[llvm] 421577f - Revert "[CHR] Fix up phi nodes with unreachable predecessors (PR64594)"

Nikita Popov via llvm-commits llvm-commits at lists.llvm.org
Fri Aug 11 01:20:53 PDT 2023


Author: Nikita Popov
Date: 2023-08-11T10:20:46+02:00
New Revision: 421577f539c79808fdcd9f372b7182f20b3c65a2

URL: https://github.com/llvm/llvm-project/commit/421577f539c79808fdcd9f372b7182f20b3c65a2
DIFF: https://github.com/llvm/llvm-project/commit/421577f539c79808fdcd9f372b7182f20b3c65a2.diff

LOG: Revert "[CHR] Fix up phi nodes with unreachable predecessors (PR64594)"

This reverts commit cfc9298dc588c626a52193260da28a630e103916.

The newly added test fails under EXPENSIVE_CHECKS, revert while I
investigate.

Added: 
    

Modified: 
    llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp

Removed: 
    llvm/test/Transforms/PGOProfile/chr-dead-pred.ll


################################################################################
diff  --git a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
index 478e45b95cbdd5..3e3be536defc5d 100644
--- a/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
+++ b/llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
@@ -1777,21 +1777,6 @@ void CHR::cloneScopeBlocks(CHRScope *Scope,
       BasicBlock *NewBB = CloneBasicBlock(BB, VMap, ".nonchr", &F);
       NewBlocks.push_back(NewBB);
       VMap[BB] = NewBB;
-
-      // Unreachable predecessors will not be cloned and will not have an edge
-      // to the cloned block. As such, also remove them from any phi nodes.
-      // To avoid iterator invalidation, first collect the dead predecessors
-      // from the first phi node, and then perform the actual removal.
-      SmallVector<BasicBlock *> DeadPreds;
-      for (PHINode &PN : NewBB->phis()) {
-        for (BasicBlock *Pred : PN.blocks())
-          if (!DT.isReachableFromEntry(Pred))
-            DeadPreds.push_back(Pred);
-        break;
-      }
-      for (PHINode &PN : make_early_inc_range(NewBB->phis()))
-        for (BasicBlock *Pred : DeadPreds)
-          PN.removeIncomingValue(Pred);
     }
 
