[compiler-rt] [llvm] Add extendhfxf2 into compiler rt (PR #111099)

[B I Mohammed Abbas via llvm-commits]

https://github.com/biabbas updated https://github.com/llvm/llvm-project/pull/111099

>From 7ea9e407015bf68a95f69daa5d86970066974256 Mon Sep 17 00:00:00 2001
From: B I Mohammed Abbas <bimohammadabbas at gmail.com>
Date: Fri, 4 Oct 2024 09:57:19 +0530
Subject: [PATCH] Add extendhfxf2 into compiler rt

---
 compiler-rt/lib/builtins/CMakeLists.txt       |  1 +
 compiler-rt/lib/builtins/extendhfxf2.c        | 18 +++++
 .../lib/builtins/macho_embedded/common.txt    |  1 +
 .../test/builtins/Unit/extendhfxf2_test.c     | 81 +++++++++++++++++++
 .../compiler-rt/lib/builtins/BUILD.gn         |  1 +
 5 files changed, 102 insertions(+)
 create mode 100644 compiler-rt/lib/builtins/extendhfxf2.c
 create mode 100644 compiler-rt/test/builtins/Unit/extendhfxf2_test.c

diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
index 9a0a50ee7003f1..97a9e508d37a32 100644
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -104,6 +104,7 @@ set(GENERIC_SOURCES
   divti3.c
   extendsfdf2.c
   extendhfsf2.c
+  extendhfxf2.c
   ffsdi2.c
   ffssi2.c
   ffsti2.c
diff --git a/compiler-rt/lib/builtins/extendhfxf2.c b/compiler-rt/lib/builtins/extendhfxf2.c
new file mode 100644
index 00000000000000..7425859f79f763
--- /dev/null
+++ b/compiler-rt/lib/builtins/extendhfxf2.c
@@ -0,0 +1,18 @@
+//===-- lib/extendhfxf2.c - half -> long double conversion --------*- C -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#define SRC_HALF
+#define DST_DOUBLE
+#include "fp_extend_impl.inc"
+
+// Use a forwarding definition and noinline to implement a poor man's alias,
+// as there isn't a good cross-platform way of defining one.
+// Long double are expected to be as precise as double.
+COMPILER_RT_ABI NOINLINE long double __extendhfxf2(src_t a) {
+  return (long double)__extendXfYf2__(a);
+}
diff --git a/compiler-rt/lib/builtins/macho_embedded/common.txt b/compiler-rt/lib/builtins/macho_embedded/common.txt
index 819109768f5298..fa99bc239e68f2 100644
--- a/compiler-rt/lib/builtins/macho_embedded/common.txt
+++ b/compiler-rt/lib/builtins/macho_embedded/common.txt
@@ -60,6 +60,7 @@ divsf3
 divsi3
 extendsfdf2
 extendhfsf2
+extendhfxf2
 ffssi2
 fixdfsi
 fixsfsi
diff --git a/compiler-rt/test/builtins/Unit/extendhfxf2_test.c b/compiler-rt/test/builtins/Unit/extendhfxf2_test.c
new file mode 100644
index 00000000000000..402a76354f4bba
--- /dev/null
+++ b/compiler-rt/test/builtins/Unit/extendhfxf2_test.c
@@ -0,0 +1,81 @@
+// RUN: %clang_builtins %s %librt -o %t && %run %t
+// REQUIRES: librt_has_extendhfxf2
+
+#include "int_lib.h"
+#include <stdio.h>
+
+#if __LDBL_MANT_DIG__ == 113 && defined(COMPILER_RT_HAS_FLOAT16)
+
+#  include "fp_test.h"
+
+COMPILER_RT_ABI long double __extendhfxf2(TYPE_FP16 a);
+
+int test__extendhfxf2(TYPE_FP16 a, uint64_t expectedHi, uint64_t expectedLo) {
+  long double x = __extendhfxf2(a);
+  int ret = compareResultF128(x, expectedHi, expectedLo);
+
+  if (ret) {
+    printf("error in test__extendhfxf2(%#.4x) = %.20Lf, "
+           "expected %.20Lf\n",
+           toRep16(a), x, fromRep128(expectedHi, expectedLo));
+  }
+  return ret;
+}
+
+char assumption_1[sizeof(TYPE_FP16) * CHAR_BIT == 16] = {0};
+
+#endif
+
+int main() {
+#if __LDBL_MANT_DIG__ == 113 && defined(COMPILER_RT_HAS_FLOAT16)
+  // qNaN
+  if (test__extendhfxf2(makeQNaN16(), UINT64_C(0x7fff800000000000),
+                        UINT64_C(0x0)))
+    return 1;
+  // NaN
+  if (test__extendhfxf2(makeNaN16(UINT16_C(0x0100)),
+                        UINT64_C(0x7fff400000000000), UINT64_C(0x0)))
+    return 1;
+  // inf
+  if (test__extendhfxf2(makeInf16(), UINT64_C(0x7fff000000000000),
+                        UINT64_C(0x0)))
+    return 1;
+  if (test__extendhfxf2(-makeInf16(), UINT64_C(0xffff000000000000),
+                        UINT64_C(0x0)))
+    return 1;
+  // zero
+  if (test__extendhfxf2(fromRep16(0x0U), UINT64_C(0x0), UINT64_C(0x0)))
+    return 1;
+  if (test__extendhfxf2(fromRep16(0x8000U), UINT64_C(0x8000000000000000),
+                        UINT64_C(0x0)))
+    return 1;
+  // denormal
+  if (test__extendhfxf2(fromRep16(0x0010U), UINT64_C(0x3feb000000000000),
+                        UINT64_C(0x0000000000000000)))
+    return 1;
+  if (test__extendhfxf2(fromRep16(0x0001U), UINT64_C(0x3fe7000000000000),
+                        UINT64_C(0x0000000000000000)))
+    return 1;
+  if (test__extendhfxf2(fromRep16(0x8001U), UINT64_C(0xbfe7000000000000),
+                        UINT64_C(0x0000000000000000)))
+    return 1;
+
+  // pi
+  if (test__extendhfxf2(fromRep16(0x4248U), UINT64_C(0x4000920000000000),
+                        UINT64_C(0x0000000000000000)))
+    return 1;
+  if (test__extendhfxf2(fromRep16(0xc248U), UINT64_C(0xc000920000000000),
+                        UINT64_C(0x0000000000000000)))
+    return 1;
+
+  if (test__extendhfxf2(fromRep16(0x508cU), UINT64_C(0x4004230000000000),
+                        UINT64_C(0x0)))
+    return 1;
+  if (test__extendhfxf2(fromRep16(0x1bb7U), UINT64_C(0x3ff6edc000000000),
+                        UINT64_C(0x0)))
+    return 1;
+#else
+  printf("skipped\n");
+#endif
+  return 0;
+}
diff --git a/llvm/utils/gn/secondary/compiler-rt/lib/builtins/BUILD.gn b/llvm/utils/gn/secondary/compiler-rt/lib/builtins/BUILD.gn
index 8904aed28229f1..efbf01960bf907 100644
--- a/llvm/utils/gn/secondary/compiler-rt/lib/builtins/BUILD.gn
+++ b/llvm/utils/gn/secondary/compiler-rt/lib/builtins/BUILD.gn
@@ -126,6 +126,7 @@ static_library("builtins") {
     "divsi3.c",
     "divti3.c",
     "extendhfsf2.c",
+    "extendhfxf2.c"
     "extendsfdf2.c",
     "ffsdi2.c",
     "ffssi2.c",