Revert "Upgrade Time::HiRes from version 1.9753 to 1.9757"

This reverts commit 13813507385079199d99d90776780dcd653f6919.

On recommendation of the Author, we are reverting these changes for
now in order to stabilize blead.

6 files changed, 123 insertions, 313 deletions

diff --git a/dist/Time-HiRes/Changes b/dist/Time-HiRes/Changes
index b8413ee5df..f3c8bbeb1f 100644
--- a/dist/Time-HiRes/Changes
+++ b/dist/Time-HiRes/Changes
@@ -1,42 +1,5 @@
 Revision history for the Perl extension Time::HiRes.
 
-1.9577 [2018-03-15]
- - fix win32 (and cygwin?) builds which have been broken since 1.9755:
-   problem was that gettimeofday() is a macro and needs to stay such
- - regenerate ppport.h with Perl 5.26.1 (was previously generated with
-   5.25.6) and Devel::PPPort 3.35 (previously 3.36) -- this doesn't
-   change the ppport.h, though
-
-1.9756 [2018-03-14]
- - division by zero in new test tv_interval.t [rt.cpan.org #124775]:
-   made the test pass even if the difference is zero, but also
-   made it practically impossible to ever be zero by adding
-   a sub-second sleep.
- - remove comments from inside qw [rt.cpan.org #124777],
-   only seemed to be caught by Perl 5.18.4
-
-1.9755 [2018-03-14]
- - adjust the error messages of tv_interval()
- - the NV_1EX constants now cast to be NV so that
-   tv_interval() with long double builds does not
-   produce ugly results [rt.cpan.org #106456]
- - add tests for tv_interval()
- - centralize the mygettimeofday() logic
- - make the mygettimeofday() a function instead of macro
- - add the OS X 10.12+ clock_gettime() constants
-   CLOCK_MONOTONIC_RAW_APPROX CLOCK_UPTIME_RAW_APPROX
- - regenerate the fallback files
-
-1.9754 [2018-02-16]
- - unify the gettimeofday() and time() forked code
-   that had near identical code paths for MacOS Classic
-   (which has two unusual features: unsigned time_t,
-   and a special tz struct member), and for non-MacOS Classic
- - tv_interval should be implemented in XS
-   [rt.cpan.org #106456]
-   thanks to Sergey Aleynikov (suggested implementation simplified
-   by the above-mentioned MacOS Classic simplification)
-
 1.9753 [2018-01-11]
  - in t/clock.t in a fast system we need to burn more CPU,
    reported and fix suggested by Joel C. Maslak <jmaslak@antelope.net>
diff --git a/dist/Time-HiRes/HiRes.pm b/dist/Time-HiRes/HiRes.pm
index 08d9a03c1f..b0bf2c840b 100644
--- a/dist/Time-HiRes/HiRes.pm
+++ b/dist/Time-HiRes/HiRes.pm
@@ -9,8 +9,7 @@ use XSLoader ();
 our @ISA = qw(Exporter);
 
 our @EXPORT = qw( );
-# TODO: this list is a superset of the @names in
-# Makefile.PL:doConstants(), automate this somehow.
+# More or less this same list is in Makefile.PL.  Should unify.
 our @EXPORT_OK = qw (usleep sleep ualarm alarm gettimeofday time tv_interval
 		 getitimer setitimer nanosleep clock_gettime clock_getres
 		 clock clock_nanosleep
@@ -22,7 +21,6 @@ our @EXPORT_OK = qw (usleep sleep ualarm alarm gettimeofday time tv_interval
 		 CLOCK_MONOTONIC_FAST
 		 CLOCK_MONOTONIC_PRECISE
 		 CLOCK_MONOTONIC_RAW
-		 CLOCK_MONOTONIC_RAW_APPROX
 		 CLOCK_PROCESS_CPUTIME_ID
 		 CLOCK_PROF
 		 CLOCK_REALTIME
@@ -39,7 +37,6 @@ our @EXPORT_OK = qw (usleep sleep ualarm alarm gettimeofday time tv_interval
 		 CLOCK_UPTIME_FAST
 		 CLOCK_UPTIME_PRECISE
 		 CLOCK_UPTIME_RAW
-		 CLOCK_UPTIME_RAW_APPROX
 		 CLOCK_VIRTUAL
 		 ITIMER_PROF
 		 ITIMER_REAL
@@ -53,7 +50,7 @@ our @EXPORT_OK = qw (usleep sleep ualarm alarm gettimeofday time tv_interval
 		 stat lstat utime
 		);
 
