[llvm] r351421 - [ARM64][Windows] Share unwind codes between epilogues
Hans Wennborg via llvm-commits
llvm-commits at lists.llvm.org
Thu Jan 17 07:43:15 PST 2019
Merged to 8.0 in r351452.
On Thu, Jan 17, 2019 at 10:49 AM Sanjin Sijaric via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
>
> Author: ssijaric
> Date: Thu Jan 17 01:45:17 2019
> New Revision: 351421
>
> URL: http://llvm.org/viewvc/llvm-project?rev=351421&view=rev
> Log:
> [ARM64][Windows] Share unwind codes between epilogues
>
> There are cases where we have multiple epilogues that have the exact same unwind
> code sequence. In that case, the epilogues can share the same unwind codes in
> the .xdata section. This should get us past the assert "SEH unwind data
> splitting not yet implemented" in many cases.
>
> We still need to add support for generating multiple .pdata/.xdata sections for
> those functions that need to be split into fragments.
>
> Differential Revision: https://reviews.llvm.org/D56813
>
> Added:
> llvm/trunk/test/CodeGen/AArch64/wineh8.mir
> Modified:
> llvm/trunk/lib/MC/MCWin64EH.cpp
> llvm/trunk/test/CodeGen/AArch64/wineh4.mir
>
> Modified: llvm/trunk/lib/MC/MCWin64EH.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCWin64EH.cpp?rev=351421&r1=351420&r2=351421&view=diff
> ==============================================================================
> --- llvm/trunk/lib/MC/MCWin64EH.cpp (original)
> +++ llvm/trunk/lib/MC/MCWin64EH.cpp Thu Jan 17 01:45:17 2019
> @@ -453,6 +453,38 @@ static void ARM64EmitUnwindCode(MCStream
> }
> }
>
> +// Returns the epilog symbol of an epilog with the exact same unwind code
> +// sequence, if it exists. Otherwise, returns nulltpr.
> +// EpilogInstrs - Unwind codes for the current epilog.
> +// Epilogs - Epilogs that potentialy match the current epilog.
> +static MCSymbol*
> +FindMatchingEpilog(const std::vector<WinEH::Instruction>& EpilogInstrs,
> + const std::vector<MCSymbol *>& Epilogs,
> + const WinEH::FrameInfo *info) {
> + for (auto *EpilogStart : Epilogs) {
> + auto InstrsIter = info->EpilogMap.find(EpilogStart);
> + assert(InstrsIter != info->EpilogMap.end() &&
> + "Epilog not found in EpilogMap");
> + const auto &Instrs = InstrsIter->second;
> +
> + if (Instrs.size() != EpilogInstrs.size())
> + continue;
> +
> + bool Match = true;
> + for (unsigned i = 0; i < Instrs.size(); ++i)
> + if (Instrs[i].Operation != EpilogInstrs[i].Operation ||
> + Instrs[i].Offset != EpilogInstrs[i].Offset ||
> + Instrs[i].Register != EpilogInstrs[i].Register) {
> + Match = false;
> + break;
> + }
> +
> + if (Match)
> + return EpilogStart;
> + }
> + return nullptr;
> +}
> +
> // Populate the .xdata section. The format of .xdata on ARM64 is documented at
> // https://docs.microsoft.com/en-us/cpp/build/arm64-exception-handling
> static void ARM64EmitUnwindInfo(MCStreamer &streamer, WinEH::FrameInfo *info) {
> @@ -477,12 +509,29 @@ static void ARM64EmitUnwindInfo(MCStream
>
> // Process epilogs.
> MapVector<MCSymbol *, uint32_t> EpilogInfo;
> + // Epilogs processed so far.
> + std::vector<MCSymbol *> AddedEpilogs;
> +
> for (auto &I : info->EpilogMap) {
> MCSymbol *EpilogStart = I.first;
> auto &EpilogInstrs = I.second;
> uint32_t CodeBytes = ARM64CountOfUnwindCodes(EpilogInstrs);
> - EpilogInfo[EpilogStart] = TotalCodeBytes;
> - TotalCodeBytes += CodeBytes;
> +
> + uint32_t NumUnwindCodes = EpilogInstrs.size();
> + MCSymbol* MatchingEpilog =
> + FindMatchingEpilog(EpilogInstrs, AddedEpilogs, info);
> + if (MatchingEpilog) {
> + assert(EpilogInfo.find(MatchingEpilog) != EpilogInfo.end() &&
> + "Duplicate epilog not found");
> + EpilogInfo[EpilogStart] = EpilogInfo[MatchingEpilog];
> + // Clear the unwind codes in the EpilogMap, so that they don't get output
> + // in the logic below.
