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[spec] Fix definition of lane ops + better xrefs #1700

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3 changes: 1 addition & 2 deletions document/core/appendix/index-instructions.py
Original file line number Diff line number Diff line change
Expand Up @@ -54,8 +54,7 @@ def RefWrap(s, kind):

def Instruction(name, opcode, type=None, validation=None, execution=None, operator=None):
if operator:
execution_str = ', '.join([RefWrap(execution, 'execution'),
RefWrap(operator, 'operator')])
execution_str = RefWrap(execution, 'execution') + ' (' + RefWrap(operator, 'operator') + ')'
else:
execution_str = RefWrap(execution, 'execution')

Expand Down
52 changes: 29 additions & 23 deletions document/core/exec/instructions.rst
Original file line number Diff line number Diff line change
Expand Up @@ -20,16 +20,15 @@ The mapping of numeric instructions to their underlying operators is expressed b

.. math::
\begin{array}{lll@{\qquad}l}
\X{op}_{\IN}(i_1,\dots,i_k) &=& \F{i}\X{op}_N(i_1,\dots,i_k) \\
\X{op}_{\FN}(z_1,\dots,z_k) &=& \F{f}\X{op}_N(z_1,\dots,z_k) \\
\X{op}_{\VN}(i_1,\dots,i_k) &=& \F{i}\X{op}_N(i_1,\dots,i_k) \\
\X{op}_{\IN}(i_1,\dots,i_k) &=& \xref{exec/numerics}{int-ops}{\F{i}\X{op}}_N(i_1,\dots,i_k) \\
\X{op}_{\FN}(z_1,\dots,z_k) &=& \xref{exec/numerics}{float-ops}{\F{f}\X{op}}_N(z_1,\dots,z_k) \\
\end{array}

And for :ref:`conversion operators <exec-cvtop>`:

.. math::
\begin{array}{lll@{\qquad}l}
\X{cvtop}^{\sx^?}_{t_1,t_2}(c) &=& \X{cvtop}^{\sx^?}_{|t_1|,|t_2|}(c) \\
\cvtop^{\sx^?}_{t_1,t_2}(c) &=& \xref{exec/numerics}{convert-ops}{\X{cvtop}}^{\sx^?}_{|t_1|,|t_2|}(c) \\
\end{array}

Where the underlying operators are partial, the corresponding instruction will :ref:`trap <trap>` when the result is not defined.
Expand Down Expand Up @@ -64,9 +63,9 @@ Where the underlying operators are non-deterministic, because they may return on

2. Pop the value :math:`t.\CONST~c_1` from the stack.

3. If :math:`\unop_t(c_1)` is defined, then:
3. If :math:`\unopF_t(c_1)` is defined, then:

a. Let :math:`c` be a possible result of computing :math:`\unop_t(c_1)`.
a. Let :math:`c` be a possible result of computing :math:`\unopF_t(c_1)`.

b. Push the value :math:`t.\CONST~c` to the stack.

Expand All @@ -77,9 +76,9 @@ Where the underlying operators are non-deterministic, because they may return on
.. math::
\begin{array}{lcl@{\qquad}l}
(t\K{.}\CONST~c_1)~t\K{.}\unop &\stepto& (t\K{.}\CONST~c)
& (\iff c \in \unop_t(c_1)) \\
& (\iff c \in \unopF_t(c_1)) \\
(t\K{.}\CONST~c_1)~t\K{.}\unop &\stepto& \TRAP
& (\iff \unop_{t}(c_1) = \{\})
& (\iff \unopF_{t}(c_1) = \{\})
\end{array}


Expand All @@ -94,9 +93,9 @@ Where the underlying operators are non-deterministic, because they may return on

3. Pop the value :math:`t.\CONST~c_1` from the stack.

4. If :math:`\binop_t(c_1, c_2)` is defined, then:
4. If :math:`\binopF_t(c_1, c_2)` is defined, then:

a. Let :math:`c` be a possible result of computing :math:`\binop_t(c_1, c_2)`.
a. Let :math:`c` be a possible result of computing :math:`\binopF_t(c_1, c_2)`.

b. Push the value :math:`t.\CONST~c` to the stack.

