[llvm] r248857 - [WinEH] Setup RBP correctly in Win64 funclet prologues
Justin Bogner via llvm-commits
llvm-commits at lists.llvm.org
Wed Sep 30 01:10:36 PDT 2015
Reid Kleckner via llvm-commits <llvm-commits at lists.llvm.org> writes:
> Author: rnk
> Date: Tue Sep 29 18:32:01 2015
> New Revision: 248857
>
> URL: http://llvm.org/viewvc/llvm-project?rev=248857&view=rev
> Log:
> [WinEH] Setup RBP correctly in Win64 funclet prologues
>
> Previously local variable captures just didn't work in 64-bit. Now we
> can access local variables more or less correctly.
>
> Modified:
> llvm/trunk/lib/Target/X86/X86FrameLowering.cpp
> llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll
> llvm/trunk/test/CodeGen/X86/win-catchpad.ll
> llvm/trunk/test/CodeGen/X86/win-cleanuppad.ll
> llvm/trunk/test/CodeGen/X86/win-funclet-cfi.ll
>
> Modified: llvm/trunk/lib/Target/X86/X86FrameLowering.cpp
> URL:
> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FrameLowering.cpp?rev=248857&r1=248856&r2=248857&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Target/X86/X86FrameLowering.cpp (original)
> +++ llvm/trunk/lib/Target/X86/X86FrameLowering.cpp Tue Sep 29 18:32:01 2015
> @@ -623,6 +623,7 @@ void X86FrameLowering::emitPrologue(Mach
> X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
> uint64_t MaxAlign = calculateMaxStackAlign(MF); // Desired stack alignment.
> uint64_t StackSize = MFI->getStackSize(); // Number of bytes to allocate.
> + bool IsFunclet = MBB.isEHFuncletEntry();
> bool HasFP = hasFP(MF);
> bool IsWin64CC = STI.isCallingConvWin64(Fn->getCallingConv());
> bool IsWin64Prologue = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
> @@ -700,46 +701,17 @@ void X86FrameLowering::emitPrologue(Mach
> uint64_t NumBytes = 0;
> int stackGrowth = -SlotSize;
>
> - if (MBB.isEHFuncletEntry()) {
> - assert(STI.isOSWindows() && "funclets only supported on Windows");
> -
> - // Set up the FramePtr and BasePtr physical registers using the address
> - // passed as EBP or RDX by the MSVC EH runtime.
> - if (STI.is32Bit()) {
> - // PUSH32r %ebp
> - BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
> - .addReg(MachineFramePtr, RegState::Kill)
> - .setMIFlag(MachineInstr::FrameSetup);
> - // Reset EBP / ESI to something good.
> - MBBI = restoreWin32EHStackPointers(MBB, MBBI, DL);
> - } else {
> - // Immediately spill RDX into the home slot. The runtime cares about this.
> - unsigned RDX = Uses64BitFramePtr ? X86::RDX : X86::EDX;
> - // MOV64mr %rdx, 16(%rsp)
> - unsigned MOVmr = Uses64BitFramePtr ? X86::MOV64mr : X86::MOV32mr;
> - addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(MOVmr)),
> - StackPtr, true, 16)
> + unsigned RDX = Uses64BitFramePtr ? X86::RDX : X86::EDX;
> + if (IsWin64Prologue && IsFunclet) {
> + // Immediately spill RDX into the home slot. The runtime cares about this.
