Add SignExtend for two's complement sign extension

dev_tools/autogenerate-bloqs-notebooks-v2.py

@@ -374,6 +374,11 @@
             qualtran.bloqs.arithmetic.comparison._LEQ_DOC,
         ],
     ),
+    NotebookSpecV2(
+        title='Sign Extension',
+        module=qualtran.bloqs.arithmetic.sign_extension,
+        bloq_specs=[qualtran.bloqs.arithmetic.sign_extension._SIGN_EXTEND_DOC],
+    ),
     NotebookSpecV2(
         title='Sorting',
         module=qualtran.bloqs.arithmetic.sorting,

docs/bloqs/index.rst

@@ -64,6 +64,7 @@ Bloqs Library
     arithmetic/subtraction.ipynb
     arithmetic/multiplication.ipynb
     arithmetic/comparison.ipynb
+    arithmetic/sign_extension.ipynb
     arithmetic/sorting.ipynb
     arithmetic/conversions.ipynb
     arithmetic/permutation.ipynb

qualtran/bloqs/arithmetic/__init__.py

@@ -35,6 +35,7 @@
     SumOfSquares,
 )
 from qualtran.bloqs.arithmetic.negate import Negate
+from qualtran.bloqs.arithmetic.sign_extension import SignExtend
 from qualtran.bloqs.arithmetic.sorting import BitonicSort, Comparator
 from qualtran.bloqs.arithmetic.subtraction import Subtract
 

qualtran/bloqs/arithmetic/sign_extension.ipynb

@@ -0,0 +1,167 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "8a2ef164",
+   "metadata": {
+    "cq.autogen": "title_cell"
+   },
+   "source": [
+    "# Sign Extension"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "76be8def",
+   "metadata": {
+    "cq.autogen": "top_imports"
+   },
+   "outputs": [],
+   "source": [
+    "from qualtran import Bloq, CompositeBloq, BloqBuilder, Signature, Register\n",
+    "from qualtran import QBit, QInt, QUInt, QAny\n",
+    "from qualtran.drawing import show_bloq, show_call_graph, show_counts_sigma\n",
+    "from typing import *\n",
+    "import numpy as np\n",
+    "import sympy\n",
+    "import cirq"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "283c1b7e",
+   "metadata": {
+    "cq.autogen": "SignExtend.bloq_doc.md"
+   },
+   "source": [
+    "## `SignExtend`\n",
+    "Sign-Extend a value to a value of larger bitsize.\n",
+    "\n",
+    "Useful to implement arithmetic operations with differing operand bitsizes.\n",
+    "A sign extension copies the MSB into the new bits of the wider value. For\n",
+    "example: a 4-bit to 6-bit sign-extension of `1010` gives `111010`.\n",
+    "\n",
+    "\n",
+    "#### Parameters\n",
+    " - `inp_dtype`: input data type.\n",
+    " - `out_dtype`: output data type. must be same class as `inp_dtype`, and have larger bitsize. \n",
+    "\n",
+    "#### Registers\n",
+    " - `x`: the input register of type `inp_dtype`\n",
+    " - `y`: the output register of type `out_dtype`\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "6504d380",
+   "metadata": {
+    "cq.autogen": "SignExtend.bloq_doc.py"
+   },
+   "outputs": [],
+   "source": [
+    "from qualtran.bloqs.arithmetic import SignExtend"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "9354fcdc",
+   "metadata": {
+    "cq.autogen": "SignExtend.example_instances.md"
+   },
+   "source": [
+    "### Example Instances"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "30a40ff3",
+   "metadata": {
+    "cq.autogen": "SignExtend.sign_extend"
+   },
+   "outputs": [],
+   "source": [
+    "from qualtran import QInt\n",
+    "\n",
+    "sign_extend = SignExtend(QInt(8), QInt(16))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "9e43e994",
+   "metadata": {
+    "cq.autogen": "SignExtend.sign_extend_fxp"
+   },
+   "outputs": [],
+   "source": [
+    "from qualtran import QFxp\n",
+    "\n",
+    "sign_extend_fxp = SignExtend(QFxp(8, 4, signed=True), QFxp(16, 4, signed=True))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "ae58afdf",
+   "metadata": {
+    "cq.autogen": "SignExtend.graphical_signature.md"
+   },
+   "source": [
+    "#### Graphical Signature"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "2c96ebb1",
+   "metadata": {
+    "cq.autogen": "SignExtend.graphical_signature.py"
+   },
+   "outputs": [],
+   "source": [
+    "from qualtran.drawing import show_bloqs\n",
+    "show_bloqs([sign_extend, sign_extend_fxp],\n",
+    "           ['`sign_extend`', '`sign_extend_fxp`'])"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "38f234ca",
+   "metadata": {
+    "cq.autogen": "SignExtend.call_graph.md"
+   },
+   "source": [
+    "### Call Graph"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "094ebe4f",
+   "metadata": {
+    "cq.autogen": "SignExtend.call_graph.py"
+   },
+   "outputs": [],
+   "source": [
+    "from qualtran.resource_counting.generalizers import ignore_split_join\n",
+    "sign_extend_g, sign_extend_sigma = sign_extend.call_graph(max_depth=1, generalizer=ignore_split_join)\n",
+    "show_call_graph(sign_extend_g)\n",
+    "show_counts_sigma(sign_extend_sigma)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "name": "python"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

