[wasm] Fix codegen issue for i64.add and i64.sub on ia32

test/cctest/wasm/test-run-wasm-64.cc

Index: test/cctest/wasm/test-run-wasm-64.cc
diff --git a/test/cctest/wasm/test-run-wasm-64.cc b/test/cctest/wasm/test-run-wasm-64.cc
index e217bb8e71e09db7e09ac4f5afd08634e2427ced..e28273d3bed2617a021fc9b9e50dba1a19448d4d 100644
--- a/test/cctest/wasm/test-run-wasm-64.cc
+++ b/test/cctest/wasm/test-run-wasm-64.cc
@@ -136,6 +136,21 @@ WASM_EXEC_TEST(I64Add) {
   }
 }
 
+// The i64 add and subtract regression tests need a 64-bit value with a non-zero
+// upper half. This upper half was clobbering eax, leading to the function
+// returning 1 rather than 0.
+const int64_t kHasBit33On = 0x100000000;
+
+WASM_EXEC_TEST(Regress5800_Add) {
+  REQUIRE(I64Add);
+  WasmRunner<int32_t> r(execution_mode);
+  BUILD(r, WASM_BLOCK(WASM_BR_IF(0, WASM_I64_EQZ(WASM_I64_ADD(
+                                        WASM_I64V(0), WASM_I64V(kHasBit33On)))),
+                      WASM_RETURN1(WASM_I32V(0))),
+        WASM_I32V(0));
+  CHECK_EQ(0, r.Call());
+}
+
 WASM_EXEC_TEST(I64Sub) {
   REQUIRE(I64Sub);
   WasmRunner<int64_t, int64_t, int64_t> r(execution_mode);
@@ -145,6 +160,16 @@ WASM_EXEC_TEST(I64Sub) {
   }
 }
 
+WASM_EXEC_TEST(Regress5800_Sub) {
+  REQUIRE(I64Sub);
+  WasmRunner<int32_t> r(execution_mode);
+  BUILD(r, WASM_BLOCK(WASM_BR_IF(0, WASM_I64_EQZ(WASM_I64_SUB(
+                                        WASM_I64V(0), WASM_I64V(kHasBit33On)))),
+                      WASM_RETURN1(WASM_I32V(0))),
+        WASM_I32V(0));
+  CHECK_EQ(0, r.Call());
+}
+
 WASM_EXEC_TEST(I64AddUseOnlyLowWord) {
   REQUIRE(I64Add);
   REQUIRE(I32ConvertI64);