-our $VERSION = '1.9757';
+our $VERSION = '1.9753';
 our $XS_VERSION = $VERSION;
 $VERSION = eval $VERSION;
 
@@ -98,6 +95,13 @@ XSLoader::load( 'Time::HiRes', $XS_VERSION );
 
 # Preloaded methods go here.
 
+sub tv_interval {
+    # probably could have been done in C
+    my ($a, $b) = @_;
+    $b = [gettimeofday()] unless defined($b);
+    (${$b}[0] - ${$a}[0]) + ((${$b}[1] - ${$a}[1]) / 1_000_000);
+}
+
 # Autoload methods go after =cut, and are processed by the autosplit program.
 
 1;
diff --git a/dist/Time-HiRes/HiRes.xs b/dist/Time-HiRes/HiRes.xs
index a8358dd952..b9eaa17cde 100644
--- a/dist/Time-HiRes/HiRes.xs
+++ b/dist/Time-HiRes/HiRes.xs
@@ -71,9 +71,9 @@ extern "C" {
 #define IV_1E7 10000000
 #define IV_1E9 1000000000
 
-#define NV_1E6 (NV)1000000.0
-#define NV_1E7 (NV)10000000.0
-#define NV_1E9 (NV)1000000000.0
+#define NV_1E6 1000000.0
+#define NV_1E7 10000000.0
+#define NV_1E9 1000000000.0
 
 #ifndef PerlProc_pause
 #   define PerlProc_pause() Pause()
@@ -1011,46 +1011,6 @@ nsec_without_unslept(struct timespec *sleepfor,
 #define IS_SAFE_PATHNAME(pv, len, opname) (((len)>1)&&memchr((pv), 0, (len)-1)?(SETERRNO(ENOENT, LIB_INVARG),WARNEMU(opname),FALSE):(TRUE))
 #endif
 
-/* Mac OS (Classic) (MacOS 9) */
-#ifdef MACOS_TRADITIONAL
-/* has tz values that matter */
-#define GETTIMEOFDAY_TZ
-/* has tz.tz_minuteswest which needs to be added to tv_sec */
-#define ADJUST_BY_TZ_MINUTES
-/* has unsigned time_t */
-#define UNSIGNED_TIME_T
-#endif
-
-#if defined(WIN32) || defined(CYGWIN_WITH_W32API)
-#  define mygettimeofday(tp, not_used) gettimeofday(tp, not_used)
-#else
-static int mygettimeofday(struct timeval *tv, struct timezone *tz)
-{                                 
-  int status;
-#  ifdef GETTIMEOFDAY_TZ
-  status = gettimeofday(tv, tz);
-#  else
-  (void) tz;
-  status = gettimeofday(tv, NULL);
-#  endif /* ifdef GETTIMEOFDAY_TZ */
-#  ifdef ADJUST_BY_TZ_MINUTES
-#    ifndef GETTIMEOFDAY_TZ
-#      error "ADJUST_BY_TZ_MINUTES requires GETTIMEOFDAY_TZ"
-#    endif /* ifndef GETTIMEOFDAY_TZ */
-  tv->tv_sec += tz->tz_minuteswest * 60;	/* adjust for TZ */
-#  endif /* ADJUST_BY_TZ_MINUTES */
-  return status;
-}
-#endif /* if defined(WIN32) || defined(CYGWIN_WITH_W32API) else */
-
-#ifdef UNSIGNED_TIME_T
-#define SvTIME(sv) SvUV(sv)
-#define newSVtimet) newSVuv(t)
-#else
-#define SvTIME(sv) SvIV(sv)
-#define newSVtime(t) newSViv(t)
-#endif
-
 MODULE = Time::HiRes            PACKAGE = Time::HiRes
 
