[llvm] c043f50 - [SimplifyCFG] Teach FoldBranchToCommonDest() to preserve DomTree, part 1
Roman Lebedev via llvm-commits
llvm-commits at lists.llvm.org
Sat Dec 19 13:19:32 PST 2020
Author: Roman Lebedev
Date: 2020-12-20T00:18:36+03:00
New Revision: c043f5055e8968ed17d2763e47862c42050302e3
URL: https://github.com/llvm/llvm-project/commit/c043f5055e8968ed17d2763e47862c42050302e3
DIFF: https://github.com/llvm/llvm-project/commit/c043f5055e8968ed17d2763e47862c42050302e3.diff
LOG: [SimplifyCFG] Teach FoldBranchToCommonDest() to preserve DomTree, part 1
... for conditional branch case
Added:
Modified:
llvm/include/llvm/Transforms/Utils/Local.h
llvm/lib/Transforms/Utils/LoopSimplify.cpp
llvm/lib/Transforms/Utils/SimplifyCFG.cpp
llvm/test/Transforms/LoopVectorize/if-pred-non-void.ll
llvm/test/Transforms/SimplifyCFG/2006-12-08-Ptr-ICmp-Branch.ll
llvm/test/Transforms/SimplifyCFG/ARM/branch-fold-threshold.ll
llvm/test/Transforms/SimplifyCFG/annotations.ll
llvm/test/Transforms/SimplifyCFG/basictest.ll
llvm/test/Transforms/SimplifyCFG/branch-fold-dbg.ll
llvm/test/Transforms/SimplifyCFG/branch-fold-threshold.ll
llvm/test/Transforms/SimplifyCFG/common-dest-folding.ll
llvm/test/Transforms/SimplifyCFG/fold-branch-to-common-dest.ll
llvm/test/Transforms/SimplifyCFG/fold-debug-location.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/Utils/Local.h b/llvm/include/llvm/Transforms/Utils/Local.h
index 7acf53df4304..f62af365a27c 100644
--- a/llvm/include/llvm/Transforms/Utils/Local.h
+++ b/llvm/include/llvm/Transforms/Utils/Local.h
@@ -201,7 +201,8 @@ bool FlattenCFG(BasicBlock *BB, AAResults *AA = nullptr);
/// If this basic block is ONLY a setcc and a branch, and if a predecessor
/// branches to us and one of our successors, fold the setcc into the
/// predecessor and use logical operations to pick the right destination.
-bool FoldBranchToCommonDest(BranchInst *BI, MemorySSAUpdater *MSSAU = nullptr,
+bool FoldBranchToCommonDest(BranchInst *BI, llvm::DomTreeUpdater *DTU = nullptr,
+ MemorySSAUpdater *MSSAU = nullptr,
const TargetTransformInfo *TTI = nullptr,
unsigned BonusInstThreshold = 1);
diff --git a/llvm/lib/Transforms/Utils/LoopSimplify.cpp b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
index 817dfc2a26b1..6337a01a4d60 100644
--- a/llvm/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/llvm/lib/Transforms/Utils/LoopSimplify.cpp
@@ -681,7 +681,7 @@ static bool simplifyOneLoop(Loop *L, SmallVectorImpl<Loop *> &Worklist,
// The block has now been cleared of all instructions except for
// a comparison and a conditional branch. SimplifyCFG may be able
// to fold it now.
- if (!FoldBranchToCommonDest(BI, MSSAU))
+ if (!FoldBranchToCommonDest(BI, /*DTU=*/nullptr, MSSAU))
continue;
// Success. The block is now dead, so remove it from the loop,
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index c2557165a0ba..777ec44cd0bd 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -2743,7 +2743,8 @@ static bool extractPredSuccWeights(BranchInst *PBI, BranchInst *BI,
/// If this basic block is simple enough, and if a predecessor branches to us
/// and one of our successors, fold the block into the predecessor and use
/// logical operations to pick the right destination.
-bool llvm::FoldBranchToCommonDest(BranchInst *BI, MemorySSAUpdater *MSSAU,
+bool llvm::FoldBranchToCommonDest(BranchInst *BI, DomTreeUpdater *DTU,
+ MemorySSAUpdater *MSSAU,
const TargetTransformInfo *TTI,
unsigned BonusInstThreshold) {
BasicBlock *BB = BI->getParent();
@@ -2907,6 +2908,8 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, MemorySSAUpdater *MSSAU,
LLVM_DEBUG(dbgs() << "FOLDING BRANCH TO COMMON DEST:\n" << *PBI << *BB);
Changed = true;
+ SmallVector<DominatorTree::UpdateType, 3> Updates;
+
IRBuilder<> Builder(PBI);
// The builder is used to create instructions to eliminate the branch in BB.
