[PATCH] D85892: [SVE] Fix bug in SVEIntrinsicOpts::optimizePTest

[David Sherwood via Phabricator via llvm-commits]

david-arm created this revision.
david-arm added reviewers: sdesmalen, ctetreau, kmclaughlin.
Herald added subscribers: llvm-commits, psnobl, hiraditya, tschuett.
Herald added a reviewer: efriedma.
Herald added a project: LLVM.
david-arm requested review of this revision.

The code wasn't taking into account that the two operands
passed to ptest could be identical and was trying to erase
them twice.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D85892

Files:
  llvm/lib/Target/AArch64/SVEIntrinsicOpts.cpp
  llvm/test/CodeGen/AArch64/sve-intrinsic-opts-ptest.ll


Index: llvm/test/CodeGen/AArch64/sve-intrinsic-opts-ptest.ll
===================================================================
--- llvm/test/CodeGen/AArch64/sve-intrinsic-opts-ptest.ll
+++ llvm/test/CodeGen/AArch64/sve-intrinsic-opts-ptest.ll
@@ -44,6 +44,16 @@
   ret i1 %out
 }
 
+define i1 @ptest_first_same_ops(<vscale x 2 x i1> %a) {
+; OPT-LABEL: ptest_first_same_ops
+; OPT: %[[OUT:.*]] = call i1 @llvm.aarch64.sve.ptest.first.nxv2i1(<vscale x 2 x i1> %a, <vscale x 2 x i1> %a)
+; OPT-NOT: convert
+; OPT-NEXT: ret i1 %[[OUT]]
+  %1 = tail call <vscale x 16 x i1> @llvm.aarch64.sve.convert.to.svbool.nxv2i1(<vscale x 2 x i1> %a)
+  %2 = tail call i1 @llvm.aarch64.sve.ptest.first.nxv16i1(<vscale x 16 x i1> %1, <vscale x 16 x i1> %1)
+  ret i1 %2
+}
+
 define i1 @ptest_last(<vscale x 8 x i1> %a) {
 ; OPT-LABEL: ptest_last
 ; OPT: %mask = tail call <vscale x 8 x i1> @llvm.aarch64.sve.ptrue.nxv8i1(i32 0)
Index: llvm/lib/Target/AArch64/SVEIntrinsicOpts.cpp
===================================================================
--- llvm/lib/Target/AArch64/SVEIntrinsicOpts.cpp
+++ llvm/lib/Target/AArch64/SVEIntrinsicOpts.cpp
@@ -160,7 +160,7 @@
     I->eraseFromParent();
     if (Op1->use_empty())
       Op1->eraseFromParent();
-    if (Op2->use_empty())
+    if (Op1 != Op2 && Op2->use_empty())
       Op2->eraseFromParent();
 
     return true;


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