[llvm] [NFC] Move llvm.fptrunc.round closer to roundeven in LangRef (PR #155854)

[Dmitry Sidorov via llvm-commits]

https://github.com/MrSidims updated https://github.com/llvm/llvm-project/pull/155854

>From 186e45ff55516f1044264bc7429424bf3d50e616 Mon Sep 17 00:00:00 2001
From: "Sidorov, Dmitry" <dmitry.sidorov at intel.com>
Date: Thu, 28 Aug 2025 08:20:19 -0700
Subject: [PATCH 1/2] [NFC] Move llvm.fptrunc.round closer to roundeven in
 LangRef

Not sure if
https://llvm.org/docs/LangRef.html#standard-c-c-library-intrinsics
is a perfect match, but the intrinsic shouldn't be a part of
https://llvm.org/docs/LangRef.html#preserving-debug-information-intrinsics

Signed-off-by: Sidorov, Dmitry <dmitry.sidorov at intel.com>
---
 llvm/docs/LangRef.rst | 79 ++++++++++++++++++++++---------------------
 1 file changed, 40 insertions(+), 39 deletions(-)

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index b122fd352eaf5..cbf5489f2a215 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -17780,6 +17780,46 @@ would, but without setting errno. If the rounded value is too large to
 be stored in the result type, the return value is a non-deterministic
 value (equivalent to `freeze poison`).
 
+'``llvm.fptrunc.round``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+      declare <ty2>
+      @llvm.fptrunc.round(<type> <value>, metadata <rounding mode>)
+
+Overview:
+"""""""""
+
+The '``llvm.fptrunc.round``' intrinsic truncates
+:ref:`floating-point <t_floating>` ``value`` to type ``ty2``
+with a specified rounding mode.
+
+Arguments:
+""""""""""
+
+The '``llvm.fptrunc.round``' intrinsic takes a :ref:`floating-point
+<t_floating>` value to cast and a :ref:`floating-point <t_floating>` type
+to cast it to. This argument must be larger in size than the result.
+
+The second argument specifies the rounding mode as described in the constrained
+intrinsics section.
+For this intrinsic, the "round.dynamic" mode is not supported.
+
+Semantics:
+""""""""""
+
+The '``llvm.fptrunc.round``' intrinsic casts a ``value`` from a larger
+:ref:`floating-point <t_floating>` type to a smaller :ref:`floating-point
+<t_floating>` type.
+This intrinsic is assumed to execute in the default :ref:`floating-point
+environment <floatenv>` *except* for the rounding mode.
+This intrinsic is not supported on all targets. Some targets may not support
+all rounding modes.
+
 Bit Manipulation Intrinsics
 ---------------------------
 
@@ -31123,42 +31163,3 @@ Semantics:
 The '``llvm.preserve.struct.access.index``' intrinsic produces the same result
 as a getelementptr with base ``base`` and access operands ``{0, gep_index}``.
 
-'``llvm.fptrunc.round``' Intrinsic
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Syntax:
-"""""""
-
-::
-
-      declare <ty2>
-      @llvm.fptrunc.round(<type> <value>, metadata <rounding mode>)
-
-Overview:
-"""""""""
-
-The '``llvm.fptrunc.round``' intrinsic truncates
-:ref:`floating-point <t_floating>` ``value`` to type ``ty2``
-with a specified rounding mode.
-
-Arguments:
-""""""""""
-
-The '``llvm.fptrunc.round``' intrinsic takes a :ref:`floating-point
-<t_floating>` value to cast and a :ref:`floating-point <t_floating>` type
-to cast it to. This argument must be larger in size than the result.
-
-The second argument specifies the rounding mode as described in the constrained
-intrinsics section.
-For this intrinsic, the "round.dynamic" mode is not supported.
-
-Semantics:
-""""""""""
-
-The '``llvm.fptrunc.round``' intrinsic casts a ``value`` from a larger
-:ref:`floating-point <t_floating>` type to a smaller :ref:`floating-point
-<t_floating>` type.
-This intrinsic is assumed to execute in the default :ref:`floating-point
-environment <floatenv>` *except* for the rounding mode.
-This intrinsic is not supported on all targets. Some targets may not support
-all rounding modes.

