From c77114f8aad085a1b704e5bb830affa02f6dd7d8 Mon Sep 17 00:00:00 2001
From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Sun, 28 Jul 2019 17:48:57 +0100
Subject: [PATCH] add NaN FP2int overflow

---
 src/ieee754/fcvt/pipeline.py                  | 5 ++++-
 src/ieee754/fcvt/test/test_fcvt_f2int_pipe.py | 5 ++++-
 src/ieee754/fpcommon/test/fpmux.py            | 1 +
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/ieee754/fcvt/pipeline.py b/src/ieee754/fcvt/pipeline.py
index f4c70d78..5a9eeddc 100644
--- a/src/ieee754/fcvt/pipeline.py
+++ b/src/ieee754/fcvt/pipeline.py
@@ -104,7 +104,10 @@ class FPCVTFloatToIntMod(Elaboratable):
         m.d.comb += signed.eq(self.i.ctx.op[0])
 
         # special cases
-        with m.If(a1.exp_n127):
+        with m.If(a1.is_nan):
+            m.d.comb += self.o.z.eq((1<<mz)-1) # NaN overflow
+
+        with m.Elif(a1.exp_n127):
             m.d.comb += self.o.z.eq(0)
 
         # unsigned, -ve, return 0
diff --git a/src/ieee754/fcvt/test/test_fcvt_f2int_pipe.py b/src/ieee754/fcvt/test/test_fcvt_f2int_pipe.py
index ac962beb..24f3fd03 100644
--- a/src/ieee754/fcvt/test/test_fcvt_f2int_pipe.py
+++ b/src/ieee754/fcvt/test/test_fcvt_f2int_pipe.py
@@ -31,6 +31,9 @@ def fcvt_64_to_32(x):
 def fcvt_f16_ui32(x):
     return sfpy.float.f16_to_ui32(x)
 
+def fcvt_f16_ui16(x):
+    return sfpy.float.f16_to_ui32(x) & 0xffff
+
 ######################
 # signed int to fp
 ######################
@@ -60,7 +63,7 @@ def test_int_pipe_f16_ui16():
     # XXX softfloat-3 doesn't have ui16_to_xxx so use ui32 instead.
     # should be fine.
     dut = FPCVTF2IntMuxInOut(16, 16, 4, op_wid=1)
-    runfp(dut, 16, "test_fcvt_f2int_pipe_f16_ui16", Float16, fcvt_f16_ui32,
+    runfp(dut, 16, "test_fcvt_f2int_pipe_f16_ui16", Float16, fcvt_f16_ui16,
                 True, n_vals=100)
 
 def test_int_pipe_ui16_f64():
diff --git a/src/ieee754/fpcommon/test/fpmux.py b/src/ieee754/fpcommon/test/fpmux.py
index 64576835..028e6350 100644
--- a/src/ieee754/fpcommon/test/fpmux.py
+++ b/src/ieee754/fpcommon/test/fpmux.py
@@ -191,6 +191,7 @@ def create_random(num_rows, width, single_op=False, n_vals=10):
                 #op1 = 0x4dc0
                 #op1 = 0x3b81
                 #op1 = 0xfcb6
+                #op1 = 0x4f8d77b3
 
                 # FCLASS
                 #op1 = 0x87d1
-- 
2.30.2