qualtran/bloqs/arithmetic/sign_extension.py

@@ -0,0 +1,125 @@
+#  Copyright 2024 Google LLC
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+from functools import cached_property
+
+import numpy as np
+from attrs import frozen
+
+from qualtran import (
+    Bloq,
+    bloq_example,
+    BloqBuilder,
+    BloqDocSpec,
+    QDType,
+    QFxp,
+    Register,
+    Side,
+    Signature,
+    Soquet,
+    SoquetT,
+)
+from qualtran.bloqs.mcmt import MultiTargetCNOT
+from qualtran.resource_counting import BloqCountT, SympySymbolAllocator
+from qualtran.symbolics import is_symbolic
+
+
+@frozen
+class SignExtend(Bloq):
+    """Sign-Extend a value to a value of larger bitsize.
+
+    Useful to implement arithmetic operations with differing operand bitsizes.
+    A sign extension copies the MSB into the new bits of the wider value. For
+    example: a 4-bit to 6-bit sign-extension of `1010` gives `111010`.
+
+
+    Args:
+        inp_dtype: input data type.
+        out_dtype: output data type. must be same class as `inp_dtype`,
+                   and have larger bitsize.
+
+    Registers:
+        x (LEFT): the input register of type `inp_dtype`
+        y (RIGHT): the output register of type `out_dtype`
+    """
+
+    inp_dtype: QDType
+    out_dtype: QDType
+
+    def __attrs_post_init__(self):
+        if not isinstance(self.inp_dtype, type(self.out_dtype)):
+            raise ValueError(
+                f"Expected same input and output base types, got: {self.inp_dtype}, {self.out_dtype}"
+            )
+
+        if isinstance(self.out_dtype, QFxp):
+            assert isinstance(self.inp_dtype, QFxp)  # checked above, but mypy does not realize
+
+            if self.out_dtype.num_frac != self.inp_dtype.num_frac:
+                raise ValueError(
+                    f"Expected same fractional sizes for QFxp, got: {self.inp_dtype.num_frac}, {self.out_dtype.num_frac}"
+                )
+
+        if not is_symbolic(self.extend_bitsize) and self.extend_bitsize <= 0:
+            raise ValueError(
+                f"input bitsize {self.inp_dtype.num_qubits} must be smaller than "
+                f"output bitsize {self.out_dtype.num_qubits}"
+            )
+
+    @cached_property
+    def signature(self) -> 'Signature':
+        return Signature(
+            [
+                Register('x', self.inp_dtype, side=Side.LEFT),
+                Register('y', self.out_dtype, side=Side.RIGHT),
+            ]
+        )
+
+    @cached_property
+    def extend_bitsize(self):
+        return self.out_dtype.num_qubits - self.inp_dtype.num_qubits
+
+    def build_composite_bloq(self, bb: 'BloqBuilder', x: 'Soquet') -> dict[str, 'SoquetT']:
+        extend_ys = bb.allocate(self.extend_bitsize)
+        xs = bb.split(x)
+
+        xs[0], extend_ys = bb.add(
+            MultiTargetCNOT(self.extend_bitsize), control=xs[0], targets=extend_ys
+        )
+
+        extend_ys = bb.split(extend_ys)
+        y = bb.join(np.concatenate([extend_ys, xs]), dtype=self.out_dtype)
+
+        return {'y': y}
+
+    def build_call_graph(self, ssa: 'SympySymbolAllocator') -> set['BloqCountT']:
+        return {(MultiTargetCNOT(self.extend_bitsize), 1)}
+
+
+@bloq_example
+def _sign_extend() -> SignExtend:
+    from qualtran import QInt
+
+    sign_extend = SignExtend(QInt(8), QInt(16))
+    return sign_extend
+
+
+@bloq_example
+def _sign_extend_fxp() -> SignExtend:
+    from qualtran import QFxp
+
+    sign_extend_fxp = SignExtend(QFxp(8, 4, signed=True), QFxp(16, 4, signed=True))
+    return sign_extend_fxp
+
+
+_SIGN_EXTEND_DOC = BloqDocSpec(bloq_cls=SignExtend, examples=[_sign_extend, _sign_extend_fxp])

