From ee957d8fe67e1b803481e7cc84813f5c9c949eec Mon Sep 17 00:00:00 2001
From: kunxian xia <xiakunxian130@gmail.com>
Date: Wed, 15 Nov 2023 19:21:48 +0800
Subject: [PATCH] use par invert

---
 halo2_proofs/src/arithmetic.rs             | 6 ++++++
 halo2_proofs/src/plonk/mv_lookup/prover.rs | 8 +++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/halo2_proofs/src/arithmetic.rs b/halo2_proofs/src/arithmetic.rs
index e820e80f06..fa8c801aee 100644
--- a/halo2_proofs/src/arithmetic.rs
+++ b/halo2_proofs/src/arithmetic.rs
@@ -532,6 +532,12 @@ where
     q
 }
 
+pub fn par_invert<F: Field>(values: &mut [F]) {
+    parallelize(values, |values, _start| {
+        values.batch_invert();
+    });
+}
+
 /// This simple utility function will parallelize an operation that is to be
 /// performed over a mutable slice.
 pub(crate) fn parallelize_internal<T: Send, F: Fn(&mut [T], usize) + Send + Sync + Clone>(
diff --git a/halo2_proofs/src/plonk/mv_lookup/prover.rs b/halo2_proofs/src/plonk/mv_lookup/prover.rs
index 59e11878a3..defe88b192 100644
--- a/halo2_proofs/src/plonk/mv_lookup/prover.rs
+++ b/halo2_proofs/src/plonk/mv_lookup/prover.rs
@@ -31,7 +31,7 @@ use std::{
     ops::{Mul, MulAssign},
 };
 
-use crate::arithmetic::parallelize_internal;
+use crate::arithmetic::{par_invert, parallelize_internal};
 use rayon::prelude::{IndexedParallelIterator, IntoParallelRefIterator, ParallelIterator};
 
 #[derive(Debug)]
@@ -256,8 +256,7 @@ impl<C: CurveAffine> Prepared<C> {
                 },
             );
             let inputs_inv_time = start_timer!(|| "batch invert");
-            // TODO: use parallelized batch invert
-            input_log_derivatives.iter_mut().batch_invert();
+            par_invert(input_log_derivatives.as_mut_slice());
             end_timer!(inputs_inv_time);
 
             // TODO: remove last blinders from this
@@ -283,8 +282,7 @@ impl<C: CurveAffine> Prepared<C> {
         );
 
         let table_inv_time = start_timer!(|| "table batch invert");
-        // TODO: use parallelized batch invert
-        table_log_derivatives.iter_mut().batch_invert();
+        par_invert(table_log_derivatives.as_mut_slice());
         end_timer!(table_inv_time);
         end_timer!(table_log_drv_time);