xpressn.c, introduce fortran style nint() rounding function

src/frontend/numparam/xpressn.c

@@ -85,13 +85,13 @@ limit(double nominal_val, double abs_variation)
 static const char *fmathS =     /* all math functions */
     "SQR SQRT SIN COS EXP LN ARCTAN ABS POW PWR MAX MIN INT LOG SINH COSH"
     " TANH TERNARY_FCN AGAUSS SGN GAUSS UNIF AUNIF LIMIT CEIL FLOOR"
-    " ASIN ACOS ATAN ASINH ACOSH ATANH TAN";
+    " ASIN ACOS ATAN ASINH ACOSH ATANH TAN NINT";
 
 
 enum {
     XFU_SQR = 1, XFU_SQRT, XFU_SIN, XFU_COS, XFU_EXP, XFU_LN, XFU_ARCTAN, XFU_ABS, XFU_POW, XFU_PWR, XFU_MAX, XFU_MIN, XFU_INT, XFU_LOG, XFU_SINH, XFU_COSH,
     XFU_TANH, XFU_TERNARY_FCN, XFU_AGAUSS, XFU_SGN, XFU_GAUSS, XFU_UNIF, XFU_AUNIF, XFU_LIMIT, XFU_CEIL, XFU_FLOOR,
-    XFU_ASIN, XFU_ACOS, XFU_ATAN, XFU_ASINH, XFU_ACOSH, XFU_ATANH, XFU_TAN,
+    XFU_ASIN, XFU_ACOS, XFU_ATAN, XFU_ASINH, XFU_ACOSH, XFU_ATANH, XFU_TAN, XFU_NINT
 };
 
 
@@ -141,6 +141,13 @@ mathfunction(int f, double z, double x)
     case XFU_INT:
         y = trunc(x);
         break;
+    case XFU_NINT:
+        /* round to "nearest integer",
+         *   round half-integers to the nearest even integer
+         *   rely on default rounding mode of IEEE 754 to do so
+         */
+        y = nearbyint(x);
+        break;
     case XFU_LOG:
         y = log(x);
         break;

src/include/ngspice/ngspice.h

@@ -160,6 +160,8 @@ extern void SetAnalyse(char *Analyse, int Percent);
 #include <process.h>
 #define trunc x_trunc
 extern double x_trunc(double);
+#define nearbyint x_nearbyint
+extern double x_nearbyint(double);
 #define asinh x_asinh
 extern double x_asinh(double);
 #define acosh x_acosh

tests/regression/parser/xpressn-1.cir

@@ -303,47 +303,88 @@ v1082_g  n1082_g 0  '-1'
 v1083_g  n1083_g 0  '-2'
 
