Initial import

third_party/duktape/duk_replacements.c

@@ -0,0 +1,82 @@
+/*
+ *  Replacements for missing platform functions.
+ *
+ *  Unlike the originals, fpclassify() and signbit() replacements don't
+ *  work on any floating point types, only doubles.  The C typing here
+ *  mimics the standard prototypes.
+ */
+
+#include "third_party/duktape/duk_internal.h"
+
+#if defined(DUK_USE_COMPUTED_NAN)
+DUK_INTERNAL double duk_computed_nan;
+#endif
+
+#if defined(DUK_USE_COMPUTED_INFINITY)
+DUK_INTERNAL double duk_computed_infinity;
+#endif
+
+#if defined(DUK_USE_REPL_FPCLASSIFY)
+DUK_INTERNAL int duk_repl_fpclassify(double x) {
+	duk_double_union u;
+	duk_uint_fast16_t expt;
+	duk_small_int_t mzero;
+
+	u.d = x;
+	expt = (duk_uint_fast16_t) (u.us[DUK_DBL_IDX_US0] & 0x7ff0UL);
+	if (expt > 0x0000UL && expt < 0x7ff0UL) {
+		/* expt values [0x001,0x7fe] = normal */
+		return DUK_FP_NORMAL;
+	}
+
+	mzero = (u.ui[DUK_DBL_IDX_UI1] == 0 && (u.ui[DUK_DBL_IDX_UI0] & 0x000fffffUL) == 0);
+	if (expt == 0x0000UL) {
+		/* expt 0x000 is zero/subnormal */
+		if (mzero) {
+			return DUK_FP_ZERO;
+		} else {
+			return DUK_FP_SUBNORMAL;
+		}
+	} else {
+		/* expt 0xfff is infinite/nan */
+		if (mzero) {
+			return DUK_FP_INFINITE;
+		} else {
+			return DUK_FP_NAN;
+		}
+	}
+}
+#endif
+
+#if defined(DUK_USE_REPL_SIGNBIT)
+DUK_INTERNAL int duk_repl_signbit(double x) {
+	duk_double_union u;
+	u.d = x;
+	return (int) (u.uc[DUK_DBL_IDX_UC0] & 0x80UL);
+}
+#endif
+
+#if defined(DUK_USE_REPL_ISFINITE)
+DUK_INTERNAL int duk_repl_isfinite(double x) {
+	int c = DUK_FPCLASSIFY(x);
+	if (c == DUK_FP_NAN || c == DUK_FP_INFINITE) {
+		return 0;
+	} else {
+		return 1;
+	}
+}
+#endif
+
+#if defined(DUK_USE_REPL_ISNAN)
+DUK_INTERNAL int duk_repl_isnan(double x) {
+	int c = DUK_FPCLASSIFY(x);
+	return (c == DUK_FP_NAN);
+}
+#endif
+
+#if defined(DUK_USE_REPL_ISINF)
+DUK_INTERNAL int duk_repl_isinf(double x) {
+	int c = DUK_FPCLASSIFY(x);
+	return (c == DUK_FP_INFINITE);
+}
+#endif