[PATCH 2/2] Use "rint()" instead of rounding manually with "+ 0.5"
Linus Torvalds
torvalds at linux-foundation.org
Wed Feb 12 14:32:01 UTC 2014
From: Linus Torvalds <torvalds at linux-foundation.org>
Date: Wed, 12 Feb 2014 14:19:53 -0800
Subject: [PATCH 2/2] Use "rint()" instead of rounding manually with "+ 0.5"
rint() is "round to nearest integer", and does a better job than +0.5
(followed by the implicit truncation inherent in integer casting). We
already used 'rint()' for values that could be negative (where +0.5 is
actively wrong), let's just make it consistent.
Of course, as is usual for the messy C math functions, it depends on the
current rounding mode. But the default round-to-nearest is what we want
and use, and the functions that explicitly always round to nearest
aren't standard enough to worry about.
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
---
This patch is somewhat big, and maybe it's not worth it. Use or not, as
you see fit.
dive.c | 2 +-
dive.h | 18 +++++++++---------
divelist.c | 2 +-
libdivecomputer.c | 30 +++++++++++++++---------------
parse-xml.c | 16 ++++++++--------
profile.c | 2 +-
uemis-downloader.c | 2 +-
uemis.c | 4 ++--
8 files changed, 38 insertions(+), 38 deletions(-)
diff --git a/dive.c b/dive.c
index 455b1288c0ee..edcb130f4ec7 100644
--- a/dive.c
+++ b/dive.c
@@ -549,7 +549,7 @@ static void sanitize_cylinder_type(cylinder_type_t *type)
volume_of_air = cuft_to_l(type->size.mliter);
/* milliliters at 1 atm: "true size" */
volume = volume_of_air / surface_volume_multiplier(type->workingpressure);
- type->size.mliter = volume + 0.5;
+ type->size.mliter = rint(volume);
}
/* Ok, we have both size and pressure: try to match a description */
diff --git a/dive.h b/dive.h
index 658b199fe4c9..16105e1ec9e4 100644
--- a/dive.h
+++ b/dive.h
@@ -155,7 +155,7 @@ static inline double grams_to_lbs(int grams)
static inline int lbs_to_grams(double lbs)
{
- return lbs * 453.6 + 0.5;
+ return rint(lbs * 453.6);
}
static inline double ml_to_cuft(int ml)
@@ -175,12 +175,12 @@ static inline double mm_to_feet(int mm)
static inline unsigned long feet_to_mm(double feet)
{
- return feet * 304.8 + 0.5;
+ return rint(feet * 304.8);
}
static inline int to_feet(depth_t depth)
{
- return mm_to_feet(depth.mm) + 0.5;
+ return rint(mm_to_feet(depth.mm));
}
static inline double mkelvin_to_C(int mkelvin)
@@ -195,12 +195,12 @@ static inline double mkelvin_to_F(int mkelvin)
static inline unsigned long F_to_mkelvin(double f)
{
- return (f-32) * 1000 / 1.8 + ZERO_C_IN_MKELVIN + 0.5;
+ return rint((f-32) * 1000 / 1.8 + ZERO_C_IN_MKELVIN);
}
static inline unsigned long C_to_mkelvin(double c)
{
- return c * 1000 + ZERO_C_IN_MKELVIN + 0.5;
+ return rint(c * 1000 + ZERO_C_IN_MKELVIN);
}
static inline double psi_to_bar(double psi)
@@ -210,12 +210,12 @@ static inline double psi_to_bar(double psi)
static inline long psi_to_mbar(double psi)
{
- return psi_to_bar(psi)*1000 + 0.5;
+ return rint(psi_to_bar(psi)*1000);
}
static inline int to_PSI(pressure_t pressure)
{
- return pressure.mbar * 0.0145037738 + 0.5;
+ return rint(pressure.mbar * 0.0145037738);
