|  | //===- 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 | 
|  | /// WebAssembly control-flow code-gen constructs. | 
|  | /// | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | let Defs = [ARGUMENTS] in { | 
|  |  | 
|  | let isBranch = 1, isTerminator = 1, hasCtrlDep = 1 in { | 
|  | // The condition operand is a boolean value which WebAssembly represents as i32. | 
|  | defm BR_IF : I<(outs), (ins bb_op:$dst, I32:$cond), | 
|  | (outs), (ins bb_op:$dst), | 
|  | [(brcond I32:$cond, bb:$dst)], | 
|  | "br_if   \t$dst, $cond", "br_if   \t$dst", 0x0d>; | 
|  | let isCodeGenOnly = 1 in | 
|  | defm BR_UNLESS : I<(outs), (ins bb_op:$dst, I32:$cond), | 
|  | (outs), (ins bb_op:$dst), []>; | 
|  | let isBarrier = 1 in { | 
|  | defm BR   : NRI<(outs), (ins bb_op:$dst), | 
|  | [(br bb:$dst)], | 
|  | "br      \t$dst", 0x0c>; | 
|  | } // isBarrier = 1 | 
|  | } // isBranch = 1, isTerminator = 1, hasCtrlDep = 1 | 
|  |  | 
|  | } // Defs = [ARGUMENTS] | 
|  |  | 
|  | def : Pat<(brcond (i32 (setne I32:$cond, 0)), bb:$dst), | 
|  | (BR_IF bb_op:$dst, I32:$cond)>; | 
|  | def : Pat<(brcond (i32 (seteq I32:$cond, 0)), bb:$dst), | 
|  | (BR_UNLESS bb_op:$dst, I32:$cond)>; | 
|  |  | 
|  | let Defs = [ARGUMENTS] in { | 
|  |  | 
|  | // TODO: SelectionDAG's lowering insists on using a pointer as the index for | 
|  | // jump tables, so in practice we don't ever use BR_TABLE_I64 in wasm32 mode | 
|  | // currently. | 
|  | // Set TSFlags{0} to 1 to indicate that the variable_ops are immediates. | 
|  | // Set TSFlags{1} to 1 to indicate that the immediates represent labels. | 
|  | // FIXME: this can't inherit from I<> since there is no way to inherit from a | 
|  | // multiclass and still have the let statements. | 
|  | let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in { | 
|  | def BR_TABLE_I32 : NI<(outs), (ins I32:$index, variable_ops), | 
|  | [(WebAssemblybr_table I32:$index)], 0, | 
|  | "br_table \t$index", 0x0e> { | 
|  | let TSFlags{0} = 1; | 
|  | let TSFlags{1} = 1; | 
|  | } | 
|  | def BR_TABLE_I32_S : NI<(outs), (ins I32:$index), | 
|  | [], 1, | 
|  | "br_table \t$index", 0x0e> { | 
|  | let TSFlags{0} = 1; | 
|  | let TSFlags{1} = 1; | 
|  | } | 
|  | def BR_TABLE_I64 : NI<(outs), (ins I64:$index, variable_ops), | 
|  | [(WebAssemblybr_table I64:$index)], 0, | 
|  | "br_table \t$index"> { | 
|  | let TSFlags{0} = 1; | 
|  | let TSFlags{1} = 1; | 
|  | } | 
|  | def BR_TABLE_I64_S : NI<(outs), (ins I64:$index), | 
|  | [], 1, | 
|  | "br_table \t$index"> { | 
|  | let TSFlags{0} = 1; | 
|  | let TSFlags{1} = 1; | 
|  | } | 
|  | } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 | 
|  |  | 
|  | // This is technically a control-flow instruction, since all it affects is the | 
|  | // IP. | 
|  | defm NOP : NRI<(outs), (ins), [], "nop", 0x01>; | 
|  |  | 
|  | // Placemarkers to indicate the start or end of a block or loop scope. | 
|  | // These use/clobber VALUE_STACK to prevent them from being moved into the | 
|  | // middle of an expression tree. | 
|  | let Uses = [VALUE_STACK], Defs = [VALUE_STACK] in { | 
|  | defm BLOCK     : NRI<(outs), (ins Signature:$sig), [], "block   \t$sig", 0x02>; | 
|  | defm LOOP      : NRI<(outs), (ins Signature:$sig), [], "loop    \t$sig", 0x03>; | 
|  |  | 
|  | // END_BLOCK, END_LOOP, and END_FUNCTION are represented with the same opcode in | 
|  | // wasm. | 
|  | defm END_BLOCK : NRI<(outs), (ins), [], "end_block", 0x0b>; | 
|  | defm END_LOOP  : NRI<(outs), (ins), [], "end_loop", 0x0b>; | 
|  | let isTerminator = 1, isBarrier = 1 in | 
|  | defm END_FUNCTION : NRI<(outs), (ins), [], "end_function", 0x0b>; | 
|  | } // Uses = [VALUE_STACK], Defs = [VALUE_STACK] | 
|  |  | 
|  | multiclass RETURN<WebAssemblyRegClass vt> { | 
|  | defm RETURN_#vt : I<(outs), (ins vt:$val), (outs), (ins), | 
|  | [(WebAssemblyreturn vt:$val)], | 
|  | "return  \t$val", "return", 0x0f>; | 
|  | // Equivalent to RETURN_#vt, for use at the end of a function when wasm | 
|  | // semantics return by falling off the end of the block. | 
|  | let isCodeGenOnly = 1 in | 
|  | defm FALLTHROUGH_RETURN_#vt : I<(outs), (ins vt:$val), (outs), (ins), []>; | 
