Vendor dependencies for 0.3.0 release

vendor/serde_json/src/lexical/shift.rs

@@ -0,0 +1,46 @@
+// Adapted from https://github.com/Alexhuszagh/rust-lexical.
+
+//! Bit-shift helpers.
+
+use super::float::ExtendedFloat;
+use core::mem;
+
+// Shift extended-precision float right `shift` bytes.
+#[inline]
+pub(crate) fn shr(fp: &mut ExtendedFloat, shift: i32) {
+    let bits: u64 = mem::size_of::<u64>() as u64 * 8;
+    debug_assert!((shift as u64) < bits, "shr() overflow in shift right.");
+
+    fp.mant >>= shift;
+    fp.exp += shift;
+}
+
+// Shift extended-precision float right `shift` bytes.
+//
+// Accepts when the shift is the same as the type size, and
+// sets the value to 0.
+#[inline]
+pub(crate) fn overflowing_shr(fp: &mut ExtendedFloat, shift: i32) {
+    let bits: u64 = mem::size_of::<u64>() as u64 * 8;
+    debug_assert!(
+        (shift as u64) <= bits,
+        "overflowing_shr() overflow in shift right."
+    );
+
+    fp.mant = if shift as u64 == bits {
+        0
+    } else {
+        fp.mant >> shift
+    };
+    fp.exp += shift;
+}
+
+// Shift extended-precision float left `shift` bytes.
+#[inline]
+pub(crate) fn shl(fp: &mut ExtendedFloat, shift: i32) {
+    let bits: u64 = mem::size_of::<u64>() as u64 * 8;
+    debug_assert!((shift as u64) < bits, "shl() overflow in shift left.");
+
+    fp.mant <<= shift;
+    fp.exp -= shift;
+}