From be77d5ae417236883c02d3d67c0716e3f669fa41 Mon Sep 17 00:00:00 2001
From: Joseph Myers <josmyers@redhat.com>
Date: Wed, 4 Sep 2024 13:20:18 +0000
Subject: [PATCH] Improve NaN payload testing

There are two separate sets of tests of NaN payloads in glibc:

* libm-test-{get,set}payload* verify that getpayload, setpayload,
  setpayloadsig and __builtin_nan functions are consistent in their
  payload handling.

* test-nan-payload verifies that strtod-family functions and the
  not-built-in nan functions are consistent in their payload handling.

Nothing, however, connects the two sets of functions (i.e., verifies
that strtod / nan are consistent with getpayload / setpayload /
__builtin_nan).

Improve test-nan-payload to check actual payload value with getpayload
rather than just verifying that the strtod and nan functions produce
the same NaN.  Also check that the NaNs produced aren't signaling and
extend the tests to cover _FloatN / _FloatNx.

Tested for x86_64.
---
 math/test-nan-payload.c | 59 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 54 insertions(+), 5 deletions(-)

diff --git a/math/test-nan-payload.c b/math/test-nan-payload.c
index 4a81dc348b..55c13de14e 100644
--- a/math/test-nan-payload.c
+++ b/math/test-nan-payload.c
@@ -16,6 +16,8 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#define _LIBC_TEST 1
+#define __STDC_WANT_IEC_60559_TYPES_EXT__
 #include <float.h>
 #include <math.h>
 #include <stdio.h>
@@ -31,7 +33,7 @@
 #define CHECK_IS_NAN(TYPE, A)			\
   do						\
     {						\
-      if (isnan (A))				\
+      if (isnan (A) && !issignaling (A))	\
 	puts ("PASS: " #TYPE " " #A);		\
       else					\
 	{					\
@@ -41,6 +43,19 @@
     }						\
   while (0)
 
+#define CHECK_PAYLOAD(TYPE, FUNC, A, P)		\
+  do						\
+    {						\
+      if (FUNC (&(A)) == (P))			\
+	puts ("PASS: " #TYPE " payload " #A);	\
+      else					\
+	{					\
+	  puts ("FAIL: " #TYPE " payload " #A);	\
+	  result = 1;				\
+	}					\
+    }						\
+  while (0)
+
 #define CHECK_SAME_NAN(TYPE, A, B)			\
   do							\
     {							\
@@ -71,7 +86,7 @@
    bits.  */
 #define CAN_TEST_EQ(MANT_DIG) ((MANT_DIG) != 64 && (MANT_DIG) != 106)
 
-#define RUN_TESTS(TYPE, SFUNC, FUNC, MANT_DIG)		\
+#define RUN_TESTS(TYPE, SFUNC, FUNC, PLFUNC, MANT_DIG)	\
   do							\
     {							\
      TYPE n123 = WRAP_NAN (FUNC, "123");		\
@@ -82,6 +97,10 @@
      CHECK_IS_NAN (TYPE, n456);				\
      TYPE s456 = WRAP_STRTO (SFUNC, "NAN(456)");	\
      CHECK_IS_NAN (TYPE, s456);				\
+     TYPE nh123 = WRAP_NAN (FUNC, "0x123");		\
+     CHECK_IS_NAN (TYPE, nh123);			\
+     TYPE sh123 = WRAP_STRTO (SFUNC, "NAN(0x123)");	\
+     CHECK_IS_NAN (TYPE, sh123);			\
      TYPE n123x = WRAP_NAN (FUNC, "123)");		\
      CHECK_IS_NAN (TYPE, n123x);			\
      TYPE nemp = WRAP_NAN (FUNC, "");			\
@@ -92,8 +111,16 @@
      CHECK_IS_NAN (TYPE, sx);				\
      if (CAN_TEST_EQ (MANT_DIG))			\
        CHECK_SAME_NAN (TYPE, n123, s123);		\
+     CHECK_PAYLOAD (TYPE, PLFUNC, n123, 123);		\
+     CHECK_PAYLOAD (TYPE, PLFUNC, s123, 123);		\
      if (CAN_TEST_EQ (MANT_DIG))			\
        CHECK_SAME_NAN (TYPE, n456, s456);		\
+     CHECK_PAYLOAD (TYPE, PLFUNC, n456, 456);		\
+     CHECK_PAYLOAD (TYPE, PLFUNC, s456, 456);		\
+     if (CAN_TEST_EQ (MANT_DIG))			\
+       CHECK_SAME_NAN (TYPE, nh123, sh123);		\
+     CHECK_PAYLOAD (TYPE, PLFUNC, nh123, 0x123);	\
+     CHECK_PAYLOAD (TYPE, PLFUNC, sh123, 0x123);	\
      if (CAN_TEST_EQ (MANT_DIG))			\
        CHECK_SAME_NAN (TYPE, nemp, semp);		\
      if (CAN_TEST_EQ (MANT_DIG))			\
@@ -110,9 +137,31 @@ static int
 do_test (void)
 {
   int result = 0;
-  RUN_TESTS (float, strtof, nanf, FLT_MANT_DIG);
-  RUN_TESTS (double, strtod, nan, DBL_MANT_DIG);
-  RUN_TESTS (long double, strtold, nanl, LDBL_MANT_DIG);
+  RUN_TESTS (float, strtof, nanf, getpayloadf, FLT_MANT_DIG);
+  RUN_TESTS (double, strtod, nan, getpayload, DBL_MANT_DIG);
+  RUN_TESTS (long double, strtold, nanl, getpayloadl, LDBL_MANT_DIG);
+#if __HAVE_FLOAT16
+  RUN_TESTS (_Float16, strtof16, nanf16, getpayloadf16, FLT16_MANT_DIG);
+#endif
+#if __HAVE_FLOAT32
+  RUN_TESTS (_Float32, strtof32, nanf32, getpayloadf32, FLT32_MANT_DIG);
+#endif
+#if __HAVE_FLOAT64
+  RUN_TESTS (_Float64, strtof64, nanf64, getpayloadf64, FLT64_MANT_DIG);
+#endif
+#if __HAVE_FLOAT128
+  RUN_TESTS (_Float128, strtof128, nanf128, getpayloadf128, FLT128_MANT_DIG);
+#endif
+#if __HAVE_FLOAT32X
+  RUN_TESTS (_Float32x, strtof32x, nanf32x, getpayloadf32x, FLT32X_MANT_DIG);
+#endif
+#if __HAVE_FLOAT64X
+  RUN_TESTS (_Float64x, strtof64x, nanf64x, getpayloadf64x, FLT64X_MANT_DIG);
+#endif
+#if __HAVE_FLOAT128X
+  RUN_TESTS (_Float128x, strtof128x, nanf128x, getpayloadf128x,
+	     FLT128X_MANT_DIG);
+#endif
   return result;
 }