From b29677dd12b5a19618295757a6044c0b0d741dbb Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Thu, 15 Apr 2021 18:20:50 +0200
Subject: [PATCH] compiler-rt: Implement __extendhftf2

---
 lib/std/special/compiler_rt/extendXfYf2.zig   |  4 ++
 .../special/compiler_rt/extendXfYf2_test.zig  | 49 ++++++++++++++++++-
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/lib/std/special/compiler_rt/extendXfYf2.zig b/lib/std/special/compiler_rt/extendXfYf2.zig
index c5b93fa51e..59be8441fa 100644
--- a/lib/std/special/compiler_rt/extendXfYf2.zig
+++ b/lib/std/special/compiler_rt/extendXfYf2.zig
@@ -23,6 +23,10 @@ pub fn __extendhfsf2(a: u16) callconv(.C) f32 {
     return @call(.{ .modifier = .always_inline }, extendXfYf2, .{ f32, f16, a });
 }
 
+pub fn __extendhftf2(a: u16) callconv(.C) f128 {
+    return @call(.{ .modifier = .always_inline }, extendXfYf2, .{ f128, f16, a });
+}
+
 pub fn __aeabi_h2f(arg: u16) callconv(.AAPCS) f32 {
     @setRuntimeSafety(false);
     return @call(.{ .modifier = .always_inline }, __extendhfsf2, .{arg});
diff --git a/lib/std/special/compiler_rt/extendXfYf2_test.zig b/lib/std/special/compiler_rt/extendXfYf2_test.zig
index 6a3f69d8e9..d97a9c2502 100644
--- a/lib/std/special/compiler_rt/extendXfYf2_test.zig
+++ b/lib/std/special/compiler_rt/extendXfYf2_test.zig
@@ -4,9 +4,10 @@
 // The MIT license requires this copyright notice to be included in all copies
 // and substantial portions of the software.
 const builtin = @import("builtin");
-const __extenddftf2 = @import("extendXfYf2.zig").__extenddftf2;
 const __extendhfsf2 = @import("extendXfYf2.zig").__extendhfsf2;
+const __extendhftf2 = @import("extendXfYf2.zig").__extendhftf2;
 const __extendsftf2 = @import("extendXfYf2.zig").__extendsftf2;
+const __extenddftf2 = @import("extendXfYf2.zig").__extenddftf2;
 
 fn test__extenddftf2(a: f64, expectedHi: u64, expectedLo: u64) void {
     const x = __extenddftf2(a);
@@ -161,3 +162,49 @@ fn makeNaN32(rand: u32) f32 {
 fn makeInf32() f32 {
     return @bitCast(f32, @as(u32, 0x7f800000));
 }
+
+fn test__extendhftf2(a: f16, expectedHi: u64, expectedLo: u64) void {
+    const x = __extendhftf2(@bitCast(u16, a));
+
+    const rep = @bitCast(u128, x);
+    const hi = @intCast(u64, rep >> 64);
+    const lo = @truncate(u64, rep);
+
+    if (hi == expectedHi and lo == expectedLo)
+        return;
+
+    // test other possible NaN representation(signal NaN)
+    if (expectedHi == 0x7fff800000000000 and expectedLo == 0x0) {
+        if ((hi & 0x7fff000000000000) == 0x7fff000000000000 and
+            ((hi & 0xffffffffffff) > 0 or lo > 0))
+        {
+            return;
+        }
+    }
+
+    @panic("__extendhftf2 test failure");
+}
+
+test "extendhftf2" {
+    // qNaN
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x7e00)), 0x7fff800000000000, 0x0);
+    // NaN
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x7d00)), 0x7fff400000000000, 0x0);
+    // inf
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x7c00)), 0x7fff000000000000, 0x0);
+    test__extendhftf2(-@bitCast(f16, @as(u16, 0x7c00)), 0xffff000000000000, 0x0);
+    // zero
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x0)), 0x0, 0x0);
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x8000)), 0x8000000000000000, 0x0);
+    // denormal
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x0010)), 0x3feb000000000000, 0x0000000000000000);
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x0001)), 0x3fe7000000000000, 0x0000000000000000);
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x8001)), 0xbfe7000000000000, 0x0000000000000000);
+
+    // pi
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x4248)), 0x4000920000000000, 0x0000000000000000);
+    test__extendhftf2(@bitCast(f16, @as(u16, 0xc248)), 0xc000920000000000, 0x0000000000000000);
+
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x508c)), 0x4004230000000000, 0x0);
+    test__extendhftf2(@bitCast(f16, @as(u16, 0x1bb7)), 0x3ff6edc000000000, 0x0);
+}