[PATCH] D138757: [zero-call-used-regs] Mark only non-debug instruction's register as used

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added inline comments.


================
Comment at: llvm/lib/CodeGen/PrologEpilogInserter.cpp:1234-1236
+        // skip debug instructions
+        if (MI.isDebugInstr())
+          continue;
----------------
Can you just use `MO.readsReg()` instead of `MO.isUse()` below (that will also skip other cases like `undef` that aren't really reading the register).


================
Comment at: llvm/lib/CodeGen/PrologEpilogInserter.cpp:1243
           MCRegister Reg = MO.getReg();
           if (AllocatableSet[Reg] && !MO.isImplicit() &&
               (MO.isDef() || MO.isUse()))
----------------
Haven't followed this patch series. But skipping implicit operands seems odd at a first glance. They can read and write registers perfectly fine...


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D138757/new/

https://reviews.llvm.org/D138757