X86: Switch to RegClassByHwMode

arsenm · arsenm · commit cbdfe4d18061 · 2025-09-12T20:11:52.000+09:00
Replace the target uses of PointerLikeRegClass with RegClassByHwMode
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp
@@ -55,6 +55,9 @@ std::string X86_MC::ParseX86Triple(const Triple &TT) {
   else
     FS = "-64bit-mode,-32bit-mode,+16bit-mode";
 
+  if (TT.isX32())
+    FS += ",+x32";
+
   return FS;
 }
 
diff --git a/llvm/lib/Target/X86/X86.td b/llvm/lib/Target/X86/X86.td
@@ -25,6 +25,8 @@ def Is32Bit : SubtargetFeature<"32bit-mode", "Is32Bit", "true",
                                "32-bit mode (80386)">;
 def Is16Bit : SubtargetFeature<"16bit-mode", "Is16Bit", "true",
                                "16-bit mode (i8086)">;
+def IsX32 : SubtargetFeature<"x32", "IsX32", "true",
+                             "64-bit with ILP32 programming model (e.g. x32 ABI)">;
 
 //===----------------------------------------------------------------------===//
 // X86 Subtarget ISA features
diff --git a/llvm/lib/Target/X86/X86InstrInfo.td b/llvm/lib/Target/X86/X86InstrInfo.td
@@ -18,14 +18,14 @@ include "X86InstrFragments.td"
 include "X86InstrFragmentsSIMD.td"
 
 //===----------------------------------------------------------------------===//
-// X86 Operand Definitions.
+// X86 Predicate Definitions.
 //
-include "X86InstrOperands.td"
+include "X86InstrPredicates.td"
 
 //===----------------------------------------------------------------------===//
-// X86 Predicate Definitions.
+// X86 Operand Definitions.
 //
-include "X86InstrPredicates.td"
+include "X86InstrOperands.td"
 
 //===----------------------------------------------------------------------===//
 // X86 Instruction Format Definitions.
diff --git a/llvm/lib/Target/X86/X86InstrOperands.td b/llvm/lib/Target/X86/X86InstrOperands.td
@@ -6,9 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
+def x86_ptr_rc : RegClassByHwMode<
+  [X86_32, X86_64, X86_64_X32],
+  [GR32, GR64, LOW32_ADDR_ACCESS]>;
+
 // A version of ptr_rc which excludes SP, ESP, and RSP. This is used for
 // the index operand of an address, to conform to x86 encoding restrictions.
-def ptr_rc_nosp : PointerLikeRegClass<1>;
+def ptr_rc_nosp : RegClassByHwMode<
+  [X86_32, X86_64, X86_64_X32],
+  [GR32_NOSP, GR64_NOSP, GR32_NOSP]>;
 
 // *mem - Operand definitions for the funky X86 addressing mode operands.
 //
@@ -53,7 +59,7 @@ class X86MemOperand<string printMethod,
                     AsmOperandClass parserMatchClass = X86MemAsmOperand,
                     int size = 0> : Operand<iPTR> {
   let PrintMethod = printMethod;
-  let MIOperandInfo = (ops ptr_rc, i8imm, ptr_rc_nosp, i32imm, SEGMENT_REG);
+  let MIOperandInfo = (ops x86_ptr_rc, i8imm, ptr_rc_nosp, i32imm, SEGMENT_REG);
   let ParserMatchClass = parserMatchClass;
   let OperandType = "OPERAND_MEMORY";
   int Size = size;
@@ -63,7 +69,7 @@ class X86MemOperand<string printMethod,
 class X86VMemOperand<RegisterClass RC, string printMethod,
                      AsmOperandClass parserMatchClass, int size = 0>
     : X86MemOperand<printMethod, parserMatchClass, size> {
-  let MIOperandInfo = (ops ptr_rc, i8imm, RC, i32imm, SEGMENT_REG);
+  let MIOperandInfo = (ops x86_ptr_rc, i8imm, RC, i32imm, SEGMENT_REG);
 }
 
 def anymem : X86MemOperand<"printMemReference">;
@@ -113,8 +119,14 @@ def sdmem : X86MemOperand<"printqwordmem", X86Mem64AsmOperand>;
 
