[PredicateInfo] Fix non-determinism in codegen uncovered by reverse iterating SmallPtrSet

Summary:
Sort OpsToRename before iterating to make iteration order deterministic.

Thanks to Daniel Berlin for the sorting logic.

Reviewers: dberlin, RKSimon, efriedma, davide

Reviewed By: dberlin, davide

Subscribers: sanjoy, davide, llvm-commits

Differential Revision: https://reviews.llvm.org/D33265

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304447 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/PredicateInfo.cpp b/lib/Transforms/Utils/PredicateInfo.cpp
index 8877aeafecdec8ebbce57a989a4c0286dce6a7d0..9e71cba4f1b7ac2b177d5706208e166efa8f38bd 100644 (file)
--- a/lib/Transforms/Utils/PredicateInfo.cpp
+++ b/lib/Transforms/Utils/PredicateInfo.cpp
@@ -541,7 +541,40 @@ Value *PredicateInfo::materializeStack(unsigned int &Counter,
 //
 // TODO: Use this algorithm to perform fast single-variable renaming in
 // promotememtoreg and memoryssa.
-void PredicateInfo::renameUses(SmallPtrSetImpl<Value *> &OpsToRename) {
+void PredicateInfo::renameUses(SmallPtrSetImpl<Value *> &OpSet) {
+  // Sort OpsToRename since we are going to iterate it.
+  SmallVector<Value *, 8> OpsToRename(OpSet.begin(), OpSet.end());
+  std::sort(OpsToRename.begin(), OpsToRename.end(), [&](const Value *A,
+                                                        const Value *B) {
+    auto *ArgA = dyn_cast_or_null<Argument>(A);
+    auto *ArgB = dyn_cast_or_null<Argument>(B);
+
+    // If A and B are args, order them based on their arg no.
+    if (ArgA && !ArgB)
+      return true;
+    if (ArgB && !ArgA)
+      return false;
+    if (ArgA && ArgB)
+      return ArgA->getArgNo() < ArgB->getArgNo();
+
+    // Else, A are B are instructions.
+    // If they belong to different BBs, order them by the dominance of BBs.
+    auto *AInst = cast<Instruction>(A);
+    auto *BInst = cast<Instruction>(B);
+    if (AInst->getParent() != BInst->getParent())
+      return DT.dominates(AInst->getParent(), BInst->getParent());
+
+    // Else, A and B belong to the same BB.
+    // Order A and B by their dominance.
+    auto *BB = AInst->getParent();
+    auto LookupResult = OBBMap.find(BB);
+    if (LookupResult != OBBMap.end())
+      return LookupResult->second->dominates(AInst, BInst);
+
+    auto Result = OBBMap.insert({BB, make_unique<OrderedBasicBlock>(BB)});
+    return Result.first->second->dominates(AInst, BInst);
+  });
+
   ValueDFS_Compare Compare(OBBMap);
   // Compute liveness, and rename in O(uses) per Op.
   for (auto *Op : OpsToRename) {

diff --git a/test/Transforms/Util/PredicateInfo/condprop.ll b/test/Transforms/Util/PredicateInfo/condprop.ll
index 79c76baa6f6191911675dc4876387d9c1a088713..61f59f03e1bc25aff29d6cf1a1e205f617c71510 100644 (file)
--- a/test/Transforms/Util/PredicateInfo/condprop.ll
+++ b/test/Transforms/Util/PredicateInfo/condprop.ll
@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -print-predicateinfo -analyze  < %s 2>&1 | FileCheck %s
+; RUN: opt -print-predicateinfo -analyze -reverse-iterate  < %s 2>&1 | FileCheck %s
 
 @a = external global i32               ; <i32*> [#uses=7]
 
@@ -98,10 +99,10 @@ define void @test3(i32 %x, i32 %y) {
 ; CHECK-NEXT:    [[XZ:%.*]] = icmp eq i32 [[X:%.*]], 0
 ; CHECK-NEXT:    [[YZ:%.*]] = icmp eq i32 [[Y:%.*]], 0
 ; CHECK-NEXT:    [[Z:%.*]] = and i1 [[XZ]], [[YZ]]
-; CHECK:         [[XZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
 ; CHECK:         [[X_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[X]])
-; CHECK:         [[YZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
 ; CHECK:         [[Y_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[Y]])
+; CHECK:         [[XZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
+; CHECK:         [[YZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
 ; CHECK:         [[Z_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[Z]])
 ; CHECK-NEXT:    br i1 [[Z]], label [[BOTH_ZERO:%.*]], label [[NOPE:%.*]]
 ; CHECK:       both_zero:
@@ -382,8 +383,8 @@ ret:
 define i32 @test10(i32 %j, i32 %i) {
 ; CHECK-LABEL: @test10(
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[I:%.*]], [[J:%.*]]
-; CHECK:         [[I_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[I]])
 ; CHECK:         [[J_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[J]])
+; CHECK:         [[I_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[I]])
 ; CHECK-NEXT:    br i1 [[CMP]], label [[COND_TRUE:%.*]], label [[RET:%.*]]
 ; CHECK:       cond_true:
 ; CHECK-NEXT:    [[DIFF:%.*]] = sub i32 [[I_0]], [[J_0]]

