https://github.com/eisenwave updated
https://github.com/llvm/llvm-project/pull/196633
>From 508d1f79bde93d8ece110641b3b2e2909f7e3307 Mon Sep 17 00:00:00 2001
From: Eisenwave
Date: Fri, 8 May 2026 22:21:33 +0200
Subject: [PATCH 1/2] Start work on __builtin_elementwise_clmul
---
clang/include/clang/Basic/Builtins.td| 6 ++
clang/lib/AST/ByteCode/InterpBuiltin.cpp | 3 +++
clang/lib/AST/ExprConstant.cpp | 12
clang/lib/CodeGen/CGBuiltin.cpp | 3 +++
clang/lib/Sema/SemaChecking.cpp | 1 +
5 files changed, 25 insertions(+)
diff --git a/clang/include/clang/Basic/Builtins.td
b/clang/include/clang/Basic/Builtins.td
index 4a7eaeb3d353e..50e4e34da69b3 100644
--- a/clang/include/clang/Basic/Builtins.td
+++ b/clang/include/clang/Basic/Builtins.td
@@ -1879,6 +1879,12 @@ def ElementwiseCttz : Builtin {
let Prototype = "void(...)";
}
+def ElementwiseClmul : Builtin {
+ let Spellings = ["__builtin_elementwise_clmul"];
+ let Attributes = [NoThrow, Const, CustomTypeChecking, Constexpr];
+ let Prototype = "void(...)";
+}
+
def ReduceMax : Builtin {
let Spellings = ["__builtin_reduce_max"];
let Attributes = [NoThrow, Const, CustomTypeChecking, Constexpr];
diff --git a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
index 11ca93c251380..cef15e41e357c 100644
--- a/clang/lib/AST/ByteCode/InterpBuiltin.cpp
+++ b/clang/lib/AST/ByteCode/InterpBuiltin.cpp
@@ -5531,6 +5531,9 @@ bool InterpretBuiltin(InterpState &S, CodePtr OpPC, const
CallExpr *Call,
case clang::X86::BI__builtin_ia32_pclmulqdq256:
case clang::X86::BI__builtin_ia32_pclmulqdq512:
return interp__builtin_ia32_pclmulqdq(S, OpPC, Call);
+ case Builtin::BI__builtin_elementwise_clmul:
+ return interp__builtin_elementwise_int_binop(
+ S, OpPC, Call, llvm::APIntOps::clmul);
case Builtin::BI__builtin_elementwise_fma:
return interp__builtin_elementwise_triop_fp(
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 3f3a80f5b77a3..7b7ca39dbcdfe 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -14071,6 +14071,18 @@ bool VectorExprEvaluator::VisitCallExpr(const CallExpr
*E) {
return Success(APValue(ResultElements.data(), ResultElements.size()), E);
}
+ case Builtin::BI__builtin_elementwise_clmul: {
+APValue LHS, RHS;
+if (!EvaluateAsRValue(Info, E->getArg(0), LHS) ||
+!EvaluateAsRValue(Info, E->getArg(1), RHS))
+ return false;
+
+const APSInt& LHSInt = LHS.getInt();
+const APSInt& RHSInt = RHS.getInt();
+APInt Result = llvm::APIntOps::clmul(LHSInt, RHSInt);
+
+return Success(APValue(APSInt(Result, LHSInt.isUnsigned())), E);
+ }
case Builtin::BI__builtin_elementwise_fshl:
case Builtin::BI__builtin_elementwise_fshr: {
APValue SourceHi, SourceLo, SourceShift;
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 67de2a34f44ea..02f46b949c84d 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -4279,6 +4279,9 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl
GD, unsigned BuiltinID,
case Builtin::BI__builtin_elementwise_fshr:
return RValue::get(
emitBuiltinWithOneOverloadedType<3>(*this, E, Intrinsic::fshr));
+ case Builtin::BI__builtin_elementwise_clmul:
+return RValue::get(
+emitBuiltinWithOneOverloadedType<2>(*this, E, Intrinsic::clmul));
case Builtin::BI__builtin_elementwise_add_sat:
case Builtin::BI__builtin_elementwise_sub_sat: {
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 4706fa5d3cde0..c79a773fe4e1f 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3615,6 +3615,7 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl,
unsigned BuiltinID,
// types only.
case Builtin::BI__builtin_elementwise_add_sat:
case Builtin::BI__builtin_elementwise_sub_sat:
+ case Builtin::BI__builtin_elementwise_clmul:
if (BuiltinElementwiseMath(TheCall,
EltwiseBuiltinArgTyRestriction::IntegerTy))
return ExprError();
>From 4ead0e223070232b4d737d6092b2a0466cda1470 Mon Sep 17 00:00:00 2001
From: Eisenwave
Date: Sat, 9 May 2026 06:44:55 +0200
Subject: [PATCH 2/2] Fix formatting, add docs
---
clang/docs/LanguageExtensions.rst| 2 ++
clang/docs/ReleaseNotes.rst | 4
clang/lib/AST/ByteCode/InterpBuiltin.cpp | 4 ++--
clang/lib/AST/ExprConstant.cpp | 8
4 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/clang/docs/LanguageExtensions.rst
b/clang/docs/LanguageExtensions.rst
index 03cb02deb5e7f..fbb9947f39d3e 100644
--- a/clang/docs/LanguageExtensions.rst
+++ b/clang/docs/LanguageExtensions.rst
@@ -903,6 +903,8 @@ T __builtin_elementwise_fshr(T x, T y, T z) perform a
funnel shift right. Co
the
