1 //===- WebAssemblyInstrControl.td-WebAssembly control-flow ------*- tablegen -*-
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
10 /// WebAssembly control-flow code-gen constructs.
12 //===----------------------------------------------------------------------===//
14 let isBranch = 1, isTerminator = 1, hasCtrlDep = 1 in {
15 // The condition operand is a boolean value which WebAssembly represents as i32.
16 defm BR_IF : I<(outs), (ins bb_op:$dst, I32:$cond),
17 (outs), (ins bb_op:$dst),
18 [(brcond I32:$cond, bb:$dst)],
19 "br_if \t$dst, $cond", "br_if \t$dst", 0x0d>;
20 let isCodeGenOnly = 1 in
21 defm BR_UNLESS : I<(outs), (ins bb_op:$dst, I32:$cond),
22 (outs), (ins bb_op:$dst), []>;
24 defm BR : NRI<(outs), (ins bb_op:$dst),
27 } // isBranch = 1, isTerminator = 1, hasCtrlDep = 1
29 def : Pat<(brcond (i32 (setne I32:$cond, 0)), bb:$dst),
30 (BR_IF bb_op:$dst, I32:$cond)>;
31 def : Pat<(brcond (i32 (seteq I32:$cond, 0)), bb:$dst),
32 (BR_UNLESS bb_op:$dst, I32:$cond)>;
34 // A list of branch targets enclosed in {} and separated by comma.
35 // Used by br_table only.
36 def BrListAsmOperand : AsmOperandClass { let Name = "BrList"; }
37 let OperandNamespace = "WebAssembly", OperandType = "OPERAND_BRLIST" in
38 def brlist : Operand<i32> {
39 let ParserMatchClass = BrListAsmOperand;
40 let PrintMethod = "printBrList";
43 // TODO: SelectionDAG's lowering insists on using a pointer as the index for
44 // jump tables, so in practice we don't ever use BR_TABLE_I64 in wasm32 mode
46 let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in {
47 defm BR_TABLE_I32 : I<(outs), (ins I32:$index, variable_ops),
48 (outs), (ins brlist:$brl),
49 [(WebAssemblybr_table I32:$index)],
50 "br_table \t$index", "br_table \t$brl",
52 defm BR_TABLE_I64 : I<(outs), (ins I64:$index, variable_ops),
53 (outs), (ins brlist:$brl),
54 [(WebAssemblybr_table I64:$index)],
55 "br_table \t$index", "br_table \t$brl",
57 } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1
59 // This is technically a control-flow instruction, since all it affects is the
61 defm NOP : NRI<(outs), (ins), [], "nop", 0x01>;
63 // Placemarkers to indicate the start or end of a block or loop scope.
64 // These use/clobber VALUE_STACK to prevent them from being moved into the
65 // middle of an expression tree.
66 let Uses = [VALUE_STACK], Defs = [VALUE_STACK] in {
67 defm BLOCK : NRI<(outs), (ins Signature:$sig), [], "block \t$sig", 0x02>;
68 defm LOOP : NRI<(outs), (ins Signature:$sig), [], "loop \t$sig", 0x03>;
70 defm IF : I<(outs), (ins Signature:$sig, I32:$cond),
71 (outs), (ins Signature:$sig),
72 [], "if \t$sig, $cond", "if \t$sig", 0x04>;
73 defm ELSE : NRI<(outs), (ins), [], "else", 0x05>;
75 // END_BLOCK, END_LOOP, END_IF and END_FUNCTION are represented with the same
77 defm END_BLOCK : NRI<(outs), (ins), [], "end_block", 0x0b>;
78 defm END_LOOP : NRI<(outs), (ins), [], "end_loop", 0x0b>;
79 defm END_IF : NRI<(outs), (ins), [], "end_if", 0x0b>;
80 // Generic instruction, for disassembler.
81 let IsCanonical = 1 in
82 defm END : NRI<(outs), (ins), [], "end", 0x0b>;
83 let isTerminator = 1, isBarrier = 1 in
84 defm END_FUNCTION : NRI<(outs), (ins), [], "end_function", 0x0b>;
85 } // Uses = [VALUE_STACK], Defs = [VALUE_STACK]
87 multiclass RETURN<WebAssemblyRegClass vt> {
88 defm RETURN_#vt : I<(outs), (ins vt:$val), (outs), (ins),
89 [(WebAssemblyreturn vt:$val)],
90 "return \t$val", "return", 0x0f>;
91 // Equivalent to RETURN_#vt, for use at the end of a function when wasm
92 // semantics return by falling off the end of the block.
93 let isCodeGenOnly = 1 in
94 defm FALLTHROUGH_RETURN_#vt : I<(outs), (ins vt:$val), (outs), (ins), []>;
97 multiclass SIMD_RETURN<ValueType vt> {
98 defm RETURN_#vt : I<(outs), (ins V128:$val), (outs), (ins),
99 [(WebAssemblyreturn (vt V128:$val))],
100 "return \t$val", "return", 0x0f>,
101 Requires<[HasSIMD128]>;
102 // Equivalent to RETURN_#vt, for use at the end of a function when wasm
103 // semantics return by falling off the end of the block.