 PROTOTYPES: ENABLE
@@ -1318,6 +1278,7 @@ alarm(seconds,interval=0)
 #endif /* #ifdef HAS_UALARM */
 
 #ifdef HAS_GETTIMEOFDAY
+#    ifdef MACOS_TRADITIONAL	/* fix epoch TZ and use unsigned time_t */
 void
 gettimeofday()
         PREINIT:
@@ -1325,11 +1286,14 @@ gettimeofday()
         struct timezone Tz;
         PPCODE:
         int status;
-	status = mygettimeofday (&Tp, &Tz);
+        status = gettimeofday (&Tp, &Tz);
+
 	if (status == 0) {
+	     Tp.tv_sec += Tz.tz_minuteswest * 60;	/* adjust for TZ */
              if (GIMME == G_ARRAY) {
                  EXTEND(sp, 2);
-                 PUSHs(sv_2mortal(newSVtime(Tp.tv_sec)));
+                 /* Mac OS (Classic) has unsigned time_t */
+                 PUSHs(sv_2mortal(newSVuv(Tp.tv_sec)));
                  PUSHs(sv_2mortal(newSViv(Tp.tv_usec)));
              } else {
                  EXTEND(sp, 1);
@@ -1344,8 +1308,9 @@ time()
         struct timezone Tz;
         CODE:
         int status;
-        status = mygettimeofday (&Tp, &Tz);
+        status = gettimeofday (&Tp, &Tz);
 	if (status == 0) {
+            Tp.tv_sec += Tz.tz_minuteswest * 60;	/* adjust for TZ */
 	    RETVAL = Tp.tv_sec + (Tp.tv_usec / NV_1E6);
         } else {
 	    RETVAL = -1.0;
@@ -1353,66 +1318,41 @@ time()
 	OUTPUT:
 	RETVAL
 
-NV
-tv_interval(SV* start, ...)
-    PREINIT:
-    struct timeval Tp;
-    struct timezone Tz;
-    SV* end;
-    time_t end_sec;
-    IV end_usec;
-    SV** avalue;
-
-    CODE:
-
-    end = NULL;
-    if (items >= 2) {
-        end = ST(1);
-    }
-    /* It would be tempting croak on items > 2
-     * but that would probably break some code. */
-
-    if (SvROK(start) && SvTYPE(SvRV(start)) == SVt_PVAV) {
-        start = SvRV(start);
-    } else {
-        croak("tv_interval() 1st argument should be an array reference");
-    }
-
-    if (end != NULL) {
-        if (SvROK(end) && SvTYPE(SvRV(end)) == SVt_PVAV) {
-            end = SvRV(end);
-            /* Resist the temptation to expect exactly
-             * an array of length two: that would
-             * no doubt break some code. */
-            avalue = av_fetch((AV*)end, 0, FALSE);
-            end_sec = avalue ? SvTIME(*avalue) : 0;
-            avalue = av_fetch((AV*)end, 1, FALSE);
-            end_usec = avalue ? SvIV(*avalue) : 0;
-        } else {
-            croak("tv_interval() 2nd argument should be an array reference");
-        }
-    } else {
-        int status;
-        status = mygettimeofday (&Tp, &Tz);
-        if (status == 0) {
-            end_sec = Tp.tv_sec;
-            end_usec = Tp.tv_usec;
-        } else {
-            end_sec = 0;
-            end_usec = 0;
+#    else	/* MACOS_TRADITIONAL */
+void
+gettimeofday()
+        PREINIT:
+        struct timeval Tp;
+        PPCODE:
+	int status;
+        status = gettimeofday (&Tp, NULL);
+	if (status == 0) {
+	     if (GIMME == G_ARRAY) {
+	         EXTEND(sp, 2);
+                 PUSHs(sv_2mortal(newSViv(Tp.tv_sec)));
+                 PUSHs(sv_2mortal(newSViv(Tp.tv_usec)));
+             } else {
+                 EXTEND(sp, 1);
+                 PUSHs(sv_2mortal(newSVnv(Tp.tv_sec + (Tp.tv_usec / NV_1E6))));
+             }
         }
-    }
-
-    /* Resist temptation to expect exactly an array
-     * of length two: that would no doubt break some code. */
-    avalue = av_fetch((AV*)start, 0, FALSE);
-    RETVAL = end_sec - (avalue ? SvTIME(*avalue) : 0);
-    avalue = av_fetch((AV*)start, 1, FALSE);
-    RETVAL += ((end_usec - (avalue ? SvIV(*avalue) : 0)) / NV_1E6);
 
