Revert "fix: have MIPS revert on add/sub overflow/underflow (#230)" (#279)

This reverts commit 864e59a821e87f9dd00ae97f85add93fa3857597.

cannon/mipsevm/exec/mips_instructions.go

@@ -240,29 +240,11 @@ func ExecuteMipsInstruction(insn, opcode, fun, rs, rt, mem uint32) uint32 {
 			return rs
 		// The rest includes transformed R-type arith imm instructions
 		case 0x20: // add
-			intRs := int32(rs)
-			intRt := int32(rt)
-			intRes := intRs + intRt
-			if intRs > 0 && intRt > 0 && intRes <= 0 {
-				panic("MIPS: add overflow")
-			}
-			if intRs < 0 && intRt < 0 && intRes >= 0 {
-				panic("MIPS: add underflow")
-			}
-			return uint32(intRes)
+			return rs + rt
 		case 0x21: // addu
 			return rs + rt
 		case 0x22: // sub
-			intRs := int32(rs)
-			intRt := int32(rt)
-			intRes := intRs - intRt
-			if intRs > 0 && intRt < 0 && intRes < 0 {
-				panic("MIPS: sub overflow")
-			}
-			if intRs < 0 && intRt > 0 && intRes > 0 {
-				panic("MIPS: sub underflow")
-			}
-			return uint32(intRes)
+			return rs - rt
 		case 0x23: // subu
 			return rs - rt
 		case 0x24: // and

cannon/mipsevm/tests/open_mips_tests/test/add_overflow_panic.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    lui     $t0, 0x7fff         # A = 0x7fffffff (maximum positive 32-bit integer)
-    ori     $t0, 0xffff
-    ori     $t1, $0, 1          # B = 0x1
-    add     $t2, $t0, $t1       # C = A + B (this should trigger an overflow)
-
-    # Unreachable ....
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

cannon/mipsevm/tests/open_mips_tests/test/add_underflow_panic.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    lui     $t0, 0x8000         # A = 0x80000000 (minimum negative 32-bit integer)
-    ori     $t0, 0x0000
-    lui     $t1, 0x8000         # B = 0x80000000 (minimum negative 32-bit integer)
-    ori     $t1, 0x0000
-    add     $t2, $t0, $t1       # C = A + B (this should trigger an underflow)
-
-    # Unreachable ....
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

cannon/mipsevm/tests/open_mips_tests/test/addi_overflow_panic.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    lui     $t0, 0x7fff         # A = 0x7fffffff (maximum positive 32-bit integer)
-    ori     $t0, 0xffff
-    addi    $t1, $t0, 1         # B = A + 1 (this should trigger an overflow)
-
-    # Unreachable...
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

cannon/mipsevm/tests/open_mips_tests/test/addi_underflow_panic.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    lui     $t0, 0x8000         # A = 0x80000000 (minimum negative 32-bit integer)
-    ori     $t0, 0x0000
-    addi    $t1, $t0, -1        # B = A - 1 (this should trigger an underflow)
-
-    # Unreachable...
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

cannon/mipsevm/tests/open_mips_tests/test/addu_overflow.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    lui     $t0, 0xffff         # A = 0xffffffff (maximum unsigned 32-bit integer)
-    ori     $t0, 0xffff
-    ori     $t1, $0, 1          # B = 1
-    addu    $t2, $t0, $t1       # C = A + B (simulate overflow)
-    sltu    $v0, $t2, $t0       # D = 1 if overflow (C < A)
-
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

cannon/mipsevm/tests/open_mips_tests/test/sub_overflow_panic.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    lui     $t0, 0x7fff         # A = 0x7fffffff (maximum positive 32-bit integer)
-    ori     $t0, 0xffff
-    lui     $t1, 0xffff         # B = 0xffffffff (-1)
-    ori     $t1, 0xffff
-    sub     $t2, $t0, $t1       # C = A - B = 0x7fffffff - (-1) = 0x80000000 (overflow)
-
-    # Unreachable...
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

cannon/mipsevm/tests/open_mips_tests/test/sub_underflow_panic.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    lui     $t0, 0x8000         # A = 0x80000000 (minimum negative 32-bit integer)
-    ori     $t0, 0x0000
-    ori     $t1, $0, 1          # B = 1
-    sub     $t2, $t0, $t1       # C = A - B = 0x80000000 - 1 (underflow)
-
-    # Unreachable...
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

cannon/mipsevm/tests/open_mips_tests/test/subu_underflow.asm

-    .section .test, "x"
-    .balign 4
-    .set    noreorder
-    .global test
-    .ent    test
-test:
-    lui     $s0, 0xbfff         # Load the base address 0xbffffff0
-    ori     $s0, 0xfff0
-    ori     $s1, $0, 1          # Prepare the 'done' status
-
-    #### Test code start ####
-
-    ori     $t0, $0, 1          # A = 1
-    ori     $t1, $0, 2          # B = 2
-    subu    $t2, $t0, $t1       # C = A - B = 0xFFFFFFFF
-    sltu    $v0, $t0, $t1       # D = 1 if underflow occurred (A < B)
-
-    #### Test code end ####
-
-    sw      $v0, 8($s0)         # Set the test result
-    sw      $s1, 4($s0)         # Set 'done'
-
-$done:
-    jr      $ra
-    nop
-
-    .end test

