From 5b6d8db53998f995fb92cba04b159a49dd478bb8 Mon Sep 17 00:00:00 2001 From: titzer Date: Mon, 8 Feb 2016 18:43:24 +0100 Subject: Add basic operators. --- BinaryEncoding.md | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-) (limited to 'BinaryEncoding.md') diff --git a/BinaryEncoding.md b/BinaryEncoding.md index 5af6dbf..c8e5052 100644 --- a/BinaryEncoding.md +++ b/BinaryEncoding.md @@ -199,13 +199,41 @@ first byte, before the child nodes. | Name | Opcode | Immediate | Description | | ---- | ---- | ---- | ---- | | `nop` | `0x00` | | no operation | -| `block` | `0x01` | count = `varuint32` | a sequence of expressions, the last of which yields a value | -| `loop` | `0x02` | count = `varuint32` | a block which can also form control flow loops | +| `block` | `0x01` | count = `uint8` | a sequence of expressions, the last of which yields a value | +| `loop` | `0x02` | count = `uint8` | a block which can also form control flow loops | | `if` | `0x03` | | high-level one-armed if | | `if_else` | `0x04` | | high-level two-armed if | | `select` | `0x05` | | select one of two values based on condition | | `br` | `0x06` | relative_depth = `uint8` | break that targets a outer nested block | | `br_if` | `0x07` | relative_depth = `uint8` | conditional break that targets a outer nested block | -| `tableswitch` | 0x08 | `tableswitch_operand` | tableswitch control flow construct | -| `return` | 0x14 | | return zero or one value from this function | -| `unreachable` | 0x15 | | trap immediately | +| `tableswitch` | `0x08` | see below | tableswitch control flow construct | +| `return` | `0x14` | | return zero or one value from this function | +| `unreachable` | `0x15` | | trap immediately | + +The `tableswitch` operator has as complex immediate operand which is encoded as follows: + +| Field | Type | Description | +| ---- | ---- | ---- | +| case_count | `uint16` | number of cases in the case_table | +| target_count | `uint16` | number of targets in the target_table | +| target_table | `uint16*` | target entries where
`>= 0x800` indicates an outer block to which to break
`<= 0x8000` indicates a case to which to jump | + +The table switch operator is then immediately followed by `case_count` case expressions which by default fall through to each other. + +## Basic operators +| Name | Opcode | Immediate | Description | +| ---- | ---- | ---- | ---- | +| `i8.const` | `0x09` | value = `uint8` | a constant value, signed extended to type `i32` | +| `i32.const` | `0x0a` | value = `uint32` | a constant value interpreted as `i32` | +| `i64.const` | `0x0b` | value = `uint64` | a constant value interpreted as `i64` | +| `f64.const` | `0x0c` | value = `uint64` | a constant value interpreted as `f64` | +| `f32.const` | `0x0d` | value = `uint32` | a constant value interpreted as `f32` | +| `get_local` | `0x0e` | local_index = `varuint32` | read a local variable or parameter | +| `set_local` | `0x0f` | local_index = `varuint32` | write a local variable or parameter | +| `load_global` | `0x10` | index = `varuint32` | * nonstandard internal opcode | +| `store_global` | `0x11` | index = `varuint32` | * nonstandard internal opcode | +| `call_function` | `0x12` | function_index = `varuint32` | call a function by its index | +| `call_indirect` | `0x13` | signature_index = `varuint32` | call a function indirect with an expected signature | + + + -- cgit v1.2.3