-    OUTPUT:
-    RETVAL
+NV
+time()
+        PREINIT:
+        struct timeval Tp;
+        CODE:
+	int status;
+        status = gettimeofday (&Tp, NULL);
+	if (status == 0) {
+            RETVAL = Tp.tv_sec + (Tp.tv_usec / NV_1E6);
+	} else {
+	    RETVAL = -1.0;
+	}
+	OUTPUT:
+	RETVAL
 
+#    endif	/* MACOS_TRADITIONAL */
 #endif /* #ifdef HAS_GETTIMEOFDAY */
 
 #if defined(HAS_GETITIMER) && defined(HAS_SETITIMER)
diff --git a/dist/Time-HiRes/Makefile.PL b/dist/Time-HiRes/Makefile.PL
index 8036fbf5cb..e0f7dd9a2f 100644
--- a/dist/Time-HiRes/Makefile.PL
+++ b/dist/Time-HiRes/Makefile.PL
@@ -966,42 +966,39 @@ sub doMakefile {
 
 sub doConstants {
     if (eval {require ExtUtils::Constant; 1}) {
-        # TODO: this list is a subset of the @EXPORT_OK in HiRes.pm,
-        # automate this somehow.
-	my @names = qw[
-		 CLOCKS_PER_SEC
-		 CLOCK_BOOTTIME
-		 CLOCK_HIGHRES
-		 CLOCK_MONOTONIC
-		 CLOCK_MONOTONIC_COARSE
-		 CLOCK_MONOTONIC_FAST
-		 CLOCK_MONOTONIC_PRECISE
-		 CLOCK_MONOTONIC_RAW
-		 CLOCK_MONOTONIC_RAW_APPROX
-		 CLOCK_PROCESS_CPUTIME_ID
-		 CLOCK_PROF
-		 CLOCK_REALTIME
-		 CLOCK_REALTIME_COARSE
-		 CLOCK_REALTIME_FAST
-		 CLOCK_REALTIME_PRECISE
-		 CLOCK_REALTIME_RAW
-		 CLOCK_SECOND
-		 CLOCK_SOFTTIME
-		 CLOCK_THREAD_CPUTIME_ID
-		 CLOCK_TIMEOFDAY
-		 CLOCK_UPTIME
-		 CLOCK_UPTIME_COARSE
-		 CLOCK_UPTIME_FAST
-		 CLOCK_UPTIME_PRECISE
-		 CLOCK_UPTIME_RAW
-		 CLOCK_UPTIME_RAW_APPROX
-		 CLOCK_VIRTUAL
-		 ITIMER_PROF
-		 ITIMER_REAL
-		 ITIMER_REALPROF
-		 ITIMER_VIRTUAL
-		 TIMER_ABSTIME
-            ];
+        # More or less this same list is in HiRes.pm.  Should unify.
+	my @names = qw(
+		       CLOCKS_PER_SEC
+		       CLOCK_BOOTTIME
+		       CLOCK_HIGHRES
+		       CLOCK_MONOTONIC
+		       CLOCK_MONOTONIC_COARSE
+		       CLOCK_MONOTONIC_FAST
+		       CLOCK_MONOTONIC_PRECISE
+		       CLOCK_MONOTONIC_RAW
+		       CLOCK_PROF
+		       CLOCK_PROCESS_CPUTIME_ID
+		       CLOCK_REALTIME
+		       CLOCK_REALTIME_COARSE
+		       CLOCK_REALTIME_FAST
+		       CLOCK_REALTIME_PRECISE
+		       CLOCK_REALTIME_RAW
+		       CLOCK_SECOND
+		       CLOCK_SOFTTIME
+		       CLOCK_THREAD_CPUTIME_ID
+		       CLOCK_TIMEOFDAY
+		       CLOCK_UPTIME
+		       CLOCK_UPTIME_COARSE
+		       CLOCK_UPTIME_FAST
+		       CLOCK_UPTIME_PRECISE
+		       CLOCK_UPTIME_RAW
+		       CLOCK_VIRTUAL
+		       ITIMER_PROF
+		       ITIMER_REAL
+		       ITIMER_REALPROF
+		       ITIMER_VIRTUAL
+		       TIMER_ABSTIME
+                      );
 	foreach (qw (d_usleep d_ualarm d_gettimeofday d_getitimer d_setitimer
 		     d_nanosleep d_clock_gettime d_clock_getres
 		     d_clock d_clock_nanosleep d_hires_stat
@@ -1040,8 +1037,6 @@ sub doConstants {
 					   NAMES => \@names,
 					  );
     } else {
-        # E.g. perl 5.6 did not have ExtUtils::Constant,
-        # use the pregenerated files instead.
         my $file;
 	foreach $file ('const-c.inc', 'const-xs.inc') {
 	    my $fallback = File::Spec->catfile('fallback', $file);
diff --git a/dist/Time-HiRes/fallback/const-c.inc b/dist/Time-HiRes/fallback/const-c.inc
index f59dc8604b..2c29a0b141 100644
--- a/dist/Time-HiRes/fallback/const-c.inc
+++ b/dist/Time-HiRes/fallback/const-c.inc
@@ -392,50 +392,6 @@ constant_19 (pTHX_ const char *name, IV *iv_return) {
 }
 
