lib/Target/WebAssembly/WebAssemblyUtilities.cpp

   1 //===-- WebAssemblyUtilities.cpp - WebAssembly Utility Functions ----------===//
   2 //
   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
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// This file implements several utility functions for WebAssembly.
  11 ///
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "WebAssemblyUtilities.h"
  15 #include "WebAssemblyMachineFunctionInfo.h"
  16 #include "llvm/CodeGen/MachineInstr.h"
  17 #include "llvm/CodeGen/MachineLoopInfo.h"
  18 using namespace llvm;
  19
  20 const char *const WebAssembly::ClangCallTerminateFn = "__clang_call_terminate";
  21 const char *const WebAssembly::CxaBeginCatchFn = "__cxa_begin_catch";
  22 const char *const WebAssembly::CxaRethrowFn = "__cxa_rethrow";
  23 const char *const WebAssembly::StdTerminateFn = "_ZSt9terminatev";
  24 const char *const WebAssembly::PersonalityWrapperFn =
  25     "_Unwind_Wasm_CallPersonality";
  26
  27 bool WebAssembly::isArgument(const MachineInstr &MI) {
  28   switch (MI.getOpcode()) {
  29   case WebAssembly::ARGUMENT_i32:
  30   case WebAssembly::ARGUMENT_i32_S:
  31   case WebAssembly::ARGUMENT_i64:
  32   case WebAssembly::ARGUMENT_i64_S:
  33   case WebAssembly::ARGUMENT_f32:
  34   case WebAssembly::ARGUMENT_f32_S:
  35   case WebAssembly::ARGUMENT_f64:
  36   case WebAssembly::ARGUMENT_f64_S:
  37   case WebAssembly::ARGUMENT_v16i8:
  38   case WebAssembly::ARGUMENT_v16i8_S:
  39   case WebAssembly::ARGUMENT_v8i16:
  40   case WebAssembly::ARGUMENT_v8i16_S:
  41   case WebAssembly::ARGUMENT_v4i32:
  42   case WebAssembly::ARGUMENT_v4i32_S:
  43   case WebAssembly::ARGUMENT_v2i64:
  44   case WebAssembly::ARGUMENT_v2i64_S:
  45   case WebAssembly::ARGUMENT_v4f32:
  46   case WebAssembly::ARGUMENT_v4f32_S:
  47   case WebAssembly::ARGUMENT_v2f64:
  48   case WebAssembly::ARGUMENT_v2f64_S:
  49     return true;
  50   default:
  51     return false;
  52   }
  53 }
  54
  55 bool WebAssembly::isCopy(const MachineInstr &MI) {
  56   switch (MI.getOpcode()) {
  57   case WebAssembly::COPY_I32:
  58   case WebAssembly::COPY_I32_S:
  59   case WebAssembly::COPY_I64:
  60   case WebAssembly::COPY_I64_S:
  61   case WebAssembly::COPY_F32:
  62   case WebAssembly::COPY_F32_S:
  63   case WebAssembly::COPY_F64:
  64   case WebAssembly::COPY_F64_S:
  65   case WebAssembly::COPY_V128:
  66   case WebAssembly::COPY_V128_S:
  67     return true;
  68   default:
  69     return false;
  70   }
  71 }
  72
  73 bool WebAssembly::isTee(const MachineInstr &MI) {
  74   switch (MI.getOpcode()) {
  75   case WebAssembly::TEE_I32:
  76   case WebAssembly::TEE_I32_S:
  77   case WebAssembly::TEE_I64:
  78   case WebAssembly::TEE_I64_S:
  79   case WebAssembly::TEE_F32:
  80   case WebAssembly::TEE_F32_S:
  81   case WebAssembly::TEE_F64:
  82   case WebAssembly::TEE_F64_S:
  83   case WebAssembly::TEE_V128:
  84   case WebAssembly::TEE_V128_S:
  85     return true;
  86   default:
  87     return false;
  88   }
  89 }
  90
  91 /// Test whether MI is a child of some other node in an expression tree.
