Index: llvm/trunk/lib/Target/X86/X86FrameLowering.cpp =================================================================== --- llvm/trunk/lib/Target/X86/X86FrameLowering.cpp +++ llvm/trunk/lib/Target/X86/X86FrameLowering.cpp @@ -1698,21 +1698,18 @@ } } -// NOTE: this only has a subset of the full frame index logic. In -// particular, the FI < 0 and AfterFPPop logic is handled in -// X86RegisterInfo::eliminateFrameIndex, but not here. Possibly -// (probably?) it should be moved into here. int X86FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI, unsigned &FrameReg) const { const MachineFrameInfo &MFI = MF.getFrameInfo(); + bool IsFixed = MFI.isFixedObjectIndex(FI); // We can't calculate offset from frame pointer if the stack is realigned, // so enforce usage of stack/base pointer. The base pointer is used when we // have dynamic allocas in addition to dynamic realignment. if (TRI->hasBasePointer(MF)) - FrameReg = TRI->getBaseRegister(); + FrameReg = IsFixed ? TRI->getFramePtr() : TRI->getBaseRegister(); else if (TRI->needsStackRealignment(MF)) - FrameReg = TRI->getStackRegister(); + FrameReg = IsFixed ? TRI->getFramePtr() : TRI->getStackRegister(); else FrameReg = TRI->getFrameRegister(MF); Index: llvm/trunk/lib/Target/X86/X86RegisterInfo.h =================================================================== --- llvm/trunk/lib/Target/X86/X86RegisterInfo.h +++ llvm/trunk/lib/Target/X86/X86RegisterInfo.h @@ -133,6 +133,11 @@ unsigned getPtrSizedFrameRegister(const MachineFunction &MF) const; unsigned getStackRegister() const { return StackPtr; } unsigned getBaseRegister() const { return BasePtr; } + /// Returns physical register used as frame pointer. + /// This will always returns the frame pointer register, contrary to + /// getFrameRegister() which returns the "base pointer" in situations + /// involving a stack, frame and base pointer. + unsigned getFramePtr() const { return FramePtr; } // FIXME: Move to FrameInfok unsigned getSlotSize() const { return SlotSize; } }; Index: llvm/trunk/test/CodeGen/X86/dbg-baseptr.ll =================================================================== --- llvm/trunk/test/CodeGen/X86/dbg-baseptr.ll +++ llvm/trunk/test/CodeGen/X86/dbg-baseptr.ll @@ -0,0 +1,75 @@ +; RUN: llc -o - %s | FileCheck %s +; This test checks that parameters on the stack pointer are correctly +; referenced by debug info. +target triple = "x86_64--" + +@glob = external global i64 +@ptr = external global i32* +%struct.s = type { i32, i32, i32, i32, i32 } + +; CHECK-LABEL: f0: +; CHECK: DEBUG_VALUE: f:input <- [%RSP+8] +define i32 @f0(%struct.s* byval align 8 %input) !dbg !8 { + call void @llvm.dbg.declare(metadata %struct.s* %input, metadata !4, metadata !17), !dbg !18 + ret i32 42 +} + +; CHECK-LABEL: f1: +; CHECK: DEBUG_VALUE: f:input <- [%RBP+16] +define i32 @f1(%struct.s* byval align 8 %input) !dbg !8 { + %val = load i64, i64* @glob + ; this alloca should force FP usage. + %stackspace = alloca i32, i64 %val, align 1 + store i32* %stackspace, i32** @ptr + call void @llvm.dbg.declare(metadata %struct.s* %input, metadata !4, metadata !17), !dbg !18 + ret i32 42 +} + +; CHECK-LABEL: f2: +; Just check that we are indeed aligning the stack and setting up a base pointer +; in RBX. +; CHECK: pushq %rbp +; CHECK: movq %rsp, %rbp +; CHECK: pushq %rbx +; CHECK: andq $-64, %rsp +; CHECK: subq $64, %rsp +; CHECK: movq %rsp, %rbx +; The parameter should still be referenced through RBP though. +; CHECK-NOT: DEBUG_VALUE: f:input <- [%RBX +; CHECK: DEBUG_VALUE: f:input <- [%RBP+16] +define i32 @f2(%struct.s* byval align 8 %input) !dbg !8 { + %val = load i64, i64* @glob + %stackspace = alloca i32, i64 %val, align 64 + store i32* %stackspace, i32** @ptr + call void @llvm.dbg.declare(metadata %struct.s* %input, metadata !4, metadata !17), !dbg !18 + ret i32 42 +} + +declare void @llvm.dbg.declare(metadata, metadata, metadata) + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!0, !1} + +!0 = !{i32 2, !"Dwarf Version", i32 4} +!1 = !{i32 2, !"Debug Info Version", i32 3} +!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3) +!3 = !DIFile(filename: "dbg-baseptr.ll", directory: "/") +!4 = !DILocalVariable(name: "input", arg: 1, scope: !8, file: !3, line: 5, type: !9) +!5 = !{} + +!6 = !DISubroutineType(types: !7) +!7 = !{!10, !9} + +!8 = distinct !DISubprogram(name: "f", file: !3, line: 5, type: !6, isLocal: false, isDefinition: true, flags: DIFlagPrototyped, unit: !2, variables: !5) + +!9 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s", elements: !11) +!10 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned) +!11 = !{!12, !13, !14, !15, !16} +!12 = !DIDerivedType(tag: DW_TAG_member, name: "a", baseType: !10, size: 32) +!13 = !DIDerivedType(tag: DW_TAG_member, name: "b", baseType: !10, size: 32, offset: 32) +!14 = !DIDerivedType(tag: DW_TAG_member, name: "c", baseType: !10, size: 32, offset: 64) +!15 = !DIDerivedType(tag: DW_TAG_member, name: "d", baseType: !10, size: 32, offset: 96) +!16 = !DIDerivedType(tag: DW_TAG_member, name: "e", baseType: !10, size: 32, offset: 128) + +!17 = !DIExpression() +!18 = !DILocation(line: 5, scope: !8)