From ad2652945a856ec20745ad1217e651722e48462f Mon Sep 17 00:00:00 2001 From: Shubham Sandeep Rastogi Date: Tue, 18 Mar 2025 13:57:22 -0700 Subject: [PATCH] [InstrRef] Preserve debug instr num in aarch64-cond-br-tuning. The aarch64-cond-br-tuning pass transforms a CBZX instruction into a conditional branch (B.cond). One of the by products of the transformation is that the source instruction of the CBZX, which is an ANDXri instruction, gets transformed into a ANDSXri instruction, however this transformation doesn't preserve it's debug instruction number. This patch fixes that issue. --- .../Target/AArch64/AArch64CondBrTuning.cpp | 6 +++ .../AArch64/cond-br-tuning-instr-ref.mir | 54 +++++++++++++++++++ 2 files changed, 60 insertions(+) create mode 100644 llvm/test/CodeGen/AArch64/cond-br-tuning-instr-ref.mir diff --git a/llvm/lib/Target/AArch64/AArch64CondBrTuning.cpp b/llvm/lib/Target/AArch64/AArch64CondBrTuning.cpp index da72e35a248eb..a091ab45c7737 100644 --- a/llvm/lib/Target/AArch64/AArch64CondBrTuning.cpp +++ b/llvm/lib/Target/AArch64/AArch64CondBrTuning.cpp @@ -102,6 +102,12 @@ MachineInstr *AArch64CondBrTuning::convertToFlagSetting(MachineInstr &MI, MachineInstrBuilder MIB = BuildMI(*MI.getParent(), MI, MI.getDebugLoc(), TII->get(NewOpc), NewDestReg); + + // If the MI has a debug instruction number, preserve that in the new Machine + // Instruction that is created. + if (MI.peekDebugInstrNum() != 0) + MIB->setDebugInstrNum(MI.peekDebugInstrNum()); + for (const MachineOperand &MO : llvm::drop_begin(MI.operands())) MIB.add(MO); diff --git a/llvm/test/CodeGen/AArch64/cond-br-tuning-instr-ref.mir b/llvm/test/CodeGen/AArch64/cond-br-tuning-instr-ref.mir new file mode 100644 index 0000000000000..589102ed63878 --- /dev/null +++ b/llvm/test/CodeGen/AArch64/cond-br-tuning-instr-ref.mir @@ -0,0 +1,54 @@ +# RUN: llc -mtriple=aarch64-unknown-linux-gnu -o - %s -run-pass=aarch64-cond-br-tuning | FileCheck %s + +# This testcase was obtained by looking at FileCheck.cpp and reducing it down via llvm-reduce + +# Check that the ANDXri preserves the debug info by retaining the debug-instr-number 1 in _ZN4llvmlsERNS_11raw_ostreamERKNS_5ErrorE after the aarch64-cond-br-tuning pass transforms it into a ANDSXri instruction. + +# CHECK: %{{[0-9]+}}:gpr64common = ANDSXri %{{[0-9]+}}, {{[0-9]+}}, implicit-def $nzcv, debug-instr-number 1 +# CHECK-NEXT: DBG_INSTR_REF !{{[0-9]+}}, !DIExpression(DW_OP_LLVM_arg, 0), dbg-instr-ref(1, 0) + +--- | + define ptr @_ZNK4llvm5Error6getPtrEv(ptr %this) local_unnamed_addr #0 { + entry: + %0 = ptrtoint ptr %this to i64 + %and = and i64 %0, -2 + %1 = inttoptr i64 %and to ptr + ret ptr %1 + } + define noalias noundef ptr @_ZN4llvmlsERNS_11raw_ostreamERKNS_5ErrorE(ptr %E) local_unnamed_addr #1 !dbg !4 { + entry: + %0 = ptrtoint ptr %E to i64, !dbg !13 + %and.i = and i64 %0, -2, !dbg !13 + %tobool.not = icmp eq i64 %and.i, 0 + br i1 %tobool.not, label %if.else, label %if.then + if.then: ; preds = %entry + unreachable + if.else: ; preds = %entry + ret ptr null + } + !llvm.module.flags = !{!0} + !llvm.dbg.cu = !{!1} + !0 = !{i32 2, !"Debug Info Version", i32 3} + !1 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !2, producer: "clang version 21.0.0git (\0A\0A\0Agit@github.com:llvm/llvm-project.git 6be6400848eeec027d0cca0662c105683bcc896b\0A\0A\0A)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, retainedTypes: !3, globals: !3, imports: !3, splitDebugInlining: false, nameTableKind: Apple, sysroot: "/Library/Developer/CommandLineTools/SDKs/MacOSX15.3.sdk", sdk: "MacOSX15.3.sdk") + !2 = !DIFile(filename: "/Users/shubhamrastogi/Development/llvm-project-instr-ref/llvm-project/llvm/lib/FileCheck/FileCheck.cpp", directory: "/Users/shubhamrastogi/Development/llvm-project-instr-ref/llvm-project/build-instr-ref-stage2", checksumkind: CSK_MD5, checksum: "ac1d2352ab68b965fe7993c780cf92d7") + !3 = !{} + !4 = distinct !DISubprogram(name: "operator<<", linkageName: "_ZN4llvmlsERNS_11raw_ostreamERKNS_5ErrorE", scope: !6, file: !5, line: 320, type: !7, scopeLine: 320, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !1, retainedNodes: !8) + !5 = !DIFile(filename: "llvm/include/llvm/Support/Error.h", directory: "/Users/shubhamrastogi/Development/llvm-project-instr-ref/llvm-project", checksumkind: CSK_MD5, checksum: "f166cdaeb719f8f71fbae8128cde93e4") + !6 = !DINamespace(name: "llvm", scope: null) + !7 = distinct !DISubroutineType(types: !3) + !8 = !{!9} + !9 = !DILocalVariable(name: "P", scope: !10, file: !5, line: 321, type: !11) + !10 = distinct !DILexicalBlock(scope: !4, file: !5, line: 321, column: 15) + !11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64) + !12 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "ErrorInfoBase", scope: !6, file: !5, line: 44, size: 64, flags: DIFlagTypePassByReference | DIFlagNonTrivial, elements: !3, vtableHolder: !12, identifier: "_ZTSN4llvm13ErrorInfoBaseE") + !13 = !DILocation(line: 321, column: 21, scope: !10) + !14 = !DILocation(line: 0, scope: !10) +name: _ZN4llvmlsERNS_11raw_ostreamERKNS_5ErrorE +body: | + bb.0.entry: + %1:gpr64 = COPY $x0 + %2:gpr64common = ANDXri %1, 8190, debug-instr-number 1, debug-location !13 + DBG_INSTR_REF !9, !DIExpression(DW_OP_LLVM_arg, 0), dbg-instr-ref(1, 0), debug-location !14 + %0:gpr64sp = COPY %2, debug-location !13 + CBZX %2, %bb.2 + bb.2.if.else: