From 4a459f3f1ba5e7a33eb6a03cdb977ef1620dce03 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Fri, 26 Apr 2019 23:09:05 +0100
Subject: [PATCH 1/2] Add support for the bignum system library

---
 Cargo.toml    |  1 +
 src/bignum.rs | 39 +++++++++++++++++++++++++++++++++++++++
 src/lib.rs    |  3 +++
 3 files changed, 43 insertions(+)
 create mode 100644 src/bignum.rs

diff --git a/Cargo.toml b/Cargo.toml
index e80b73c..b68eff0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,3 +14,4 @@ wee_alloc = "0.4.4"
 default = [ "std" ]
 std = []
 debug = []
+bignum = []
diff --git a/src/bignum.rs b/src/bignum.rs
new file mode 100644
index 0000000..6a8ab5a
--- /dev/null
+++ b/src/bignum.rs
@@ -0,0 +1,39 @@
+//! The bignum system library.
+
+use super::*;
+
+pub mod native {
+    extern "C" {
+        pub fn bignum_mul256(a: *const u32, b: *const u32, ret: *const u32);
+        pub fn bignum_umulmod256(a: *const u32, b: *const u32, modulo: *const u32, ret: *const u32);
+    }
+}
+
+pub fn mul256(a: &Uint256, b: &Uint256) -> Uint256 {
+    let mut ret = Uint256::default();
+
+    unsafe {
+        native::bignum_mul256(
+            a.bytes.as_ptr() as *const u32,
+            b.bytes.as_ptr() as *const u32,
+            ret.bytes.as_mut_ptr() as *const u32,
+        )
+    }
+
+    ret
+}
+
+pub fn umulmod256(a: &Uint256, b: &Uint256, modulo: &Uint256) -> Uint256 {
+    let mut ret = Uint256::default();
+
+    unsafe {
+        native::bignum_umulmod256(
+            a.bytes.as_ptr() as *const u32,
+            b.bytes.as_ptr() as *const u32,
+            modulo.bytes.as_ptr() as *const u32,
+            ret.bytes.as_mut_ptr() as *const u32,
+        )
+    }
+
+    ret
+}
diff --git a/src/lib.rs b/src/lib.rs
index 30cd945..46c61cb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -31,6 +31,9 @@ mod utils;
 #[cfg(feature = "debug")]
 pub mod debug;
 
+#[cfg(feature = "bignum")]
+pub mod bignum;
+
 #[cfg(not(feature = "std"))]
 pub mod convert;
 

From 9f7aef7832f12daa07f63b083f500f170f2299f9 Mon Sep 17 00:00:00 2001
From: Alex Beregszaszi <alex@rtfs.hu>
Date: Tue, 28 May 2019 20:16:10 +0100
Subject: [PATCH 2/2] Move bignum under the "experimental" feature flag

Previously it was the "bignum" feature flag
---
 Cargo.toml | 2 +-
 circle.yml | 4 ++++
 src/lib.rs | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index b68eff0..ce9bc0f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,4 +14,4 @@ wee_alloc = "0.4.4"
 default = [ "std" ]
 std = []
 debug = []
-bignum = []
+experimental = []
diff --git a/circle.yml b/circle.yml
index c1c1c1f..402a919 100644
--- a/circle.yml
+++ b/circle.yml
@@ -30,3 +30,7 @@ jobs:
              cargo build --release --no-default-features
              cargo build --release --features debug
              cargo build --release --no-default-features --features debug
+             cargo build --release --features experimental
+             cargo build --release --no-default-features --features experimental
+             cargo build --release --features experimental,debug
+             cargo build --release --no-default-features --features experimental,debug
diff --git a/src/lib.rs b/src/lib.rs
index 46c61cb..145c623 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -31,7 +31,7 @@ mod utils;
 #[cfg(feature = "debug")]
 pub mod debug;
 
-#[cfg(feature = "bignum")]
+#[cfg(feature = "experimental")]
 pub mod bignum;
 
 #[cfg(not(feature = "std"))]