 static int
-constant_23 (pTHX_ const char *name, IV *iv_return) {
-  /* When generated this function returned values for the list of names given
-     here.  However, subsequent manual editing may have added or removed some.
-     CLOCK_MONOTONIC_PRECISE CLOCK_THREAD_CPUTIME_ID CLOCK_UPTIME_RAW_APPROX */
-  /* Offset 8 gives the best switch position.  */
-  switch (name[8]) {
-  case 'N':
-    if (memEQ(name, "CLOCK_MONOTONIC_PRECISE", 23)) {
-    /*                       ^                     */
-#ifdef CLOCK_MONOTONIC_PRECISE
-      *iv_return = CLOCK_MONOTONIC_PRECISE;
-      return PERL_constant_ISIV;
-#else
-      return PERL_constant_NOTDEF;
-#endif
-    }
-    break;
-  case 'R':
-    if (memEQ(name, "CLOCK_THREAD_CPUTIME_ID", 23)) {
-    /*                       ^                     */
-#ifdef CLOCK_THREAD_CPUTIME_ID
-      *iv_return = CLOCK_THREAD_CPUTIME_ID;
-      return PERL_constant_ISIV;
-#else
-      return PERL_constant_NOTDEF;
-#endif
-    }
-    break;
-  case 'T':
-    if (memEQ(name, "CLOCK_UPTIME_RAW_APPROX", 23)) {
-    /*                       ^                     */
-#ifdef CLOCK_UPTIME_RAW_APPROX
-      *iv_return = CLOCK_UPTIME_RAW_APPROX;
-      return PERL_constant_ISIV;
-#else
-      return PERL_constant_NOTDEF;
-#endif
-    }
-    break;
-  }
-  return PERL_constant_NOTFOUND;
-}
-
-static int
 constant (pTHX_ const char *name, STRLEN len, IV *iv_return) {
   /* Initially switch on the length of the name.  */
   /* When generated this function returned values for the list of names given
@@ -448,21 +404,20 @@ constant (pTHX_ const char *name, STRLEN len, IV *iv_return) {
      Regenerate these constant functions by feeding this entire source file to
      perl -x
 
