[llvm] [AMDGPU][CodeGen] LocalStackSlotAllocation: record per-instr FI offsets (PR #166979)

[Jay Foad via llvm-commits]

================
@@ -52,19 +52,23 @@ namespace {
     MachineBasicBlock::iterator MI; // Instr referencing the frame
     int64_t LocalOffset;            // Local offset of the frame idx referenced
     int FrameIdx;                   // The frame index
+    int64_t InstOffset; // Offset of the instruction from the base register
 
     // Order reference instruction appears in program. Used to ensure
     // deterministic order when multiple instructions may reference the same
     // location.
     unsigned Order;
 
   public:
-    FrameRef(MachineInstr *I, int64_t Offset, int Idx, unsigned Ord) :
-      MI(I), LocalOffset(Offset), FrameIdx(Idx), Order(Ord) {}
+    FrameRef(MachineInstr *I, int64_t Offset, int Idx, int64_t InstOffset,
+             unsigned Ord)
+        : MI(I), LocalOffset(Offset), FrameIdx(Idx), InstOffset(InstOffset),
+          Order(Ord) {}
 
     bool operator<(const FrameRef &RHS) const {
-      return std::tie(LocalOffset, FrameIdx, Order) <
-             std::tie(RHS.LocalOffset, RHS.FrameIdx, RHS.Order);
+      return std::make_tuple(LocalOffset + InstOffset, FrameIdx, Order) <
+             std::make_tuple(RHS.LocalOffset + RHS.InstOffset, RHS.FrameIdx,
----------------
jayfoad wrote:

Since C++17 you should not normally need make_tuple:
```suggestion
      return std::tuple(LocalOffset + InstOffset, FrameIdx, Order) <
             std::tuple(RHS.LocalOffset + RHS.InstOffset, RHS.FrameIdx,
```

https://github.com/llvm/llvm-project/pull/166979