[LoopUnrollPass] Recalculate task info if loop unrolling makes any ch…

…anges.
OpenCilk · Feb 13, 2024 · 66e744b · 66e744b
1 parent 3a0979d
commit 66e744b
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diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -1657,6 +1657,12 @@ PreservedAnalyses LoopUnrollPass::run(Function &F,
   if (!Changed)
     return PreservedAnalyses::all();
 
+  // Update TaskInfo manually using the updated DT.
+  //
+  // FIXME: Recalculating TaskInfo for the whole function is wasteful.
+  // Optimize this routine in the future.
+  TI.recalculate(*DT.getRoot()->getParent(), DT);
+
   return getLoopPassPreservedAnalyses();
 }
 

diff --git a/llvm/test/Transforms/Tapir/loop-unroll-task-info-update.ll b/llvm/test/Transforms/Tapir/loop-unroll-task-info-update.ll
@@ -0,0 +1,76 @@
+; Check that Task Info is properly updated by loop unrolling.
+;
+; RUN: opt < %s -passes="function<eager-inv>(loop-unroll<O3>,loop-mssa(licm<allowspeculation>))" -S | FileCheck %s
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @"_ZN102_$LT$core..iter..adapters..map..Map$LT$I$C$F$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4fold17h7ca9d764f65b661fE"() personality ptr null {
+  br label %1
+
+1:                                                ; preds = %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread", %2, %0
+  %.sroa.9.0 = phi i16 [ 0, %0 ], [ 1, %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread" ], [ 0, %2 ]
+  %.sroa.12.0 = phi i16 [ 1, %0 ], [ 0, %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread" ], [ %.sroa.12.0, %2 ]
+  br i1 false, label %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit", label %2
+
+"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit": ; preds = %1
+  tail call void @llvm.assume(i1 false)
+  br label %2
+
+2:                                                ; preds = %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit", %1
+  br i1 false, label %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread", label %1
+
+"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread": ; preds = %2
+  br label %1
+}
+
+; CHECK: define void @"_ZN102_$LT$core..iter..adapters..map..Map$LT$I$C$F$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4fold17h7ca9d764f65b661fE"()
+; CHECK-NEXT: br label %.outer
+
+; CHECK: .outer:
+; CHECK-NEXT: br label %.peel.begin
+
+; CHECK: .peel.begin:
+; CHECK-NEXT: br label %1
+
+; CHECK: 1:
+; CHECK-NEXT: br i1 false, label %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit.peel", label %2
+
+; CHECK: "_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit.peel":
+; CHECK-NEXT: tail call void @llvm.assume(i1 false)
+; CHECK-NEXT: br label %2
+
+; CHECK: 2:
+; CHECK-NEXT: br i1 false, label %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread", label %.peel.next
+
+; CHECK: .peel.next:
+; CHECK-NEXT: br label %.peel.next1
+
+; CHECK: .peel.next1:
+; CHECK-NEXT: br label %.outer.peel.newph
+
+; CHECK: .outer.peel.newph:
+; CHECK-NEXT: br label %3
+
+; CHECK: 3:
+; CHECK-NEXT: br i1 false, label %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit", label %4
+
+; CHECK: "_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit":
+; CHECK-NEXT: tail call void @llvm.assume(i1 false)
+; CHECK-NEXT: br label %4
+
+; CHECK: 4:
+; CHECK-NEXT: br i1 false, label %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread.loopexit", label %3
+
+; CHECK: "_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread.loopexit":
+; CHECK-NEXT: br label %"_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread"
+
+; CHECK: "_ZN104_$LT$core..iter..adapters..cloned..Cloned$LT$I$GT$$u20$as$u20$core..iter..traits..iterator..Iterator$GT$4next17h2f9fd05836d8afd1E.exit3.thread":
+; CHECK-NEXT: br label %.outer
+
+; Function Attrs: nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: readwrite)
+declare void @llvm.assume(i1 noundef) #0
+
+; uselistorder directives
+uselistorder ptr null, { 1, 2, 0 }
+
+attributes #0 = { nocallback nofree nosync nounwind willreturn memory(inaccessiblemem: readwrite) }