () -> testIllegalInput("0x1")),
+                dynamicTest("0xp1", () -> testIllegalInput("0xp1")),
+                dynamicTest("0x1.", () -> testIllegalInput("0x1.")),
                 dynamicTest(".e2", () -> testIllegalInput(".e2"))
         );
     }
diff --git a/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractLexicallyGeneratedTest.java b/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractLexicallyGeneratedTest.java
index 3b7617e4d1..27f6dbb8f4 100644
--- a/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractLexicallyGeneratedTest.java
+++ b/src/test/java/com/fasterxml/jackson/core/io/doubleparser/AbstractLexicallyGeneratedTest.java
@@ -14,8 +14,6 @@
 import org.junit.jupiter.api.DynamicTest;
 import org.junit.jupiter.api.TestFactory;
 
-import java.util.ArrayList;
-import java.util.List;
 import java.util.Random;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -46,15 +44,15 @@ abstract class AbstractLexicallyGeneratedTest {
      * (Make sure to take a note of the seed value if
      * tests failed.)
      */
-    public static final long SEED = 0;//System.nanoTime();
+    public static final long SEED = System.nanoTime();
 
     @TestFactory
     @Disabled
-    Stream<DynamicTest> dynamicTestsRandomStringFrom10SyntaxRuleWithoutWhitespace() {
+    Stream<DynamicTest> dynamicTestsRandomStringFrom1SyntaxRuleWithoutWhitespace() {
         Random rng = new Random(SEED);
         LexicalGenerator gen = new LexicalGenerator(false, true);
-        return IntStream.range(1, 10_000).mapToObj(i -> {
-                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(10, rng);
+        return IntStream.range(0, 100).mapToObj(i -> {
+                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(1, rng);
                     return dynamicTest(i + ": " + str,
                             () -> testAgainstJdk(str));
                 }
@@ -63,11 +61,24 @@ Stream<DynamicTest> dynamicTestsRandomStringFrom10SyntaxRuleWithoutWhitespace()
 
     @TestFactory
     @Disabled
-    Stream<DynamicTest> dynamicTestsRandomStringFrom1SyntaxRuleWithoutWhitespace() {
+    Stream<DynamicTest> dynamicTestsRandomStringFrom2SyntaxRuleWithoutWhitespace() {
         Random rng = new Random(SEED);
         LexicalGenerator gen = new LexicalGenerator(false, true);
-        return IntStream.range(1, 10_000).mapToObj(i -> {
-                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(1, rng);
+        return IntStream.range(0, 10_000).mapToObj(i -> {
+                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(2, rng);
+                    return dynamicTest(i + ": " + str,
+                            () -> testAgainstJdk(str));
+                }
+        );
+    }
+
+    @TestFactory
+    @Disabled
+    Stream<DynamicTest> dynamicTestsRandomStringFrom3SyntaxRuleWithoutWhitespace() {
+        Random rng = new Random(SEED);
+        LexicalGenerator gen = new LexicalGenerator(false, true);
+        return IntStream.range(0, 10_000).mapToObj(i -> {
+                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(3, rng);
                     return dynamicTest(i + ": " + str,
                             () -> testAgainstJdk(str));
                 }
@@ -76,11 +87,24 @@ Stream<DynamicTest> dynamicTestsRandomStringFrom1SyntaxRuleWithoutWhitespace() {
 
     @TestFactory
     @Disabled
-    Stream<DynamicTest> dynamicTestsRandomStringFrom40SyntaxRuleWithoutWhitespace() {
+    Stream<DynamicTest> dynamicTestsRandomStringFrom4SyntaxRuleWithoutWhitespace() {
         Random rng = new Random(SEED);
         LexicalGenerator gen = new LexicalGenerator(false, true);
-        return IntStream.range(1, 10_000).mapToObj(i -> {
-                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(40, rng);
+        return IntStream.range(0, 10_000).mapToObj(i -> {
+                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(4, rng);
+                    return dynamicTest(i + ": " + str,
+                            () -> testAgainstJdk(str));
+                }
+        );
+    }
+
+    @TestFactory
+    @Disabled
+    Stream<DynamicTest> dynamicTestsRandomStringFrom10SyntaxRuleWithoutWhitespace() {
+        Random rng = new Random(SEED);
+        LexicalGenerator gen = new LexicalGenerator(false, true);
+        return IntStream.range(0, 10_000).mapToObj(i -> {
+                    String str = gen.produceRandomInputStringFromLexicalRuleWithoutWhitespace(10, rng);
                     return dynamicTest(i + ": " + str,
                             () -> testAgainstJdk(str));
                 }
@@ -102,13 +126,38 @@ Stream<DynamicTest> dynamicTestsRandomStringsOfIncreasingLengthWithWhitespace()
 
