[tessellator] Replace open-coding _cairo_int64_cmp().

We often use the construct:
  if (_cairo_int64_lt (A, B)
     return -1;
  if (_cairo_int64_gt (A, B)
     return 1;
  return 0;
to compare two large integers (int64, or int128) which does twice the
required work on CPUs without large integer support. So replace it with a
single wideint function _cairo_int64_cmp() and therefore allow
opportunities to both shrink the code size and write a more efficient
comparison. (The primarily motivation is to simply replace each block with
a single more expressive line.)

1 files changed, 48 insertions, 0 deletions

diff --git a/src/cairo-wideint.c b/src/cairo-wideint.c
index e8d3ab69..45655938 100644
--- a/src/cairo-wideint.c
+++ b/src/cairo-wideint.c
@@ -235,6 +235,32 @@ _cairo_int64_lt (cairo_int64_t a, cairo_int64_t b)
     return _cairo_uint64_lt (a, b);
 }
 
+int
+_cairo_uint64_cmp (cairo_uint64_t a, cairo_uint64_t b)
+{
+    if (a.hi < b.hi)
+	return -1;
+    else if (a.hi > b.hi)
+	return 1;
+    else if (a.lo < b.lo)
+	return -1;
+    else if (a.lo > b.lo)
+	return 1;
+    else
+	return 0;
+}
+
+int
+_cairo_int64_cmp (cairo_int64_t a, cairo_int64_t b)
+{
+    if (_cairo_int64_negative (a) && !_cairo_int64_negative (b))
+	return -1;
+    if (!_cairo_int64_negative (a) && _cairo_int64_negative (b))
+	return 1;
+
+    return _cairo_uint64_cmp (a, b);
+}
+
 cairo_uint64_t
 _cairo_uint64_not (cairo_uint64_t a)
 {
@@ -570,6 +596,28 @@ _cairo_int128_lt (cairo_int128_t a, cairo_int128_t b)
 }
 
 int
+_cairo_uint128_cmp (cairo_uint128_t a, cairo_uint128_t b)
+{
+    int cmp;
+
+    cmp = _cairo_uint64_cmp (a.hi, b.hi);
+    if (cmp)
+	return cmp;
+    return _cairo_uint64_cmp (a.lo, b.lo);
+}
+
+int
+_cairo_int128_cmp (cairo_int128_t a, cairo_int128_t b)
+{
+    if (_cairo_int128_negative (a) && !_cairo_int128_negative (b))
+	return -1;
+    if (!_cairo_int128_negative (a) && _cairo_int128_negative (b))
+	return 1;
+
+    return _cairo_uint128_cmp (a, b);
+}
+
+int
 _cairo_uint128_eq (cairo_uint128_t a, cairo_uint128_t b)
 {
     return (_cairo_uint64_eq (a.hi, b.hi) &&