[PATCH] D46992: [AMDGPU] Add perf hints to functions

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: lib/Target/AMDGPU/AMDGPUPerfHintAnalysis.cpp:257-261
+        APInt Off(DL->getIndexSizeInBits(GEP->getPointerAddressSpace()), 0);
+        if (GEP->accumulateConstantOffset(*DL, Off)) {
+          if (Off.isIntN(12))
+            // Offset will likely be folded into load or store
+            continue;
----------------
isLegalAddressingMode.

I'm not sure I understand why this pass is doing most of what it's doing. Why does the addressing mode match matter for determining if the function is probably memory bound?

With a machine pass you would have a much more exact idea of the number of memory operations really being executed


https://reviews.llvm.org/D46992