[llvm] 9224d32 - [IndVars] Fix branches exiting by true with invariant conditions

[Max Kazantsev via llvm-commits]

Author: Max Kazantsev
Date: 2020-11-13T15:52:00+07:00
New Revision: 9224d322a27fa383d9c33d4eee4d8aa7842a939b

URL: https://github.com/llvm/llvm-project/commit/9224d322a27fa383d9c33d4eee4d8aa7842a939b
DIFF: https://github.com/llvm/llvm-project/commit/9224d322a27fa383d9c33d4eee4d8aa7842a939b.diff

LOG: [IndVars] Fix branches exiting by true with invariant conditions

Forgot to invert the condition for them.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
    llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index cc3bf87be46e..4c31064a77da 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1432,6 +1432,9 @@ bool IndVarSimplify::optimizeLoopExits(Loop *L, SCEVExpander &Rewriter) {
     Rewriter.setInsertPoint(BI);
     auto *LHSV = Rewriter.expandCodeFor(InvariantLHS);
     auto *RHSV = Rewriter.expandCodeFor(InvariantRHS);
+    bool ExitIfTrue = !L->contains(*succ_begin(ExitingBB));
+    if (ExitIfTrue)
+      InvariantPred = ICmpInst::getInversePredicate(InvariantPred);
     IRBuilder<> Builder(BI);
     auto *NewCond = Builder.CreateICmp(InvariantPred, LHSV, RHSV,
                                        BI->getCondition()->getName());

diff  --git a/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll b/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll
index 664af7adcb44..b0629ed79483 100644
--- a/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll
+++ b/llvm/test/Transforms/IndVarSimplify/predicated_ranges.ll
@@ -529,7 +529,7 @@ define void @test_can_predicate_simple_unsigned_inverted(i32* %p, i32* %arr) {
 ; CHECK-NEXT:    br i1 [[ZERO_COND]], label [[EXIT:%.*]], label [[RANGE_CHECK_BLOCK:%.*]]
 ; CHECK:       range_check_block:
 ; CHECK-NEXT:    [[IV_NEXT]] = sub i32 [[IV]], 1
-; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp ult i32 [[TMP0]], [[LEN]]
+; CHECK-NEXT:    [[RANGE_CHECK1:%.*]] = icmp uge i32 [[TMP0]], [[LEN]]
 ; CHECK-NEXT:    br i1 [[RANGE_CHECK1]], label [[FAIL:%.*]], label [[BACKEDGE]]
 ; CHECK:       backedge:
 ; CHECK-NEXT:    [[EL_PTR:%.*]] = getelementptr i32, i32* [[P]], i32 [[IV]]