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g1second_order_general_extended_packing: preserve significant bits for signedness on 32bit 

In g1second_order_general_extended_packing, firstOrderValues or so are restored
with grib_get_long_array(), and the restored values are stored in "long" type array.
So on 32 bit system, when "bits_per_value" is set to 32 and 32 bit unsigned values
are saved with grib_set_long_array(), restored values by grib_get_long_array()
are recognized as negative value, which results in wrong result
(in grib_second_order.sh).

For now, on linux 32 bit system, save 1 significant bit for signedness and
restrict bits_per_value to 31, and relax allowed error due to this change.
This commit is contained in:
Mamoru TASAKA 2021-12-21 20:07:43 +09:00
parent bf09266b21
commit 580c760e55
2 changed files with 15 additions and 2 deletions
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10
src/grib_accessor_class_data_g1second_order_general_extended_packing.c
View File

@ -1248,7 +1248,15 @@ static int get_bits_per_value(grib_handle* h, const char* bits_per_value_str, lo
* because it has already been changed to second order!
* We have to take precision=1 for IEEE which is 32bits
*/
*bits_per_value = 32;
/* But on 32bit, the most significant bit is for signnedness, so we have to drop one bit
* because it has already been changed to second order!
* We have to take precision=1 for IEEE which is 32bits
*/
if (sizeof(long) == 4) {
*bits_per_value = 31;
} else {
*bits_per_value = 32;
}
}
return err;
}

7
tests/grib_second_order.sh
View File

@ -143,11 +143,16 @@ grib_check_key_equals $temp3 packingType grid_second_order
# ECC-1219: packingType conversion from grid_ieee to grid_second_order
# ---------------------------------------------------------------------
if [ $ECCODES_ON_LINUX_32BIT -eq 1 ] ; then
ALLOWED_ERROR=7e-06
else
ALLOWED_ERROR=3e-06
fi
if [ $ECCODES_ON_WINDOWS -eq 0 ]; then
infile=grid_ieee.grib
${tools_dir}/grib_set -r -s packingType=grid_second_order $infile $temp1
grib_check_key_equals $temp1 packingType grid_second_order
${tools_dir}/grib_compare -cdata:n -R all=3e-06 $infile $temp1
${tools_dir}/grib_compare -cdata:n -R all=$ALLOWED_ERROR $infile $temp1
fi
# Second order doesn't have a proper representation for constant fields