{"record":{"id":"6ed0bf8606274073","repo":"wasmerio/wasmer","slug":"currently-only-simd-instructions-are-mapped-to-the","errorCode":null,"errorMessage":"Currently only SIMD instructions are mapped to their return type; the following instruction is not mapped: {:?}","messagePattern":"Currently only SIMD instructions are mapped to their return type; the following instruction is not mapped: (.+?)","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"error","filePath":"lib/compiler-cranelift/src/translator/code_translator.rs","lineNumber":3687,"sourceCode":"        | Operator::F64x2Sqrt\n        | Operator::F64x2Add\n        | Operator::F64x2Sub\n        | Operator::F64x2Mul\n        | Operator::F64x2Div\n        | Operator::F64x2Min\n        | Operator::F64x2Max\n        | Operator::F64x2PMin\n        | Operator::F64x2PMax\n        | Operator::F64x2RelaxedMin\n        | Operator::F64x2RelaxedMax\n        | Operator::F64x2RelaxedMadd\n        | Operator::F64x2RelaxedNmadd\n        | Operator::F64x2Ceil\n        | Operator::F64x2Floor\n        | Operator::F64x2Trunc\n        | Operator::F64x2Nearest => F64X2,\n\n        _ => unimplemented!(\n            \"Currently only SIMD instructions are mapped to their return type; the \\\n             following instruction is not mapped: {:?}\",\n            operator\n        ),\n    }\n}\n\n/// Some SIMD operations only operate on I8X16 in CLIF; this will convert them to that type by\n/// adding a raw_bitcast if necessary.\nfn optionally_bitcast_vector(\n    value: Value,\n    needed_type: Type,\n    builder: &mut FunctionBuilder,\n) -> Value {\n    if builder.func.dfg.value_type(value) != needed_type {\n        builder.ins().bitcast(\n            needed_type,\n            MemFlagsData::new().with_endianness(ir::Endianness::Little),","sourceCodeStart":3669,"sourceCodeEnd":3705,"githubUrl":"https://github.com/wasmerio/wasmer/blob/8c4b9ee9d33fb2068863fbb3d328683e7e6ff7f5/lib/compiler-cranelift/src/translator/code_translator.rs#L3669-L3705","documentation":"Cranelift's internal type_of helper maps Wasm SIMD operators to their result WasmType for type inference during translation; it is only written to cover SIMD instructions. If a non-SIMD operator reaches it, it panics. This is an internal translation-table completeness guard, normally unreachable from user code.","triggerScenarios":"translate_operator calls type_of with an operator not present in the SIMD mapping (e.g. a scalar or newly added relaxed-simd instruction) — typically after a new Wasm proposal's opcodes are parsed but not yet added to the mapping.","commonSituations":"Using a cutting-edge Wasmer build with newly standardized relaxed SIMD/GC instructions whose type mapping lags; compiling modules that use very new opcodes with an older Wasmer version.","solutions":["Update Wasmer to a version that maps the offending instruction","Check whether the instruction requires an engine feature flag and enable it explicitly so the correct translation path runs","File a bug with the exact instruction name from the panic message","Downgrade/normalize the Wasm module (e.g. re-emit without the new opcodes via wasm-tools)"],"exampleFix":"// before\n_ => unimplemented!(\n    \"Currently only SIMD instructions are mapped to their return type; the \\\n     following instruction is not mapped: {:?}\",\n    operator\n),\n// after\nOperator::F32x4RelaxedSwizzle => F32X4, // add the missing opcode arm\n_ => unreachable!(\"type_of called with non-SIMD operator: {:?}\", operator),","handlingStrategy":"validation","validationCode":"// Before compiling, ensure the module's opcodes are supported by the installed Wasmer\n// e.g. reject unknown relaxed-SIMD proposals:\nlet features = Features { simd: true, relaxed_simd: false, ..Default::default() };\n// compiling with relaxed_simd disabled makes unknown relaxed opcodes a validation error, not a panic","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Enable only the SIMD feature flags your module actually needs","Keep Wasmer current when consuming modules using new Wasm proposals","Validate modules with wasm-tools/wasmparser before feeding them to the engine","Capture the offending instruction from the panic message and check the Wasmer issue tracker"],"tags":["rust","cranelift","wasm","simd","translator"],"backgroundTag":"unsupported-wasm-opcode","analyzedSha":"8c4b9ee9d33fb2068863fbb3d328683e7e6ff7f5","analyzedAt":"2026-09-01T23:06:31.009Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-09T06:17:21.866Z"}