> + // MOV64mr %rdx, 16(%rsp)
> + unsigned MOVmr = Uses64BitFramePtr ? X86::MOV64mr : X86::MOV32mr;
> + addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(MOVmr)), StackPtr, true, 16)
> .addReg(RDX)
> .setMIFlag(MachineInstr::FrameSetup);
> - // PUSH64r %rbp
> - BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH64r))
> - .addReg(MachineFramePtr, RegState::Kill)
> - .setMIFlag(MachineInstr::FrameSetup);
> - BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_PushReg))
> - .addImm(MachineFramePtr)
> - .setMIFlag(MachineInstr::FrameSetup);
> - // MOV64rr %rdx, %rbp
> - unsigned MOVrr = Uses64BitFramePtr ? X86::MOV64rr : X86::MOV32rr;
> - BuildMI(MBB, MBBI, DL, TII.get(MOVrr), FramePtr)
> - .addReg(RDX)
> - .setMIFlag(MachineInstr::FrameSetup);
> - assert(!TRI->hasBasePointer(MF) &&
> - "x64 funclets with base ptrs not yet implemented");
> - }
> + }
>
> - // For EH funclets, only allocate enough space for outgoing calls.
> - NumBytes = MFI->getMaxCallFrameSize();
> - } else if (HasFP) {
> + if (HasFP) {
> // Calculate required stack adjustment.
> uint64_t FrameSize = StackSize - SlotSize;
> // If required, include space for extra hidden slot for stashing base pointer.
> @@ -755,7 +727,11 @@ void X86FrameLowering::emitPrologue(Mach
> // Get the offset of the stack slot for the EBP register, which is
> // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
> // Update the frame offset adjustment.
> - MFI->setOffsetAdjustment(-NumBytes);
> + if (!IsFunclet)
> + MFI->setOffsetAdjustment(-NumBytes);
> + else
> + assert(MFI->getOffsetAdjustment() == -NumBytes &&
> + "should calculate same local variable offset for funclets");
I get a -Wsign-compare warning after this change:
.../llvm/lib/Target/X86/X86FrameLowering.cpp:733:41: error: comparison of integers of different signs: 'int' and 'uint64_t' (aka 'unsigned long long') [-Werror,-Wsign-compare]
assert(MFI->getOffsetAdjustment() == -NumBytes &&
~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~
>
> // Save EBP/RBP into the appropriate stack slot.
> BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
> @@ -781,30 +757,37 @@ void X86FrameLowering::emitPrologue(Mach
> .setMIFlag(MachineInstr::FrameSetup);
> }
>
> - if (!IsWin64Prologue) {
> + if (!IsWin64Prologue && !IsFunclet) {
> // Update EBP with the new base value.
> BuildMI(MBB, MBBI, DL,
> TII.get(Uses64BitFramePtr ? X86::MOV64rr : X86::MOV32rr),
> FramePtr)
> .addReg(StackPtr)
> .setMIFlag(MachineInstr::FrameSetup);
> - }
>
> - if (NeedsDwarfCFI) {
> - // Mark effective beginning of when frame pointer becomes valid.
> - // Define the current CFA to use the EBP/RBP register.
> - unsigned DwarfFramePtr = TRI->getDwarfRegNum(MachineFramePtr, true);
> - BuildCFI(MBB, MBBI, DL,
> - MCCFIInstruction::createDefCfaRegister(nullptr, DwarfFramePtr));
> + if (NeedsDwarfCFI) {
> + // Mark effective beginning of when frame pointer becomes valid.
> + // Define the current CFA to use the EBP/RBP register.
> + unsigned DwarfFramePtr = TRI->getDwarfRegNum(MachineFramePtr, true);
> + BuildCFI(MBB, MBBI, DL, MCCFIInstruction::createDefCfaRegister(
> + nullptr, DwarfFramePtr));
> + }
> }
>
> // Mark the FramePtr as live-in in every block.
> for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
> I->addLiveIn(MachineFramePtr);
> } else {
> + assert(!IsFunclet && "funclets without FPs not yet implemented");
> NumBytes = StackSize - X86FI->getCalleeSavedFrameSize();
> }
>
> + // For EH funclets, only allocate enough space for outgoing calls. Save the
> + // NumBytes value that we would've used for the parent frame.
> + unsigned ParentFrameNumBytes = NumBytes;
> + if (IsFunclet)
> + NumBytes = MFI->getMaxCallFrameSize();
> +
> // Skip the callee-saved push instructions.
