diff --git a/msm/pippenger.cuh b/msm/pippenger.cuh
index 841f4f7..0481abc 100644
--- a/msm/pippenger.cuh
+++ b/msm/pippenger.cuh
@@ -504,7 +504,34 @@ class msm_t {
     }
 
     RustError invoke(point_t &out, const scalar_t *scalars, size_t nscalars, uint32_t pidx[], bool mont = true) {
-        assert(this->nscalars <= nscalars);
+        // assert(this->nscalars <= nscalars);
+        
+        wbits = 17;
+        if (nscalars > 192) {
+            wbits = std::min(lg2(nscalars + nscalars/2) - 8, 18);
+            if (wbits < 10)
+                wbits = 10;
+        } else if (nscalars > 0) {
+            wbits = 10;
+        }
+        nwins = (scalar_t::bit_length() - 1) / wbits + 1;
+
+        uint32_t row_sz = 1U << (wbits-1);
+
+        size_t d_buckets_sz = (nwins * row_sz)
+                            + (gpu.sm_count() * BATCH_ADD_BLOCK_SIZE / WARP_SZ);
+        size_t d_blob_sz = (d_buckets_sz * sizeof(d_buckets[0]))
+                         + (nwins * row_sz * sizeof(uint32_t));
+
+        d_buckets = reinterpret_cast<decltype(d_buckets)>(gpu.Dmalloc(d_blob_sz));
+        d_hist = vec2d_t<uint32_t>(&d_buckets[d_buckets_sz], row_sz);
+
+        uint32_t lg_n = lg2(nscalars + nscalars/2);
+        size_t batch = 1 << (std::max(lg_n, wbits) - wbits);
+        batch >>= 6;
+        batch = batch ? batch : 1;
+        uint32_t stride = (nscalars + batch - 1) / batch;
+        stride = (stride+WARP_SZ-1) & ((size_t)0-WARP_SZ);
 
         std::vector<result_t> res(nwins);
         std::vector<bucket_t> ones(gpu.sm_count() * BATCH_ADD_BLOCK_SIZE / WARP_SZ);
@@ -513,6 +540,20 @@ class msm_t {
         point_t p;
 
         try {
+            // |scalars| being nullptr means the scalars are pre-loaded to
+            // |d_scalars|, otherwise allocate stride.
+            size_t temp_sz = scalars ? sizeof(scalar_t) : 0;
+            temp_sz = stride * std::max(2*sizeof(uint2), temp_sz);
+
+            size_t digits_sz = nwins * stride * sizeof(uint32_t);
+
+            dev_ptr_t<uint8_t> d_temp{temp_sz + digits_sz, gpu[2]};
+
+            vec2d_t<uint2> d_temps{&d_temp[0], stride};
+            vec2d_t<uint32_t> d_digits{&d_temp[temp_sz], stride};
+
+            scalar_t* d_scalars = scalars ? (scalar_t*)&d_temp[0]
+                                          : this->d_scalars;
             size_t d_off = 0; // device offset
             size_t h_off = 0; // host offset
             size_t num = stride > nscalars ? nscalars : stride;
@@ -709,7 +750,7 @@ static RustError mult_pippenger(point_t *out, const affine_t points[], size_t np
                                 size_t nscalars, bool mont = true) {
     try {
         msm_t<bucket_t, point_t, affine_t, scalar_t> msm{points, npoints, true};
-        msm.setup_scratch(nscalars);
+        // msm.setup_scratch(nscalars);
         return msm.invoke(*out, scalars, nscalars, nullptr, mont);
     } catch (const cuda_error &e) {
         out->inf();
@@ -727,7 +768,7 @@ static RustError mult_pippenger_with(point_t *out, msm_context_t<affine_h> *msm_
                                      const scalar_t scalars[], size_t nscalars, uint32_t pidx[], bool mont = true) {
     try {
         msm_t<bucket_t, point_t, affine_t, scalar_t> msm{msm_context->d_points, msm_context->npoints};
-        msm.setup_scratch(nscalars);
+        // msm.setup_scratch(nscalars);
         return msm.invoke(*out, scalars, nscalars, pidx, mont);
     } catch (const cuda_error &e) {
         out->inf();