     @TestFactory
     @Disabled
-    List<DynamicNode> dynamicTestsAllSingleCharacterInputs() {
-        ArrayList<DynamicNode> list = new ArrayList<>();
-        for (int codePoint = 0; codePoint <= Character.MAX_VALUE; codePoint++) {
-            String str = "" + (char) codePoint;
-            list.add(dynamicTest("0x" + Integer.toHexString(codePoint), () -> testAgainstJdk(str)));
-        }
-        return list;
+    Stream<DynamicNode> dynamicTestsAsciiCharacterInputsUpTo4Characters() {
+        int maxLength = 4;
+        Random rng = new Random();
+        return IntStream.range(0, 10_000).mapToObj(i -> {
+            char[] ch = new char[4];
+            int n = rng.nextInt(maxLength) + 1;
+            for (int j = 0; j < n; j++) {
+                ch[j] = nextAsciiChar(rng);
+            }
+            StringBuilder str = new StringBuilder();
+            StringBuilder title = new StringBuilder(Integer.toString(n));
+            title.append(':');
+            for (int j = 0; j < 4; j++) {
+                char c = ch[j];
+                if (c >= ' ') {
+                    if (Character.isISOControl(c) || Character.isWhitespace(c)) {
+                        title.append("&#x").append(Integer.toHexString(c)).append(';');
+                        str.append(c);
+                    } else {
+                        title.append((char) c);
+                        str.append(c);
+                    }
+                }
+            }
+            return dynamicTest(title.toString(), () -> testAgainstJdk(str.toString()));
+        });
+    }
+
+    private static char nextAsciiChar(Random rng) {
+        //U+0020 SPACE
+        //U+007F DELETE
+        return (char) (rng.nextInt(0x7f - 0x20) + 0x20);
     }
 
     /**
diff --git a/src/test/java/com/fasterxml/jackson/core/io/doubleparser/LexicalGenerator.java b/src/test/java/com/fasterxml/jackson/core/io/doubleparser/LexicalGenerator.java
index 5cf55154dc..91baee71b3 100644
--- a/src/test/java/com/fasterxml/jackson/core/io/doubleparser/LexicalGenerator.java
+++ b/src/test/java/com/fasterxml/jackson/core/io/doubleparser/LexicalGenerator.java
@@ -132,40 +132,46 @@ private int produceRandomDecimalFloatingPointLiteral(int remaining, Random rng,
             remaining = produceRandomDigits(remaining, rng, buf);
             buf.append('.');
             remaining--;
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomDigits(remaining, rng, buf);
             }
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomExponentPart(remaining, rng, buf);
             }
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomFloatTypeSuffix(remaining, rng, buf);
             }
             break;
         case 1:
             buf.append('.');
             remaining--;
-            remaining = produceRandomDigits(remaining, rng, buf);
-            if (rng.nextBoolean()) {
+            if (remaining > 0) {
+                remaining = produceRandomDigits(remaining, rng, buf);
+            }
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomExponentPart(remaining, rng, buf);
             }
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomFloatTypeSuffix(remaining, rng, buf);
             }
             break;
         case 2:
             remaining = produceRandomDigits(remaining, rng, buf);
-            remaining = produceRandomExponentPart(remaining, rng, buf);
-            if (rng.nextBoolean()) {
+            if (remaining > 0) {
+                remaining = produceRandomExponentPart(remaining, rng, buf);
+            }
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomFloatTypeSuffix(remaining, rng, buf);
             }
             break;
         case 3:
             remaining = produceRandomDigits(remaining, rng, buf);
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomExponentPart(remaining, rng, buf);
             }
-            remaining = produceRandomFloatTypeSuffix(remaining, rng, buf);
+            if (remaining > 0) {
+                remaining = produceRandomFloatTypeSuffix(remaining, rng, buf);
+            }
             break;
         }
         return remaining;
@@ -205,10 +211,12 @@ private int produceRandomDigits(int remaining, Random rng, StringBuilder buf) {
             break;
         case 1:
             remaining = produceRandomDigit(remaining, rng, buf);
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomDigitsAndUnderscores(remaining, rng, buf);
             }
-            remaining = produceRandomDigit(remaining, rng, buf);
+            if (remaining > 0) {
+                remaining = produceRandomDigit(remaining, rng, buf);
+            }
             break;
         }
 
