Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Utility/Overflow.c

Index: third_party/cython/src/Cython/Utility/Overflow.c
diff --git a/third_party/cython/src/Cython/Utility/Overflow.c b/third_party/cython/src/Cython/Utility/Overflow.c
new file mode 100644
index 0000000000000000000000000000000000000000..1ac58df5b25fd34f3b25b68b8bedc78e0e36640b
--- /dev/null
+++ b/third_party/cython/src/Cython/Utility/Overflow.c
@@ -0,0 +1,284 @@
+/*
+These functions provide integer arithmetic with integer checking.  They do not
+actually raise an exception when an overflow is detected, but rather set a bit
+in the overflow parameter.  (This parameter may be re-used accross several
+arithmetic operations, so should be or-ed rather than assigned to.)
+
+The implementation is divided into two parts, the signed and unsigned basecases,
+which is where the magic happens, and a generic template matching a specific
+type to an implementation based on its (c-compile-time) size and signedness.
+
+When possible, branching is avoided, and preference is given to speed over
+accuracy (a low rate of falsely "detected" overflows are acceptable,
+undetected overflows are not).
+
+
+TODO: Hook up checking.
+TODO: Conditionally support 128-bit with intmax_t?
+*/
+
+/////////////// Common.proto ///////////////
+
+static int __Pyx_check_twos_complement(void) {
+    if (-1 != ~0) {
+        PyErr_SetString(PyExc_RuntimeError, "Two's complement required for overflow checks.");
+        return 1;
+    } else if (sizeof(short) == sizeof(int)) {
+        PyErr_SetString(PyExc_RuntimeError, "sizeof(short) < sizeof(int) required for overflow checks.");
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+#define __PYX_IS_UNSIGNED(type) (((type) -1) > 0)
+#define __PYX_SIGN_BIT(type)    (((unsigned type) 1) << (sizeof(type) * 8 - 1))
+#define __PYX_HALF_MAX(type)    (((type) 1) << (sizeof(type) * 8 - 2))
+#define __PYX_MIN(type)         (__PYX_IS_UNSIGNED(type) ? (type) 0 : 0 - __PYX_HALF_MAX(type) - __PYX_HALF_MAX(type))
+#define __PYX_MAX(type)         (~__PYX_MIN(type))
+
+#define __Pyx_add_no_overflow(a, b, overflow) ((a) + (b))
+#define __Pyx_add_const_no_overflow(a, b, overflow) ((a) + (b))
+#define __Pyx_sub_no_overflow(a, b, overflow) ((a) - (b))
+#define __Pyx_sub_const_no_overflow(a, b, overflow) ((a) - (b))
+#define __Pyx_mul_no_overflow(a, b, overflow) ((a) * (b))
+#define __Pyx_mul_const_no_overflow(a, b, overflow) ((a) * (b))
+#define __Pyx_div_no_overflow(a, b, overflow) ((a) / (b))
+#define __Pyx_div_const_no_overflow(a, b, overflow) ((a) / (b))
+
+/////////////// Common.init ///////////////
+
+__Pyx_check_twos_complement();
+
+/////////////// BaseCaseUnsigned.proto ///////////////
+
+static CYTHON_INLINE {{UINT}} __Pyx_add_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow);
+static CYTHON_INLINE {{UINT}} __Pyx_sub_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow);
+static CYTHON_INLINE {{UINT}} __Pyx_mul_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow);
+static CYTHON_INLINE {{UINT}} __Pyx_div_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow);
+
+// Use these when b is known at compile time.
+#define __Pyx_add_const_{{NAME}}_checking_overflow __Pyx_add_{{NAME}}_checking_overflow
+#define __Pyx_sub_const_{{NAME}}_checking_overflow __Pyx_sub_{{NAME}}_checking_overflow
+static CYTHON_INLINE {{UINT}} __Pyx_mul_const_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} constant, int *overflow);
+#define __Pyx_div_const_{{NAME}}_checking_overflow __Pyx_div_{{NAME}}_checking_overflow
+
+/////////////// BaseCaseUnsigned ///////////////
+
+static CYTHON_INLINE {{UINT}} __Pyx_add_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow) {
+    {{UINT}} r = a + b;
+    *overflow |= r < a;
+    return r;
+}
+
+static CYTHON_INLINE {{UINT}} __Pyx_sub_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow) {
+    {{UINT}} r = a - b;
+    *overflow |= r > a;
+    return r;
+}
+
+static CYTHON_INLINE {{UINT}} __Pyx_mul_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow) {
+    if (sizeof({{UINT}}) < sizeof(unsigned long)) {
+        unsigned long big_r = ((unsigned long) a) * ((unsigned long) b);
+        {{UINT}} r = ({{UINT}}) big_r;
+        *overflow |= big_r != r;
+        return r;
+    } else if (sizeof({{UINT}}) < sizeof(unsigned long long)) {
+        unsigned long long big_r = ((unsigned long long) a) * ((unsigned long long) b);
+        {{UINT}} r = ({{UINT}}) big_r;
+        *overflow |= big_r != r;
+        return r;
+    } else {
+        {{UINT}} prod = a * b;
+        double dprod = ((double) a) * ((double) b);
+        // Overflow results in an error of at least 2^sizeof(UINT),
+        // whereas rounding represents an error on the order of 2^(sizeof(UINT)-53).