diff --git a/test/Transforms/Util/PredicateInfo/testandor.ll b/test/Transforms/Util/PredicateInfo/testandor.ll
index 5942ed155318ceb71c9cc5930d166bee427fc486..43c508670908b0e3f42af75a29053d3e70f39a05 100644 (file)
--- a/test/Transforms/Util/PredicateInfo/testandor.ll
+++ b/test/Transforms/Util/PredicateInfo/testandor.ll
@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -print-predicateinfo < %s 2>&1 | FileCheck %s
+; RUN: opt -print-predicateinfo -reverse-iterate < %s 2>&1 | FileCheck %s
 
 declare void @foo(i1)
 declare void @bar(i32)
@@ -10,10 +11,10 @@ define void @testor(i32 %x, i32 %y) {
 ; CHECK-NEXT:    [[XZ:%.*]] = icmp eq i32 [[X:%.*]], 0
 ; CHECK-NEXT:    [[YZ:%.*]] = icmp eq i32 [[Y:%.*]], 0
 ; CHECK-NEXT:    [[Z:%.*]] = or i1 [[XZ]], [[YZ]]
-; CHECK:         [[XZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
 ; CHECK:         [[X_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[X]])
-; CHECK:         [[YZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
 ; CHECK:         [[Y_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[Y]])
+; CHECK:         [[XZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
+; CHECK:         [[YZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
 ; CHECK:         [[Z_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[Z]])
 ; CHECK-NEXT:    br i1 [[Z]], label [[ONEOF:%.*]], label [[NEITHER:%.*]]
 ; CHECK:       oneof:
@@ -54,10 +55,10 @@ define void @testand(i32 %x, i32 %y) {
 ; CHECK-NEXT:    [[XZ:%.*]] = icmp eq i32 [[X:%.*]], 0
 ; CHECK-NEXT:    [[YZ:%.*]] = icmp eq i32 [[Y:%.*]], 0
 ; CHECK-NEXT:    [[Z:%.*]] = and i1 [[XZ]], [[YZ]]
-; CHECK:         [[XZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
 ; CHECK:         [[X_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[X]])
-; CHECK:         [[YZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
 ; CHECK:         [[Y_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[Y]])
+; CHECK:         [[XZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
+; CHECK:         [[YZ_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
 ; CHECK:         [[Z_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[Z]])
 ; CHECK-NEXT:    br i1 [[Z]], label [[BOTH:%.*]], label [[NOPE:%.*]]
 ; CHECK:       both:
@@ -98,9 +99,9 @@ define void @testandsame(i32 %x, i32 %y) {
 ; CHECK-NEXT:    [[XGT:%.*]] = icmp sgt i32 [[X:%.*]], 0
 ; CHECK-NEXT:    [[XLT:%.*]] = icmp slt i32 [[X]], 100
 ; CHECK-NEXT:    [[Z:%.*]] = and i1 [[XGT]], [[XLT]]
-; CHECK:         [[XGT_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XGT]])
 ; CHECK:         [[X_0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[X]])
 ; CHECK:         [[X_0_1:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[X_0]])
+; CHECK:         [[XGT_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XGT]])
 ; CHECK:         [[XLT_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XLT]])
 ; CHECK:         [[Z_0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[Z]])
 ; CHECK-NEXT:    br i1 [[Z]], label [[BOTH:%.*]], label [[NOPE:%.*]]
@@ -136,23 +137,23 @@ define void @testandassume(i32 %x, i32 %y) {
 ; CHECK-NEXT:    [[XZ:%.*]] = icmp eq i32 [[X:%.*]], 0
 ; CHECK-NEXT:    [[YZ:%.*]] = icmp eq i32 [[Y:%.*]], 0
 ; CHECK-NEXT:    [[Z:%.*]] = and i1 [[XZ]], [[YZ]]
-; CHECK:         [[TMP1:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
-; CHECK:         [[TMP2:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[X]])
-; CHECK:         [[TMP3:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
-; CHECK:         [[TMP4:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[Y]])
+; CHECK:         [[TMP1:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[X]])
+; CHECK:         [[TMP2:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[Y]])
+; CHECK:         [[TMP3:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[XZ]])
+; CHECK:         [[TMP4:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[YZ]])
 ; CHECK:         [[TMP5:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[Z]])
 ; CHECK-NEXT:    call void @llvm.assume(i1 [[TMP5]])
-; CHECK:         [[DOT0:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[TMP1]])
+; CHECK:         [[DOT0:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[TMP1]])
 ; CHECK:         [[DOT01:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[TMP2]])
 ; CHECK:         [[DOT02:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[TMP3]])
-; CHECK:         [[DOT03:%.*]] = call i32 @llvm.ssa.copy.i32(i32 [[TMP4]])
+; CHECK:         [[DOT03:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[TMP4]])
 ; CHECK:         [[DOT04:%.*]] = call i1 @llvm.ssa.copy.i1(i1 [[TMP5]])
 ; CHECK-NEXT:    br i1 [[TMP5]], label [[BOTH:%.*]], label [[NOPE:%.*]]
 ; CHECK:       both:
-; CHECK-NEXT:    call void @foo(i1 [[DOT0]])
 ; CHECK-NEXT:    call void @foo(i1 [[DOT02]])
+; CHECK-NEXT:    call void @foo(i1 [[DOT03]])
+; CHECK-NEXT:    call void @bar(i32 [[DOT0]])
 ; CHECK-NEXT:    call void @bar(i32 [[DOT01]])
-; CHECK-NEXT:    call void @bar(i32 [[DOT03]])
 ; CHECK-NEXT:    ret void
 ; CHECK:       nope:
 ; CHECK-NEXT:    call void @foo(i1 [[DOT04]])