Make the merkle tree implementation perform better.

Dockerfile

@@ -103,6 +103,7 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
 COPY arbitrator/Cargo.* arbitrator/
 COPY ./Makefile ./
 COPY arbitrator/arbutil arbitrator/arbutil
+COPY arbitrator/bench arbitrator/bench
 COPY arbitrator/brotli arbitrator/brotli
 COPY arbitrator/caller-env arbitrator/caller-env
 COPY arbitrator/prover arbitrator/prover
@@ -131,21 +132,28 @@ RUN wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add - && \
 COPY --from=brotli-library-export / target/
 COPY arbitrator/Cargo.* arbitrator/
 COPY arbitrator/arbutil arbitrator/arbutil
+COPY arbitrator/bench arbitrator/bench
 COPY arbitrator/brotli arbitrator/brotli
 COPY arbitrator/caller-env arbitrator/caller-env
 COPY arbitrator/prover/Cargo.toml arbitrator/prover/
+COPY arbitrator/prover/benches arbitrator/prover/benches
+COPY arbitrator/bench/Cargo.toml arbitrator/bench/
 COPY arbitrator/jit/Cargo.toml arbitrator/jit/
 COPY arbitrator/stylus/Cargo.toml arbitrator/stylus/
 COPY arbitrator/tools/wasmer arbitrator/tools/wasmer
 COPY arbitrator/wasm-libraries/user-host-trait/Cargo.toml arbitrator/wasm-libraries/user-host-trait/Cargo.toml
 RUN bash -c 'mkdir arbitrator/{prover,jit,stylus}/src arbitrator/wasm-libraries/user-host-trait/src'
 RUN echo "fn test() {}" > arbitrator/jit/src/lib.rs && \
     echo "fn test() {}" > arbitrator/prover/src/lib.rs && \
+    echo "fn test() {}" > arbitrator/bench/src/lib.rs && \
+    echo "fn test() {}" > arbitrator/prover/benches/merkle_bench.rs && \
     echo "fn test() {}" > arbitrator/stylus/src/lib.rs && \
     echo "fn test() {}" > arbitrator/wasm-libraries/user-host-trait/src/lib.rs && \
     cargo build --manifest-path arbitrator/Cargo.toml --release --lib && \
     rm arbitrator/prover/src/lib.rs arbitrator/jit/src/lib.rs arbitrator/stylus/src/lib.rs && \
-    rm arbitrator/wasm-libraries/user-host-trait/src/lib.rs
+    rm arbitrator/wasm-libraries/user-host-trait/src/lib.rs && \
+    rm arbitrator/prover/benches/merkle_bench.rs && \
+    rm arbitrator/bench/src/lib.rs
 COPY ./Makefile ./
 COPY arbitrator/prover arbitrator/prover
 COPY arbitrator/wasm-libraries arbitrator/wasm-libraries

Makefile

@@ -428,10 +428,10 @@ $(stylus_test_erc20_wasm): $(stylus_test_erc20_src)
 	@touch -c $@ # cargo might decide to not rebuild the binary
 
 contracts/test/prover/proofs/float%.json: $(arbitrator_cases)/float%.wasm $(prover_bin) $(output_latest)/soft-float.wasm
-	$(prover_bin) $< -l $(output_latest)/soft-float.wasm -o $@ -b --allow-hostapi --require-success --always-merkleize
+	$(prover_bin) $< -l $(output_latest)/soft-float.wasm -o $@ -b --allow-hostapi --require-success
 
 contracts/test/prover/proofs/no-stack-pollution.json: $(arbitrator_cases)/no-stack-pollution.wasm $(prover_bin)
-	$(prover_bin) $< -o $@ --allow-hostapi --require-success --always-merkleize
+	$(prover_bin) $< -o $@ --allow-hostapi --require-success
 
 target/testdata/preimages.bin:
 	mkdir -p `dirname $@`
@@ -455,19 +455,19 @@ contracts/test/prover/proofs/global-state.json:
 	echo "[]" > $@
 
 contracts/test/prover/proofs/forward-test.json: $(arbitrator_cases)/forward-test.wasm $(arbitrator_tests_forward_deps) $(prover_bin)
-	$(prover_bin) $< -o $@ --allow-hostapi --always-merkleize $(patsubst %,-l %, $(arbitrator_tests_forward_deps))
+	$(prover_bin) $< -o $@ --allow-hostapi $(patsubst %,-l %, $(arbitrator_tests_forward_deps))
 
 contracts/test/prover/proofs/link.json: $(arbitrator_cases)/link.wasm $(arbitrator_tests_link_deps) $(prover_bin)
-	$(prover_bin) $< -o $@ --allow-hostapi --always-merkleize --stylus-modules $(arbitrator_tests_link_deps) --require-success
+	$(prover_bin) $< -o $@ --allow-hostapi --stylus-modules $(arbitrator_tests_link_deps) --require-success
 
 contracts/test/prover/proofs/dynamic.json: $(patsubst %,$(arbitrator_cases)/%.wasm, dynamic user) $(prover_bin)
-	$(prover_bin) $< -o $@ --allow-hostapi --always-merkleize --stylus-modules $(arbitrator_cases)/user.wasm --require-success
+	$(prover_bin) $< -o $@ --allow-hostapi --stylus-modules $(arbitrator_cases)/user.wasm --require-success
 
 contracts/test/prover/proofs/bulk-memory.json: $(patsubst %,$(arbitrator_cases)/%.wasm, bulk-memory) $(prover_bin)
-	$(prover_bin) $< -o $@ --allow-hostapi --always-merkleize --stylus-modules $(arbitrator_cases)/user.wasm -b
+	$(prover_bin) $< -o $@ --allow-hostapi --stylus-modules $(arbitrator_cases)/user.wasm -b
 
 contracts/test/prover/proofs/%.json: $(arbitrator_cases)/%.wasm $(prover_bin)
-	$(prover_bin) $< -o $@ --allow-hostapi --always-merkleize
+	$(prover_bin) $< -o $@ --allow-hostapi
 
 # strategic rules to minimize dependency building