104 let isCodeGenOnly = 1 in
105 defm FALLTHROUGH_RETURN_#vt : I<(outs), (ins V128:$val), (outs), (ins),
107 Requires<[HasSIMD128]>;
110 let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in {
112 let isReturn = 1 in {
113 defm "": RETURN<I32>;
114 defm "": RETURN<I64>;
115 defm "": RETURN<F32>;
116 defm "": RETURN<F64>;
117 defm "": RETURN<EXNREF>;
118 defm "": SIMD_RETURN<v16i8>;
119 defm "": SIMD_RETURN<v8i16>;
120 defm "": SIMD_RETURN<v4i32>;
121 defm "": SIMD_RETURN<v2i64>;
122 defm "": SIMD_RETURN<v4f32>;
123 defm "": SIMD_RETURN<v2f64>;
125 defm RETURN_VOID : NRI<(outs), (ins), [(WebAssemblyreturn)], "return", 0x0f>;
127 // This is to RETURN_VOID what FALLTHROUGH_RETURN_#vt is to RETURN_#vt.
128 let isCodeGenOnly = 1 in
129 defm FALLTHROUGH_RETURN_VOID : NRI<(outs), (ins), []>;
132 defm UNREACHABLE : NRI<(outs), (ins), [(trap)], "unreachable", 0x00>;
133 } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1
135 //===----------------------------------------------------------------------===//
136 // Exception handling instructions
137 //===----------------------------------------------------------------------===//
139 let Predicates = [HasExceptionHandling] in {
141 // Throwing an exception: throw / rethrow
142 let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in {
143 defm THROW : I<(outs), (ins event_op:$tag, variable_ops),
144 (outs), (ins event_op:$tag),
145 [(WebAssemblythrow (WebAssemblywrapper texternalsym:$tag))],
146 "throw \t$tag", "throw \t$tag", 0x08>;
147 defm RETHROW : I<(outs), (ins EXNREF:$exn), (outs), (ins), [],
148 "rethrow \t$exn", "rethrow", 0x09>;
149 // Pseudo instruction to be the lowering target of int_wasm_rethrow_in_catch
150 // intrinsic. Will be converted to the real rethrow instruction later.
152 defm RETHROW_IN_CATCH : NRI<(outs), (ins), [(int_wasm_rethrow_in_catch)],
153 "rethrow_in_catch", 0>;
154 } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1
156 // Region within which an exception is caught: try / end_try
157 let Uses = [VALUE_STACK], Defs = [VALUE_STACK] in {
158 defm TRY : NRI<(outs), (ins Signature:$sig), [], "try \t$sig", 0x06>;
159 defm END_TRY : NRI<(outs), (ins), [], "end_try", 0x0b>;
160 } // Uses = [VALUE_STACK], Defs = [VALUE_STACK]
162 // Catching an exception: catch / extract_exception
163 let hasCtrlDep = 1, hasSideEffects = 1 in
164 defm CATCH : I<(outs EXNREF:$dst), (ins), (outs), (ins), [],
165 "catch \t$dst", "catch", 0x07>;
167 // Querying / extracing exception: br_on_exn
168 // br_on_exn queries an exnref to see if it matches the corresponding exception
169 // tag index. If true it branches to the given label and pushes the
170 // corresponding argument values of the exception onto the stack.
171 let isBranch = 1, isTerminator = 1, hasCtrlDep = 1 in
172 defm BR_ON_EXN : I<(outs), (ins bb_op:$dst, event_op:$tag, EXNREF:$exn),
173 (outs), (ins bb_op:$dst, event_op:$tag), [],
174 "br_on_exn \t$dst, $tag, $exn", "br_on_exn \t$dst, $tag",
176 // This is a pseudo instruction that simulates popping a value from stack, which
177 // has been pushed by br_on_exn
178 let isCodeGenOnly = 1, hasSideEffects = 1 in
179 defm EXTRACT_EXCEPTION_I32 : NRI<(outs I32:$dst), (ins),
180 [(set I32:$dst, (int_wasm_extract_exception))],
181 "extract_exception\t$dst">;
183 // Pseudo instructions: cleanupret / catchret
184 let isTerminator = 1, hasSideEffects = 1, isBarrier = 1, hasCtrlDep = 1,
185 isPseudo = 1, isEHScopeReturn = 1 in {
186 defm CLEANUPRET : NRI<(outs), (ins), [(cleanupret)], "cleanupret", 0>;
187 defm CATCHRET : NRI<(outs), (ins bb_op:$dst, bb_op:$from),
188 [(catchret bb:$dst, bb:$from)], "catchret", 0>;
189 } // isTerminator = 1, hasSideEffects = 1, isBarrier = 1, hasCtrlDep = 1,
190 // isPseudo = 1, isEHScopeReturn = 1
191 } // Predicates = [HasExceptionHandling]