Incorrect code emitted involving unreachable code.

[ghost]

The following code emits a single unreachable operator which does not appear correct. When $i1 is zero this function would return 1.

(module
 (func (param $i1 i32) (result i32)
   (if_else (get_local $i1)
     (block (unreachable))
     (i32.const 1))))

0000004: 02                                         ; WASM_SECTION_FUNCTIONS
0000005: 01                                         ; num functions
; function 0
0000006: 00                                         ; func flags
0000007: 0000                                       ; func signature index
0000009: 0000                                       ; func body size
000000b: 01                                         ; OPCODE_BLOCK
000000c: 01                                         ; num expressions
000000d: 15                                         ; OPCODE_UNREACHABLE
0000009: 0300                                       ; FIXUP func body size
000000e: 06                                         ; WASM_SECTION_END

Some discussion at WebAssembly/design#527

[binji]

Just tested this and got the following output:

0000000: 01                                         ; WASM_SECTION_SIGNATURES
0000001: 01                                         ; num signatures
; signature 0
0000002: 01                                         ; num params
0000003: 01                                         ; result_type
0000004: 01                                         ; param type
0000005: 02                                         ; WASM_SECTION_FUNCTIONS
0000006: 01                                         ; num functions
; function 0
0000007: 00                                         ; func flags
0000008: 0000                                       ; func signature index
000000a: 0000                                       ; func body size
000000c: 04                                         ; OPCODE_IF_THEN
000000d: 0e                                         ; OPCODE_GET_LOCAL
000000e: 00                                         ; remapped local index
000000f: 01                                         ; OPCODE_BLOCK
0000010: 01                                         ; num expressions
0000011: 15                                         ; OPCODE_UNREACHABLE
0000012: 09                                         ; OPCODE_I8_CONST
0000013: 01                                         ; u8 literal
000000a: 0800                                       ; FIXUP func body size
0000014: 06                                         ; WASM_SECTION_END

Looks right to me.

[ghost]

Sorry for the noise, my mix-up.