From c96c85aba28089ec840a867e289782831e9637ee Mon Sep 17 00:00:00 2001 From: Alexander Kornienko Date: Wed, 21 Jun 2023 16:41:05 +0200 Subject: [PATCH] Revert "[LoopSink] Allow sinking to PHI-use" This reverts commit 54711a6a5872d5f97da4c0a1bd7e58d0546ca701. The commit is causing a clang crash: https://reviews.llvm.org/D152772#4437254 --- llvm/lib/Transforms/Scalar/LoopSink.cpp | 22 ++---- llvm/test/Transforms/LICM/loopsink-phi.ll | 115 ------------------------------ 2 files changed, 4 insertions(+), 133 deletions(-) delete mode 100644 llvm/test/Transforms/LICM/loopsink-phi.ll diff --git a/llvm/lib/Transforms/Scalar/LoopSink.cpp b/llvm/lib/Transforms/Scalar/LoopSink.cpp index 1d827b0..7eeb1e7 100644 --- a/llvm/lib/Transforms/Scalar/LoopSink.cpp +++ b/llvm/lib/Transforms/Scalar/LoopSink.cpp @@ -177,27 +177,13 @@ static bool sinkInstruction( SmallPtrSet BBs; for (auto &U : I.uses()) { Instruction *UI = cast(U.getUser()); - + // We cannot sink I to PHI-uses. + if (isa(UI)) + return false; // We cannot sink I if it has uses outside of the loop. if (!L.contains(LI.getLoopFor(UI->getParent()))) return false; - - if (!isa(UI)) { - BBs.insert(UI->getParent()); - continue; - } - - // We cannot sink I to PHI-uses, try to look through PHI to find the incoming - // block of the value being used. - PHINode *PN = dyn_cast(UI); - BasicBlock *PhiBB = PN->getIncomingBlock(U); - - // If value's incoming block is from loop preheader directly, there's no - // place to sink to, bailout. - if (L.getLoopPreheader() == PhiBB) - return false; - - BBs.insert(PhiBB); + BBs.insert(UI->getParent()); } // findBBsToSinkInto is O(BBs.size() * ColdLoopBBs.size()). We cap the max diff --git a/llvm/test/Transforms/LICM/loopsink-phi.ll b/llvm/test/Transforms/LICM/loopsink-phi.ll deleted file mode 100644 index 3a3fd31..0000000 --- a/llvm/test/Transforms/LICM/loopsink-phi.ll +++ /dev/null @@ -1,115 +0,0 @@ -; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2 -; RUN: opt -S -verify-memoryssa -passes=loop-sink < %s | FileCheck %s -; Make sure that unprofitable loop ICM can be undone by loop sink, and loop sink can handle -; sinking through PHI use. - - -define dso_local i32 @_Z3fooii(i32 %arg, i32 %arg1, i32 %arg2) local_unnamed_addr #0 !prof !29 { -; CHECK-LABEL: define dso_local i32 @_Z3fooii -; CHECK-SAME: (i32 [[ARG:%.*]], i32 [[ARG1:%.*]], i32 [[ARG2:%.*]]) local_unnamed_addr #[[ATTR0:[0-9]+]] !prof [[PROF29:![0-9]+]] { -; CHECK-NEXT: .l.check.preheader: -; CHECK-NEXT: br label [[DOTL_CHECK:%.*]] -; CHECK: .l.ret.loopexit: -; CHECK-NEXT: [[DOTLCSSA:%.*]] = phi i32 [ [[I10:%.*]], [[DOTL_ITERATE:%.*]] ] -; CHECK-NEXT: ret i32 [[DOTLCSSA]] -; CHECK: .l.check: -; CHECK-NEXT: [[I4:%.*]] = phi i32 [ 0, [[DOTL_CHECK_PREHEADER:%.*]] ], [ [[I11:%.*]], [[DOTL_ITERATE]] ] -; CHECK-NEXT: [[I5:%.*]] = phi i32 [ [[ARG]], [[DOTL_CHECK_PREHEADER]] ], [ [[I10]], [[DOTL_ITERATE]] ] -; CHECK-NEXT: [[I6:%.*]] = icmp eq i32 [[I4]], [[ARG1]] -; CHECK-NEXT: br i1 [[I6]], label [[DOTL_COLD:%.*]], label [[DOTL_ITERATE]], !prof [[PROF30:![0-9]+]] -; CHECK: .l.cold: -; CHECK-NEXT: [[FLAG:%.*]] = icmp eq i32 [[ARG1]], 5 -; CHECK-NEXT: br i1 [[FLAG]], label [[DOTL_COLD1:%.