[X86][AMX][NFC] Remove assert for comparison between different BBs.

[pengfei]

Summary

SmallSet may use operator < when we insert MIRef elements, so we
cannot limit the comparison between different BBs.

We alow MIRef() to be less that any initialized MIRef object, otherwise,
we always reture false when compare between different BBs.

[LuoYuanke]

Is there any test case for it?

[pengfei]

In D101039#2707914, @LuoYuanke wrote:

Is there any test case for it?

I don't have a small case. On another hand, removing assert supposes to be NFC. The previous functionality still be checked by existing tests.

[LuoYuanke]

LGTM.

llvm/lib/Target/X86/X86PreTileConfig.cpp

 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/InitializePasses.h"
 
 using namespace llvm;
 
 #define DEBUG_TYPE "tile-pre-config"
-#define ASSERT_VALID_COMPARE                                                   \
-  assert((!MBB || !RHS.MBB || MBB == RHS.MBB) &&                               \
-         "Cannot compare between different BBs");
 #define REPORT_CONFIG_FAIL                                                     \
   report_fatal_error(                                                          \
       MF.getName() +                                                           \
       ": Failed to config tile register, please define the shape earlier");
 
 namespace {
 
 struct MIRef {
MIRef(MachineInstr *MI, MachineBasicBlock *MBB)
         Pos(std::distance(MBB->instr_begin(), ++MI->getIterator())) {}
   MIRef(MachineInstr *MI, MachineBasicBlock *MBB, size_t Pos)
       : MI(MI), MBB(MBB), Pos(Pos) {}
   operator bool() const { return MBB != nullptr; }
   bool operator==(const MIRef &RHS) const {
     return MI == RHS.MI && MBB == RHS.MBB;
   }
   bool operator<(const MIRef &RHS) const {
-    ASSERT_VALID_COMPARE;
-    return Pos < RHS.Pos;
+    return (!MBB && RHS.MBB) || (MBB == RHS.MBB && Pos < RHS.Pos);
   }
   bool operator>(const MIRef &RHS) const {
-    ASSERT_VALID_COMPARE;
-    return Pos > RHS.Pos;
+    return (!RHS.MBB && MBB) || (MBB == RHS.MBB && Pos > RHS.Pos);
   }
 };
 
 struct BBInfo {
   MIRef FirstAMX;
   MIRef LastCall;
   MIRef LastShape;
   bool TileCfgForbidden = false;