+        *overflow |= fabs(dprod - prod) > (__PYX_MAX({{UINT}}) / 2);
+        return prod;
+    }
+}
+
+static CYTHON_INLINE {{UINT}} __Pyx_mul_const_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow) {
+    if (b > 1) {
+        *overflow |= a > __PYX_MAX({{UINT}}) / b;
+    }
+    return a * b;
+}
+
+
+static CYTHON_INLINE {{UINT}} __Pyx_div_{{NAME}}_checking_overflow({{UINT}} a, {{UINT}} b, int *overflow) {
+    if (b == 0) {
+        *overflow |= 1;
+        return 0;
+    }
+    return a / b;
+}
+
+
+/////////////// BaseCaseSigned.proto ///////////////
+
+static CYTHON_INLINE {{INT}} __Pyx_add_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow);
+static CYTHON_INLINE {{INT}} __Pyx_sub_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow);
+static CYTHON_INLINE {{INT}} __Pyx_mul_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow);
+static CYTHON_INLINE {{INT}} __Pyx_div_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow);
+
+
+// Use when b is known at compile time.
+static CYTHON_INLINE {{INT}} __Pyx_add_const_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow);
+static CYTHON_INLINE {{INT}} __Pyx_sub_const_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow);
+static CYTHON_INLINE {{INT}} __Pyx_mul_const_{{NAME}}_checking_overflow({{INT}} a, {{INT}} constant, int *overflow);
+#define __Pyx_div_const_{{NAME}}_checking_overflow __Pyx_div_{{NAME}}_checking_overflow
+
+/////////////// BaseCaseSigned ///////////////
+
+static CYTHON_INLINE {{INT}} __Pyx_add_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow) {
+    if (sizeof({{INT}}) < sizeof(long)) {
+        long big_r = ((long) a) + ((long) b);
+        {{INT}} r = ({{INT}}) big_r;
+        *overflow |= big_r != r;
+        return r;
+    } else if (sizeof({{INT}}) < sizeof(long long)) {
+        long long big_r = ((long long) a) + ((long long) b);
+        {{INT}} r = ({{INT}}) big_r;
+        *overflow |= big_r != r;
+        return r;
+    } else {
+        // Signed overflow undefined, but unsigned overflow is well defined.
+        {{INT}} r = ({{INT}}) ((unsigned {{INT}}) a + (unsigned {{INT}}) b);
+        // Overflow happened if the operands have the same sign, but the result
+        // has opposite sign.
+        // sign(a) == sign(b) != sign(r)
+        {{INT}} sign_a = __PYX_SIGN_BIT({{INT}}) & a;
+        {{INT}} sign_b = __PYX_SIGN_BIT({{INT}}) & b;
+        {{INT}} sign_r = __PYX_SIGN_BIT({{INT}}) & r;
+        *overflow |= (sign_a == sign_b) & (sign_a != sign_r);
+        return r;
+    }
+}
+
+static CYTHON_INLINE {{INT}} __Pyx_add_const_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow) {
+    if (b > 0) {
+        *overflow |= a > __PYX_MAX({{INT}}) - b;
+    } else if (b < 0) {
+        *overflow |= a < __PYX_MIN({{INT}}) - b;
+    }
+    return a + b;
+}
+
+static CYTHON_INLINE {{INT}} __Pyx_sub_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow) {
+    *overflow |= b == __PYX_MIN({{INT}});
+    return __Pyx_add_{{NAME}}_checking_overflow(a, -b, overflow);
+}
+
+static CYTHON_INLINE {{INT}} __Pyx_sub_const_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow) {
+    *overflow |= b == __PYX_MIN({{INT}});
+    return __Pyx_add_const_{{NAME}}_checking_overflow(a, -b, overflow);
+}
+
+static CYTHON_INLINE {{INT}} __Pyx_mul_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow) {
+    if (sizeof({{INT}}) < sizeof(long)) {
+        long big_r = ((long) a) * ((long) b);
+        {{INT}} r = ({{INT}}) big_r;
+        *overflow |= big_r != r;
+        return ({{INT}}) r;
+    } else if (sizeof({{INT}}) < sizeof(long long)) {
+        long long big_r = ((long long) a) * ((long long) b);
+        {{INT}} r = ({{INT}}) big_r;
+        *overflow |= big_r != r;
+        return ({{INT}}) r;
+    } else {
+        {{INT}} prod = a * b;
+        double dprod = ((double) a) * ((double) b);
+        // Overflow results in an error of at least 2^sizeof(INT),
+        // whereas rounding represents an error on the order of 2^(sizeof(INT)-53).