*]], label [[DOTL_COLD2:%.*]] -; CHECK: .l.cold1: -; CHECK-NEXT: [[TMP1:%.*]] = mul nsw i32 [[ARG2]], [[ARG2]] -; CHECK-NEXT: br label [[DOTL_COLD3:%.*]] -; CHECK: .l.cold2: -; CHECK-NEXT: [[TMP2:%.*]] = add nsw i32 [[ARG2]], [[ARG2]] -; CHECK-NEXT: br label [[DOTL_COLD3]] -; CHECK: .l.cold3: -; CHECK-NEXT: [[I7:%.*]] = phi i32 [ [[TMP1]], [[DOTL_COLD1]] ], [ [[TMP2]], [[DOTL_COLD2]] ] -; CHECK-NEXT: [[I8:%.*]] = tail call i32 @_Z3bari(i32 [[I5]]) -; CHECK-NEXT: [[I9:%.*]] = add nsw i32 [[I8]], [[I7]] -; CHECK-NEXT: br label [[DOTL_ITERATE]] -; CHECK: .l.iterate: -; CHECK-NEXT: [[I10]] = phi i32 [ [[I9]], [[DOTL_COLD3]] ], [ [[I5]], [[DOTL_CHECK]] ] -; CHECK-NEXT: [[I11]] = add nuw nsw i32 [[I4]], 1 -; CHECK-NEXT: [[I12:%.*]] = icmp eq i32 [[I11]], [[I10]] -; CHECK-NEXT: br i1 [[I12]], label [[DOTL_RET_LOOPEXIT:%.*]], label [[DOTL_CHECK]] -; - -.l.check.preheader: - %flag = icmp eq i32 %arg1, 5 - %tmp2 = add nsw i32 %arg2, %arg2 - %tmp1 = mul nsw i32 %arg2, %arg2 - br label %.l.check - -.l.ret.loopexit: ; preds = %.l.iterate - %.lcssa = phi i32 [ %i10, %.l.iterate ] - ret i32 %.lcssa - -.l.check: ; preds = %.l.iterate, %.l.check.preheader - %i4 = phi i32 [ 0, %.l.check.preheader ], [ %i11, %.l.iterate ] - %i5 = phi i32 [ %arg, %.l.check.preheader ], [ %i10, %.l.iterate ] - %i6 = icmp eq i32 %i4, %arg1 - br i1 %i6, label %.l.cold, label %.l.iterate, !prof !30 - -.l.cold: ; preds = %.l.check - br i1 %flag, label %.l.cold1, label %.l.cold2 - -.l.cold1: ; preds = %.l.cold - br label %.l.cold3 - -.l.cold2: ; preds = %.l.cold - br label %.l.cold3 - -.l.cold3: ; preds = %.l.cold2, %.l.cold1 - %i7 = phi i32 [ %tmp1, %.l.cold1 ], [ %tmp2, %.l.cold2 ] - %i8 = tail call i32 @_Z3bari(i32 %i5) - %i9 = add nsw i32 %i8, %i7 - br label %.l.iterate - -.l.iterate: ; preds = %.l.cold3, %.l.check - %i10 = phi i32 [ %i9, %.l.cold3 ], [ %i5, %.l.check ] - %i11 = add nuw nsw i32 %i4, 1 - %i12 = icmp eq i32 %i11, %i10 - br i1 %i12, label %.l.ret.loopexit, label %.l.check -} - -declare dso_local i32 @_Z3bari(i32) local_unnamed_addr - -attributes #0 = { "use-sample-profile" } - -!llvm.module.flags = !{!0} - -!0 = !{i32 1, !"ProfileSummary", !1} -!1 = !{!2, !3, !4, !5, !6, !7, !8, !9, !10, !11} -!2 = !{!"ProfileFormat", !"SampleProfile"} -!3 = !{!"TotalCount", i64 403} -!4 = !{!"MaxCount", i64 200} -!5 = !{!"MaxInternalCount", i64 0} -!6 = !{!"MaxFunctionCount", i64 1} -!7 = !{!"NumCounts", i64 6} -!8 = !{!"NumFunctions", i64 1} -!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 200, i32 2} -!14 = !{i32 100000, i64 200, i32 2} -!15 = !{i32 200000, i64 200, i32 2} -!16 = !{i32 300000, i64 200, i32 2} -!17 = !{i32 400000, i64 200, i32 2} -!18 = !{i32 500000, i64 200, i32 2} -!19 = !{i32 600000, i64 200, i32 2} -!20 = !{i32 700000, i64 200, i32 2} -!21 = !{i32 800000, i64 200, i32 2} -!22 = !{i32 900000, i64 200, i32 2} -!23 = !{i32 950000, i64 200, i32 2} -!24 = !{i32 990000, i64 200, i32 2} -!25 = !{i32 999000, i64 1, i32 5} -!26 = !{i32 999900, i64 1, i32 5} -!27 = !{i32 999990, i64 1, i32 5} -!28 = !{i32 999999, i64 1, i32 5} -!29 = !{!"function_entry_count", i64 2} -!30 = !{!"branch_weights", i32 1, i32 201} -- 2.7.4