|  | } | 
|  |  | 
|  | multiclass SIMD_RETURN<ValueType vt> { | 
|  | defm RETURN_#vt : SIMD_I<(outs), (ins V128:$val), (outs), (ins), | 
|  | [(WebAssemblyreturn (vt V128:$val))], | 
|  | "return  \t$val", "return", 0x0f>; | 
|  | // Equivalent to RETURN_#vt, for use at the end of a function when wasm | 
|  | // semantics return by falling off the end of the block. | 
|  | let isCodeGenOnly = 1 in | 
|  | defm FALLTHROUGH_RETURN_#vt : SIMD_I<(outs), (ins V128:$val), (outs), (ins), | 
|  | []>; | 
|  | } | 
|  |  | 
|  | let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in { | 
|  |  | 
|  | let isReturn = 1 in { | 
|  | defm "": RETURN<I32>; | 
|  | defm "": RETURN<I64>; | 
|  | defm "": RETURN<F32>; | 
|  | defm "": RETURN<F64>; | 
|  | defm "": RETURN<EXCEPT_REF>; | 
|  | defm "": SIMD_RETURN<v16i8>; | 
|  | defm "": SIMD_RETURN<v8i16>; | 
|  | defm "": SIMD_RETURN<v4i32>; | 
|  | defm "": SIMD_RETURN<v4f32>; | 
|  |  | 
|  | defm RETURN_VOID : NRI<(outs), (ins), [(WebAssemblyreturn)], "return", 0x0f>; | 
|  |  | 
|  | // This is to RETURN_VOID what FALLTHROUGH_RETURN_#vt is to RETURN_#vt. | 
|  | let isCodeGenOnly = 1 in | 
|  | defm FALLTHROUGH_RETURN_VOID : NRI<(outs), (ins), []>; | 
|  | } // isReturn = 1 | 
|  |  | 
|  | defm UNREACHABLE : NRI<(outs), (ins), [(trap)], "unreachable", 0x00>; | 
|  | } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 | 
|  |  | 
|  | //===----------------------------------------------------------------------===// | 
|  | // Exception handling instructions | 
|  | //===----------------------------------------------------------------------===// | 
|  |  | 
|  | let Predicates = [HasExceptionHandling] in { | 
|  |  | 
|  | // Throwing an exception: throw / rethrow | 
|  | let isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 in { | 
|  | defm THROW_I32 : I<(outs), (ins i32imm:$tag, I32:$val), | 
|  | (outs), (ins i32imm:$tag), | 
|  | [(int_wasm_throw imm:$tag, I32:$val)], | 
|  | "throw   \t$tag, $val", "throw   \t$tag", | 
|  | 0x08>; | 
|  | defm THROW_I64 : I<(outs), (ins i32imm:$tag, I64:$val), | 
|  | (outs), (ins i32imm:$tag), | 
|  | [(int_wasm_throw imm:$tag, I64:$val)], | 
|  | "throw   \t$tag, $val", "throw   \t$tag", | 
|  | 0x08>; | 
|  | defm RETHROW : NRI<(outs), (ins bb_op:$dst), [], "rethrow \t$dst", 0x09>; | 
|  | let isCodeGenOnly = 1 in | 
|  | // This is used when the destination for rethrow is the caller function. This | 
|  | // will be converted to a rethrow in CFGStackify. | 
|  | defm RETHROW_TO_CALLER : NRI<(outs), (ins), [], "rethrow">; | 
|  | } // isTerminator = 1, hasCtrlDep = 1, isBarrier = 1 | 
|  |  | 
|  | // Region within which an exception is caught: try / end_try | 
|  | let Uses = [VALUE_STACK], Defs = [VALUE_STACK] in { | 
|  | defm TRY     : NRI<(outs), (ins Signature:$sig), [], "try     \t$sig", 0x06>; | 
|  | defm END_TRY : NRI<(outs), (ins), [], "end_try", 0x0b>; | 
|  | } // Uses = [VALUE_STACK], Defs = [VALUE_STACK] | 
|  |  | 
|  | // Catching an exception: catch / catch_all | 
|  | let hasCtrlDep = 1 in { | 
|  | defm CATCH_I32 : I<(outs I32:$dst), (ins i32imm:$tag), | 
|  | (outs), (ins i32imm:$tag), | 
|  | [(set I32:$dst, (int_wasm_catch imm:$tag))], | 
|  | "i32.catch   \t$dst, $tag", "i32.catch   \t$tag", 0x07>; | 
|  | defm CATCH_I64 : I<(outs I64:$dst), (ins i32imm:$tag), | 
|  | (outs), (ins i32imm:$tag), | 
|  | [(set I64:$dst, (int_wasm_catch imm:$tag))], | 
|  | "i64.catch   \t$dst, $tag", "i64.catch   \t$tag", 0x07>; | 
|  | defm CATCH_ALL : NRI<(outs), (ins), [], "catch_all", 0x05>; | 
|  | } | 
|  |  | 
|  | // Pseudo instructions: cleanupret / catchret | 
|  | // They are not return instructions in wasm, but setting 'isReturn' to true as | 
|  | // in X86 is necessary for computing EH scope membership. | 
|  | let isTerminator = 1, hasSideEffects = 1, isBarrier = 1, hasCtrlDep = 1, | 
|  | isCodeGenOnly = 1, isReturn = 1 in { | 
|  | defm CLEANUPRET : NRI<(outs), (ins), [(cleanupret)], "", 0>; | 
|  | defm CATCHRET : NRI<(outs), (ins bb_op:$dst, bb_op:$from), | 
|  | [(catchret bb:$dst, bb:$from)], "", 0>; | 
|  | } | 
|  | } | 
|  |  | 
|  | } // Defs = [ARGUMENTS] |