}
static inline double bar_to_atm(double bar)
@@ -446,7 +446,7 @@ static inline int calculate_depth_to_mbar(int depth, pressure_t surface_pressure
if (!salinity)
salinity = SEAWATER_SALINITY;
specific_weight = salinity / 10000.0 * 0.981;
- mbar += depth / 10.0 * specific_weight + 0.5;
+ mbar += rint(depth / 10.0 * specific_weight);
return mbar;
}
@@ -471,7 +471,7 @@ static inline int rel_mbar_to_depth(int mbar, struct dive *dive)
if (dive->dc.salinity)
specific_weight = dive->dc.salinity / 10000.0 * 0.981;
/* whole mbar gives us cm precision */
- cm = mbar / specific_weight + 0.5;
+ cm = rint(mbar / specific_weight);
return cm * 10;
}
diff --git a/divelist.c b/divelist.c
index a9a2b451c057..9dc4b9438015 100644
--- a/divelist.c
+++ b/divelist.c
@@ -226,7 +226,7 @@ static int calculate_otu(struct dive *dive)
if (po2 >= 500)
otu += pow((po2 - 500) / 1000.0, 0.83) * t / 30.0;
}
- return otu + 0.5;
+ return rint(otu);
}
/* calculate CNS for a dive - this only takes the first divecomputer into account */
int const cns_table[][3] = {
diff --git a/libdivecomputer.c b/libdivecomputer.c
index f93b2c0fc9bb..7cc3894f9cb5 100644
--- a/libdivecomputer.c
+++ b/libdivecomputer.c
@@ -77,13 +77,13 @@ static bool get_tanksize(device_data_t *devdata, const unsigned char *data, cyli
case COBALT_CFATPSI:
airvolume = cuft_to_l(atomics_gas_info[idx].tanksize) * 1000.0;
mbar = psi_to_mbar(atomics_gas_info[idx].workingpressure);
- cyl[idx].type.size.mliter = airvolume / bar_to_atm(mbar / 1000.0) + 0.5;
+ cyl[idx].type.size.mliter = rint(airvolume / bar_to_atm(mbar / 1000.0));
cyl[idx].type.workingpressure.mbar = mbar;
break;
case COBALT_CFATBAR:
airvolume = cuft_to_l(atomics_gas_info[idx].tanksize) * 1000.0;
mbar = atomics_gas_info[idx].workingpressure * 1000;
- cyl[idx].type.size.mliter = airvolume / bar_to_atm(mbar / 1000.0) + 0.5;
+ cyl[idx].type.size.mliter = rint(airvolume / bar_to_atm(mbar / 1000.0));
cyl[idx].type.workingpressure.mbar = mbar;
break;
case COBALT_WETINDL:
@@ -112,8 +112,8 @@ static int parse_gasmixes(device_data_t *devdata, struct dive *dive, dc_parser_t
if (i >= MAX_CYLINDERS)
continue;
- o2 = gasmix.oxygen * 1000 + 0.5;
- he = gasmix.helium * 1000 + 0.5;
+ o2 = rint(gasmix.oxygen * 1000);
+ he = rint(gasmix.helium * 1000);
/* Ignore bogus data - libdivecomputer does some crazy stuff */
if (o2 + he <= O2_IN_AIR || o2 >= 1000)
@@ -204,11 +204,11 @@ sample_cb(dc_sample_type_t type, dc_sample_value_t value, void *userdata)
finish_sample(dc);
break;
case DC_SAMPLE_DEPTH:
- sample->depth.mm = value.depth * 1000 + 0.5;
+ sample->depth.mm = rint(value.depth * 1000);
break;
case DC_SAMPLE_PRESSURE:
sample->sensor = value.pressure.tank;
- sample->cylinderpressure.mbar = value.pressure.value * 1000 + 0.5;
+ sample->cylinderpressure.mbar = rint(value.pressure.value * 1000);
break;
case DC_SAMPLE_TEMPERATURE:
sample->temperature.mkelvin = C_to_mkelvin(value.temperature);
@@ -235,28 +235,28 @@ sample_cb(dc_sample_type_t type, dc_sample_value_t value, void *userdata)
#if DC_VERSION_CHECK(0, 3, 0)
case DC_SAMPLE_SETPOINT:
/* for us a setpoint means constant pO2 from here */
