STATISTIC(NonEmptyGuardBlock, "Candidate has a non-empty guard block with "
"instructions that cannot be moved");
STATISTIC(NotRotated, "Candidate is not rotated");
+STATISTIC(OnlySecondCandidateIsGuarded,
+ "The second candidate is guarded while the first one is not");
enum FusionDependenceAnalysisChoice {
FUSION_DEPENDENCE_ANALYSIS_SCEV,
continue;
}
+ if (!FC0->GuardBranch && FC1->GuardBranch) {
+ LLVM_DEBUG(dbgs() << "The second candidate is guarded while the "
+ "first one is not. Not fusing.\n");
+ reportLoopFusion<OptimizationRemarkMissed>(
+ *FC0, *FC1, OnlySecondCandidateIsGuarded);
+ continue;
+ }
+
// Ensure that FC0 and FC1 have identical guards.
// If one (or both) are not guarded, this check is not necessary.
if (FC0->GuardBranch && FC1->GuardBranch &&
--- /dev/null
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -loop-fusion < %s | FileCheck %s
+; RUN: opt -S -loop-fusion -pass-remarks-output=%t < %s
+; RUN: FileCheck --input-file=%t %s --check-prefix REMARKS
+
+define dso_local void @pr48060(i1 %cond) {
+; CHECK-LABEL: @pr48060(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[FOR_1_PH:%.*]]
+; CHECK: for.1.ph:
+; CHECK-NEXT: br label [[FOR_1:%.*]]
+; CHECK: for.1:
+; CHECK-NEXT: [[I:%.*]] = phi i32 [ 0, [[FOR_1_PH]] ], [ [[I_NEXT:%.*]], [[FOR_1]] ]
+; CHECK-NEXT: [[I_NEXT]] = add i32 [[I]], 1
+; CHECK-NEXT: [[COND_1:%.*]] = icmp eq i32 [[I_NEXT]], 10
+; CHECK-NEXT: br i1 [[COND_1]], label [[FOR_1_EXIT:%.*]], label [[FOR_1]]
+; CHECK: for.1.exit:
+; CHECK-NEXT: br i1 [[COND:%.*]], label [[END:%.*]], label [[FOR_2_PH:%.*]]
+; CHECK: for.2.ph:
+; CHECK-NEXT: br label [[FOR_2:%.*]]
+; CHECK: for.2:
+; CHECK-NEXT: [[J:%.*]] = phi i32 [ 0, [[FOR_2_PH]] ], [ [[J_NEXT:%.*]], [[FOR_2]] ]
+; CHECK-NEXT: [[J_NEXT]] = add i32 [[J]], 1
+; CHECK-NEXT: [[COND_2:%.*]] = icmp eq i32 [[J_NEXT]], 10
+; CHECK-NEXT: br i1 [[COND_2]], label [[FOR_2_EXIT:%.*]], label [[FOR_2]]
+; CHECK: for.2.exit:
+; CHECK-NEXT: br label [[END]]
+; CHECK: end:
+; CHECK-NEXT: ret void
+;
+
+; REMARKS: --- !Missed
+; REMARKS-NEXT: Pass: loop-fusion
+; REMARKS-NEXT: Name: OnlySecondCandidateIsGuarded
+; REMARKS-NEXT: Function: pr48060
+; REMARKS-NEXT: Args:
+; REMARKS: - Cand1: for.1.ph
+; REMARKS: - Cand2: for.2.ph
+; REMARKS: - String: The second candidate is guarded while the first one is not
+entry:
+ br label %for.1.ph
+
+for.1.ph: ; preds = %entry
+ br label %for.1
+
+for.1: ; preds = %for.1, %for.1.ph
+ %i = phi i32 [ 0, %for.1.ph ], [ %i.next, %for.1 ]
+ %i.next = add i32 %i, 1
+ %cond.1 = icmp eq i32 %i.next, 10
+ br i1 %cond.1, label %for.1.exit, label %for.1
+
+for.1.exit: ; preds = %for.1
+ br i1 %cond, label %end, label %for.2.ph
+
+for.2.ph: ; preds = %for.1.exit
+ br label %for.2
+
+for.2: ; preds = %for.2, %for.2.ph
+ %j = phi i32 [ 0, %for.2.ph ], [ %j.next, %for.2 ]
+ %j.next = add i32 %j, 1
+ %cond.2 = icmp eq i32 %j.next, 10
+ br i1 %cond.2, label %for.2.exit, label %for.2
+
+for.2.exit: ; preds = %for.2
+ br label %end
+
+end: ; preds = %for.1.exit, %for.2.exit
+ ret void
+}