// If BB's terminator has !annotation metadata, add it to the new
@@ -3055,6 +3058,9 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, MemorySSAUpdater *MSSAU,
setBranchWeights(PBI, MDWeights[0], MDWeights[1]);
} else
PBI->setMetadata(LLVMContext::MD_prof, nullptr);
+
+ Updates.push_back({DominatorTree::Delete, PredBlock, BB});
+ Updates.push_back({DominatorTree::Insert, PredBlock, UniqueSucc});
} else {
// Update PHI nodes in the common successors.
for (unsigned i = 0, e = PHIs.size(); i != e; ++i) {
@@ -3102,6 +3108,9 @@ bool llvm::FoldBranchToCommonDest(BranchInst *BI, MemorySSAUpdater *MSSAU,
PBI = New_PBI;
}
+ if (DTU)
+ DTU->applyUpdatesPermissive(Updates);
+
// If BI was a loop latch, it may have had associated loop metadata.
// We need to copy it to the new latch, that is, PBI.
if (MDNode *LoopMD = BI->getMetadata(LLVMContext::MD_loop))
@@ -6194,7 +6203,8 @@ bool SimplifyCFGOpt::simplifyUncondBranch(BranchInst *BI,
// branches to us and our successor, fold the comparison into the
// predecessor and use logical operations to update the incoming value
// for PHI nodes in common successor.
- if (FoldBranchToCommonDest(BI, nullptr, &TTI, Options.BonusInstThreshold))
+ if (FoldBranchToCommonDest(BI, DTU, /*MSSAU=*/nullptr, &TTI,
+ Options.BonusInstThreshold))
return requestResimplify();
return false;
}
@@ -6257,7 +6267,8 @@ bool SimplifyCFGOpt::simplifyCondBranch(BranchInst *BI, IRBuilder<> &Builder) {
// If this basic block is ONLY a compare and a branch, and if a predecessor
// branches to us and one of our successors, fold the comparison into the
// predecessor and use logical operations to pick the right destination.
- if (FoldBranchToCommonDest(BI, nullptr, &TTI, Options.BonusInstThreshold))
+ if (FoldBranchToCommonDest(BI, DTU, /*MSSAU=*/nullptr, &TTI,
+ Options.BonusInstThreshold))
return requestResimplify();
// We have a conditional branch to two blocks that are only reachable
diff --git a/llvm/test/Transforms/LoopVectorize/if-pred-non-void.ll b/llvm/test/Transforms/LoopVectorize/if-pred-non-void.ll
index 60139ffb8522..94bdbb5fdab4 100644
--- a/llvm/test/Transforms/LoopVectorize/if-pred-non-void.ll
+++ b/llvm/test/Transforms/LoopVectorize/if-pred-non-void.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -force-vector-width=2 -force-vector-interleave=1 -loop-vectorize -verify-loop-info -simplifycfg < %s | FileCheck %s
+; RUN: opt -S -force-vector-width=2 -force-vector-interleave=1 -loop-vectorize -verify-loop-info -simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s
; RUN: opt -S -force-vector-width=1 -force-vector-interleave=2 -loop-vectorize -verify-loop-info < %s | FileCheck %s --check-prefix=UNROLL-NO-VF
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
diff --git a/llvm/test/Transforms/SimplifyCFG/2006-12-08-Ptr-ICmp-Branch.ll b/llvm/test/Transforms/SimplifyCFG/2006-12-08-Ptr-ICmp-Branch.ll
index dcf241255d85..58fc770d08f9 100644
--- a/llvm/test/Transforms/SimplifyCFG/2006-12-08-Ptr-ICmp-Branch.ll
+++ b/llvm/test/Transforms/SimplifyCFG/2006-12-08-Ptr-ICmp-Branch.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg | llvm-dis
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 | llvm-dis
; END.
; ModuleID = '2006-12-08-Ptr-ICmp-Branch.ll'
diff --git a/llvm/test/Transforms/SimplifyCFG/ARM/branch-fold-threshold.ll b/llvm/test/Transforms/SimplifyCFG/ARM/branch-fold-threshold.ll
index ffb13ca583f7..a3d4129e0af8 100644
--- a/llvm/test/Transforms/SimplifyCFG/ARM/branch-fold-threshold.ll
+++ b/llvm/test/Transforms/SimplifyCFG/ARM/branch-fold-threshold.ll
@@ -1,7 +1,7 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -mtriple=thumbv8m.main %s -simplifycfg -S | FileCheck %s --check-prefix=CHECK --check-prefix=THUMB
-; RUN: opt -mtriple=thumbv8a %s -simplifycfg -S | FileCheck %s --check-prefix=CHECK --check-prefix=THUMB
-; RUN: opt -mtriple=armv8a %s -simplifycfg -S | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
+; RUN: opt -mtriple=thumbv8m.main %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s --check-prefix=CHECK --check-prefix=THUMB
+; RUN: opt -mtriple=thumbv8a %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s --check-prefix=CHECK --check-prefix=THUMB
+; RUN: opt -mtriple=armv8a %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s --check-prefix=CHECK --check-prefix=ARM
define i32 @foo(i32 %a, i32 %b, i32 %c, i32 %d, i32* %input) {
; CHECK-LABEL: @foo(
diff --git a/llvm/test/Transforms/SimplifyCFG/annotations.ll b/llvm/test/Transforms/SimplifyCFG/annotations.ll
index e6bc73d16992..c10a2a8bd1f3 100644
--- a/llvm/test/Transforms/SimplifyCFG/annotations.ll
+++ b/llvm/test/Transforms/SimplifyCFG/annotations.ll
@@ -1,4 +1,4 @@
-; RUN: opt -simplifycfg -S %s | FileCheck --match-full-lines %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S %s | FileCheck --match-full-lines %s
; The branch in %cont has !annotation metadata. Make sure generated AND
; has !annotation metadata.
