From 2957433b25373dccc336492f6817a1cefadb945c Mon Sep 17 00:00:00 2001
From: LemonBoy <thatlemon@gmail.com>
Date: Sun, 1 Nov 2020 18:25:43 +0100
Subject: [PATCH] stage1: Fix comptime comparison of NaNs

---
 src/stage1/ir.cpp        |  4 ++--
 src/stage1/softfloat.hpp | 13 +++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/stage1/ir.cpp b/src/stage1/ir.cpp
index 98422ef578..c85c26f2c0 100644
--- a/src/stage1/ir.cpp
+++ b/src/stage1/ir.cpp
@@ -10953,13 +10953,13 @@ static bool float_is_nan(ZigValue *op) {
     } else if (op->type->id == ZigTypeIdFloat) {
         switch (op->type->data.floating.bit_count) {
             case 16:
-                return f16_isSignalingNaN(op->data.x_f16);
+                return zig_f16_isNaN(op->data.x_f16);
             case 32:
                 return op->data.x_f32 != op->data.x_f32;
             case 64:
                 return op->data.x_f64 != op->data.x_f64;
             case 128:
-                return f128M_isSignalingNaN(&op->data.x_f128);
+                return zig_f128_isNaN(&op->data.x_f128);
             default:
                 zig_unreachable();
         }
diff --git a/src/stage1/softfloat.hpp b/src/stage1/softfloat.hpp
index a1173690b5..57e60a5fc0 100644
--- a/src/stage1/softfloat.hpp
+++ b/src/stage1/softfloat.hpp
@@ -29,4 +29,17 @@ static inline double zig_f16_to_double(float16_t x) {
     return z;
 }
 
+static inline bool zig_f16_isNaN(float16_t a) {
+    union { uint16_t ui; float16_t f; } uA;
+    uA.f = a;
+    return 0x7C00 < (uA.ui & 0x7FFF);
+}
+
+static inline bool zig_f128_isNaN(float128_t *aPtr) {
+    uint64_t absA64 = aPtr->v[1] & UINT64_C(0x7FFFFFFFFFFFFFFF);
+    return
+        (UINT64_C(0x7FFF000000000000) < absA64)
+            || ((absA64 == UINT64_C(0x7FFF000000000000)) && aPtr->v[0]);
+}
+
 #endif