   // Place the cloned blocks right after the original blocks (right before the

diff  --git a/llvm/test/Transforms/PGOProfile/chr-dead-pred.ll b/llvm/test/Transforms/PGOProfile/chr-dead-pred.ll
deleted file mode 100644
index bdbf0640035d41..00000000000000
--- a/llvm/test/Transforms/PGOProfile/chr-dead-pred.ll
+++ /dev/null
@@ -1,106 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
-; RUN: opt -S -passes='require<profile-summary>,chr' < %s | FileCheck %s
-
-define void @test(i1 %c, i1 %c2) !prof !29 {
-; CHECK-LABEL: define void @test
-; CHECK-SAME: (i1 [[C:%.*]], i1 [[C2:%.*]]) !prof [[PROF29:![0-9]+]] {
-; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[TMP0:%.*]] = xor i1 true, [[C]]
-; CHECK-NEXT:    [[TMP1:%.*]] = freeze i1 [[TMP0]]
-; CHECK-NEXT:    [[TMP2:%.*]] = select i1 true, i1 [[TMP1]], i1 false
-; CHECK-NEXT:    [[TMP3:%.*]] = xor i1 true, [[C2]]
-; CHECK-NEXT:    [[TMP4:%.*]] = freeze i1 [[TMP3]]
-; CHECK-NEXT:    [[TMP5:%.*]] = select i1 [[TMP2]], i1 [[TMP4]], i1 false
-; CHECK-NEXT:    br i1 [[TMP5]], label [[ENTRY_SPLIT:%.*]], label [[ENTRY_SPLIT_NONCHR:%.*]], !prof [[PROF30:![0-9]+]]
-; CHECK:       entry.split:
-; CHECK-NEXT:    switch i8 0, label [[BB1:%.*]] [
-; CHECK-NEXT:    i8 1, label [[BB2:%.*]]
-; CHECK-NEXT:    i8 2, label [[BB3:%.*]]
-; CHECK-NEXT:    ]
-; CHECK:       bb1:
-; CHECK-NEXT:    [[SELECT:%.*]] = select i1 false, i32 0, i32 1, !prof [[PROF31:![0-9]+]]
-; CHECK-NEXT:    br label [[EXIT:%.*]]
-; CHECK:       bb2:
-; CHECK-NEXT:    [[SELECT3:%.*]] = select i1 false, i32 0, i32 1, !prof [[PROF32:![0-9]+]]
-; CHECK-NEXT:    br label [[EXIT]]
-; CHECK:       dead:
-; CHECK-NEXT:    br label [[BB3]]
-; CHECK:       bb3:
-; CHECK-NEXT:    [[PHI:%.*]] = phi i64 [ 0, [[DEAD:%.*]] ], [ 1, [[ENTRY_SPLIT]] ]
-; CHECK-NEXT:    br label [[EXIT]]
-; CHECK:       entry.split.nonchr:
-; CHECK-NEXT:    switch i8 0, label [[BB1_NONCHR:%.*]] [
-; CHECK-NEXT:    i8 1, label [[BB2_NONCHR:%.*]]
-; CHECK-NEXT:    i8 2, label [[BB3_NONCHR:%.*]]
-; CHECK-NEXT:    ]
-; CHECK:       bb1.nonchr:
-; CHECK-NEXT:    [[SELECT_NONCHR:%.*]] = select i1 [[C]], i32 0, i32 1, !prof [[PROF31]]
-; CHECK-NEXT:    br label [[EXIT]]
-; CHECK:       bb2.nonchr:
-; CHECK-NEXT:    [[SELECT3_NONCHR:%.*]] = select i1 [[C2]], i32 0, i32 1, !prof [[PROF32]]
-; CHECK-NEXT:    br label [[EXIT]]
-; CHECK:       bb3.nonchr:
-; CHECK-NEXT:    [[PHI_NONCHR:%.*]] = phi i64 [ 1, [[ENTRY_SPLIT_NONCHR]] ]
-; CHECK-NEXT:    br label [[EXIT]]
-; CHECK:       exit:
-; CHECK-NEXT:    ret void
-;
-entry:
-  switch i8 0, label %bb1 [
-  i8 1, label %bb2
-  i8 2, label %bb3
-  ]
-
-bb1:                                              ; preds = %entry
-  %select = select i1 %c, i32 0, i32 1, !prof !30
-  br label %exit
-
-bb2:                                              ; preds = %entry
-  %select3 = select i1 %c2, i32 0, i32 1, !prof !31
-  br label %exit
-
-dead:                                             ; No predecessors!
-  br label %bb3
-
-bb3:                                              ; preds = %dead, %entry
-  %phi = phi i64 [ 0, %dead ], [ 1, %entry ]
-  br label %exit
-
-exit:                                             ; preds = %bb3, %bb2, %bb1
-  ret void
-}
-
-!llvm.module.flags = !{!0}
-
-!0 = !{i32 1, !"ProfileSummary", !1}
-!1 = !{!2, !3, !4, !5, !6, !7, !8, !9, !10, !11}
-!2 = !{!"ProfileFormat", !"InstrProf"}
-!3 = !{!"TotalCount", i64 597326977313}
-!4 = !{!"MaxCount", i64 12561793713}
-!5 = !{!"MaxInternalCount", i64 2509052618}
-!6 = !{!"MaxFunctionCount", i64 12561793713}
-!7 = !{!"NumCounts", i64 1694881}
-!8 = !{!"NumFunctions", i64 129214}
-!9 = !{!"IsPartialProfile", i64 0}
-!10 = !{!"PartialProfileRatio", double 0.000000e+00}
-!11 = !{!"DetailedSummary", !12}
-!12 = !{!13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25, !26, !27, !28}
-!13 = !{i32 10000, i64 12561793713, i32 1}
-!14 = !{i32 100000, i64 1733566697, i32 20}
-!15 = !{i32 200000, i64 820928443, i32 71}
-!16 = !{i32 300000, i64 404967336, i32 182}
-!17 = !{i32 400000, i64 233162193, i32 376}
-!18 = !{i32 500000, i64 120552435, i32 741}
-!19 = !{i32 600000, i64 69388652, i32 1402}
-!20 = !{i32 700000, i64 33926336, i32 2643}
-!21 = !{i32 800000, i64 15635940, i32 5288}
-!22 = !{i32 900000, i64 5547105, i32 11637}
-!23 = !{i32 950000, i64 2224405, i32 20074}
-!24 = !{i32 990000, i64 359838, i32 44778}
-!25 = !{i32 999000, i64 37485, i32 81744}
-!26 = !{i32 999900, i64 3465, i32 119656}
-!27 = !{i32 999990, i64 529, i32 155440}
-!28 = !{i32 999999, i64 70, i32 178344}
-!29 = !{!"function_entry_count", i64 33781183}
-!30 = !{!"branch_weights", i32 0, i32 9263770}
-!31 = !{!"branch_weights", i32 0, i32 634318}


        


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