Expand All @@ -107,9 +106,9 @@ Where the underlying operators are non-deterministic, because they may return on
.. math::
\begin{array}{lcl@{\qquad}l}
(t\K{.}\CONST~c_1)~(t\K{.}\CONST~c_2)~t\K{.}\binop &\stepto& (t\K{.}\CONST~c)
& (\iff c \in \binop_t(c_1,c_2)) \\
& (\iff c \in \binopF_t(c_1,c_2)) \\
(t\K{.}\CONST~c_1)~(t\K{.}\CONST~c_2)~t\K{.}\binop &\stepto& \TRAP
& (\iff \binop_{t}(c_1,c_2) = \{\})
& (\iff \binopF_{t}(c_1,c_2) = \{\})
\end{array}


Expand All @@ -122,14 +121,14 @@ Where the underlying operators are non-deterministic, because they may return on

2. Pop the value :math:`t.\CONST~c_1` from the stack.

3. Let :math:`c` be the result of computing :math:`\testop_t(c_1)`.
3. Let :math:`c` be the result of computing :math:`\testopF_t(c_1)`.

4. Push the value :math:`\I32.\CONST~c` to the stack.

.. math::
\begin{array}{lcl@{\qquad}l}
(t\K{.}\CONST~c_1)~t\K{.}\testop &\stepto& (\I32\K{.}\CONST~c)
& (\iff c = \testop_t(c_1)) \\
& (\iff c = \testopF_t(c_1)) \\
\end{array}


Expand All @@ -144,14 +143,14 @@ Where the underlying operators are non-deterministic, because they may return on

3. Pop the value :math:`t.\CONST~c_1` from the stack.

4. Let :math:`c` be the result of computing :math:`\relop_t(c_1, c_2)`.
4. Let :math:`c` be the result of computing :math:`\relopF_t(c_1, c_2)`.

5. Push the value :math:`\I32.\CONST~c` to the stack.

.. math::
\begin{array}{lcl@{\qquad}l}
(t\K{.}\CONST~c_1)~(t\K{.}\CONST~c_2)~t\K{.}\relop &\stepto& (\I32\K{.}\CONST~c)
& (\iff c = \relop_t(c_1,c_2)) \\
& (\iff c = \relopF_t(c_1,c_2)) \\
\end{array}