- sample->po2 = po2 = value.setpoint * 1000 + 0.5;
+ sample->po2 = po2 = rint(value.setpoint * 1000);
break;
case DC_SAMPLE_PPO2:
- sample->po2 = po2 = value.ppo2 * 1000 + 0.5;
+ sample->po2 = po2 = rint(value.ppo2 * 1000);
break;
case DC_SAMPLE_CNS:
- sample->cns = cns = value.cns * 100 + 0.5;
+ sample->cns = cns = rint(value.cns * 100);
break;
case DC_SAMPLE_DECO:
if (value.deco.type == DC_DECO_NDL) {
sample->ndl.seconds = ndl = value.deco.time;
- sample->stopdepth.mm = stopdepth = value.deco.depth * 1000.0 + 0.5;
+ sample->stopdepth.mm = stopdepth = rint(value.deco.depth * 1000.0);
sample->in_deco = in_deco = false;
} else if (value.deco.type == DC_DECO_DECOSTOP ||
value.deco.type == DC_DECO_DEEPSTOP) {
sample->in_deco = in_deco = true;
- sample->stopdepth.mm = stopdepth = value.deco.depth * 1000.0 + 0.5;
+ sample->stopdepth.mm = stopdepth = rint(value.deco.depth * 1000.0);
sample->stoptime.seconds = stoptime = value.deco.time;
ndl = 0;
} else if (value.deco.type == DC_DECO_SAFETYSTOP) {
sample->in_deco = in_deco = false;
- sample->stopdepth.mm = stopdepth = value.deco.depth * 1000.0 + 0.5;
+ sample->stopdepth.mm = stopdepth = rint(value.deco.depth * 1000.0);
sample->stoptime.seconds = stoptime = value.deco.time;
}
#endif
@@ -451,7 +451,7 @@ static int dive_cb(const unsigned char *data, unsigned int size,
dc_parser_destroy(parser);
return false;
}
- dive->dc.maxdepth.mm = maxdepth * 1000 + 0.5;
+ dive->dc.maxdepth.mm = rint(maxdepth * 1000);
// Parse the gas mixes.
unsigned int ngases = 0;
@@ -474,7 +474,7 @@ static int dive_cb(const unsigned char *data, unsigned int size,
dc_parser_destroy(parser);
return false;
}
- dive->dc.salinity = salinity.density * 10.0 + 0.5;
+ dive->dc.salinity = rint(salinity.density * 10.0);
double surface_pressure = 0;
rc = dc_parser_get_field(parser, DC_FIELD_ATMOSPHERIC, 0, &surface_pressure);
@@ -483,7 +483,7 @@ static int dive_cb(const unsigned char *data, unsigned int size,
dc_parser_destroy(parser);
return false;
}
- dive->dc.surface_pressure.mbar = surface_pressure * 1000.0 + 0.5;
+ dive->dc.surface_pressure.mbar = rint(surface_pressure * 1000.0);
#endif
rc = parse_gasmixes(devdata, dive, parser, ngases, data);
diff --git a/parse-xml.c b/parse-xml.c
index 3c536ed4b6ed..2a98d39046e5 100644
--- a/parse-xml.c
+++ b/parse-xml.c
@@ -326,7 +326,7 @@ static void pressure(char *buffer, void *_press)
break;
}
if (mbar > 5 && mbar < 500000) {
- pressure->mbar = mbar + 0.5;
+ pressure->mbar = rint(mbar);
break;
}
/* fallthrough */
@@ -341,7 +341,7 @@ static void salinity(char *buffer, void *_salinity)
union int_or_float val;
switch (integer_or_float(buffer, &val)) {
case FLOAT:
- *salinity = val.fp * 10.0 + 0.5;
+ *salinity = rint(val.fp * 10.0);
break;
default:
printf("Strange salinity reading %s\n", buffer);
@@ -357,7 +357,7 @@ static void depth(char *buffer, void *_depth)
case FLOAT:
switch (xml_parsing_units.length) {
case METERS:
- depth->mm = val.fp * 1000 + 0.5;
+ depth->mm = rint(val.fp * 1000);
break;
case FEET:
depth->mm = feet_to_mm(val.fp);
