[AMDGPU] Allow register tuples to set asm names

This change reverts most of the previous register name generation.
The real problem is that RegisterTuple does not generate asm names.
Added optional operand to RegisterTuple. This way we can simplify
register name access and dramatically reduce the size of static
tables for the backend.

Differential Revision: https://reviews.llvm.org/D64967

llvm-svn: 366598

1 files changed, 12 insertions, 3 deletions

diff --git a/llvm/utils/TableGen/CodeGenRegisters.cpp b/llvm/utils/TableGen/CodeGenRegisters.cpp
index f87c6d6c945..9325c464144 100644
--- a/llvm/utils/TableGen/CodeGenRegisters.cpp
+++ b/llvm/utils/TableGen/CodeGenRegisters.cpp
@@ -639,7 +639,8 @@ struct TupleExpander : SetTheory::Expander {
     // Precompute some types.
     Record *RegisterCl = Def->getRecords().getClass("Register");
     RecTy *RegisterRecTy = RecordRecTy::get(RegisterCl);
-    StringInit *BlankName = StringInit::get("");
+    std::vector<StringRef> RegNames =
+      Def->getValueAsListOfStrings("RegAsmNames");
 
     // Zip them up.
     for (unsigned n = 0; n != Length; ++n) {
@@ -656,6 +657,15 @@ struct TupleExpander : SetTheory::Expander {
                               unsigned(Reg->getValueAsInt("CostPerUse")));
       }
 
+      StringInit *AsmName = StringInit::get("");
+      if (!RegNames.empty()) {
+        if (RegNames.size() <= n)
+          PrintFatalError(Def->getLoc(),
+                          "Register tuple definition missing name for '" +
+                            Name + "'.");
+        AsmName = StringInit::get(RegNames[n]);
+      }
+
       // Create a new Record representing the synthesized register. This record
       // is only for consumption by CodeGenRegister, it is not added to the
       // RecordKeeper.
@@ -683,9 +693,8 @@ struct TupleExpander : SetTheory::Expander {
         if (Field == "SubRegs")
           RV.setValue(ListInit::get(Tuple, RegisterRecTy));
 
-        // Provide a blank AsmName. MC hacks are required anyway.
         if (Field == "AsmName")
-          RV.setValue(BlankName);
+          RV.setValue(AsmName);
 
         // CostPerUse is aggregated from all Tuple members.
         if (Field == "CostPerUse")