[PATCH] D103867: [CHR] Don't run ControlHeightReduction if any BB has address taken

[Xun Li via Phabricator via llvm-commits]

lxfind updated this revision to Diff 350750.
lxfind added a comment.

Add test case


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103867/new/

https://reviews.llvm.org/D103867

Files:
  llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
  llvm/test/Transforms/PGOProfile/chr.ll


Index: llvm/test/Transforms/PGOProfile/chr.ll
===================================================================
--- llvm/test/Transforms/PGOProfile/chr.ll
+++ llvm/test/Transforms/PGOProfile/chr.ll
@@ -2527,6 +2527,55 @@
   ret void
 }
 
+; Test that chr will skip this function when addresses are taken on basic blocks.
+ at gototable = weak_odr dso_local local_unnamed_addr constant [2 x i8*] [i8* blockaddress(@test_chr_with_bbs_address_taken, %bb3), i8* blockaddress(@test_chr_with_bbs_address_taken, %bb3)]
+define void @test_chr_with_bbs_address_taken(i32* %i) !prof !14 {
+; CHECK-LABEL: @test_chr_with_bbs_address_taken(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = load i32, i32* [[I:%.*]], align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[TMP0]], 1
+; CHECK-NEXT:    [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 0
+; CHECK-NEXT:    br i1 [[TMP2]], label [[BB1:%.*]], label [[BB0:%.*]], !prof [[PROF16]]
+; CHECK:       bb0:
+; CHECK-NEXT:    call void @foo()
+; CHECK-NEXT:    br label [[BB1]]
+; CHECK:       bb1:
+; CHECK-NEXT:    [[TMP3:%.*]] = and i32 [[TMP0]], 2
+; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i32 [[TMP3]], 0
+; CHECK-NEXT:    br i1 [[TMP4]], label [[BB4:%.*]], label [[BB2:%.*]], !prof [[PROF16]]
+; CHECK:       bb2:
+; CHECK-NEXT:    call void @foo()
+; CHECK-NEXT:    br label [[BB4]]
+; CHECK:       bb4:
+; CHECK-NEXT:    ret void
+;
+entry:
+  %0 = load i32, i32* %i
+  %1 = and i32 %0, 1
+  %2 = icmp eq i32 %1, 0
+  br i1 %2, label %bb1, label %bb0, !prof !15
+
+bb0:
+  call void @foo()
+  br label %bb1
+
+bb1:
+  %3 = and i32 %0, 2
+  %4 = icmp eq i32 %3, 0
+  br i1 %4, label %bb4, label %bb2, !prof !15
+
+bb2:
+  call void @foo()
+  %pc = bitcast i32* %i to i8*
+  indirectbr i8* %pc, [label %bb3, label %bb3]
+
+bb3:
+  br label %bb4
+
+bb4:
+  ret void
+}
+
 !llvm.module.flags = !{!0}
 !0 = !{i32 1, !"ProfileSummary", !1}
 !1 = !{!2, !3, !4, !5, !6, !7, !8, !9}
Index: llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
===================================================================
--- llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
+++ llvm/lib/Transforms/Instrumentation/ControlHeightReduction.cpp
@@ -437,6 +437,16 @@
 }
 
 static bool shouldApply(Function &F, ProfileSummaryInfo& PSI) {
+  // If any of the basic blocks have address taken, we should skip this pass
+  // because the cloned blocks by this pass will not have address taken, and
+  // hence they may be optimized out by SimplifyCFG if they are targets of
+  // indirect branches.
+  bool HasBBAddressTaken =
+      llvm::any_of(F.getBasicBlockList(),
+                   [](const BasicBlock &BB) { return BB.hasAddressTaken(); });
+  if (HasBBAddressTaken)
+    return false;
+
   if (ForceCHR)
     return true;
 


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