  92 bool WebAssembly::isChild(const MachineInstr &MI,
  93                           const WebAssemblyFunctionInfo &MFI) {
  94   if (MI.getNumOperands() == 0)
  95     return false;
  96   const MachineOperand &MO = MI.getOperand(0);
  97   if (!MO.isReg() || MO.isImplicit() || !MO.isDef())
  98     return false;
  99   unsigned Reg = MO.getReg();
 100   return TargetRegisterInfo::isVirtualRegister(Reg) &&
 101          MFI.isVRegStackified(Reg);
 102 }
 103
 104 bool WebAssembly::isCallDirect(const MachineInstr &MI) {
 105   switch (MI.getOpcode()) {
 106   case WebAssembly::CALL_VOID:
 107   case WebAssembly::CALL_VOID_S:
 108   case WebAssembly::CALL_I32:
 109   case WebAssembly::CALL_I32_S:
 110   case WebAssembly::CALL_I64:
 111   case WebAssembly::CALL_I64_S:
 112   case WebAssembly::CALL_F32:
 113   case WebAssembly::CALL_F32_S:
 114   case WebAssembly::CALL_F64:
 115   case WebAssembly::CALL_F64_S:
 116   case WebAssembly::CALL_v16i8:
 117   case WebAssembly::CALL_v16i8_S:
 118   case WebAssembly::CALL_v8i16:
 119   case WebAssembly::CALL_v8i16_S:
 120   case WebAssembly::CALL_v4i32:
 121   case WebAssembly::CALL_v4i32_S:
 122   case WebAssembly::CALL_v2i64:
 123   case WebAssembly::CALL_v2i64_S:
 124   case WebAssembly::CALL_v4f32:
 125   case WebAssembly::CALL_v4f32_S:
 126   case WebAssembly::CALL_v2f64:
 127   case WebAssembly::CALL_v2f64_S:
 128   case WebAssembly::CALL_EXCEPT_REF:
 129   case WebAssembly::CALL_EXCEPT_REF_S:
 130     return true;
 131   default:
 132     return false;
 133   }
 134 }
 135
 136 bool WebAssembly::isCallIndirect(const MachineInstr &MI) {
 137   switch (MI.getOpcode()) {
 138   case WebAssembly::CALL_INDIRECT_VOID:
 139   case WebAssembly::CALL_INDIRECT_VOID_S:
 140   case WebAssembly::CALL_INDIRECT_I32:
 141   case WebAssembly::CALL_INDIRECT_I32_S:
 142   case WebAssembly::CALL_INDIRECT_I64:
 143   case WebAssembly::CALL_INDIRECT_I64_S:
 144   case WebAssembly::CALL_INDIRECT_F32:
 145   case WebAssembly::CALL_INDIRECT_F32_S:
 146   case WebAssembly::CALL_INDIRECT_F64:
 147   case WebAssembly::CALL_INDIRECT_F64_S:
 148   case WebAssembly::CALL_INDIRECT_v16i8:
 149   case WebAssembly::CALL_INDIRECT_v16i8_S:
 150   case WebAssembly::CALL_INDIRECT_v8i16:
 151   case WebAssembly::CALL_INDIRECT_v8i16_S:
 152   case WebAssembly::CALL_INDIRECT_v4i32:
 153   case WebAssembly::CALL_INDIRECT_v4i32_S:
 154   case WebAssembly::CALL_INDIRECT_v2i64:
 155   case WebAssembly::CALL_INDIRECT_v2i64_S:
 156   case WebAssembly::CALL_INDIRECT_v4f32:
 157   case WebAssembly::CALL_INDIRECT_v4f32_S:
 158   case WebAssembly::CALL_INDIRECT_v2f64:
 159   case WebAssembly::CALL_INDIRECT_v2f64_S:
 160   case WebAssembly::CALL_INDIRECT_EXCEPT_REF:
 161   case WebAssembly::CALL_INDIRECT_EXCEPT_REF_S:
 162     return true;
 163   default:
 164     return false;
 165   }
 166 }
 167
 168 unsigned WebAssembly::getCalleeOpNo(const MachineInstr &MI) {
 169   switch (MI.getOpcode()) {
 170   case WebAssembly::CALL_VOID:
 171   case WebAssembly::CALL_VOID_S:
 172   case WebAssembly::CALL_INDIRECT_VOID:
 173   case WebAssembly::CALL_INDIRECT_VOID_S:
 174     return 0;
 175   case WebAssembly::CALL_I32:
 176   case WebAssembly::CALL_I32_S:
 177   case WebAssembly::CALL_I64:
 178   case WebAssembly::CALL_I64_S:
