cannon: Implement bltzal in the onchain MIPS64 FPVM (#13429)

cannon/mipsevm/tests/evm_common64_test.go

@@ -484,6 +484,15 @@ func TestEVM_SingleStep_Branch64(t *testing.T) {
 		{name: "bltz sign-extended offset", pc: 0x10, opcode: 0x1, regimm: 0x0, rs: -1, offset: 0x80_00, expectNextPC: 0xFF_FF_FF_FF_FF_FE_00_14},
 		{name: "bltz large offset no-sign", pc: 0x10, opcode: 0x1, regimm: 0x0, rs: -1, offset: 0x7F_FF, expectNextPC: 0x2_00_10},
 
+		// bltzal t0, $x
+		{name: "bltzal", pc: 0, opcode: 0x1, regimm: 0x10, rs: 0x5, offset: 0x100, expectNextPC: 0x8, expectLink: true},
+		{name: "bltzal large rs", pc: 0x10, opcode: 0x1, regimm: 0x10, rs: 0x7F_FF_FF_FF_FF_FF_FF_FF, offset: 0x100, expectNextPC: 0x18, expectLink: true},
+		{name: "bltzal zero rs", pc: 0x10, opcode: 0x1, regimm: 0x10, rs: 0x0, offset: 0x100, expectNextPC: 0x18, expectLink: true},
+		{name: "bltzal sign rs", pc: 0x10, opcode: 0x1, regimm: 0x10, rs: -1, offset: 0x100, expectNextPC: 0x414, expectLink: true},
+		{name: "bltzal rs only sign bit set", pc: 0x10, opcode: 0x1, regimm: 0x10, rs: testutil.ToSignedInteger(0x80_00_00_00_00_00_00_00), offset: 0x100, expectNextPC: 0x414, expectLink: true},
+		{name: "bltzal sign-extended offset", pc: 0x10, opcode: 0x1, regimm: 0x10, rs: -1, offset: 0x80_00, expectNextPC: 0xFF_FF_FF_FF_FF_FE_00_14, expectLink: true},
+		{name: "bltzal large offset no-sign", pc: 0x10, opcode: 0x1, regimm: 0x10, rs: -1, offset: 0x7F_FF, expectNextPC: 0x2_00_10, expectLink: true},
+
 		// bgez t0, $x
 		{name: "bgez", pc: 0, opcode: 0x1, regimm: 0x1, rs: 0x5, offset: 0x100, expectNextPC: 0x404},
 		{name: "bgez large rs", pc: 0x10, opcode: 0x1, regimm: 0x1, rs: 0x7F_FF_FF_FF_FF_FF_FF_FF, offset: 0x100, expectNextPC: 0x414},

packages/contracts-bedrock/snapshots/semver-lock.json

@@ -144,8 +144,8 @@
     "sourceCodeHash": "0x8da8be0b7d60af0eb11bd58653f1854d56a8f0616f3aeaeba7ab9ec340d02ac7"
   },
   "src/cannon/MIPS64.sol": {
-    "initCodeHash": "0x6516160f35a85abb65d8102fa71f03cb57518787f9af85bc951f27ee60e6bb8f",
-    "sourceCodeHash": "0xd0802842e5656639f33324ed6498c60013e6d9cd63c9f097090da9a0a61700a4"
+    "initCodeHash": "0xdef0bd64af2541644e1fba56cb443650749dee201a38053c02464584f2e806a9",
+    "sourceCodeHash": "0x16b46d17dff5b772675bdd280dddea482e85c707a8779694f10cc78b05de871d"
   },
   "src/cannon/PreimageOracle.sol": {
     "initCodeHash": "0xf08736a5af9277a4f3498dfee84a40c9b05f1a2ba3177459bebe2b0b54f99343",

packages/contracts-bedrock/src/cannon/MIPS64.sol

@@ -67,8 +67,8 @@ contract MIPS64 is ISemver {
     }
 
     /// @notice The semantic version of the MIPS64 contract.
-    /// @custom:semver 1.0.0-beta.7
-    string public constant version = "1.0.0-beta.7";
+    /// @custom:semver 1.0.0-beta.8
+    string public constant version = "1.0.0-beta.8";
 
     /// @notice The preimage oracle contract.
     IPreimageOracle internal immutable ORACLE;

packages/contracts-bedrock/src/cannon/libraries/MIPS64Instructions.sol

@@ -644,6 +644,11 @@ library MIPS64Instructions {
                 if (rtv == 0) {
                     shouldBranch = int64(_rs) < 0;
                 }
+                // bltzal
+                if (rtv == 0x10) {
+                    shouldBranch = int64(_rs) < 0;
+                    _registers[REG_RA] = _cpu.pc + 8; // always set regardless of branch taken
+                }
                 if (rtv == 1) {
                     shouldBranch = int64(_rs) >= 0;
                 }