> bool PushedRegs = false;
> int StackOffset = 2 * stackGrowth;
> @@ -835,7 +818,7 @@ void X86FrameLowering::emitPrologue(Mach
> // Realign stack after we pushed callee-saved registers (so that we'll be
> // able to calculate their offsets from the frame pointer).
> // Don't do this for Win64, it needs to realign the stack after the prologue.
> - if (!IsWin64Prologue && TRI->needsStackRealignment(MF)) {
> + if (!IsWin64Prologue && !IsFunclet && TRI->needsStackRealignment(MF)) {
> assert(HasFP && "There should be a frame pointer if stack is realigned.");
> BuildStackAlignAND(MBB, MBBI, DL, MaxAlign);
> }
> @@ -856,7 +839,7 @@ void X86FrameLowering::emitPrologue(Mach
> // increments is necessary to ensure that the guard pages used by the OS
> // virtual memory manager are allocated in correct sequence.
> uint64_t AlignedNumBytes = NumBytes;
> - if (IsWin64Prologue && TRI->needsStackRealignment(MF))
> + if (IsWin64Prologue && !IsFunclet && TRI->needsStackRealignment(MF))
> AlignedNumBytes = RoundUpToAlignment(AlignedNumBytes, MaxAlign);
> if (AlignedNumBytes >= StackProbeSize && UseStackProbe) {
> // Check whether EAX is livein for this function.
> @@ -927,18 +910,27 @@ void X86FrameLowering::emitPrologue(Mach
>
> int SEHFrameOffset = 0;
> if (IsWin64Prologue && HasFP) {
> - SEHFrameOffset = calculateSetFPREG(NumBytes);
> + // Set RBP to a small fixed offset from RSP. In the funclet case, we base
> + // this calculation on the incoming RDX, which holds the value of RSP from
> + // the parent frame at the end of the prologue.
> + unsigned SPOrRDX = !IsFunclet ? StackPtr : RDX;
> + SEHFrameOffset = calculateSetFPREG(ParentFrameNumBytes);
> if (SEHFrameOffset)
> addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(X86::LEA64r), FramePtr),
> - StackPtr, false, SEHFrameOffset);
> + SPOrRDX, false, SEHFrameOffset);
> else
> - BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64rr), FramePtr).addReg(StackPtr);
> + BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64rr), FramePtr)
> + .addReg(SPOrRDX);
>
> - if (NeedsWinCFI)
> + // If this is not a funclet, emit the CFI describing our frame pointer.
> + if (NeedsWinCFI && !IsFunclet)
> BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_SetFrame))
> .addImm(FramePtr)
> .addImm(SEHFrameOffset)
> .setMIFlag(MachineInstr::FrameSetup);
> + } else if (IsFunclet && STI.is32Bit()) {
> + // Reset EBP / ESI to something good for funclets.
> + MBBI = restoreWin32EHStackPointers(MBB, MBBI, DL);
> }
>
> while (MBBI != MBB.end() && MBBI->getFlag(MachineInstr::FrameSetup)) {
>
> Modified: llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll?rev=248857&r1=248856&r2=248857&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll (original)
> +++ llvm/trunk/test/CodeGen/X86/win-catchpad-csrs.ll Tue Sep 29 18:32:01 2015