-#!/opt/local/perl-5.26.1/bin/perl -w
+#!/opt/local/perl-5.25.6/bin/perl -w
 use ExtUtils::Constant qw (constant_types C_constant XS_constant);
 
 my $types = {map {($_, 1)} qw(IV)};
 my @names = (qw(CLOCKS_PER_SEC CLOCK_BOOTTIME CLOCK_HIGHRES CLOCK_MONOTONIC
 	       CLOCK_MONOTONIC_COARSE CLOCK_MONOTONIC_FAST
 	       CLOCK_MONOTONIC_PRECISE CLOCK_MONOTONIC_RAW
-	       CLOCK_MONOTONIC_RAW_APPROX CLOCK_PROCESS_CPUTIME_ID CLOCK_PROF
-	       CLOCK_REALTIME CLOCK_REALTIME_COARSE CLOCK_REALTIME_FAST
-	       CLOCK_REALTIME_PRECISE CLOCK_REALTIME_RAW CLOCK_SECOND
-	       CLOCK_SOFTTIME CLOCK_THREAD_CPUTIME_ID CLOCK_TIMEOFDAY
-	       CLOCK_UPTIME CLOCK_UPTIME_COARSE CLOCK_UPTIME_FAST
-	       CLOCK_UPTIME_PRECISE CLOCK_UPTIME_RAW CLOCK_UPTIME_RAW_APPROX
-	       CLOCK_VIRTUAL ITIMER_PROF ITIMER_REAL ITIMER_REALPROF
-	       ITIMER_VIRTUAL TIMER_ABSTIME),
+	       CLOCK_PROCESS_CPUTIME_ID CLOCK_PROF CLOCK_REALTIME
+	       CLOCK_REALTIME_COARSE CLOCK_REALTIME_FAST CLOCK_REALTIME_PRECISE
+	       CLOCK_REALTIME_RAW CLOCK_SECOND CLOCK_SOFTTIME
+	       CLOCK_THREAD_CPUTIME_ID CLOCK_TIMEOFDAY CLOCK_UPTIME
+	       CLOCK_UPTIME_COARSE CLOCK_UPTIME_FAST CLOCK_UPTIME_PRECISE
+	       CLOCK_UPTIME_RAW CLOCK_VIRTUAL ITIMER_PROF ITIMER_REAL
+	       ITIMER_REALPROF ITIMER_VIRTUAL TIMER_ABSTIME),
             {name=>"d_clock", type=>"IV", macro=>"TIME_HIRES_CLOCK", value=>"1", default=>["IV", "0"]},
             {name=>"d_clock_getres", type=>"IV", macro=>"TIME_HIRES_CLOCK_GETRES", value=>"1", default=>["IV", "0"]},
             {name=>"d_clock_gettime", type=>"IV", macro=>"TIME_HIRES_CLOCK_GETTIME", value=>"1", default=>["IV", "0"]},
@@ -697,7 +652,33 @@ __END__
     }
     break;
   case 23:
-    return constant_23 (aTHX_ name, iv_return);
+    /* Names all of length 23.  */
+    /* CLOCK_MONOTONIC_PRECISE CLOCK_THREAD_CPUTIME_ID */
+    /* Offset 22 gives the best switch position.  */
+    switch (name[22]) {
+    case 'D':
+      if (memEQ(name, "CLOCK_THREAD_CPUTIME_I", 22)) {
+      /*                                     D      */
+#ifdef CLOCK_THREAD_CPUTIME_ID
+        *iv_return = CLOCK_THREAD_CPUTIME_ID;
+        return PERL_constant_ISIV;
+#else
+        return PERL_constant_NOTDEF;
+#endif
+      }
+      break;
+    case 'E':
+      if (memEQ(name, "CLOCK_MONOTONIC_PRECIS", 22)) {
+      /*                                     E      */
+#ifdef CLOCK_MONOTONIC_PRECISE
+        *iv_return = CLOCK_MONOTONIC_PRECISE;
+        return PERL_constant_ISIV;
+#else
+        return PERL_constant_NOTDEF;
+#endif
+      }
+      break;
+    }
     break;
   case 24:
     if (memEQ(name, "CLOCK_PROCESS_CPUTIME_ID", 24)) {
@@ -709,16 +690,6 @@ __END__
 #endif
     }
     break;
-  case 26:
-    if (memEQ(name, "CLOCK_MONOTONIC_RAW_APPROX", 26)) {
-#ifdef CLOCK_MONOTONIC_RAW_APPROX
-      *iv_return = CLOCK_MONOTONIC_RAW_APPROX;
-      return PERL_constant_ISIV;
-#else
-      return PERL_constant_NOTDEF;
-#endif
-    }
-    break;
   }
   return PERL_constant_NOTFOUND;
 }
diff --git a/dist/Time-HiRes/t/tv_interval.t b/dist/Time-HiRes/t/tv_interval.t
index 06b50e31a7..8ac876daf3 100644
--- a/dist/Time-HiRes/t/tv_interval.t
+++ b/dist/Time-HiRes/t/tv_interval.t
@@ -1,73 +1,10 @@
 use strict;
 
