commit 388cacb341917964ee87b23c0af2990af9e66fe0
author Cullen Rhodes <cullen.rhodes@arm.com> Wed Oct 12 08:36:03 2022 +0000
committer Cullen Rhodes <cullen.rhodes@arm.com> Wed Oct 12 09:14:08 2022 +0000
tree bdf505ae961624f5b91803a08cc9dc96c87a0090
parent 5b5756e6e31488f2cda2b15544b731b25e7899cf

[AArch64][SVE] Add instcombine for PTEST_ANY(X=OP(PG,...), X) -> PTEST_ANY(PG, X))

Given this is an OR reduction the two are equivalent and later
optimizations (AArch64InstrInfo::optimizePTestInstr) may rewrite the
sequence to use the flag-setting variant of instruction X, to remove the
PTEST altogether.

Reviewed By: paulwalker-arm, bsmith

Differential Revision: https://reviews.llvm.org/D134946

llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp

diff --git a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
index 725d263..c1c4a28 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetTransformInfo.cpp
@@ -966,14 +966,15 @@
   IntrinsicInst *Op1 = dyn_cast<IntrinsicInst>(II.getArgOperand(0));
   IntrinsicInst *Op2 = dyn_cast<IntrinsicInst>(II.getArgOperand(1));
 
-  if (Op1 && Op2 &&
-      Op1->getIntrinsicID() == Intrinsic::aarch64_sve_convert_to_svbool &&
+  if (!Op1 || !Op2)
+    return None;
+
+  IRBuilder<> Builder(II.getContext());
+  Builder.SetInsertPoint(&II);
+
+  if (Op1->getIntrinsicID() == Intrinsic::aarch64_sve_convert_to_svbool &&
       Op2->getIntrinsicID() == Intrinsic::aarch64_sve_convert_to_svbool &&
       Op1->getArgOperand(0)->getType() == Op2->getArgOperand(0)->getType()) {
-
-    IRBuilder<> Builder(II.getContext());
-    Builder.SetInsertPoint(&II);
-
     Value *Ops[] = {Op1->getArgOperand(0), Op2->getArgOperand(0)};
     Type *Tys[] = {Op1->getArgOperand(0)->getType()};
 
@@ -983,6 +984,22 @@
     return IC.replaceInstUsesWith(II, PTest);
   }
 
+  // Transform PTEST_ANY(X=OP(PG,...), X) -> PTEST_ANY(PG, X)).
+  // Later optimizations may rewrite sequence to use the flag-setting variant
+  // of instruction X to remove PTEST.
+  if ((Op1 == Op2) &&
+      (II.getIntrinsicID() == Intrinsic::aarch64_sve_ptest_any) &&
+      ((Op1->getIntrinsicID() == Intrinsic::aarch64_sve_brkb_z) ||
+       (Op1->getIntrinsicID() == Intrinsic::aarch64_sve_rdffr_z))) {
+    Value *Ops[] = {Op1->getArgOperand(0), Op1};
+    Type *Tys[] = {Op1->getType()};
+
+    auto *PTest = Builder.CreateIntrinsic(II.getIntrinsicID(), Tys, Ops);
+    PTest->takeName(&II);
+
+    return IC.replaceInstUsesWith(II, PTest);
+  }
+
   return None;
 }