1 files changed, 51 insertions, 0 deletions
diff --git a/vendor/p384/src/arithmetic/macros.rs b/vendor/p384/src/arithmetic/macros.rs
new file mode 100644
index 0000000..88c4629
--- /dev/null
+++ b/vendor/p384/src/arithmetic/macros.rs
@@ -0,0 +1,51 @@
+/// Implement field element inversion.
+macro_rules! impl_field_invert {
+    (
+        $a:expr,
+        $one:expr,
+        $word_bits:expr,
+        $nlimbs:expr,
+        $mul:ident,
+        $neg:ident,
+        $divstep_precomp:ident,
+        $divstep:ident,
+        $msat:ident,
+        $selectznz:ident,
+    ) => {{
+        const ITERATIONS: usize = (49 * $nlimbs * $word_bits + 57) / 17;
+
+        let mut d = 1;
+        let mut f = $msat();
+        let mut g = [0; $nlimbs + 1];
+        let mut v = [0; $nlimbs];
+        let mut r = $one;
+        let mut i = 0;
+        let mut j = 0;
+
+        while j < $nlimbs {
+            g[j] = $a[j];
+            j += 1;
+        }
+
+        while i < ITERATIONS - ITERATIONS % 2 {
+            let (out1, out2, out3, out4, out5) = $divstep(d, &f, &g, &v, &r);
+            let (out1, out2, out3, out4, out5) = $divstep(out1, &out2, &out3, &out4, &out5);
+            d = out1;
+            f = out2;
+            g = out3;
+            v = out4;
+            r = out5;
+            i += 2;
+        }
+
+        if ITERATIONS % 2 != 0 {
+            let (_out1, out2, _out3, out4, _out5) = $divstep(d, &f, &g, &v, &r);
+            v = out4;
+            f = out2;
+        }
+
+        let s = ((f[f.len() - 1] >> $word_bits - 1) & 1) as u8;
+        let v = $selectznz(s, &v, &$neg(&v));
+        $mul(&v, &$divstep_precomp())
+    }};
+}