+        *overflow |= fabs(dprod - prod) > (__PYX_MAX({{INT}}) / 2);
+        return prod;
+    }
+}
+
+static CYTHON_INLINE {{INT}} __Pyx_mul_const_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow) {
+    if (b > 1) {
+        *overflow |= a > __PYX_MAX({{INT}}) / b;
+        *overflow |= a < __PYX_MIN({{INT}}) / b;
+    } else if (b == -1) {
+        *overflow |= a == __PYX_MIN({{INT}});
+    } else if (b < -1) {
+        *overflow |= a > __PYX_MIN({{INT}}) / b;
+        *overflow |= a < __PYX_MAX({{INT}}) / b;
+    }
+    return a * b;
+}
+
+static CYTHON_INLINE {{INT}} __Pyx_div_{{NAME}}_checking_overflow({{INT}} a, {{INT}} b, int *overflow) {
+    if (b == 0) {
+        *overflow |= 1;
+        return 0;
+    }
+    *overflow |= (a == __PYX_MIN({{INT}})) & (b == -1);
+    return a / b;
+}
+
+
+/////////////// SizeCheck.init ///////////////
+
+__Pyx_check_sane_{{NAME}}();
+
+/////////////// SizeCheck.proto ///////////////
+
+static int __Pyx_check_sane_{{NAME}}(void) {
+    if (sizeof({{TYPE}}) <= sizeof(int) ||
+        sizeof({{TYPE}}) == sizeof(long) ||
+        sizeof({{TYPE}}) == sizeof(long long)) {
+        return 0;
+    } else {
+        PyErr_Format(PyExc_RuntimeError, \
+            "Bad size for int type %.{{max(60, len(TYPE))}}s: %d", "{{TYPE}}", (int) sizeof({{TYPE}}));
+        return 1;
+    }
+}
+
+
+/////////////// Binop.proto ///////////////
+
+static CYTHON_INLINE {{TYPE}} __Pyx_{{BINOP}}_{{NAME}}_checking_overflow({{TYPE}} a, {{TYPE}} b, int *overflow);
+
+/////////////// Binop ///////////////
+
+static CYTHON_INLINE {{TYPE}} __Pyx_{{BINOP}}_{{NAME}}_checking_overflow({{TYPE}} a, {{TYPE}} b, int *overflow) {
+    if (sizeof({{TYPE}}) < sizeof(int)) {
+        return __Pyx_{{BINOP}}_no_overflow(a, b, overflow);
+    } else if (__PYX_IS_UNSIGNED({{TYPE}})) {
+        if (sizeof({{TYPE}}) == sizeof(unsigned int)) {
+            return __Pyx_{{BINOP}}_unsigned_int_checking_overflow(a, b, overflow);
+        } else if (sizeof({{TYPE}}) == sizeof(unsigned long)) {
+            return __Pyx_{{BINOP}}_unsigned_long_checking_overflow(a, b, overflow);
+        } else if (sizeof({{TYPE}}) == sizeof(unsigned long long)) {
+            return __Pyx_{{BINOP}}_unsigned_long_long_checking_overflow(a, b, overflow);
+        } else {
+            abort(); return 0; // handled elsewhere
+        }
+    } else {
+        if (sizeof({{TYPE}}) == sizeof(int)) {
+            return __Pyx_{{BINOP}}_int_checking_overflow(a, b, overflow);
+        } else if (sizeof({{TYPE}}) == sizeof(long)) {
+            return __Pyx_{{BINOP}}_long_checking_overflow(a, b, overflow);
+        } else if (sizeof({{TYPE}}) == sizeof(long long)) {
+            return __Pyx_{{BINOP}}_long_long_checking_overflow(a, b, overflow);
+        } else {
+            abort(); return 0; // handled elsewhere
+        }
+    }
+}
+
+/////////////// LeftShift.proto ///////////////
+
+static CYTHON_INLINE {{TYPE}} __Pyx_lshift_{{NAME}}_checking_overflow({{TYPE}} a, {{TYPE}} b, int *overflow) {
+    *overflow |=
+#if {{SIGNED}}
+        (b < 0) |
+#endif
+        (b > ({{TYPE}}) (8 * sizeof({{TYPE}}))) | (a > (__PYX_MAX({{TYPE}}) >> b));
+    return a << b;
+}
+#define __Pyx_lshift_const_{{NAME}}_checking_overflow __Pyx_lshift_{{NAME}}_checking_overflow
+