> @@ -75,8 +75,8 @@ catchendblock:
> ; X86: LBB0_[[catch1bb]]: # %catch{{$}}
> ; X86: pushl %ebp
> ; X86-NOT: pushl
> -; X86: addl $12, %ebp
> ; X86: subl $16, %esp
> +; X86: addl $12, %ebp
> ; X86: movl $1, -{{[0-9]+}}(%ebp)
> ; X86: movl $2, (%esp)
> ; X86: calll _f
> @@ -105,6 +105,7 @@ catchendblock:
> ; X64: .seh_stackalloc 40
> ; X64: leaq 32(%rsp), %rbp
> ; X64: .seh_setframe 5, 32
> +; X64: .seh_endprologue
> ; X64: callq getint
> ; X64: callq getint
> ; X64: callq getint
> @@ -121,8 +122,11 @@ catchendblock:
> ; X64: LBB0_[[catch1bb]]: # %catch{{$}}
> ; X64: movq %rdx, 16(%rsp)
> ; X64: pushq %rbp
> -; X64: movq %rdx, %rbp
> +; X64: .seh_pushreg 5
> ; X64: subq $32, %rsp
> +; X64: .seh_stackalloc 32
> +; X64: leaq 32(%rdx), %rbp
> +; X64: .seh_endprologue
> ; X64: movl $2, %ecx
> ; X64: callq f
> ; X64: leaq [[contbb]](%rip), %rax
>
> Modified: llvm/trunk/test/CodeGen/X86/win-catchpad.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win-catchpad.ll?rev=248857&r1=248856&r2=248857&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/win-catchpad.ll (original)
> +++ llvm/trunk/test/CodeGen/X86/win-catchpad.ll Tue Sep 29 18:32:01 2015
> @@ -87,8 +87,8 @@ catchendblock:
> ; X86: "?catch$[[catch1bb:[0-9]+]]@?0?try_catch_catch at 4HA":
> ; X86: LBB0_[[catch1bb]]: # %catch{{$}}
> ; X86: pushl %ebp
> -; X86: addl $12, %ebp
> ; X86: subl $8, %esp
> +; X86: addl $12, %ebp
> ; X86: movl -32(%ebp), %[[e_reg:[a-z]+]]
> ; X86: movl $1, -{{[0-9]+}}(%ebp)
> ; X86: leal -[[local_offs]](%ebp), %[[addr_reg:[a-z]+]]
> @@ -103,8 +103,8 @@ catchendblock:
> ; X86: "?catch$[[catch2bb:[0-9]+]]@?0?try_catch_catch at 4HA":
> ; X86: LBB0_[[catch2bb]]: # %catch.2{{$}}
> ; X86: pushl %ebp
> -; X86: addl $12, %ebp
> ; X86: subl $8, %esp
> +; X86: addl $12, %ebp
> ; X86: movl $1, -{{[0-9]+}}(%ebp)
> ; X86: leal -[[local_offs]](%ebp), %[[addr_reg:[a-z]+]]
> ; X86-DAG: movl %[[addr_reg]], 4(%esp)
> @@ -134,6 +134,7 @@ catchendblock:
> ; X64: .seh_stackalloc 48
> ; X64: leaq 48(%rsp), %rbp
> ; X64: .seh_setframe 5, 48
> +; X64: .seh_endprologue
> ; X64: .Ltmp0
> ; X64-DAG: leaq -[[local_offs:[0-9]+]](%rbp), %rdx
> ; X64-DAG: movl $1, %ecx
> @@ -147,8 +148,11 @@ catchendblock:
> ; X64: LBB0_[[catch1bb]]: # %catch{{$}}
> ; X64: movq %rdx, 16(%rsp)
> ; X64: pushq %rbp
> -; X64: movq %rdx, %rbp
> +; X64: .seh_pushreg 5
> ; X64: subq $32, %rsp
> +; X64: .seh_stackalloc 32
> +; X64: leaq 48(%rdx), %rbp
> +; X64: .seh_endprologue
> ; X64-DAG: .Ltmp4
> ; X64-DAG: leaq -[[local_offs]](%rbp), %rdx
> ; X64-DAG: movl [[e_addr:[-0-9]+]](%rbp), %ecx
> @@ -162,8 +166,11 @@ catchendblock:
> ; X64: LBB0_[[catch2bb]]: # %catch.2{{$}}
> ; X64: movq %rdx, 16(%rsp)
> ; X64: pushq %rbp
> -; X64: movq %rdx, %rbp
> +; X64: .seh_pushreg 5
> ; X64: subq $32, %rsp