-use Test::More tests => 13;
+use Test::More tests => 2;
 
 BEGIN { require_ok "Time::HiRes"; }
 
-my $d0 = Time::HiRes::tv_interval [5, 100_000], [10, 500_000];
-ok(abs($d0 - 5.4) < 0.001, "10.5 - 5.1 = $d0");
-
-my $d1 = Time::HiRes::tv_interval([], []);
-is($d1, 0, "[] - [] = $d1");
-
-my $t0 = [Time::HiRes::gettimeofday()];
-Time::HiRes::sleep 0.1;
-my $t1 = [Time::HiRes::gettimeofday()];
-my $d2 = Time::HiRes::tv_interval($t1); # NOTE: only one arg. 
-
-# This test will fail if between the $t1 and $d2 the time goes backwards:
-# this will happen if the clock is adjusted for example by NTP.
-ok($d2 >= 0, "now - [@$t0] = $d2 >= 0");
-
-my $d3 = Time::HiRes::tv_interval($t0, $t0);
-is($d3, 0, "[@$t0] - [@$t0] = $d3");
-
-my $d4 = Time::HiRes::tv_interval($t0, $t1);
-
-# Compute in Perl what tv_interval() used to do pre-1.9754. 
-# This test will fail if too much wallclock time passes between
-# the $t0 and $t1: this can happen in a heavily loaded system.
-my $d5 = ($t1->[0] - $t0->[0]) + ($t1->[1] - $t0->[1]) / 1e6;
-if ($d4 > 0) {
-  my $rd4d5 = $d5 / $d4;
-  ok(abs($rd4d5 - 1) < 0.001, "[@$t1] - [@$t0] = $d4 ($d5, $rd4d5)");
-} else {
-  is($d4, $d5, "$d4 == $d5");
-}
-
-# Then test errorneous inputs.
-
-eval 'Time::HiRes::tv_interval()';
-like($@, qr/Not enough arguments/, "at least one arg");
-
-eval 'Time::HiRes::tv_interval(1)';
-like($@, qr/1st argument should be an array reference/, "1st arg aref");
-
-eval 'Time::HiRes::tv_interval(undef)';
-like($@, qr/1st argument should be an array reference/, "1st arg aref");
-
-eval 'Time::HiRes::tv_interval({})';
-like($@, qr/1st argument should be an array reference/, "1st arg aref");
-
-eval 'Time::HiRes::tv_interval([], 1)';
-like($@, qr/2nd argument should be an array reference/, "2nd arg aref");
-
-eval 'Time::HiRes::tv_interval([], {})';
-like($@, qr/2nd argument should be an array reference/, "2nd arg aref");
-
-# Would be tempting but would probably break some code.
-# eval 'Time::HiRes::tv_interval([], [], [])';
-# like($@, qr/expects two arguments/, "two args");
-
-my $t2 = [Time::HiRes::gettimeofday];
-Time::HiRes::sleep 0.1;
-my $d6 = Time::HiRes::tv_interval($t2);
-# This test originally for long double builds,
-# has considerable flakness potential:
-# (1) if the sleep takes exactly one second (or two, ...)
-# (2) if the floating point operations in tv_interval()
-#     come up with a floating point result that does not
-#     format as a nicely "terminating" decimal number
-like($d6, qr/\.\d{1,6}$/, "no extra decimals");
+my $f = Time::HiRes::tv_interval [5, 100_000], [10, 500_000];
+ok abs($f - 5.4) < 0.001 or print("# $f\n");
 
 1;