Expand Down Expand Up @@ -256,20 +255,27 @@ Reference Instructions
Vector Instructions
~~~~~~~~~~~~~~~~~~~

Most vector instructions are defined in terms of generic numeric operators applied lane-wise based on the :ref:`shape <syntax-vec-shape>`.
Vector instructions that operate bitwise are handled as integer operations of respective width.

.. math::
\begin{array}{lll@{\qquad}l}
\X{op}_{\VN}(i_1,\dots,i_k) &=& \xref{exec/numerics}{int-ops}{\F{i}\X{op}}_N(i_1,\dots,i_k) \\
\end{array}

Most other vector instructions are defined in terms of numeric operators that are applied lane-wise according to the given :ref:`shape <syntax-vec-shape>`.

.. math::
\begin{array}{llll}
\X{op}_{t\K{x}N}(n_1,\dots,n_k) &=&
\lanes^{-1}_{t\K{x}N}(op_t(\lanes_{t\K{x}N}(n_1) ~\dots~ \lanes_{t\K{x}N}(n_k))
\lanes^{-1}_{t\K{x}N}(\xref{exec/instructions}{exec-instr-numeric}{\X{op}}_t(i_1,\dots,i_k)^\ast) & \qquad(\iff i_1^\ast = \lanes_{t\K{x}N}(n_1) \land \dots \land i_k^\ast = \lanes_{t\K{x}N}(n_k) \\
\end{array}

.. note::
For example, the result of instruction :math:`\K{i32x4}.\ADD` applied to operands :math:`i_1, i_2`
invokes :math:`\ADD_{\K{i32x4}}(i_1, i_2)`, which maps to
:math:`\lanes^{-1}_{\K{i32x4}}(\ADD_{\I32}(i_1^+, i_2^+))`,
where :math:`i_1^+` and :math:`i_2^+` are sequences resulting from invoking
:math:`\lanes_{\K{i32x4}}(i_1)` and :math:`\lanes_{\K{i32x4}}(i_2)`
For example, the result of instruction :math:`\K{i32x4}.\ADD` applied to operands :math:`v_1, v_2`
invokes :math:`\ADD_{\K{i32x4}}(v_1, v_2)`, which maps to
:math:`\lanes^{-1}_{\K{i32x4}}(\ADD_{\I32}(i_1, i_2)^\ast)`,
where :math:`i_1^\ast` and :math:`i_2^\ast` are sequences resulting from invoking
:math:`\lanes_{\K{i32x4}}(v_1)` and :math:`\lanes_{\K{i32x4}}(v_2)`
respectively.


Expand Down
17 changes: 9 additions & 8 deletions document/core/exec/numerics.rst
Original file line number Diff line number Diff line change
Expand Up @@ -169,24 +169,25 @@ where :math:`M = \significand(N)` and :math:`E = \exponent(N)`.
Vectors
.......

Numeric vectors have the same underlying representation as an |i128|.
They can also be interpreted as a sequence of numeric values packed into a |V128| with a particular |shape|.
Numeric vectors of type |VN| have the same underlying representation as an |IN|.
They can also be interpreted as a sequence of numeric values packed into a |VN| with a particular |shape| :math:`t\K{x}M`,
provided that :math:`N = |t|\cdot M`.

.. math::
\begin{array}{l}
\begin{array}{lll@{\qquad}l}
\lanes_{t\K{x}N}(c) &=&
c_0~\dots~c_{N-1} \\
\lanes_{t\K{x}M}(c) &=&
c_0~\dots~c_{M-1} \\
\end{array}
\\ \qquad
\begin{array}[t]{@{}r@{~}l@{}l@{~}l@{~}l}
(\where & B &=& |t| / 8 \\
\wedge & b^{16} &=& \bytes_{\i128}(c) \\
\wedge & c_i &=& \bytes_{t}^{-1}(b^{16}[i \cdot B \slice B]))
(\where & w &=& |t| / 8 \\
\wedge & b^\ast &=& \bytes_{\IN}(c) \\
\wedge & c_i &=& \bytes_{t}^{-1}(b^\ast[i \cdot w \slice w]))
\end{array}
\end{array}

These functions are bijections, so they are invertible.
This function is a bijection on |IN|, hence it is invertible.


.. index:: byte, little endian, memory
Expand Down
6 changes: 6 additions & 0 deletions document/core/util/macros.def
Original file line number Diff line number Diff line change
Expand Up @@ -500,6 +500,12 @@
.. |relop| mathdef:: \xref{syntax/instructions}{syntax-relop}{\X{relop}}
.. |cvtop| mathdef:: \xref{syntax/instructions}{syntax-cvtop}{\X{cvtop}}

.. |unopF| mathdef:: \xref{exec/instructions}{exec-instr-numeric}{\X{unop}}
.. |binopF| mathdef:: \xref{exec/instructions}{exec-instr-numeric}{\X{binop}}
.. |testopF| mathdef:: \xref{exec/instructions}{exec-instr-numeric}{\X{testop}}
.. |relopF| mathdef:: \xref{exec/instructions}{exec-instr-numeric}{\X{relop}}
.. |cvtopF| mathdef:: \xref{exec/instructions}{exec-instr-numeric}{\X{cvtop}}

.. |iunop| mathdef:: \xref{syntax/instructions}{syntax-iunop}{\X{iunop}}
.. |ibinop| mathdef:: \xref{syntax/instructions}{syntax-ibinop}{\X{ibinop}}
.. |itestop| mathdef:: \xref{syntax/instructions}{syntax-itestop}{\X{itestop}}
Expand Down
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