[flang] add folding support for quad bessels

[jeanPerier]

This is done using libquadmath and the mappings are only available if libquadmath was found by cmake.
Support for non quad bessels is already available on POSIX platform using libm extensions.

[llvmbot]

@llvm/pr-subscribers-flang-semantics

Author: None (jeanPerier)

Changes

This is done using libquadmath and the mappings are only available if libquadmath was found by cmake.
Support for non quad bessels is already available on POSIX platform using libm extensions.

---

Full diff: https://github.com/llvm/llvm-project/pull/77314.diff

1 Files Affected:

• (modified) flang/lib/Evaluate/intrinsics-library.cpp (+7)

diff --git a/flang/lib/Evaluate/intrinsics-library.cpp b/flang/lib/Evaluate/intrinsics-library.cpp
index 892b8d0b6a0639..e68c5ed3f6a8b1 100644
--- a/flang/lib/Evaluate/intrinsics-library.cpp
+++ b/flang/lib/Evaluate/intrinsics-library.cpp
@@ -321,6 +321,7 @@ template <> struct HostRuntimeLibrary<float, LibraryVersion::LibmExtensions> {
 template <> struct HostRuntimeLibrary<__float128, LibraryVersion::Libm> {
   using F = FuncPointer<__float128, __float128>;
   using F2 = FuncPointer<__float128, __float128, __float128>;
+  using FN = FuncPointer<__float128, int, __float128>;
   static constexpr HostRuntimeFunction table[]{
       FolderFactory<F, F{::acosq}>::Create("acos"),
       FolderFactory<F, F{::acoshq}>::Create("acosh"),
@@ -329,6 +330,12 @@ template <> struct HostRuntimeLibrary<__float128, LibraryVersion::Libm> {
       FolderFactory<F, F{::atanq}>::Create("atan"),
       FolderFactory<F2, F2{::atan2q}>::Create("atan2"),
       FolderFactory<F, F{::atanhq}>::Create("atanh"),
+      FolderFactory<F, F{::j0q}>::Create("bessel_j0"),
+      FolderFactory<F, F{::j1q}>::Create("bessel_j1"),
+      FolderFactory<FN, FN{::jnq}>::Create("bessel_jn"),
+      FolderFactory<F, F{::y0q}>::Create("bessel_y0"),
+      FolderFactory<F, F{::y1q}>::Create("bessel_y1"),
+      FolderFactory<FN, FN{::ynq}>::Create("bessel_yn"),
       FolderFactory<F, F{::cosq}>::Create("cos"),
       FolderFactory<F, F{::coshq}>::Create("cosh"),
       FolderFactory<F, F{::erfq}>::Create("erf"),

[psteinfeld]

It would be nice to have a test.

Otherwise, all builds and tests correctly and looks good.

[jeanPerier]

It would be nice to have a test.

Is there a place where quadmath folding is already tested ? I briefly looked and could not find/did not want to add some ifdef HAS_QUADMATHLIB dependent testing.