2 files changed, 17 insertions, 6 deletions
diff --git a/llvm/lib/Target/X86/X86InstrInfo.td b/llvm/lib/Target/X86/X86InstrInfo.td
index 5618c779608..73136d9c5d9 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.td
+++ b/llvm/lib/Target/X86/X86InstrInfo.td
@@ -341,18 +341,21 @@ def vy64xmem : X86VMemOperand<VR256X, "printi64mem", X86MemVY64XOperand>;
 def vz32mem  : X86VMemOperand<VR512,  "printi32mem", X86MemVZ32Operand>;
 def vz64mem  : X86VMemOperand<VR512,  "printi64mem", X86MemVZ64Operand>;
 
-// A version of i8mem for use on x86-64 that uses GR64_NOREX instead of
-// plain GR64, so that it doesn't potentially require a REX prefix.
-def i8mem_NOREX : Operand<i64> {
+// 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 i8mem_NOREX : Operand<iPTR> {
   let PrintMethod = "printi8mem";
-  let MIOperandInfo = (ops GR64_NOREX, i8imm, GR64_NOREX_NOSP, i32imm, i8imm);
+  let MIOperandInfo = (ops ptr_rc_norex, i8imm, ptr_rc_norex_nosp, i32imm, i8imm);
   let ParserMatchClass = X86Mem8AsmOperand;
   let OperandType = "OPERAND_MEMORY";
 }
 
 // GPRs available for tailcall.
 // It represents GR32_TC, GR64_TC or GR64_TCW64.
-def ptr_rc_tailcall : PointerLikeRegClass<2>;
+def ptr_rc_tailcall : PointerLikeRegClass<4>;
 
 // Special i32mem for addresses of load folding tail calls. These are not
 // allowed to use callee-saved registers since they must be scheduled
diff --git a/llvm/lib/Target/X86/X86RegisterInfo.cpp b/llvm/lib/Target/X86/X86RegisterInfo.cpp
index ff6b204482e..7b04e81c483 100644
--- a/llvm/lib/Target/X86/X86RegisterInfo.cpp
+++ b/llvm/lib/Target/X86/X86RegisterInfo.cpp
@@ -168,7 +168,15 @@ X86RegisterInfo::getPointerRegClass(const MachineFunction &MF,
     if (Subtarget.isTarget64BitLP64())
       return &X86::GR64_NOSPRegClass;
     return &X86::GR32_NOSPRegClass;
-  case 2: // Available for tailcall (not callee-saved GPRs).
+  case 2: // NOREX GPRs.
+    if (Subtarget.isTarget64BitLP64())
+      return &X86::GR64_NOREXRegClass;
+    return &X86::GR32_NOREXRegClass;
+  case 3: // NOREX GPRs except the stack pointer (for encoding reasons).
+    if (Subtarget.isTarget64BitLP64())
+      return &X86::GR64_NOREX_NOSPRegClass;
+    return &X86::GR32_NOREX_NOSPRegClass;
+  case 4: // Available for tailcall (not callee-saved GPRs).
     const Function *F = MF.getFunction();
     if (IsWin64 || (F && F->getCallingConv() == CallingConv::X86_64_Win64))
       return &X86::GR64_TCW64RegClass;