@@ -226,17 +234,21 @@ private int produceRandomDigitsAndUnderscores(int remaining, Random rng, StringB
         switch (rng.nextInt(2)) {
         case 0:
             remaining = produceRandomDigitOrUnderscore(remaining, rng, buf);
-            int todo = rng.nextInt(Math.max(remaining, 1));
-            for (int i = 0; i < todo; i++) {
-                remaining = produceRandomDigitOrUnderscore(remaining, rng, buf);
+            if (remaining > 0) {
+                int todo = rng.nextInt(Math.max(remaining, 1));
+                for (int i = 0; i < todo; i++) {
+                    remaining = produceRandomDigitOrUnderscore(remaining, rng, buf);
+                }
             }
             break;
         case 1:
             remaining = produceRandomDigit(remaining, rng, buf);
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomDigitsAndUnderscores(remaining, rng, buf);
             }
-            remaining = produceRandomDigit(remaining, rng, buf);
+            if (remaining > 0) {
+                remaining = produceRandomDigit(remaining, rng, buf);
+            }
             break;
         }
         return remaining;
@@ -289,22 +301,28 @@ private int produceRandomFloatTypeSuffix(int remaining, Random rng, StringBuilde
     private int produceRandomFloatValue(int remaining, Random rng, StringBuilder buf) {
         switch (rng.nextInt(4)) {
         case 0:
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
                 remaining = produceRandomSign(remaining, rng, buf);
             }
-            remaining = produceRandomNaNOrInfinity(remaining, rng, buf);
+            if (remaining > 0 && remaining > 0) {
+                remaining = produceRandomNaNOrInfinity(remaining, rng, buf);
+            }
             break;
         case 1:
             if (rng.nextBoolean()) {
                 remaining = produceRandomSign(remaining, rng, buf);
             }
-            remaining = produceRandomDecimalFloatingPointLiteral(remaining, rng, buf);
+            if (remaining > 0) {
+                remaining = produceRandomDecimalFloatingPointLiteral(remaining, rng, buf);
+            }
             break;
         case 2:
             if (rng.nextBoolean()) {
                 remaining = produceRandomSign(remaining, rng, buf);
             }
-            remaining = produceRandomHexFloatingPointLiteral(remaining, rng, buf);
+            if (remaining > 0) {
+                remaining = produceRandomHexFloatingPointLiteral(remaining, rng, buf);
+            }
             break;
         case 3:
             remaining = produceRandomSignedInteger(remaining, rng, buf);
@@ -348,15 +366,21 @@ private int produceRandomHexDigitsAndUnderscores(int remaining, Random rng, Stri
 
     private int produceRandomHexFloatingPointLiteral(int remaining, Random rng, StringBuilder buf) {
         remaining = produceRandomHexSignificand(remaining, rng, buf);
-        remaining = produceRandomBinaryExponent(remaining, rng, buf);
-        remaining = produceRandomFloatTypeSuffix(remaining, rng, buf);
+        if (remaining > 0) {
+            remaining = produceRandomBinaryExponent(remaining, rng, buf);
+        }
+        if (remaining > 0) {
+            remaining = produceRandomFloatTypeSuffix(remaining, rng, buf);
+        }
         return remaining;
     }
 
     private int produceRandomHexNumeral(int remaining, Random rng, StringBuilder buf) {
         buf.append(rng.nextBoolean() ? "0x" : "0X");
         remaining--;
-        remaining = produceRandomHexDigits(remaining, rng, buf);
+        if (remaining > 0) {
+            remaining = produceRandomHexDigits(remaining, rng, buf);
+        }
         return remaining;
     }
 
@@ -382,12 +406,14 @@ private int produceRandomHexSignificand(int remaining, Random rng, StringBuilder
         case 2:
             buf.append(rng.nextBoolean() ? "0x" : "0X");
             remaining--;
-            if (rng.nextBoolean()) {
+            if (remaining > 0 && rng.nextBoolean()) {
+                remaining = produceRandomHexDigits(remaining, rng, buf);
+            }
+            if (remaining > 0 && rng.nextBoolean()) {
+                buf.append('.');
+                remaining--;
                 remaining = produceRandomHexDigits(remaining, rng, buf);
             }
-            buf.append('.');
-            remaining--;
-            remaining = produceRandomHexDigits(remaining, rng, buf);
             break;
         }
         return remaining;
@@ -403,8 +429,12 @@ private int produceRandomHexSignificand(int remaining, Random rng, StringBuilder
     public String produceRandomInputStringFromLexicalRuleWithWhitespace(int remaining, Random rng) {
         StringBuilder buf = new StringBuilder();
         remaining = produceRandomWhitespaces(remaining, rng, buf);
-        remaining = produceRandomFloatValue(remaining, rng, buf);
-        remaining = produceRandomWhitespaces(remaining, rng, buf);
+        if (remaining > 0) {
+            remaining = produceRandomFloatValue(remaining, rng, buf);
+        }
+        if (remaining > 0) {
+            remaining = produceRandomWhitespaces(remaining, rng, buf);
+        }
         return buf.toString();
     }
 
@@ -452,7 +482,9 @@ private int produceRandomSignedInteger(int remaining, Random rng, StringBuilder
         if (rng.nextBoolean()) {
             remaining = produceRandomSign(remaining, rng, buf);
         }
-        remaining = produceRandomDigits(remaining, rng, buf);
+        if (remaining > 0) {
+            remaining = produceRandomDigits(remaining, rng, buf);
+        }
         return remaining;
     }