packages/contracts-bedrock/semver-lock.json

@@ -140,11 +140,11 @@
     "sourceCodeHash": "0x3ff4a3f21202478935412d47fd5ef7f94a170402ddc50e5c062013ce5544c83f"
   },
   "src/cannon/MIPS.sol": {
-    "initCodeHash": "0xc783f01a426b889cd80d242cf01901fc34c595e59e74d50e3a0a8cb1fa226b3f",
+    "initCodeHash": "0x328f14e6c171957a5225378f0b49e3dd5e92c6ddc815552216ce066415bf972a",
     "sourceCodeHash": "0xfa6e6eacba6be2c9489f828f8a50dda40565eef5c73a2cf8e274e1fd4410d38a"
   },
   "src/cannon/MIPS2.sol": {
-    "initCodeHash": "0xeac747751362183e6e0e4caa34f07284823449867897a39bd036db5ea189e2c7",
+    "initCodeHash": "0x69bfafb485944e36f95a1123e0da5c7da09cde23a216d0402d3219d2a8df410d",
     "sourceCodeHash": "0x115bd6a4c4d77ed210dfd468675b409fdae9f79b932063c138f0765ba9063462"
   },
   "src/cannon/PreimageOracle.sol": {

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

@@ -364,12 +364,7 @@ library MIPSInstructions {
                 // The rest includes transformed R-type arith imm instructions
                 // add
                 else if (_fun == 0x20) {
-                    int32 rs = int32(_rs);
-                    int32 rt = int32(_rt);
-                    int32 res = rs + rt;
-                    require(!(rs > 0 && rt > 0 && res <= 0), "MIPS: add overflow");
-                    require(!(rs < 0 && rt < 0 && res >= 0), "MIPS: add underflow");
-                    return uint32(res);
+                    return (_rs + _rt);
                 }
                 // addu
                 else if (_fun == 0x21) {
@@ -377,12 +372,7 @@ library MIPSInstructions {
                 }
                 // sub
                 else if (_fun == 0x22) {
-                    int32 rs = int32(_rs);
-                    int32 rt = int32(_rt);
-                    int32 res = rs - rt;
-                    require(!(rs > 0 && rt < 0 && res <= 0), "MIPS: sub overflow");
-                    require(!(rs < 0 && rt > 0 && res >= 0), "MIPS: sub underflow");
-                    return uint32(res);
+                    return (_rs - _rt);
                 }
                 // subu
                 else if (_fun == 0x23) {

packages/contracts-bedrock/test/kontrol/proofs/utils/DeploymentSummary.sol

@@ -27,7 +27,7 @@ contract DeploymentSummary is DeploymentSummaryCode {
     address internal constant l1StandardBridgeProxyAddress = 0x20A42a5a785622c6Ba2576B2D6e924aA82BFA11D;
     address internal constant l2OutputOracleAddress = 0x19652082F846171168Daf378C4fD3ee85a0D4A60;
     address internal constant l2OutputOracleProxyAddress = 0x39Af23E00F1e662025aA01b0cEdA19542B78DF99;
-    address internal constant mipsAddress = 0xcFf3d2300Bf09462BBA3D23EF284a5C60Ef7c187;
+    address internal constant mipsAddress = 0xD9377D0e45e94F9928F419BfFF5097E65A01630B;
     address internal constant optimismMintableERC20FactoryAddress = 0x39Aea2Dd53f2d01c15877aCc2791af6BDD7aD567;
     address internal constant optimismMintableERC20FactoryProxyAddress = 0xc7B87b2b892EA5C3CfF47168881FE168C00377FB;
     address internal constant optimismPortalAddress = 0xbdD90485FCbcac869D5b5752179815a3103d8131;

packages/contracts-bedrock/test/kontrol/proofs/utils/DeploymentSummaryFaultProofs.sol

@@ -27,7 +27,7 @@ contract DeploymentSummaryFaultProofs is DeploymentSummaryFaultProofsCode {
     address internal constant l1StandardBridgeProxyAddress = 0x20A42a5a785622c6Ba2576B2D6e924aA82BFA11D;
     address internal constant l2OutputOracleAddress = 0x19652082F846171168Daf378C4fD3ee85a0D4A60;
     address internal constant l2OutputOracleProxyAddress = 0x39Af23E00F1e662025aA01b0cEdA19542B78DF99;
-    address internal constant mipsAddress = 0xcFf3d2300Bf09462BBA3D23EF284a5C60Ef7c187;
+    address internal constant mipsAddress = 0xD9377D0e45e94F9928F419BfFF5097E65A01630B;
     address internal constant optimismMintableERC20FactoryAddress = 0x39Aea2Dd53f2d01c15877aCc2791af6BDD7aD567;
     address internal constant optimismMintableERC20FactoryProxyAddress = 0xc7B87b2b892EA5C3CfF47168881FE168C00377FB;
     address internal constant optimismPortalAddress = 0xbdD90485FCbcac869D5b5752179815a3103d8131;