From 51853f7488afa69c0d14b0e96f1da84822cd83f1 Mon Sep 17 00:00:00 2001
From: Bhavana Kilambi <bkilambi@openjdk.org>
Date: Mon, 5 Feb 2024 18:29:32 +0000
Subject: [PATCH] 8324724: Add Stub routines for FP16 conversions on aarch64

Reviewed-by: aph, ngasson
---
 .../cpu/aarch64/stubGenerator_aarch64.cpp     | 34 ++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp b/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp
index dfdfa194c4e..46a7d796267 100644
--- a/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp
+++ b/src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2014, 2022, Red Hat Inc. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -5474,6 +5474,32 @@ class StubGenerator: public StubCodeGenerator {
     return entry;
   }
 
+  // r0 = input (float16)
+  // v0 = result (float)
+  // v1 = temporary float register
+  address generate_float16ToFloat() {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", "float16ToFloat");
+    address entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    __ flt16_to_flt(v0, r0, v1);
+    __ ret(lr);
+    return entry;
+  }
+
+  // v0 = input (float)
+  // r0 = result (float16)
+  // v1 = temporary float register
+  address generate_floatToFloat16() {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", "floatToFloat16");
+    address entry = __ pc();
+    BLOCK_COMMENT("Entry:");
+    __ flt_to_flt16(r0, v0, v1);
+    __ ret(lr);
+    return entry;
+  }
+
   address generate_method_entry_barrier() {
     __ align(CodeEntryAlignment);
     StubCodeMark mark(this, "StubRoutines", "nmethod_entry_barrier");
@@ -8327,6 +8353,12 @@ class StubGenerator: public StubCodeGenerator {
     if (vmIntrinsics::is_intrinsic_available(vmIntrinsics::_dcos)) {
       StubRoutines::_dcos = generate_dsin_dcos(/* isCos = */ true);
     }
+
+    if (vmIntrinsics::is_intrinsic_available(vmIntrinsics::_float16ToFloat) &&
+        vmIntrinsics::is_intrinsic_available(vmIntrinsics::_floatToFloat16)) {
+      StubRoutines::_hf2f = generate_float16ToFloat();
+      StubRoutines::_f2hf = generate_floatToFloat16();
+    }
   }
 
   void generate_continuation_stubs() {