[CIR][CIRGen] handle __builtin_elementwise_exp

[FantasqueX]

Original Clang's implementation:

clangir/clang/lib/CodeGen/CGBuiltin.cpp

Lines 4131 to 4133 in 2df2022

	case Builtin::BI__builtin_elementwise_exp:
	return RValue::get(emitBuiltinWithOneOverloadedType<1>(
	*this, E, llvm::Intrinsic::exp, "elt.exp"));

clangir/clang/lib/CodeGen/CGBuiltin.cpp

Lines 762 to 776 in 2df2022

	// Emit a simple intrinsic that has N scalar arguments and a return type
	// matching the argument type. It is assumed that only the first argument is
	// overloaded.
	template <unsigned N>
	static Value *emitBuiltinWithOneOverloadedType(CodeGenFunction &CGF,
	const CallExpr *E,
	unsigned IntrinsicID,
	llvm::StringRef Name = "") {
	static_assert(N, "expect non-empty argument");
	SmallVector<Value *, N> Args;
	for (unsigned I = 0; I < N; ++I)
	Args.push_back(CGF.EmitScalarExpr(E->getArg(I)));
	Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Args[0]->getType());
	return CGF.Builder.CreateCall(F, Args, Name);
	}

Compared with non-elementwise exp

clangir/clang/lib/CodeGen/CGBuiltin.cpp

Lines 3006 to 3016 in 2df2022

	case Builtin::BIexp:
	case Builtin::BIexpf:
	case Builtin::BIexpl:
	case Builtin::BI__builtin_exp:
	case Builtin::BI__builtin_expf:
	case Builtin::BI__builtin_expf16:
	case Builtin::BI__builtin_expl:
	case Builtin::BI__builtin_expf128:
	return RValue::get(emitUnaryMaybeConstrainedFPBuiltin(*this, E,
	Intrinsic::exp,
	Intrinsic::experimental_constrained_exp));

clangir/clang/lib/CodeGen/CGBuiltin.cpp

Lines 669 to 685 in 2df2022

	// Emit a simple mangled intrinsic that has 1 argument and a return type
	// matching the argument type. Depending on mode, this may be a constrained
	// floating-point intrinsic.
	static Value *emitUnaryMaybeConstrainedFPBuiltin(CodeGenFunction &CGF,
	const CallExpr *E, unsigned IntrinsicID,
	unsigned ConstrainedIntrinsicID) {
	llvm::Value *Src0 = CGF.EmitScalarExpr(E->getArg(0));
	CodeGenFunction::CGFPOptionsRAII FPOptsRAII(CGF, E);
	if (CGF.Builder.getIsFPConstrained()) {
	Function *F = CGF.CGM.getIntrinsic(ConstrainedIntrinsicID, Src0->getType());
	return CGF.Builder.CreateConstrainedFPCall(F, { Src0 });
	} else {
	Function *F = CGF.CGM.getIntrinsic(IntrinsicID, Src0->getType());
	return CGF.Builder.CreateCall(F, Src0);
	}
	}

elementwise version doesn't handle constrained situation. I'm not sure whether it is intended.

For renaming, it is to match original clang's implementation closely.

Resolves: #1375

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[bcardosolopes]

Awesome, thanks!