[PATCH] D143578: [VP] Add vp.powi and a pass for expanding vp.powi before DAG.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/CodeGen/ExpandPowi.cpp:34
+
+// The expansioin is based on the c code of compiler-rt/__powidf2.c,
+// const int recip = b < 0;
----------------
expansion*


================
Comment at: llvm/lib/CodeGen/ExpandPowi.cpp:69
+  // Create phi of base.
+  Value *Base = Builder.CreatePHI(BaseTy, 2, "base");
+  cast<PHINode>(Base)->addIncoming(OrigBase, PreLoopBB);
----------------
CreatePHI returns a PHINode*, can we use that to avoid casts?


================
Comment at: llvm/lib/CodeGen/ExpandPowi.cpp:123
+    if (auto *II = dyn_cast<IntrinsicInst>(&I)) {
+      // TODO: Also suppot llvm.powi.
+      if (II->getIntrinsicID() == Intrinsic::vp_powi) {
----------------
support*


================
Comment at: llvm/lib/CodeGen/ExpandPowi.cpp:156
+    AU.addRequired<TargetPassConfig>();
+    AU.addPreserved<AAResultsWrapperPass>();
+    AU.addPreserved<GlobalsAAWrapperPass>();
----------------
Why does this require AA?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D143578/new/

https://reviews.llvm.org/D143578