[llvm] r312352 - NewGVN: Make sure we don't incorrectly use PredicateInfo when doing PHI of ops
Daniel Berlin via llvm-commits
llvm-commits at lists.llvm.org
Fri Sep 1 12:20:19 PDT 2017
Author: dannyb
Date: Fri Sep 1 12:20:18 2017
New Revision: 312352
URL: http://llvm.org/viewvc/llvm-project?rev=312352&view=rev
Log:
NewGVN: Make sure we don't incorrectly use PredicateInfo when doing PHI of ops
Summary: When we backtranslate expressions, we can't use the predicateinfo, since we are evaluating them in a different context.
Reviewers: davide, mcrosier
Subscribers: sanjoy, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D37174
Added:
llvm/trunk/test/Transforms/NewGVN/pr34135.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp?rev=312352&r1=312351&r2=312352&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/NewGVN.cpp Fri Sep 1 12:20:18 2017
@@ -1782,10 +1782,15 @@ const Expression *NewGVN::performSymboli
if (PI == LastPredInfo)
continue;
LastPredInfo = PI;
-
- // TODO: Along the false edge, we may know more things too, like icmp of
+ // In phi of ops cases, we may have predicate info that we are evaluating
+ // in a different context.
+ if (!DT->dominates(PBranch->To, getBlockForValue(I)))
+ continue;
+ // TODO: Along the false edge, we may know more things too, like
+ // icmp of
// same operands is false.
- // TODO: We only handle actual comparison conditions below, not and/or.
+ // TODO: We only handle actual comparison conditions below, not
+ // and/or.
auto *BranchCond = dyn_cast<CmpInst>(PBranch->Condition);
if (!BranchCond)
continue;
@@ -2533,11 +2538,13 @@ NewGVN::makePossiblePhiOfOps(Instruction
// and make sure anything that tries to add it's DFS number is
// redirected to the instruction we are making a phi of ops
// for.
+ TempToBlock.insert({ValueOp, PredBB});
InstrDFS.insert({ValueOp, IDFSNum});
const Expression *E = performSymbolicEvaluation(ValueOp, Visited);
InstrDFS.erase(ValueOp);
AllTempInstructions.erase(ValueOp);
ValueOp->deleteValue();
+ TempToBlock.erase(ValueOp);
if (MemAccess)
TempToMemory.erase(ValueOp);
if (!E)
Added: llvm/trunk/test/Transforms/NewGVN/pr34135.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/NewGVN/pr34135.ll?rev=312352&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/NewGVN/pr34135.ll (added)
+++ llvm/trunk/test/Transforms/NewGVN/pr34135.ll Fri Sep 1 12:20:18 2017
@@ -0,0 +1,44 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -newgvn -enable-phi-of-ops=true -S | FileCheck %s
+;; Make sure we don't incorrectly use predicateinfo to simplify phi of ops cases
+source_filename = "pr34135.ll"
+
+define void @snork(i32 %arg) {
+; CHECK-LABEL: @snork(
+; CHECK-NEXT: bb:
+; CHECK-NEXT: [[TMP:%.*]] = sext i32 [[ARG:%.*]] to i64
+; CHECK-NEXT: br label [[BB1:%.*]]
+; CHECK: bb1:
+; CHECK-NEXT: [[TMP2:%.*]] = phi i64 [ 0, [[BB:%.*]] ], [ [[TMP3:%.*]], [[BB1]] ]
+; CHECK-NEXT: [[TMP3]] = add i64 [[TMP2]], 1
+; CHECK-NEXT: [[TMP4:%.*]] = icmp slt i64 [[TMP3]], [[TMP]]
+; CHECK-NEXT: br i1 [[TMP4]], label [[BB1]], label [[BB7:%.*]]
+; CHECK: bb5:
+; CHECK-NEXT: [[TMP6:%.*]] = icmp sgt i64 [[TMP]], 1
+; CHECK-NEXT: br i1 [[TMP6]], label [[BB7]], label [[BB9:%.*]]
+; CHECK: bb7:
+; CHECK-NEXT: br label [[BB5:%.*]]
+; CHECK: bb9:
+; CHECK-NEXT: unreachable
+;
+bb:
+ %tmp = sext i32 %arg to i64
+ br label %bb1
+
+bb1: ; preds = %bb1, %bb
+ %tmp2 = phi i64 [ 0, %bb ], [ %tmp3, %bb1 ]
+ %tmp3 = add i64 %tmp2, 1
+ %tmp4 = icmp slt i64 %tmp3, %tmp
+ br i1 %tmp4, label %bb1, label %bb7
+
+bb5: ; preds = %bb7
+ %tmp6 = icmp sgt i64 %tmp8, 1
+ br i1 %tmp6, label %bb7, label %bb9
+
+bb7: ; preds = %bb5, %bb1
+ %tmp8 = phi i64 [ undef, %bb5 ], [ %tmp, %bb1 ]
+ br label %bb5
+
+bb9: ; preds = %bb5
+ unreachable
+}
More information about the llvm-commits
mailing list