[llvm] Spaceship intrinsic for GSoC 2024 (PR #83227)

[Miguel Raz Guzmán Macedo via llvm-commits]

https://github.com/miguelraz updated https://github.com/llvm/llvm-project/pull/83227

>From 9d7134fbc570d8ce3218a69c56562aabda7a6be1 Mon Sep 17 00:00:00 2001
From: miguelraz <miguelraz at ciencias.unam.mx>
Date: Thu, 29 Feb 2024 20:01:20 -0600
Subject: [PATCH 1/3] add sthreecmp and uthreecmp intrinsics to LangRef

---
 llvm/docs/LangRef.rst | 92 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index f56d4ed28f2855..ceffd33cdc54f5 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -11976,6 +11976,98 @@ Example:
       <result> = icmp ule i16 -4, 5        ; yields: result=false
       <result> = icmp sge i16  4, 5        ; yields: result=false
 
+.. _i_sthreecmp:
+
+'``sthreecmp``' Instruction
+^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+      <result> = sthreecmp <op1>, <op2>  ; yields i2 or <N x i2>:result
+
+Overview:
+"""""""""
+
+The '``sthreecmp``' instruction returns an integer value or a vector of
+integer values based on comparison of its two integer, integer vector,
+pointer, or pointer vector operands.
+
+Arguments:
+""""""""""
+
+The '``sthreecmp``' instruction takes two signed integer operands.
+
+Semantics:
+""""""""""
+If the operands are equal, it returns 0. If ``op1`` is less than ``op2``,
+it returns -1, and if ``op1`` is greater than ``op2``, it returns 1.
+It is also known as the '``<=>``' spaceship operator.
+
+If the operands are :ref:`pointer <t_pointer>` typed, the pointer values
+are compared as if they were integers.
+
+If the operands are integer vectors, then they are compared element by
+element. The result is an ``i2`` vector with the same number of elements
+as the values being compared. Otherwise, the result is an ``i2``.
+
+Example:
+""""""""
+
+.. code-block:: text
+
+      <result> = sthreecmp 4, 5          ; yields: result=-1
+      <result> = sthreecmp 2, 2          ; yields: result=0
+      <result> = sthreecmp -2, -1        ; yields: result=1
+
+.. _i_uthreecmp:
+
+'``uthreecmp``' Instruction
+^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+      <result> = uthreecmp <op1>, <op2>  ; yields i2 or <N x i2>:result
+
+Overview:
+"""""""""
+
+The '``uthreecmp``' instruction returns an integer value or a vector of
+integer values based on comparison of its two integer, integer vector,
+pointer, or pointer vector operands.
+
+Arguments:
+""""""""""
+
+The '``uthreecmp``' instruction takes two signed integer operands.
+
+Semantics:
+""""""""""
+If the operands are equal, it returns 0. If ``op1`` is less than ``op2``,
+it returns -1, and if ``op1`` is greater than ``op2``, it returns 1.
+It is also known as the '``<=>``' spaceship operator.
+
+If the operands are :ref:`pointer <t_pointer>` typed, the pointer values
+are compared as if they were integers.
+
+If the operands are integer vectors, then they are compared element by
+element. The result is an ``i2`` vector with the same number of elements
+as the values being compared. Otherwise, the result is an ``i2``.
+
+Example:
+""""""""
+
+.. code-block:: text
+
+      <result> = uthreecmp 4, 5          ; yields: result=-1
+      <result> = uthreecmp 2, 2          ; yields: result=0
+      <result> = uthreecmp 9, 0          ; yields: result=1
+
 .. _i_fcmp:
 
 '``fcmp``' Instruction

>From 57ec729bd308d43adaedb7e095541991f4377111 Mon Sep 17 00:00:00 2001
From: miguelraz <miguelraz at ciencias.unam.mx>
Date: Thu, 29 Feb 2024 20:49:59 -0600
Subject: [PATCH 2/3] add tablegen for sthreecmp and usthreecmp intrinsics

---
 llvm/include/llvm/IR/Intrinsics.td | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/llvm/include/llvm/IR/Intrinsics.td b/llvm/include/llvm/IR/Intrinsics.td
index 0f13d25eb30ebf..15df2e7b76577e 100644
--- a/llvm/include/llvm/IR/Intrinsics.td
+++ b/llvm/include/llvm/IR/Intrinsics.td
@@ -2136,7 +2136,14 @@ let IntrProperties = [IntrNoMem, IntrNoSync, IntrWillReturn] in {
                                llvm_metadata_ty,
                                LLVMScalarOrSameVectorWidth<0, llvm_i1_ty>,
                                llvm_i32_ty]>;
-
+  def int_vp_sthreecmp : DefaultAttrsIntrinsic<[ LLVMScalarOrSameVectorWidth<0, llvm_i8_ty> ],
+                             [LLVMMatchType<0>,
+                              LLVMMatchType<0>],
+                              [IntrSpeculatable]>;
+  def int_vp_uthreecmp : DefaultAttrsIntrinsic<[ LLVMScalarOrSameVectorWidth<0, llvm_i8_ty>],
+                             [LLVMMatchType<0>,
+                              LLVMMatchType<0>],
+                              [IntrSpeculatable]>;
   // Reductions
   def int_vp_reduce_fadd : DefaultAttrsIntrinsic<[LLVMVectorElementType<0>],
                              [ LLVMVectorElementType<0>,

>From 34c0531ef62460e17c9e96e964f51d5017581680 Mon Sep 17 00:00:00 2001
From: miguelraz <miguelraz at ciencias.unam.mx>
Date: Thu, 29 Feb 2024 20:50:37 -0600
Subject: [PATCH 3/3] typo fix unsigned integer for uthreecmp

---
 llvm/docs/LangRef.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index ceffd33cdc54f5..5eae1015bffb18 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -12044,7 +12044,7 @@ pointer, or pointer vector operands.
 Arguments:
 """"""""""
 
-The '``uthreecmp``' instruction takes two signed integer operands.
+The '``uthreecmp``' instruction takes two unsigned integer operands.
 
 Semantics:
 """"""""""