@@ -378,7 +378,7 @@ static void weight(char *buffer, void *_weight)
case FLOAT:
switch (xml_parsing_units.weight) {
case KG:
- weight->grams = val.fp * 1000 + 0.5;
+ weight->grams = rint(val.fp * 1000);
break;
case LBS:
weight->grams = lbs_to_grams(val.fp);
@@ -472,7 +472,7 @@ static void percent(char *buffer, void *_fraction)
/* Then turn percent into our integer permille format */
if (val >= 0 && val <= 100.0) {
- fraction->permille = val * 10 + 0.5;
+ fraction->permille = rint(val * 10);
break;
}
default:
@@ -502,7 +502,7 @@ static void cylindersize(char *buffer, void *_volume)
switch (integer_or_float(buffer, &val)) {
case FLOAT:
- volume->mliter = val.fp * 1000 + 0.5;
+ volume->mliter = rint(val.fp * 1000);
break;
default:
@@ -549,7 +549,7 @@ static void get_rating(char *buffer, void *_i)
static void double_to_permil(char *buffer, void *_i)
{
int *i = _i;
- *i = ascii_strtod(buffer, NULL) * 1000.0 + 0.5;
+ *i = rint(ascii_strtod(buffer, NULL) * 1000.0);
}
static void hex_value(char *buffer, void *_i)
@@ -636,7 +636,7 @@ static void psi_or_bar(char *buffer, void *_pressure)
if (val.fp > 400)
pressure->mbar = psi_to_mbar(val.fp);
else
- pressure->mbar = val.fp * 1000 + 0.5;
+ pressure->mbar = rint(val.fp * 1000);
break;
default:
fprintf(stderr, "Crazy Diving Log PSI reading %s\n", buffer);
diff --git a/profile.c b/profile.c
index 07328580f982..bcf4fb183944 100644
--- a/profile.c
+++ b/profile.c
@@ -627,7 +627,7 @@ static void fill_missing_tank_pressures(struct dive *dive, struct plot_info *pi,
magic = (interpolate.end - interpolate.start) / (double) interpolate.pressure_time;
/* Use that overall pressure change to update the current pressure */
- cur_pr[cyl] = interpolate.start + magic * interpolate.acc_pressure_time + 0.5;
+ cur_pr[cyl] = rint(interpolate.start + magic * interpolate.acc_pressure_time);
}
INTERPOLATED_PRESSURE(entry) = cur_pr[cyl];
}
diff --git a/uemis-downloader.c b/uemis-downloader.c
index ceac292353ee..99a1a8bc8b8c 100644
--- a/uemis-downloader.c
+++ b/uemis-downloader.c
@@ -65,7 +65,7 @@ static void uemis_ts(char *buffer, void *_when)
/* float minutes */
static void uemis_duration(char *buffer, duration_t *duration)
{
- duration->seconds = ascii_strtod(buffer, NULL) * 60 + 0.5;
+ duration->seconds = rint(ascii_strtod(buffer, NULL) * 60);
}
/* int cm */
diff --git a/uemis.c b/uemis.c
index 27e526f1dfd7..c43606d9c042 100644
--- a/uemis.c
+++ b/uemis.c
@@ -329,9 +329,9 @@ void uemis_parse_divelog_binary(char *base64, void *datap) {
* we store the incorrect working pressure to get the SAC calculations "close"
* but the user will have to correct this manually
*/
- dive->cylinder[i].type.size.mliter = volume;
+ dive->cylinder[i].type.size.mliter = rint(volume);
dive->cylinder[i].type.workingpressure.mbar = 202600;
- dive->cylinder[i].gasmix.o2.permille = *(uint8_t *)(data+120+25*(gasoffset + i)) * 10 + 0.5;
+ dive->cylinder[i].gasmix.o2.permille = *(uint8_t *)(data+120+25*(gasoffset + i)) * 10;
dive->cylinder[i].gasmix.he.permille = 0;
}
/* first byte of divelog data is at offset 0x123 */
--
1.9.0.rc3
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