 // A version of i8mem for use on x86-64 and x32 that uses a NOREX GPR instead
 // of a plain GPR, so that it doesn't potentially require a REX prefix.
-def ptr_rc_norex : PointerLikeRegClass<2>;
-def ptr_rc_norex_nosp : PointerLikeRegClass<3>;
+def ptr_rc_norex : RegClassByHwMode<
+  [X86_32, X86_64, X86_64_X32],
+  [GR32_NOREX, GR64_NOREX, GR32_NOREX]>;
+
+def ptr_rc_norex_nosp : RegClassByHwMode<
+  [X86_32, X86_64, X86_64_X32],
+  [GR32_NOREX_NOSP, GR64_NOREX_NOSP, GR32_NOREX_NOSP]>;
+
 
 def i8mem_NOREX : X86MemOperand<"printbytemem", X86Mem8AsmOperand, 8> {
   let MIOperandInfo = (ops ptr_rc_norex, i8imm, ptr_rc_norex_nosp, i32imm,
@@ -123,7 +135,9 @@ def i8mem_NOREX : X86MemOperand<"printbytemem", X86Mem8AsmOperand, 8> {
 
 // GPRs available for tailcall.
 // It represents GR32_TC, GR64_TC or GR64_TCW64.
-def ptr_rc_tailcall : PointerLikeRegClass<4>;
+def ptr_rc_tailcall : RegClassByHwMode<
+  [X86_32, X86_64, X86_64_X32],
+  [GR32_TC, GR64_TC, GR64_TC]>;
 
 // Special i32mem for addresses of load folding tail calls. These are not
 // allowed to use callee-saved registers since they must be scheduled
@@ -270,12 +284,12 @@ let RenderMethod = "addMemOffsOperands" in {
 
 class X86SrcIdxOperand<string printMethod, AsmOperandClass parserMatchClass>
     : X86MemOperand<printMethod, parserMatchClass> {
-  let MIOperandInfo = (ops ptr_rc, SEGMENT_REG);
+  let MIOperandInfo = (ops x86_ptr_rc, SEGMENT_REG);
 }
 
 class X86DstIdxOperand<string printMethod, AsmOperandClass parserMatchClass>
     : X86MemOperand<printMethod, parserMatchClass> {
-  let MIOperandInfo = (ops ptr_rc);
+  let MIOperandInfo = (ops x86_ptr_rc);
 }
 
 def srcidx8  : X86SrcIdxOperand<"printSrcIdx8",  X86SrcIdx8Operand>;
diff --git a/llvm/lib/Target/X86/X86InstrPredicates.td b/llvm/lib/Target/X86/X86InstrPredicates.td
@@ -195,6 +195,12 @@ def Not64BitMode : Predicate<"!Subtarget->is64Bit()">,
                              AssemblerPredicate<(all_of (not Is64Bit)), "Not 64-bit mode">;
 def In64BitMode  : Predicate<"Subtarget->is64Bit()">,
                              AssemblerPredicate<(all_of Is64Bit), "64-bit mode">;
+
+def IsX32Mode  : Predicate<"Subtarget->getTargetTriple().isX32()">,
+                            AssemblerPredicate<(all_of IsX32), "x32 ABI">;
+def NotX32Mode  : Predicate<"!Subtarget->getTargetTriple().isX32()">,
+                            AssemblerPredicate<(all_of (not IsX32)), "not x32 ABI">;
+
 def IsLP64  : Predicate<"Subtarget->isTarget64BitLP64()">;
 def NotLP64 : Predicate<"!Subtarget->isTarget64BitLP64()">;
 def In16BitMode  : Predicate<"Subtarget->is16Bit()">,
@@ -250,3 +256,11 @@ def HasMFence    : Predicate<"Subtarget->hasMFence()">;
 def HasFastDPWSSD: Predicate<"Subtarget->hasFastDPWSSD()">;
 def UseIndirectThunkCalls : Predicate<"Subtarget->useIndirectThunkCalls()">;
 def NotUseIndirectThunkCalls : Predicate<"!Subtarget->useIndirectThunkCalls()">;
+
+//===----------------------------------------------------------------------===//
+// HwModes
+//===----------------------------------------------------------------------===//
+
+defvar X86_32 = DefaultMode;
+def X86_64 : HwMode<[In64BitMode, NotX32Mode]>;
+def X86_64_X32 : HwMode<[IsX32Mode]>;
diff --git a/llvm/lib/Target/X86/X86RegisterInfo.cpp b/llvm/lib/Target/X86/X86RegisterInfo.cpp
@@ -194,33 +194,14 @@ X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
 
