[PATCH] D122477: [X86][tablgen] Consider the mnemonic when auto-generating memory folding table

[Kan Shengchen via Phabricator via llvm-commits]

skan updated this revision to Diff 418378.
skan added a comment.

Remove redundant NotMemoryFoldable


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122477/new/

https://reviews.llvm.org/D122477

Files:
  llvm/lib/Target/X86/CMakeLists.txt
  llvm/lib/Target/X86/X86InstrInfo.td
  llvm/utils/TableGen/X86FoldTablesEmitter.cpp


Index: llvm/utils/TableGen/X86FoldTablesEmitter.cpp
===================================================================
--- llvm/utils/TableGen/X86FoldTablesEmitter.cpp
+++ llvm/utils/TableGen/X86FoldTablesEmitter.cpp
@@ -303,10 +303,11 @@
 // matches the EVEX instruction of this object.
 class IsMatch {
   const CodeGenInstruction *MemInst;
+  unsigned Variant;
 
 public:
-  IsMatch(const CodeGenInstruction *Inst, const RecordKeeper &Records)
-      : MemInst(Inst) {}
+  IsMatch(const CodeGenInstruction *Inst, unsigned V)
+      : MemInst(Inst), Variant(V) {}
 
   bool operator()(const CodeGenInstruction *RegInst) {
     X86Disassembler::RecognizableInstrBase RegRI(*RegInst);
@@ -323,6 +324,16 @@
     if (!areOppositeForms(RegRI.Form, MemRI.Form))
       return false;
 
+    // X86 encoding is crazy, e.g
+    //
+    // f3 0f c7 30       vmxon   (%rax)
+    // f3 0f c7 f0       senduipi        %rax
+    //
+    // This two instruction have similiar encoding fields but are unrelated
+    if (X86Disassembler::getMnemonic(MemInst, Variant) !=
+        X86Disassembler::getMnemonic(RegInst, Variant))
+      return false;
+
     // Return false if one (at least) of the encoding fields of both
     // instructions do not match.
     if (RegRI.Encoding != MemRI.Encoding || RegRI.Opcode != MemRI.Opcode ||
@@ -584,6 +595,8 @@
     }
   }
 
+  Record *AsmWriter = Target.getAsmWriter();
+  unsigned Variant = AsmWriter->getValueAsInt("Variant");
   // For each memory form instruction, try to find its register form
   // instruction.
   for (const CodeGenInstruction *MemInst : MemInsts) {
@@ -599,7 +612,7 @@
     // opcode.
     std::vector<const CodeGenInstruction *> &OpcRegInsts = RegInstsIt->second;
 
-    auto Match = find_if(OpcRegInsts, IsMatch(MemInst, Records));
+    auto Match = find_if(OpcRegInsts, IsMatch(MemInst, Variant));
     if (Match != OpcRegInsts.end()) {
       const CodeGenInstruction *RegInst = *Match;
       // If the matched instruction has it's "FoldGenRegForm" set, map the
Index: llvm/lib/Target/X86/X86InstrInfo.td
===================================================================
--- llvm/lib/Target/X86/X86InstrInfo.td
+++ llvm/lib/Target/X86/X86InstrInfo.td
@@ -2851,7 +2851,7 @@
     def TPAUSE : I<0xAE, MRM6r,
                      (outs), (ins GR32orGR64:$src), "tpause\t$src",
                      [(set EFLAGS, (X86tpause GR32orGR64:$src, EDX, EAX))]>,
-                     PD, Requires<[HasWAITPKG]>, NotMemoryFoldable;
+                     PD, Requires<[HasWAITPKG]>;
   }
 } // SchedRW
 
@@ -3124,7 +3124,7 @@
 
 let Predicates = [HasCLWB], SchedRW = [WriteLoad] in
 def CLWB       : I<0xAE, MRM6m, (outs), (ins i8mem:$src), "clwb\t$src",
-                   [(int_x86_clwb addr:$src)]>, PD, NotMemoryFoldable;
+                   [(int_x86_clwb addr:$src)]>, PD;
 
 let Predicates = [HasCLDEMOTE], SchedRW = [WriteLoad] in
 def CLDEMOTE : I<0x1C, MRM0m, (outs), (ins i8mem:$src), "cldemote\t$src",
Index: llvm/lib/Target/X86/CMakeLists.txt
===================================================================
--- llvm/lib/Target/X86/CMakeLists.txt
+++ llvm/lib/Target/X86/CMakeLists.txt
@@ -19,7 +19,7 @@
 tablegen(LLVM X86GenSubtargetInfo.inc -gen-subtarget)
 
 if (X86_GEN_FOLD_TABLES)
-  tablegen(LLVM X86GenFoldTables.inc -gen-x86-fold-tables)
+  tablegen(LLVM X86GenFoldTables.inc -gen-x86-fold-tables -asmwriternum=1)
 endif()
 
 add_public_tablegen_target(X86CommonTableGen)


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