 179   case WebAssembly::CALL_F32:
 180   case WebAssembly::CALL_F32_S:
 181   case WebAssembly::CALL_F64:
 182   case WebAssembly::CALL_F64_S:
 183   case WebAssembly::CALL_v16i8:
 184   case WebAssembly::CALL_v16i8_S:
 185   case WebAssembly::CALL_v8i16:
 186   case WebAssembly::CALL_v8i16_S:
 187   case WebAssembly::CALL_v4i32:
 188   case WebAssembly::CALL_v4i32_S:
 189   case WebAssembly::CALL_v2i64:
 190   case WebAssembly::CALL_v2i64_S:
 191   case WebAssembly::CALL_v4f32:
 192   case WebAssembly::CALL_v4f32_S:
 193   case WebAssembly::CALL_v2f64:
 194   case WebAssembly::CALL_v2f64_S:
 195   case WebAssembly::CALL_EXCEPT_REF:
 196   case WebAssembly::CALL_EXCEPT_REF_S:
 197   case WebAssembly::CALL_INDIRECT_I32:
 198   case WebAssembly::CALL_INDIRECT_I32_S:
 199   case WebAssembly::CALL_INDIRECT_I64:
 200   case WebAssembly::CALL_INDIRECT_I64_S:
 201   case WebAssembly::CALL_INDIRECT_F32:
 202   case WebAssembly::CALL_INDIRECT_F32_S:
 203   case WebAssembly::CALL_INDIRECT_F64:
 204   case WebAssembly::CALL_INDIRECT_F64_S:
 205   case WebAssembly::CALL_INDIRECT_v16i8:
 206   case WebAssembly::CALL_INDIRECT_v16i8_S:
 207   case WebAssembly::CALL_INDIRECT_v8i16:
 208   case WebAssembly::CALL_INDIRECT_v8i16_S:
 209   case WebAssembly::CALL_INDIRECT_v4i32:
 210   case WebAssembly::CALL_INDIRECT_v4i32_S:
 211   case WebAssembly::CALL_INDIRECT_v2i64:
 212   case WebAssembly::CALL_INDIRECT_v2i64_S:
 213   case WebAssembly::CALL_INDIRECT_v4f32:
 214   case WebAssembly::CALL_INDIRECT_v4f32_S:
 215   case WebAssembly::CALL_INDIRECT_v2f64:
 216   case WebAssembly::CALL_INDIRECT_v2f64_S:
 217   case WebAssembly::CALL_INDIRECT_EXCEPT_REF:
 218   case WebAssembly::CALL_INDIRECT_EXCEPT_REF_S:
 219     return 1;
 220   default:
 221     llvm_unreachable("Not a call instruction");
 222   }
 223 }
 224
 225 bool WebAssembly::isMarker(const MachineInstr &MI) {
 226   switch (MI.getOpcode()) {
 227   case WebAssembly::BLOCK:
 228   case WebAssembly::BLOCK_S:
 229   case WebAssembly::END_BLOCK:
 230   case WebAssembly::END_BLOCK_S:
 231   case WebAssembly::LOOP:
 232   case WebAssembly::LOOP_S:
 233   case WebAssembly::END_LOOP:
 234   case WebAssembly::END_LOOP_S:
 235   case WebAssembly::TRY:
 236   case WebAssembly::TRY_S:
 237   case WebAssembly::END_TRY:
 238   case WebAssembly::END_TRY_S:
 239     return true;
 240   default:
 241     return false;
 242   }
 243 }
 244
 245 bool WebAssembly::mayThrow(const MachineInstr &MI) {
 246   switch (MI.getOpcode()) {
 247   case WebAssembly::THROW:
 248   case WebAssembly::THROW_S:
 249   case WebAssembly::RETHROW:
 250   case WebAssembly::RETHROW_S:
 251     return true;
 252   }
 253   if (isCallIndirect(MI))
 254     return true;
 255   if (!MI.isCall())
 256     return false;
 257
 258   const MachineOperand &MO = MI.getOperand(getCalleeOpNo(MI));
 259   assert(MO.isGlobal());
 260   const auto *F = dyn_cast<Function>(MO.getGlobal());
 261   if (!F)
 262     return true;
 263   if (F->doesNotThrow())
 264     return false;
 265   // These functions never throw
 266   if (F->getName() == CxaBeginCatchFn || F->getName() == PersonalityWrapperFn ||
 267       F->getName() == ClangCallTerminateFn || F->getName() == StdTerminateFn)
 268     return false;
 269   return true;
 270 }