https://sqlite.org/forum/forumpost/7dfd585ce1
https://sqlite.org/src/info/d0fbe779bc2460e1

Index: test/func4.test
==================================================================
--- a/test/func4.test
+++ b/test/func4.test
@@ -1,6 +1,6 @@
-# 2013 March 10
+# 2023-03-10
 #
 # The author disclaims copyright to this source code.  In place of
 # a legal notice, here is a blessing:
 #
 #    May you do good and not evil.
@@ -7,11 +7,14 @@
 #    May you find forgiveness for yourself and forgive others.
 #    May you share freely, never taking more than you give.
 #
 #***********************************************************************
 # This file implements regression tests for SQLite library. The focus of
-# this file is testing the tointeger() and toreal() functions.
+# this file is testing the tointeger() and toreal() functions that are
+# part of the "totype.c" extension.  This file does not test the core
+# SQLite library.  Failures of tests in this file are related to the
+# ext/misc/totype.c extension.
 #
 # Several of the toreal() tests are disabled on platforms where floating
 # point precision is not high enough to represent their constant integer
 # expression arguments as double precision floating point values.
 #
@@ -21,10 +24,24 @@
 set tcl_precision 0
 load_static_extension db totype
 
 set highPrecision(1) [expr \
     {[db eval {SELECT tointeger(9223372036854775807 + 1);}] eq {{}}}]
+set highPrecision(2) [expr \
+    {[db eval {SELECT toreal(-9223372036854775808 + 1);}] eq {{}}}]
+
+# highPrecision(3) is only known to be false on i586 with gcc-13 and -O2.
+# It is true on the exact same platform with -O0.  Both results seem
+# reasonable, so we'll just very the expectation accordingly.
+#
+set highPrecision(3) [expr \
+    {[db eval {SELECT toreal(9007199254740992 + 1);}] eq {{}}}]
+
+if {!$highPrecision(1) || !$highPrecision(2) || !$highPrecision(3)} {
+  puts "NOTICE: use_long_double: [use_long_double] \
+        highPrecision: $highPrecision(1) $highPrecision(2) $highPrecision(3)"
+}
 
 do_execsql_test func4-1.1 {
   SELECT tointeger(NULL);
 } {{}}
 do_execsql_test func4-1.2 {
@@ -193,12 +210,10 @@
 do_execsql_test func4-1.55 {
   SELECT tointeger(18446744073709551616 + 1);
 } {{}}
 
 ifcapable floatingpoint {
-  set highPrecision(2) [expr \
-      {[db eval {SELECT toreal(-9223372036854775808 + 1);}] eq {{}}}]
 
   do_execsql_test func4-2.1 {
     SELECT toreal(NULL);
   } {{}}
   do_execsql_test func4-2.2 {
@@ -339,14 +354,18 @@
     SELECT toreal(9007199254740992 - 1);
   } {9007199254740991.0}
   do_execsql_test func4-2.45 {
     SELECT toreal(9007199254740992);
   } {9007199254740992.0}
-  if {$highPrecision(2)} {
+  if {$highPrecision(3)} {
+    do_execsql_test func4-2.46 {
+      SELECT toreal(9007199254740992 + 1);
+    } {{}}
+  } else {
     do_execsql_test func4-2.46 {
       SELECT toreal(9007199254740992 + 1);
-    } {{}}
+    } {9007199254740992.0}
   }
   do_execsql_test func4-2.47 {
     SELECT toreal(9007199254740992 + 2);
   } {9007199254740994.0}
   do_execsql_test func4-2.48 {
@@ -624,14 +643,18 @@
     SELECT tointeger(toreal(9007199254740992 - 1));
   } {9007199254740991}
   do_execsql_test func4-5.22 {
     SELECT tointeger(toreal(9007199254740992));
   } {9007199254740992}
-  if {$highPrecision(2)} {
+  if {$highPrecision(3)} {
     do_execsql_test func4-5.23 {
       SELECT tointeger(toreal(9007199254740992 + 1));
     } {{}}
+  } else {
+    do_execsql_test func4-5.23 {
+      SELECT tointeger(toreal(9007199254740992 + 1));
+    } {9007199254740992}
   }
   do_execsql_test func4-5.24 {
     SELECT tointeger(toreal(9007199254740992 + 2));
   } {9007199254740994}
   if {$highPrecision(1)} {