GlobalISel: add implicit defs & uses when mutating an instruction.

Otherwise a scheduler might do bad things to the code we produce.

llvm-svn: 298311

1 files changed, 18 insertions, 1 deletions

diff --git a/llvm/utils/TableGen/GlobalISelEmitter.cpp b/llvm/utils/TableGen/GlobalISelEmitter.cpp
index 596cd3cddb9..169dd32daa6 100644
--- a/llvm/utils/TableGen/GlobalISelEmitter.cpp
+++ b/llvm/utils/TableGen/GlobalISelEmitter.cpp
@@ -835,8 +835,25 @@ public:
   void emitCxxActionStmts(raw_ostream &OS, RuleMatcher &Rule,
                           StringRef RecycleVarName) const override {
     if (canMutate()) {
-      OS << RecycleVarName << ".setDesc(TII.get(" << I->Namespace
+      OS << "    " << RecycleVarName << ".setDesc(TII.get(" << I->Namespace
          << "::" << I->TheDef->getName() << "));\n";
+
+      if (!I->ImplicitDefs.empty() || !I->ImplicitUses.empty()) {
+        OS << "    auto MIB = MachineInstrBuilder(MF, &" << RecycleVarName
+           << ");\n";
+
+        for (auto Def : I->ImplicitDefs) {
+          auto Namespace = Def->getValueAsString("Namespace");
+          OS << "    MIB.addDef(" << Namespace << "::" << Def->getName()
+             << ", RegState::Implicit);\n";
+        }
+        for (auto Use : I->ImplicitUses) {
+          auto Namespace = Use->getValueAsString("Namespace");
+          OS << "    MIB.addUse(" << Namespace << "::" << Use->getName()
+             << ", RegState::Implicit);\n";
+        }
+      }
+
       OS << "    MachineInstr &NewI = " << RecycleVarName << ";\n";
       return;
     }