[DAG] Add generic expansion for ISD::FCANONICALIZE nodes (#142105)

This PR takes the work previously done by @pawan-nirpal-031 on X86 in
#106370, and makes it available in common code. This should enable all
targets to use `__builtin_canonicalize` for all `f(16|32|64|128)` data
types.

Canonicalization is implemented here as multiplication by `1.0`, as
suggested in [the
docs](https://llvm.org/docs/LangRef.html#llvm-canonicalize-intrinsic).

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/TargetLoweringBase.cpp b/llvm/lib/CodeGen/TargetLoweringBase.cpp
index 4f72200..c9f927a 100644
--- a/llvm/lib/CodeGen/TargetLoweringBase.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringBase.cpp
@@ -875,6 +875,10 @@ void TargetLoweringBase::initActions() {
                       ISD::FATAN2},
                      {MVT::f32, MVT::f64, MVT::f128}, Expand);
 
+  // Insert custom handling default for llvm.canonicalize.*.
+  setOperationAction(ISD::FCANONICALIZE,
+                     {MVT::f16, MVT::f32, MVT::f64, MVT::f128}, Expand);
+
   // FIXME: Query RuntimeLibCalls to make the decision.
   setOperationAction({ISD::LRINT, ISD::LLRINT, ISD::LROUND, ISD::LLROUND},
                      {MVT::f32, MVT::f64, MVT::f128}, LibCall);