[PATCH] D66678: [GlobalISel] Replace hard coded dynamic alloca handling with G_DYN_STACKALLOC

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp:1795-1796
+  // an address inside an alloca.
+  SDNodeFlags Flags;
+  Flags.setNoUnsignedWrap(true);
+  auto SAMinusOne = MIRBuilder.buildConstant(IntPtrTy, StackAlign - 1);
----------------
SDNodeFlags?


================
Comment at: llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp:1798-1800
+  auto AllocAdd =
+      MIRBuilder.buildInstr(TargetOpcode::G_ADD, {IntPtrTy},
+                            {AllocSize, SAMinusOne}, MachineInstr::NoUWrap);
----------------
buildAdd?


================
Comment at: llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp:1803
+      MIRBuilder.buildConstant(IntPtrTy, ~(uint64_t)(StackAlign - 1));
+  auto AlignedAlloc = MIRBuilder.buildAnd(IntPtrTy, AllocAdd, AlignCst);
+
----------------
Why not use PtrMask?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D66678/new/

https://reviews.llvm.org/D66678