diff --git a/bolt/lib/Passes/BinaryPasses.cpp b/bolt/lib/Passes/BinaryPasses.cpp index c0ba73108f577..df6dbcddeed56 100644 --- a/bolt/lib/Passes/BinaryPasses.cpp +++ b/bolt/lib/Passes/BinaryPasses.cpp @@ -910,6 +910,11 @@ uint64_t SimplifyConditionalTailCalls::fixTailCalls(BinaryFunction &BF) { auto &CTCAnnotation = MIB->getOrCreateAnnotationAs(*CondBranch, "CTCTakenCount"); CTCAnnotation = CTCTakenFreq; + // Preserve Offset annotation, used in BAT. + // Instr is a direct tail call instruction that was created when CTCs are + // first expanded, and has the original CTC offset set. + if (std::optional Offset = MIB->getOffset(*Instr)) + MIB->setOffset(*CondBranch, *Offset); // Remove the unused successor which may be eliminated later // if there are no other users. diff --git a/bolt/test/X86/sctc-bug4.test b/bolt/test/X86/sctc-bug4.test index 00f5ee429b635..92aca5110059f 100644 --- a/bolt/test/X86/sctc-bug4.test +++ b/bolt/test/X86/sctc-bug4.test @@ -1,20 +1,23 @@ -# Check that fallthrough blocks are handled properly. +# Check that fallthrough blocks are handled properly and Offset annotation is +# set for conditional tail calls. RUN: %clang %cflags %S/Inputs/sctc_bug4.s -o %t -RUN: llvm-bolt %t -o %t.null \ +RUN: llvm-bolt %t -o %t.null --enable-bat \ RUN: -funcs=test_func -print-sctc -sequential-disassembly 2>&1 | FileCheck %s CHECK: .Ltmp2 (3 instructions, align : 1) CHECK-NEXT: CFI State : 0 +CHECK-NEXT: Input offset: 0x24 CHECK-NEXT: Predecessors: .LFT1 CHECK-NEXT: 00000024: cmpq $0x20, %rsi -CHECK-NEXT: 00000028: ja dummy # TAILCALL {{.*}}# CTCTakenCount: 0 +CHECK-NEXT: 00000028: ja dummy # TAILCALL # Offset: 53 # CTCTakenCount: 0 CHECK-NEXT: 0000002a: jmp .Ltmp4 CHECK-NEXT: Successors: .Ltmp4 CHECK-NEXT: CFI State: 0 CHECK: .Ltmp1 (2 instructions, align : 1) CHECK-NEXT: CFI State : 0 +CHECK-NEXT: Input offset: 0x2c CHECK-NEXT: Predecessors: .LFT0 CHECK-NEXT: 0000002c: xorq %r11, %rax CHECK-NEXT: 0000002f: retq @@ -22,4 +25,5 @@ CHECK-NEXT: CFI State: 0 CHECK: .Ltmp4 (4 instructions, align : 1) CHECK-NEXT: CFI State : 0 +CHECK-NEXT: Input offset: 0x3a CHECK-NEXT: Predecessors: .Ltmp2