 
-v1084_t  n1084_t 0  'floor(2.1)'
-v1085_t  n1085_t 0  'floor(1.9)'
-v1086_t  n1086_t 0  'floor(0)'
-v1087_t  n1087_t 0  'floor(-1.9)'
-v1088_t  n1088_t 0  'floor(-2.1)'
-
-v1084_g  n1084_g 0  '2'
-v1085_g  n1085_g 0  '1'
-v1086_g  n1086_g 0  '0'
-v1087_g  n1087_g 0  '-2'
-v1088_g  n1088_g 0  '-3'
-
-
-v1089_t  n1089_t 0  'ceil(2.1)'
-v1090_t  n1090_t 0  'ceil(1.9)'
-v1091_t  n1091_t 0  'ceil(0)'
-v1092_t  n1092_t 0  'ceil(-1.9)'
-v1093_t  n1093_t 0  'ceil(-2.1)'
-
-v1089_g  n1089_g 0  '3'
-v1090_g  n1090_g 0  '2'
+v1084_t  n1084_t 0  'nint(2.6)'
+v1085_t  n1085_t 0  'nint(2.5)'
+v1086_t  n1086_t 0  'nint(2.4)'
+v1087_t  n1087_t 0  'nint(1.6)'
+v1088_t  n1088_t 0  'nint(1.5)'
+v1089_t  n1089_t 0  'nint(1.4)'
+v1090_t  n1090_t 0  'nint(0.6)'
+v1091_t  n1091_t 0  'nint(0.5)'
+v1092_t  n1092_t 0  'nint(0.4)'
+v1093_t  n1093_t 0  'nint(0)'
+v1094_t  n1094_t 0  'nint(-0.4)'
+v1095_t  n1095_t 0  'nint(-0.5)'
+v1096_t  n1096_t 0  'nint(-0.6)'
+v1097_t  n1097_t 0  'nint(-1.4)'
+v1098_t  n1098_t 0  'nint(-1.5)'
+v1099_t  n1099_t 0  'nint(-1.6)'
+v1100_t  n1100_t 0  'nint(-2.4)'
+v1101_t  n1101_t 0  'nint(-2.5)'
+v1102_t  n1102_t 0  'nint(-2.6)'
+
+v1084_g  n1084_g 0  '3'
+v1085_g  n1085_g 0  '2'
+v1086_g  n1086_g 0  '2'
+v1087_g  n1087_g 0  '2'
+v1088_g  n1088_g 0  '2'
+v1089_g  n1089_g 0  '1'
+v1090_g  n1090_g 0  '1'
 v1091_g  n1091_g 0  '0'
-v1092_g  n1092_g 0  '-1'
-v1093_g  n1093_g 0  '-2'
+v1092_g  n1092_g 0  '0'
+v1093_g  n1093_g 0  '0'
+v1094_g  n1094_g 0  '0'
+v1095_g  n1095_g 0  '0'
+v1096_g  n1096_g 0  '-1'
+v1097_g  n1097_g 0  '-1'
+v1098_g  n1098_g 0  '-2'
+v1099_g  n1099_g 0  '-2'
+v1100_g  n1100_g 0  '-2'
+v1101_g  n1101_g 0  '-2'
+v1102_g  n1102_g 0  '-3'
+
+
+v1103_t  n1103_t 0  'floor(2.1)'
+v1104_t  n1104_t 0  'floor(1.9)'
+v1105_t  n1105_t 0  'floor(0)'
+v1106_t  n1106_t 0  'floor(-1.9)'
+v1107_t  n1107_t 0  'floor(-2.1)'
+
+v1103_g  n1103_g 0  '2'
+v1104_g  n1104_g 0  '1'
+v1105_g  n1105_g 0  '0'
+v1106_g  n1106_g 0  '-2'
+v1107_g  n1107_g 0  '-3'
+
+
+v1108_t  n1108_t 0  'ceil(2.1)'
+v1109_t  n1109_t 0  'ceil(1.9)'
+v1110_t  n1110_t 0  'ceil(0)'
+v1111_t  n1111_t 0  'ceil(-1.9)'
+v1112_t  n1112_t 0  'ceil(-2.1)'
+
+v1108_g  n1108_g 0  '3'
+v1109_g  n1109_g 0  '2'
+v1110_g  n1110_g 0  '0'
+v1111_g  n1111_g 0  '-1'
+v1112_g  n1112_g 0  '-2'
 
 
 * ----------------------------------------
 * min(a,b) max(a,b)
 
-v1094_t  n1094_t 0  'min(1.1, 2.1)'
-v1095_t  n1095_t 0  'min(2.1, 1.1)'
+v1113_t  n1113_t 0  'min(1.1, 2.1)'
+v1114_t  n1114_t 0  'min(2.1, 1.1)'
 
-v1094_g  n1094_g 0  '1.1'
-v1095_g  n1095_g 0  '1.1'
+v1113_g  n1113_g 0  '1.1'
+v1114_g  n1114_g 0  '1.1'
 
 
-v1096_t  n1096_t 0  'max(1.1, 2.1)'
-v1097_t  n1097_t 0  'max(2.1, 1.1)'
+v1115_t  n1115_t 0  'max(1.1, 2.1)'
+v1116_t  n1116_t 0  'max(2.1, 1.1)'
 
-v1096_g  n1096_g 0  '2.1'
-v1097_g  n1097_g 0  '2.1'
+v1115_g  n1115_g 0  '2.1'
+v1116_g  n1116_g 0  '2.1'
 
 
 * ----------------------------------------
@@ -357,7 +398,7 @@ op
 let total_count = 0
 let fail_count = 0
 
-let tests = 1001 + vector(97)
+let tests = 1001 + vector(116)
 
 foreach n $&tests
   set n_test = "n{$n}_t"

visualc/msvc-compat.c

@@ -12,6 +12,14 @@ x_trunc(double x)
 }
 
 
+double
+x_nearbyint(double x)
+{
+    /* thats grossly incorrect, anyway, don't worry, be crappy ... */
+    return floor(x + 0.5);
+}
+
+
 double
 x_asinh(double x)
 {