From 29b2552facd2e79f74f11eb8e8f074080b4b4720 Mon Sep 17 00:00:00 2001
From: Dmitry Vagner <typecat@dmitrys-mbp.lan>
Date: Mon, 26 Sep 2022 20:17:41 -0700
Subject: [PATCH] majorly simplify update2

---
 evm/src/cpu/kernel/asm/ripemd/update.asm | 47 ++++++++----------------
 evm/src/cpu/kernel/tests/ripemd.rs       | 25 ++++++-------
 2 files changed, 28 insertions(+), 44 deletions(-)

diff --git a/evm/src/cpu/kernel/asm/ripemd/update.asm b/evm/src/cpu/kernel/asm/ripemd/update.asm
index 8620b7aa..a9ef166a 100644
--- a/evm/src/cpu/kernel/asm/ripemd/update.asm
+++ b/evm/src/cpu/kernel/asm/ripemd/update.asm
@@ -85,43 +85,28 @@ update_1a:
     %jump(compress)
 
 /// def update_2():
-///     while length - shift >= 64:
-///         state   = compress(state, bytestring[shift:])
+///     while length >= shift + 64:
 ///         shift += 64
-///         cond  -= 64
+///         state  = compress(state, bytestring[shift-64:])
 
 update_2:
-    // stack:               STATE, shift, need, have, count, length, virt, retdest
-    %stack (STATE: 5, shift, need, have, count, length) -> (length, shift, STATE, shift, need, have, count, length) 
-    SUB
-    %ge_const(64)
-    // stack:         cond, STATE, shift, need, have, count, length, virt, retdest
-    DUP12
-    DUP8
+    // stack:       STATE, shift, need, have, count, length, virt, retdest
+    %stack (STATE: 5, shift, need, have, count, length) -> (64, shift, length, STATE, shift, need, have, count, length) 
     ADD
-    // stack: offset, cond, STATE, shift, need, have, count, length, virt, retdest
-    %stack (offset, cond, STATE: 5) -> (cond, STATE, offset, compression_loop)
-    // stack: cond, STATE, offset, compression_loop, shift, need, have, count, length, virt, retdest
-    %jumpi(compress)
-    %stack (STATE: 5, offset, compression_loop) -> (STATE)
-    %jump(final_update)
-compression_loop:
-    // stack: STATE, offset   ,        cond   , shift, need, have, count, length, virt, retdest
+    GT
+    // stack: cond, STATE, shift, need, have, count, length, virt, retdest
+    %jumpi(final_update)
     SWAP5
     %add_const(64)
-    SWAP5 
-    SWAP6
-    %sub_const(64)
-    SWAP6
-    SWAP7 
-    %add_const(64)
-    SWAP7 
-    // stack: STATE, offset+64,        cond-64, shift+64, need, have, count, length, virt, retdest
-    %stack (STATE: 5, offset, cond, shift) -> (cond, 0, STATE, offset, compression_loop, cond, shift)
-    %jumpi(compress)
-    // stack: STATE, offset   , label, cond   , shift   , need, have, count, length, virt, retdest
-    %stack (STATE: 5, offset, label, cond, shift, need, have, count, length, virt, retdest) -> (shift, need, have, STATE, count, length, virt, retdest)
-    %jump(final_update)
+    SWAP5
+    %stack (STATE: 5, shift) -> (shift, 64, STATE)
+    DUP14
+    ADD
+    SUB
+    // stack: offset, STATE, shift, need, have, count, length, virt, retdest
+    %stack (offset, STATE: 5) -> (STATE, offset, update_2)
+    // stack: STATE, offset, update_2, shift, need, have, count, length, virt, retdest
+    %jump(compress)
 
 
 /// def buffer_update(get, set, times):
diff --git a/evm/src/cpu/kernel/tests/ripemd.rs b/evm/src/cpu/kernel/tests/ripemd.rs
index d614b157..8741103f 100644
--- a/evm/src/cpu/kernel/tests/ripemd.rs
+++ b/evm/src/cpu/kernel/tests/ripemd.rs
@@ -12,8 +12,6 @@ fn make_input(word: &str) -> Vec<u8> {
 
 #[test]
 fn test_ripemd() -> Result<()> {
-    // let input: Vec<u8> = make_input("12345678901234567890123456789012345678901234567890123456789012345678901234567890");
-    // let expected = U256::from("0x9b752e45573d4b39f4dbd3323cab82bf63326bfb");
     let reference = vec![
         ("", "0x9c1185a5c5e9fc54612808977ee8f548b2258d31"),
         ("a", "0x0bdc9d2d256b3ee9daae347be6f4dc835a467ffe"),
@@ -34,6 +32,10 @@ fn test_ripemd() -> Result<()> {
             "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
             "0xb0e20b6e3116640286ed3a87a5713079b21f5189",
         ),
+        // (
+        //     "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
+        //     "0x9b752e45573d4b39f4dbd3323cab82bf63326bfb",
+        // )
     ];
 
     for (x, y) in reference {
@@ -41,21 +43,18 @@ fn test_ripemd() -> Result<()> {
         let expected = U256::from(y);
 
         let kernel = combined_kernel();
-        let label = kernel.global_labels["ripemd_alt"];
-        let stack_input: Vec<U256> = input.iter().map(|&x| U256::from(x as u8)).rev().collect();
-        let stack_output: Vec<U256> = run_with_kernel(&kernel, label, stack_input)?
+        let initial_offset = kernel.global_labels["ripemd_alt"];
+        let initial_stack: Vec<U256> = input.iter().map(|&x| U256::from(x as u8)).rev().collect();
+        let final_stack: Vec<U256> = run_with_kernel(&kernel, initial_offset, initial_stack)?
             .stack()
             .to_vec();
 
-        let actual = stack_output[0];
+        let actual = final_stack[0];
+    
+        let read_out: Vec<String> = final_stack.iter().map(|x| format!("{:x}", x)).rev().collect();
+        println!("{:x?}", read_out);
+
         assert_eq!(actual, expected);
     }
     Ok(())
-
-    // let input: Vec<u8> = make_input("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
-    // let expected = U256::from("0xb0e20b6e3116640286ed3a87a5713079b21f5189");
-    // let input: Vec<u8> = make_input("");
-    // let expected = U256::from("0x9c1185a5c5e9fc54612808977ee8f548b2258d31");
-    // let read_out: Vec<String> = stack_output.iter().map(|x| format!("{:x}", x)).rev().collect();
-    // println!("{:x?}", read_out);
 }