diff options
| -rw-r--r-- | llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp | 9 | ||||
| -rw-r--r-- | llvm/utils/TableGen/WebAssemblyStackifierEmitter.cpp | 13 |
2 files changed, 19 insertions, 3 deletions
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp index 0a58b9f47ac..3dca75dfefa 100644 --- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp +++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp @@ -285,8 +285,13 @@ static void removeRegisterOperands(const MachineInstr *MI, MCInst &OutMI) { static unsigned regInstructionToStackInstruction(unsigned OpCode) { // For most opcodes, this function could have been implemented as "return // OpCode + 1", but since table-gen alphabetically sorts them, this cannot be - // guaranteed (see e.g. BR and BR_IF), so we table-gen a giant switch - // statement instead. + // guaranteed (see e.g. BR and BR_IF). Instead we use a giant switch statement + // generated by a custom TableGen backend (WebAssemblyStackifierEmitter.cpp) + // that emits switch cases of the form + // + // case WebAssembly::RegisterInstr: return WebAssembly::StackInstr; + // + // for every pair of equivalent register and stack instructions. switch (OpCode) { default: llvm_unreachable( diff --git a/llvm/utils/TableGen/WebAssemblyStackifierEmitter.cpp b/llvm/utils/TableGen/WebAssemblyStackifierEmitter.cpp index de637e5be57..0b9741d22b8 100644 --- a/llvm/utils/TableGen/WebAssemblyStackifierEmitter.cpp +++ b/llvm/utils/TableGen/WebAssemblyStackifierEmitter.cpp @@ -17,6 +17,17 @@ namespace llvm { +// Find all register WebAssembly instructions and their corresponding stack +// instructions. For each pair, emit a switch case of the form +// +// case WebAssembly::RegisterInstr: return WebAssembly::StackInstr; +// +// For example, +// +// case WebAssembly::ADD_I32: return WebAssembly::ADD_I32_S; +// +// This is useful for converting instructions from their register form to their +// equivalent stack form. void EmitWebAssemblyStackifier(RecordKeeper &RK, raw_ostream &OS) { Record *InstrClass = RK.getClass("WebAssemblyInst"); for (auto &RecordPair : RK.getDefs()) { @@ -26,7 +37,7 @@ void EmitWebAssemblyStackifier(RecordKeeper &RK, raw_ostream &OS) { if (IsStackBased) continue; OS << " case WebAssembly::" << RecordPair.first << ": return " - << "WebAssembly::" << RecordPair.first << "_S; break;\n"; + << "WebAssembly::" << RecordPair.first << "_S;\n"; } } |
