llvm/lib/Target/WebAssembly/WebAssemblyInstrControl.td
Dan Gohman d39c38d2bc [WebAssembly] Reapply r252858, with svn add for the new file.
Switch to MC for instruction printing.

This encompasses several changes which are all interconnected:
 - Use the MC framework for printing almost all instructions.
 - AsmStrings are now live.
 - This introduces an indirection between LLVM vregs and WebAssembly registers,
   and a new pass, WebAssemblyRegNumbering, for computing a basic the mapping.
   This addresses some basic issues with argument registers and unused registers.
 - The way ARGUMENT instructions are handled no longer generates redundant
   get_local+set_local for every argument.

This also changes the assembly syntax somewhat; most notably, MC's printing
does not use sigils on label names, so those are no longer present, and
push/pop now have a sigil to keep them unambiguous.

The usage of set_local/get_local/$push/$pop will continue to evolve
significantly. This patch is just one step of a larger change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252910 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-12 17:04:33 +00:00

70 lines
2.6 KiB
TableGen

//===- WebAssemblyInstrControl.td-WebAssembly control-flow ------*- tablegen -*-
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief WebAssembly control-flow code-gen constructs.
///
//===----------------------------------------------------------------------===//
/*
* TODO(jfb): Add the following.
*
* block: a fixed-length sequence of statements
* if: if statement
* do_while: do while statement, basically a loop with a conditional branch
* forever: infinite loop statement (like while (1)), basically an unconditional
* branch (back to the top of the loop)
* continue: continue to start of nested loop
* break: break to end from nested loop or block
* switch: switch statement with fallthrough
*/
let isBranch = 1, isTerminator = 1, hasCtrlDep = 1 in {
def BR_IF_ : I<(outs), (ins bb_op:$dst, I32:$a),
[(brcond I32:$a, bb:$dst)],
"br_if $dst, $a">;
let isBarrier = 1 in {
def BR : I<(outs), (ins bb_op:$dst),
[(br bb:$dst)],
"br $dst">;
} // isBarrier = 1
} // isBranch = 1, isTerminator = 1, hasCtrlDep = 1
// TODO: SelectionDAG's lowering insists on using a pointer as the index for
// jump tables, so in practice we don't ever use SWITCH_I64 in wasm32 mode
// currently.
let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in {
def SWITCH_I32 : I<(outs), (ins I32:$index, variable_ops),
[(WebAssemblyswitch I32:$index)],
"switch $index">;
def SWITCH_I64 : I<(outs), (ins I64:$index, variable_ops),
[(WebAssemblyswitch I64:$index)],
"switch $index">;
} // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1
// Placemarkers to indicate the start of a block or loop scope.
def BLOCK : I<(outs), (ins bb_op:$dst), [], "block $dst">;
def LOOP : I<(outs), (ins bb_op:$dst), [], "loop $dst">;
multiclass RETURN<WebAssemblyRegClass vt> {
def RETURN_#vt : I<(outs), (ins vt:$val), [(WebAssemblyreturn vt:$val)],
"return $val">;
}
let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in {
let isReturn = 1 in {
defm : RETURN<I32>;
defm : RETURN<I64>;
defm : RETURN<F32>;
defm : RETURN<F64>;
def RETURN_VOID : I<(outs), (ins), [(WebAssemblyreturn)], "return">;
} // isReturn = 1
def UNREACHABLE : I<(outs), (ins), [(trap)], "unreachable">;
} // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1