1 //===- WebAssemblyInstrControl.td-WebAssembly control-flow ------*- tablegen -*- 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 /// 10 /// \file 11 /// \brief WebAssembly control-flow code-gen constructs. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 let Defs = [ARGUMENTS] in { 16 17 let isBranch = 1, isTerminator = 1, hasCtrlDep = 1 in { 18 // The condition operand is a boolean value which WebAssembly represents as i32. 19 def BR_IF : I<(outs), (ins bb_op:$dst, I32:$cond), 20 [(brcond I32:$cond, bb:$dst)], 21 "br_if \t$dst, $cond">; 22 let isCodeGenOnly = 1 in 23 def BR_UNLESS : I<(outs), (ins bb_op:$dst, I32:$cond), [], 24 "br_unless\t$dst, $cond">; 25 let isBarrier = 1 in { 26 def BR : I<(outs), (ins bb_op:$dst), 27 [(br bb:$dst)], 28 "br \t$dst">; 29 } // isBarrier = 1 30 } // isBranch = 1, isTerminator = 1, hasCtrlDep = 1 31 32 } // Defs = [ARGUMENTS] 33 34 def : Pat<(brcond (i32 (setne I32:$cond, 0)), bb:$dst), 35 (BR_IF bb_op:$dst, I32:$cond)>; 36 def : Pat<(brcond (i32 (seteq I32:$cond, 0)), bb:$dst), 37 (BR_UNLESS bb_op:$dst, I32:$cond)>; 38 39 let Defs = [ARGUMENTS] in { 40 41 // TODO: SelectionDAG's lowering insists on using a pointer as the index for 42 // jump tables, so in practice we don't ever use BR_TABLE_I64 in wasm32 mode 43 // currently. 44 // Set TSFlags{0} to 1 to indicate that the variable_ops are immediates. 45 // Set TSFlags{1} to 1 to indicate that the immediates represent labels. 46 let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in { 47 def BR_TABLE_I32 : I<(outs), (ins I32:$index, variable_ops), 48 [(WebAssemblybr_table I32:$index)], 49 "br_table \t$index"> { 50 let TSFlags{0} = 1; 51 let TSFlags{1} = 1; 52 } 53 def BR_TABLE_I64 : I<(outs), (ins I64:$index, variable_ops), 54 [(WebAssemblybr_table I64:$index)], 55 "br_table \t$index"> { 56 let TSFlags{0} = 1; 57 let TSFlags{1} = 1; 58 } 59 } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 60 61 // Placemarkers to indicate the start or end of a block or loop scope. These 62 // use/clobber EXPR_STACK to prevent them from being moved into the middle of 63 // an expression tree. 64 let Uses = [EXPR_STACK], Defs = [EXPR_STACK] in { 65 def BLOCK : I<(outs), (ins), [], "block">; 66 def LOOP : I<(outs), (ins), [], "loop">; 67 def END_BLOCK : I<(outs), (ins), [], "end_block">; 68 def END_LOOP : I<(outs), (ins), [], "end_loop">; 69 } // Uses = [EXPR_STACK], Defs = [EXPR_STACK] 70 71 multiclass RETURN<WebAssemblyRegClass vt> { 72 def RETURN_#vt : I<(outs), (ins vt:$val), [(WebAssemblyreturn vt:$val)], 73 "return \t$val">; 74 // Equivalent to RETURN_#vt, for use at the end of a function when wasm 75 // semantics return by falling off the end of the block. 76 let isCodeGenOnly = 1 in 77 def FALLTHROUGH_RETURN_#vt : I<(outs), (ins vt:$val), []>; 78 } 79 80 let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in { 81 let isReturn = 1 in { 82 defm : RETURN<I32>; 83 defm : RETURN<I64>; 84 defm : RETURN<F32>; 85 defm : RETURN<F64>; 86 def RETURN_VOID : I<(outs), (ins), [(WebAssemblyreturn)], "return">; 87 88 // This is to RETURN_VOID what FALLTHROUGH_RETURN_#vt is to RETURN_#vt. 89 let isCodeGenOnly = 1 in 90 def FALLTHROUGH_RETURN_VOID : I<(outs), (ins), []>; 91 } // isReturn = 1 92 def UNREACHABLE : I<(outs), (ins), [(trap)], "unreachable">; 93 } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 94 95 } // Defs = [ARGUMENTS] 96