diff --git a/llvm/test/Transforms/SimplifyCFG/basictest.ll b/llvm/test/Transforms/SimplifyCFG/basictest.ll
index 6d513441bf37..9f9ed4ab9eac 100644
--- a/llvm/test/Transforms/SimplifyCFG/basictest.ll
+++ b/llvm/test/Transforms/SimplifyCFG/basictest.ll
@@ -1,6 +1,6 @@
; Test CFG simplify removal of branch instructions.
;
-; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
; RUN: opt < %s -passes=simplify-cfg -S | FileCheck %s
define void @test1() {
diff --git a/llvm/test/Transforms/SimplifyCFG/branch-fold-dbg.ll b/llvm/test/Transforms/SimplifyCFG/branch-fold-dbg.ll
index 2414b569ba4e..a44abe041e77 100644
--- a/llvm/test/Transforms/SimplifyCFG/branch-fold-dbg.ll
+++ b/llvm/test/Transforms/SimplifyCFG/branch-fold-dbg.ll
@@ -1,4 +1,4 @@
-; RUN: opt -simplifycfg -S < %s | FileCheck %s
+; RUN: opt -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S < %s | FileCheck %s
%0 = type { i32*, i32* }
diff --git a/llvm/test/Transforms/SimplifyCFG/branch-fold-threshold.ll b/llvm/test/Transforms/SimplifyCFG/branch-fold-threshold.ll
index 592873fad23f..8f53b95419ec 100644
--- a/llvm/test/Transforms/SimplifyCFG/branch-fold-threshold.ll
+++ b/llvm/test/Transforms/SimplifyCFG/branch-fold-threshold.ll
@@ -1,6 +1,6 @@
-; RUN: opt %s -simplifycfg -S | FileCheck %s --check-prefix=NORMAL
-; RUN: opt %s -simplifycfg -S -bonus-inst-threshold=2 | FileCheck %s --check-prefix=AGGRESSIVE
-; RUN: opt %s -simplifycfg -S -bonus-inst-threshold=4 | FileCheck %s --check-prefix=WAYAGGRESSIVE
+; RUN: opt %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s --check-prefix=NORMAL
+; RUN: opt %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -bonus-inst-threshold=2 | FileCheck %s --check-prefix=AGGRESSIVE
+; RUN: opt %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S -bonus-inst-threshold=4 | FileCheck %s --check-prefix=WAYAGGRESSIVE
; RUN: opt %s -passes=simplify-cfg -S | FileCheck %s --check-prefix=NORMAL
; RUN: opt %s -passes='simplify-cfg<bonus-inst-threshold=2>' -S | FileCheck %s --check-prefix=AGGRESSIVE
; RUN: opt %s -passes='simplify-cfg<bonus-inst-threshold=4>' -S | FileCheck %s --check-prefix=WAYAGGRESSIVE
diff --git a/llvm/test/Transforms/SimplifyCFG/common-dest-folding.ll b/llvm/test/Transforms/SimplifyCFG/common-dest-folding.ll
index e3e27c706d1d..0035a445cca1 100644
--- a/llvm/test/Transforms/SimplifyCFG/common-dest-folding.ll
+++ b/llvm/test/Transforms/SimplifyCFG/common-dest-folding.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
;CHECK: @foo
;CHECK: and i32 %c1, %k
diff --git a/llvm/test/Transforms/SimplifyCFG/fold-branch-to-common-dest.ll b/llvm/test/Transforms/SimplifyCFG/fold-branch-to-common-dest.ll
index 549c4d884d14..3a70241fed16 100644
--- a/llvm/test/Transforms/SimplifyCFG/fold-branch-to-common-dest.ll
+++ b/llvm/test/Transforms/SimplifyCFG/fold-branch-to-common-dest.ll
@@ -1,5 +1,5 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -S -simplifycfg -bonus-inst-threshold=10 | FileCheck %s
+; RUN: opt < %s -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -bonus-inst-threshold=10 | FileCheck %s
declare void @sideeffect0()
declare void @sideeffect1()
diff --git a/llvm/test/Transforms/SimplifyCFG/fold-debug-location.ll b/llvm/test/Transforms/SimplifyCFG/fold-debug-location.ll
index 4c79a63cbbb4..0d1cfeebcdea 100644
--- a/llvm/test/Transforms/SimplifyCFG/fold-debug-location.ll
+++ b/llvm/test/Transforms/SimplifyCFG/fold-debug-location.ll
@@ -1,4 +1,4 @@
-; RUN: opt -S -simplifycfg < %s | FileCheck %s --match-full-lines
+; RUN: opt -S -simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s --match-full-lines
; Make sure we reset the debug location when folding instructions.
; CHECK: [[VAL:%.*]] = and i32 %c2, %k
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