[SDAG] Avoid creating redundant stack slots when lowering FSINCOS (#108401)

When lowering `FSINCOS` to a library call (that takes output pointers)
we can avoid creating new stack allocations if the results of the
`FSINCOS` are being stored. Instead, we can take the destination
pointers from the stores and pass those to the library call.

---

Note: As a NFC this also adds (and uses) `RTLIB::getFSINCOS()`.

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index 9fdde45..1f49d60 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -400,6 +400,11 @@ RTLIB::Libcall RTLIB::getFREXP(EVT RetVT) {
                       FREXP_PPCF128);
 }
 
+RTLIB::Libcall RTLIB::getFSINCOS(EVT RetVT) {
+  return getFPLibCall(RetVT, SINCOS_F32, SINCOS_F64, SINCOS_F80, SINCOS_F128,
+                      SINCOS_PPCF128);
+}
+
 RTLIB::Libcall RTLIB::getOutlineAtomicHelper(const Libcall (&LC)[5][4],
                                              AtomicOrdering Order,
                                              uint64_t MemSize) {