[clang] [compiler-rt] [llvm] [SystemZ] Add support for half (fp16) (PR #109164)

[Trevor Gross via llvm-commits]

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@@ -548,11 +543,28 @@ SystemZTargetLowering::SystemZTargetLowering(const TargetMachine &TM,
   }
 
   // Handle floating-point types.
+  if (!useSoftFloat()) {
+    // Promote all f16 operations to float, with some exceptions below.
+    for (unsigned Opc = 0; Opc < ISD::BUILTIN_OP_END; ++Opc)
+      setOperationAction(Opc, MVT::f16, Promote);
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tgross35 wrote:

For the second one, it should be sufficient to ensure that i16<->f16 conversions are asm-only with no libcalls (it's possible this is tested somewhere and I'm just overlooking it in the large diff)

https://github.com/llvm/llvm-project/pull/109164