 const TargetRegisterClass *
 X86RegisterInfo::getPointerRegClass(unsigned Kind) const {
-  switch (Kind) {
-  default: llvm_unreachable("Unexpected Kind in getPointerRegClass!");
-  case 0: // Normal GPRs.
-    if (IsTarget64BitLP64)
-      return &X86::GR64RegClass;
-    // If the target is 64bit but we have been told to use 32bit addresses,
-    // we can still use 64-bit register as long as we know the high bits
-    // are zeros.
-    // Reflect that in the returned register class.
-    return Is64Bit ? &X86::LOW32_ADDR_ACCESSRegClass : &X86::GR32RegClass;
-  case 1: // Normal GPRs except the stack pointer (for encoding reasons).
-    if (IsTarget64BitLP64)
-      return &X86::GR64_NOSPRegClass;
-    // NOSP does not contain RIP, so no special case here.
-    return &X86::GR32_NOSPRegClass;
-  case 2: // NOREX GPRs.
-    if (IsTarget64BitLP64)
-      return &X86::GR64_NOREXRegClass;
-    return &X86::GR32_NOREXRegClass;
-  case 3: // NOREX GPRs except the stack pointer (for encoding reasons).
-    if (IsTarget64BitLP64)
-      return &X86::GR64_NOREX_NOSPRegClass;
-    // NOSP does not contain RIP, so no special case here.
-    return &X86::GR32_NOREX_NOSPRegClass;
-  case 4: // Available for tailcall (not callee-saved GPRs).
-    return Is64Bit ? &X86::GR64_TCRegClass : &X86::GR32_TCRegClass;
-  }
+  assert(Kind == 0 && "this should only be used for default cases");
+  if (IsTarget64BitLP64)
+    return &X86::GR64RegClass;
+  // If the target is 64bit but we have been told to use 32bit addresses,
+  // we can still use 64-bit register as long as we know the high bits
+  // are zeros.
+  // Reflect that in the returned register class.
+  return Is64Bit ? &X86::LOW32_ADDR_ACCESSRegClass : &X86::GR32RegClass;
 }
 
 const TargetRegisterClass *
diff --git a/llvm/lib/Target/X86/X86Subtarget.h b/llvm/lib/Target/X86/X86Subtarget.h
@@ -170,10 +170,10 @@ class X86Subtarget final : public X86GenSubtargetInfo {
 #include "X86GenSubtargetInfo.inc"
 
   /// Is this x86_64 with the ILP32 programming model (x32 ABI)?
-  bool isTarget64BitILP32() const { return Is64Bit && (TargetTriple.isX32()); }
+  bool isTarget64BitILP32() const { return Is64Bit && IsX32; }
 
   /// Is this x86_64 with the LP64 programming model (standard AMD64, no x32)?
-  bool isTarget64BitLP64() const { return Is64Bit && (!TargetTriple.isX32()); }
+  bool isTarget64BitLP64() const { return Is64Bit && !IsX32; }
 
   PICStyles::Style getPICStyle() const { return PICStyle; }
   void setPICStyle(PICStyles::Style Style)  { PICStyle = Style; }
diff --git a/llvm/utils/TableGen/X86FoldTablesEmitter.cpp b/llvm/utils/TableGen/X86FoldTablesEmitter.cpp
@@ -553,10 +553,10 @@ void X86FoldTablesEmitter::updateTables(const CodeGenInstruction *RegInst,
     for (unsigned I = RegOutSize, E = RegInst->Operands.size(); I < E; I++) {
       const Record *RegOpRec = RegInst->Operands[I].Rec;
       const Record *MemOpRec = MemInst->Operands[I].Rec;
-      // PointerLikeRegClass: For instructions like TAILJMPr, TAILJMPr64,
+      // RegClassByHwMode: For instructions like TAILJMPr, TAILJMPr64,
       // TAILJMPr64_REX
       if ((isRegisterOperand(RegOpRec) ||
-           RegOpRec->isSubClassOf("PointerLikeRegClass")) &&
+           (RegOpRec->isSubClassOf("RegClassByHwMode"))) &&
           isMemoryOperand(MemOpRec)) {
         switch (I) {
         case 0:

Original file line number	Diff line number	Diff line change
`@@ -55,6 +55,9 @@ std::string X86_MC::ParseX86Triple(const Triple &TT) {`
`55`	`55`	`else`
`56`	`56`	`FS = "-64bit-mode,-32bit-mode,+16bit-mode";`
`57`	`57`
	`58`	`+ if (TT.isX32())`
	`59`	`+ FS += ",+x32";`
	`60`	`+`
`58`	`61`	`return FS;`
`59`	`62`	`}`
`60`	`63`