Index: bolt/lib/Passes/TailDuplication.cpp =================================================================== --- bolt/lib/Passes/TailDuplication.cpp +++ bolt/lib/Passes/TailDuplication.cpp @@ -303,7 +303,7 @@ if (isInCacheLine(BB, Tail)) return BlocksToDuplicate; - BinaryBasicBlock *CurrBB = &BB; + BinaryBasicBlock *CurrBB = &Tail; while (CurrBB) { LLVM_DEBUG(dbgs() << "Aggressive tail duplication: adding " << CurrBB->getName() << " to duplication list\n";); Index: bolt/test/X86/tail-duplication-pass.s =================================================================== --- bolt/test/X86/tail-duplication-pass.s +++ bolt/test/X86/tail-duplication-pass.s @@ -7,12 +7,21 @@ # RUN: llvm-bolt %t.exe --data %t.fdata --reorder-blocks=ext-tsp \ # RUN: --print-finalized --tail-duplication=moderate \ # RUN: --tail-duplication-minimum-offset=1 -o %t.out | FileCheck %s +# RUN: llvm-bolt %t.exe --data %t.fdata --print-finalized \ +# RUN: --tail-duplication=aggressive --tail-duplication-minimum-offset=1 \ +# RUN: -o %t.out | FileCheck %s --check-prefix CHECK-NOLOOP # FDATA: 1 main 2 1 main #.BB2# 0 10 # FDATA: 1 main 4 1 main #.BB2# 0 20 # CHECK: BOLT-INFO: tail duplication modified 1 ({{.*}}%) functions; duplicated 1 blocks (1 bytes) responsible for {{.*}} dynamic executions ({{.*}}% of all block executions) # CHECK: BB Layout : .LBB00, .Ltail-dup0, .Ltmp0, .Ltmp1 +# Check that the successor of Ltail-dup0 is .LBB00, not itself. +# CHECK-NOLOOP: .Ltail-dup0 (1 instructions, align : 1) +# CHECK-NOLOOP: Predecessors: .LBB00 +# CHECK-NOLOOP: retq +# CHECK-NOLOOP: .Ltmp0 (1 instructions, align : 1) + .text .globl main .type main, %function