qualtran/bloqs/arithmetic/sign_extension_test.py

@@ -0,0 +1,42 @@
+#  Copyright 2024 Google LLC
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+import numpy as np
+import pytest
+
+from qualtran import BloqBuilder, QInt, QUInt
+from qualtran.bloqs.arithmetic.sign_extension import _sign_extend, _sign_extend_fxp, SignExtend
+from qualtran.bloqs.basic_gates import IntEffect, IntState
+
+
+def test_examples(bloq_autotester):
+    bloq_autotester(_sign_extend)
+    bloq_autotester(_sign_extend_fxp)
+
+
+@pytest.mark.parametrize("l, r", [(2, 4)])
+def test_sign_extend_tensor(l: int, r: int):
+    bloq = SignExtend(QInt(l), QInt(r))
+
+    def _as_unsigned(num: int, bitsize: int):
+        # TODO remove this once IntState supports signed values
+        return QUInt(bitsize).from_bits(QInt(bitsize).to_bits(num))
+
+    for x in QInt(l).get_classical_domain():
+        bb = BloqBuilder()
+        qx = bb.add(IntState(_as_unsigned(x, l), l))
+        qx = bb.add(bloq, x=qx)
+        bb.add(IntEffect(_as_unsigned(x, r), r), val=qx)
+        cbloq = bb.finalize()
+
+        np.testing.assert_allclose(cbloq.tensor_contract(), 1)

qualtran/serialization/resolver_dict.py

@@ -22,6 +22,7 @@
 import qualtran.bloqs.arithmetic.multiplication
 import qualtran.bloqs.arithmetic.negate
 import qualtran.bloqs.arithmetic.permutation
+import qualtran.bloqs.arithmetic.sign_extension
 import qualtran.bloqs.arithmetic.sorting
 import qualtran.bloqs.basic_gates.cnot
 import qualtran.bloqs.basic_gates.hadamard
@@ -170,6 +171,7 @@
     "qualtran.bloqs.arithmetic.negate.Negate": qualtran.bloqs.arithmetic.negate.Negate,
     "qualtran.bloqs.arithmetic.permutation.Permutation": qualtran.bloqs.arithmetic.permutation.Permutation,
     "qualtran.bloqs.arithmetic.permutation.PermutationCycle": qualtran.bloqs.arithmetic.permutation.PermutationCycle,
+    "qualtran.bloqs.arithmetic.sign_extension.SignExtend": qualtran.bloqs.arithmetic.sign_extension.SignExtend,
     "qualtran.bloqs.arithmetic.sorting.BitonicMerge": qualtran.bloqs.arithmetic.sorting.BitonicMerge,
     "qualtran.bloqs.arithmetic.sorting.BitonicSort": qualtran.bloqs.arithmetic.sorting.BitonicSort,
     "qualtran.bloqs.arithmetic.sorting.Comparator": qualtran.bloqs.arithmetic.sorting.Comparator,