> +; X64: .seh_stackalloc 32
> +; X64: leaq 48(%rdx), %rbp
> +; X64: .seh_endprologue
> ; X64-DAG: leaq -[[local_offs]](%rbp), %rdx
> ; X64-DAG: movl $3, %ecx
> ; X64: callq f
>
> Modified: llvm/trunk/test/CodeGen/X86/win-cleanuppad.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win-cleanuppad.ll?rev=248857&r1=248856&r2=248857&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/win-cleanuppad.ll (original)
> +++ llvm/trunk/test/CodeGen/X86/win-cleanuppad.ll Tue Sep 29 18:32:01 2015
> @@ -99,18 +99,18 @@ cleanup.outer:
>
> ; X64-LABEL: nested_cleanup:
> ; X64: .Lfunc_begin1:
> -; X64: .Ltmp14:
> +; X64: .Ltmp13:
> ; X64: movl $1, %ecx
> ; X64: callq f
> -; X64: .Ltmp16:
> +; X64: .Ltmp15:
> ; X64: movl $2, %ecx
> ; X64: callq f
> -; X64: .Ltmp17:
> +; X64: .Ltmp16:
> ; X64: callq "??1Dtor@@QAE at XZ"
> -; X64: .Ltmp18:
> +; X64: .Ltmp17:
> ; X64: movl $3, %ecx
> ; X64: callq f
> -; X64: .Ltmp19:
> +; X64: .Ltmp18:
>
> ; X64: "?dtor$[[cleanup_inner:[0-9]+]]@?0?nested_cleanup at 4HA":
> ; X64: LBB1_[[cleanup_inner]]: # %cleanup.inner{{$}}
> @@ -155,13 +155,13 @@ cleanup.outer:
> ; X64: $ip2state$nested_cleanup:
> ; X64-NEXT: .long .Lfunc_begin1 at IMGREL
> ; X64-NEXT: .long -1
> -; X64-NEXT: .long .Ltmp14 at IMGREL
> +; X64-NEXT: .long .Ltmp13 at IMGREL
> ; X64-NEXT: .long 0
> -; X64-NEXT: .long .Ltmp16 at IMGREL
> +; X64-NEXT: .long .Ltmp15 at IMGREL
> ; X64-NEXT: .long 1
> -; X64-NEXT: .long .Ltmp18 at IMGREL
> +; X64-NEXT: .long .Ltmp17 at IMGREL
> ; X64-NEXT: .long 0
> -; X64-NEXT: .long .Ltmp19 at IMGREL+1
> +; X64-NEXT: .long .Ltmp18 at IMGREL+1
> ; X64-NEXT: .long -1
>
> attributes #0 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
>
> Modified: llvm/trunk/test/CodeGen/X86/win-funclet-cfi.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win-funclet-cfi.ll?rev=248857&r1=248856&r2=248857&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/X86/win-funclet-cfi.ll (original)
> +++ llvm/trunk/test/CodeGen/X86/win-funclet-cfi.ll Tue Sep 29 18:32:01 2015
> @@ -51,9 +51,8 @@ declare i32 @__CxxFrameHandler3(...)
> ; CHECK: subq $32, %rsp
> ; CHECK: .seh_stackalloc 32
>
> -; FIXME: This looks wrong...
> -; CHECK: leaq 32(%rsp), %rbp
> -; CHECK: .seh_setframe 5, 32
> +; CHECK: leaq 48(%rdx), %rbp
> +; CHECK-NOT: .seh_setframe
>
> ; Prologue is done, emit the .seh_endprologue directive.
> ; CHECK: .seh_endprologue
> @@ -82,9 +81,8 @@ declare i32 @__CxxFrameHandler3(...)
> ; CHECK: subq $32, %rsp
> ; CHECK: .seh_stackalloc 32
>
> -; FIXME: This looks wrong...
> -; CHECK: leaq 32(%rsp), %rbp
> -; CHECK: .seh_setframe 5, 32
> +; CHECK: leaq 48(%rdx), %rbp
> +; CHECK-NOT: .seh_setframe
>
> ; Prologue is done, emit the .seh_endprologue directive.
> ; CHECK: .seh_endprologue
>
>
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