[PATCH] D134167: [LoopRotate] Drop loop dispositions when rotating loops. PR56260

[Max Kazantsev via Phabricator via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rG92e9bddc49b6: [LoopRotate] Drop loop dispositions when rotating loops. PR56260 (authored by mkazantsev).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D134167/new/

https://reviews.llvm.org/D134167

Files:
  llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
  llvm/test/Transforms/LoopRotate/pr56260.ll


Index: llvm/test/Transforms/LoopRotate/pr56260.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopRotate/pr56260.ll
@@ -0,0 +1,58 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes='loop(loop-rotate,loop-deletion)' -S | FileCheck %s
+
+target datalayout = "e-m:o-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @main() {
+; CHECK-LABEL: @main(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[L0_PREHEADER:%.*]]
+; CHECK:       L0.L0.preheader.loopexit_crit_edge:
+; CHECK-NEXT:    br label [[L0_PREHEADER_LOOPEXIT:%.*]]
+; CHECK:       L0.preheader.loopexit:
+; CHECK-NEXT:    br label [[L0_PREHEADER]]
+; CHECK:       L0.preheader:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 0, 0
+; CHECK-NEXT:    [[INC:%.*]] = zext i1 [[CMP]] to i32
+; CHECK-NEXT:    [[SPEC_SELECT1:%.*]] = add nsw i32 0, [[INC]]
+; CHECK-NEXT:    [[TOBOOL3_NOT2:%.*]] = icmp eq i32 [[SPEC_SELECT1]], 0
+; CHECK-NEXT:    br i1 [[TOBOOL3_NOT2]], label [[L0_PREHEADER_LOOPEXIT]], label [[L1_PREHEADER_LR_PH:%.*]]
+; CHECK:       L1.preheader.lr.ph:
+; CHECK-NEXT:    br label [[L1_PREHEADER:%.*]]
+; CHECK:       L1.preheader:
+; CHECK-NEXT:    [[SPEC_SELECT4:%.*]] = phi i32 [ [[SPEC_SELECT1]], [[L1_PREHEADER_LR_PH]] ], [ [[SPEC_SELECT:%.*]], [[L0_LATCH:%.*]] ]
+; CHECK-NEXT:    [[K_03:%.*]] = phi i32 [ 0, [[L1_PREHEADER_LR_PH]] ], [ [[SPEC_SELECT4]], [[L0_LATCH]] ]
+; CHECK-NEXT:    [[TOBOOL8_NOT:%.*]] = icmp eq i32 [[K_03]], 0
+; CHECK-NEXT:    br label [[L0_LATCH]]
+; CHECK:       L0.latch:
+; CHECK-NEXT:    [[SPEC_SELECT]] = add nsw i32 [[SPEC_SELECT4]], [[INC]]
+; CHECK-NEXT:    [[TOBOOL3_NOT:%.*]] = icmp eq i32 [[SPEC_SELECT]], 0
+; CHECK-NEXT:    br i1 [[TOBOOL3_NOT]], label [[L0_L0_PREHEADER_LOOPEXIT_CRIT_EDGE:%.*]], label [[L1_PREHEADER]]
+;
+entry:
+  br label %L0.preheader
+
+L0.preheader:
+  br label %L0
+
+L0:                                               ; preds = %L0.latch, %L0.preheader
+  %k.0 = phi i32 [ 0, %L0.preheader ], [ %spec.select, %L0.latch ]
+  %cmp = icmp slt i32 0, 0
+  %inc = zext i1 %cmp to i32
+  %spec.select = add nsw i32 %k.0, %inc
+  %tobool3.not = icmp eq i32 %spec.select, 0
+  br i1 %tobool3.not, label %L0.preheader, label %L1.preheader
+
+L1.preheader:
+  %tobool8.not = icmp eq i32 %k.0, 0
+  br label %L1
+
+L1:
+  br i1 %tobool8.not, label %L1.latch, label %L0.latch
+
+L1.latch:
+  br i1 false, label %L1, label %L0.latch
+
+L0.latch:
+  br label %L0
+}
Index: llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
+++ llvm/lib/Transforms/Utils/LoopRotationUtils.cpp
@@ -345,8 +345,12 @@
     // all outer loops because insertion and deletion of blocks that happens
     // during the rotation may violate invariants related to backedge taken
     // infos in them.
-    if (SE)
+    if (SE) {
       SE->forgetTopmostLoop(L);
+      // We may hoist some instructions out of loop. In case if they were cached
+      // as "loop variant" or "loop computable", these caches must be dropped.
+      SE->forgetLoopDispositions();
+    }
 
     LLVM_DEBUG(dbgs() << "LoopRotation: rotating "; L->dump());
     if (MSSAU && VerifyMemorySSA)


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D134167.461181.patch
Type: text/x-patch
Size: 3334 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20220919/9fe42ce2/attachment.bin>