Merge branch 'dev/gfdl' into popcnt

.testing/Makefile

@@ -181,7 +181,7 @@ define CMP_RULE
 
 .PRECIOUS: $(foreach b,$(2),results/%/chksum_diag.$(b))
 %.$(1).diag: $(foreach b,$(2),results/%/chksum_diag.$(b))
-	cmp $$^ || true
+	cmp $$^
 endef
 
 $(eval $(call CMP_RULE,regression,symmetric target))
@@ -255,7 +255,7 @@ results/%/ocean.stats.restart: ../build/symmetric/MOM6
 	rm -rf work/$*/restart
 	mkdir -p work/$*/restart
 	cp -rL $*/* work/$*/restart
-	mkdir work/$*/restart/RESTART
+	mkdir -p work/$*/restart/RESTART
 	# Generate the half-period input namelist
 	# TODO: Assumes runtime set by DAYMAX, will fail if set by input.nml
 	cd work/$*/restart \

src/framework/MOM_checksums.F90

@@ -1822,8 +1822,11 @@ subroutine chk_sum_msg3(fmsg, aMean, aMin, aMax, mesg, iounit)
   real,             intent(in) :: aMax !< The maximum value of the array
   integer,          intent(in) :: iounit !< Checksum logger IO unit
 
+  ! NOTE: We add zero to aMin and aMax to remove any negative zeros.
+  ! This is due to inconsistencies of signed zero in local vs MPI calculations.
+
   if (is_root_pe()) write(iounit, '(A,3(A,ES25.16,1X),A)') &
-    fmsg, " mean=", aMean, "min=", aMin, "max=", aMax, trim(mesg)
+    fmsg, " mean=", aMean, "min=", (0. + aMin), "max=", (0. + aMax), trim(mesg)
 end subroutine chk_sum_msg3
 
 !> MOM_checksums_init initializes the MOM_checksums module. As it happens, the