>From 1703c4149d7a76a1fc1c536f747d6eac34eff125 Mon Sep 17 00:00:00 2001
From: "Sidorov, Dmitry" <dmitry.sidorov at intel.com>
Date: Mon, 8 Sep 2025 04:51:02 -0700
Subject: [PATCH 2/2] add dedicated category

---
 llvm/docs/LangRef.rst | 87 +++++++++++++++++++++++--------------------
 1 file changed, 47 insertions(+), 40 deletions(-)

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index cbf5489f2a215..52ecff051dae3 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -17780,46 +17780,6 @@ would, but without setting errno. If the rounded value is too large to
 be stored in the result type, the return value is a non-deterministic
 value (equivalent to `freeze poison`).
 
-'``llvm.fptrunc.round``' Intrinsic
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Syntax:
-"""""""
-
-::
-
-      declare <ty2>
-      @llvm.fptrunc.round(<type> <value>, metadata <rounding mode>)
-
-Overview:
-"""""""""
-
-The '``llvm.fptrunc.round``' intrinsic truncates
-:ref:`floating-point <t_floating>` ``value`` to type ``ty2``
-with a specified rounding mode.
-
-Arguments:
-""""""""""
-
-The '``llvm.fptrunc.round``' intrinsic takes a :ref:`floating-point
-<t_floating>` value to cast and a :ref:`floating-point <t_floating>` type
-to cast it to. This argument must be larger in size than the result.
-
-The second argument specifies the rounding mode as described in the constrained
-intrinsics section.
-For this intrinsic, the "round.dynamic" mode is not supported.
-
-Semantics:
-""""""""""
-
-The '``llvm.fptrunc.round``' intrinsic casts a ``value`` from a larger
-:ref:`floating-point <t_floating>` type to a smaller :ref:`floating-point
-<t_floating>` type.
-This intrinsic is assumed to execute in the default :ref:`floating-point
-environment <floatenv>` *except* for the rounding mode.
-This intrinsic is not supported on all targets. Some targets may not support
-all rounding modes.
-
 Bit Manipulation Intrinsics
 ---------------------------
 
@@ -21120,6 +21080,53 @@ Example:
       %c = call i8 @llvm.fptosi.sat.i8.f32(float 999.0)              ; yields i8:  127
       %d = call i8 @llvm.fptosi.sat.i8.f32(float 0xFFF8000000000000) ; yields i8:    0
 
+Floating-Point Conversion Intrinsics
+------------------------------------
+
+This class of intrinsics is designed for floating-point conversions that do
+not fall into other categories. For example conversions with specified rounding
+mode or mini-float conversions.
+
+'``llvm.fptrunc.round``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+      declare <ty2>
+      @llvm.fptrunc.round(<type> <value>, metadata <rounding mode>)
+
+Overview:
+"""""""""
+
+The '``llvm.fptrunc.round``' intrinsic truncates
+:ref:`floating-point <t_floating>` ``value`` to type ``ty2``
+with a specified rounding mode.
+
+Arguments:
+""""""""""
+
+The '``llvm.fptrunc.round``' intrinsic takes a :ref:`floating-point
+<t_floating>` value to cast and a :ref:`floating-point <t_floating>` type
+to cast it to. This argument must be larger in size than the result.
+
+The second argument specifies the rounding mode as described in the constrained
+intrinsics section.
+For this intrinsic, the "round.dynamic" mode is not supported.
+
+Semantics:
+""""""""""
+
+The '``llvm.fptrunc.round``' intrinsic casts a ``value`` from a larger
+:ref:`floating-point <t_floating>` type to a smaller :ref:`floating-point
+<t_floating>` type.
+This intrinsic is assumed to execute in the default :ref:`floating-point
+environment <floatenv>` *except* for the rounding mode.
+This intrinsic is not supported on all targets. Some targets may not support
+all rounding modes.
+
 Convergence Intrinsics
 ----------------------