[llvm-branch-commits] [llvm] AMDGPU/GlobalISel: RegBankLegalize rules for load (PR #112882)

[Petar Avramovic via llvm-branch-commits]

================
@@ -290,7 +504,86 @@ RegBankLegalizeRules::RegBankLegalizeRules(const GCNSubtarget &_ST,
       .Any({{UniS64, S32}, {{Sgpr64}, {Sgpr32}, Ext32To64}})
       .Any({{DivS64, S32}, {{Vgpr64}, {Vgpr32}, Ext32To64}});
 
-  addRulesForGOpcs({G_LOAD}).Any({{DivS32, DivP1}, {{Vgpr32}, {VgprP1}}});
+  bool hasUnAlignedLoads = ST->getGeneration() >= AMDGPUSubtarget::GFX12;
+  bool hasSMRDSmall = ST->hasScalarSubwordLoads();
+
+  Predicate isAlign16([](const MachineInstr &MI) -> bool {
+    return (*MI.memoperands_begin())->getAlign() >= Align(16);
+  });
+
+  Predicate isAlign4([](const MachineInstr &MI) -> bool {
+    return (*MI.memoperands_begin())->getAlign() >= Align(4);
+  });
+
+  Predicate isAtomicMMO([](const MachineInstr &MI) -> bool {
+    return (*MI.memoperands_begin())->isAtomic();
+  });
+
+  Predicate isUniMMO([](const MachineInstr &MI) -> bool {
+    return AMDGPUInstrInfo::isUniformMMO(*MI.memoperands_begin());
+  });
+
+  Predicate isConst([](const MachineInstr &MI) -> bool {
+    // Address space in MMO be different then address space on pointer.
+    const MachineMemOperand *MMO = *MI.memoperands_begin();
+    const unsigned AS = MMO->getAddrSpace();
+    return AS == AMDGPUAS::CONSTANT_ADDRESS ||
+           AS == AMDGPUAS::CONSTANT_ADDRESS_32BIT;
+  });
+
+  Predicate isVolatileMMO([](const MachineInstr &MI) -> bool {
+    return (*MI.memoperands_begin())->isVolatile();
+  });
+
+  Predicate isInvMMO([](const MachineInstr &MI) -> bool {
+    return (*MI.memoperands_begin())->isInvariant();
+  });
+
+  Predicate isNoClobberMMO([](const MachineInstr &MI) -> bool {
+    return (*MI.memoperands_begin())->getFlags() & MONoClobber;
+  });
+
+  Predicate isNaturalAlignedSmall([](const MachineInstr &MI) -> bool {
+    const MachineMemOperand *MMO = *MI.memoperands_begin();
+    const unsigned MemSize = 8 * MMO->getSize().getValue();
+    return (MemSize == 16 && MMO->getAlign() >= Align(2)) ||
+           (MemSize == 8 && MMO->getAlign() >= Align(1));
+  });
+
+  auto isUL = !isAtomicMMO && isUniMMO && (isConst || !isVolatileMMO) &&
+              (isConst || isInvMMO || isNoClobberMMO);
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petar-avramovic wrote:

It is copied from current implementation in AMDGPURegisterBankInfo::isScalarLoadLegal
isConst checks for address space in MMO, which can be different that address space of pointer operand

https://github.com/llvm/llvm-project/pull/112882