> + EpilogInstrs.clear();
> + } else {
> + EpilogInfo[EpilogStart] = TotalCodeBytes;
> + TotalCodeBytes += CodeBytes;
> + AddedEpilogs.push_back(EpilogStart);
> + }
> }
>
> // Code Words, Epilog count, E, X, Vers, Function Length
>
> Modified: llvm/trunk/test/CodeGen/AArch64/wineh4.mir
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/wineh4.mir?rev=351421&r1=351420&r2=351421&view=diff
> ==============================================================================
> --- llvm/trunk/test/CodeGen/AArch64/wineh4.mir (original)
> +++ llvm/trunk/test/CodeGen/AArch64/wineh4.mir Thu Jan 17 01:45:17 2019
> @@ -1,7 +1,7 @@
> # RUN: llc -o - %s -mtriple=aarch64-windows -start-after=prologepilog \
> # RUN: -disable-branch-fold -filetype=obj \
> # RUN: | llvm-readobj -unwind | FileCheck %s
> -# Check that multiple epilgoues are correctly placed in .xdata.
> +# Check that identical multiple epilgoues are correctly shared in .xdata.
>
> # CHECK: ExceptionData {
> # CHECK-NEXT: FunctionLength: 164
> @@ -9,7 +9,7 @@
> # CHECK-NEXT: ExceptionData: No
> # CHECK-NEXT: EpiloguePacked: No
> # CHECK-NEXT: EpilogueScopes: 2
> -# CHECK-NEXT: ByteCodeLength: 48
> +# CHECK-NEXT: ByteCodeLength: 32
> # CHECK-NEXT: Prologue [
> # CHECK-NEXT: 0xc80c ; stp x19, x20, [sp, #96]
> # CHECK-NEXT: 0xc88a ; stp x21, x22, [sp, #80]
> @@ -37,7 +37,7 @@
> # CHECK-NEXT: }
> # CHECK-NEXT: EpilogueScope {
> # CHECK-NEXT: StartOffset: 33
> -# CHECK-NEXT: EpilogueStartIndex: 30
> +# CHECK-NEXT: EpilogueStartIndex: 15
> # CHECK-NEXT: Opcodes [
> # CHECK-NEXT: 0xc80c ; ldp x19, x20, [sp, #96]
> # CHECK-NEXT: 0xc88a ; ldp x21, x22, [sp, #80]
>
> Added: llvm/trunk/test/CodeGen/AArch64/wineh8.mir
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/wineh8.mir?rev=351421&view=auto
> ==============================================================================
> --- llvm/trunk/test/CodeGen/AArch64/wineh8.mir (added)
> +++ llvm/trunk/test/CodeGen/AArch64/wineh8.mir Thu Jan 17 01:45:17 2019
> @@ -0,0 +1,225 @@
> +# RUN: llc -o - %s -mtriple=aarch64-windows -start-after=prologepilog \
> +# RUN: -disable-branch-fold -filetype=obj \
> +# RUN: | llvm-readobj -unwind | FileCheck %s
> +# Check that non-identical multiple epilgoues are correctly shared in .xdata.
> +
> +# CHECK: ExceptionData {
> +# CHECK-NEXT: FunctionLength: 160
> +# CHECK-NEXT: Version: 0
> +# CHECK-NEXT: ExceptionData: No
> +# CHECK-NEXT: EpiloguePacked: No
> +# CHECK-NEXT: EpilogueScopes: 2
> +# CHECK-NEXT: ByteCodeLength: 44
> +# CHECK-NEXT: Prologue [
> +# CHECK-NEXT: 0xc80c ; stp x19, x20, [sp, #96]
> +# CHECK-NEXT: 0xc88a ; stp x21, x22, [sp, #80]
> +# CHECK-NEXT: 0xc908 ; stp x23, x24, [sp, #64]
> +# CHECK-NEXT: 0xc986 ; stp x25, x26, [sp, #48]
> +# CHECK-NEXT: 0xca04 ; stp x27, x28, [sp, #32]
> +# CHECK-NEXT: 0xd802 ; stp d8, d9, [sp, #16]
> +# CHECK-NEXT: 0xda8d ; stp d10, d11, [sp, #-112]!
> +# CHECK-NEXT: 0xe4 ; end
> +# CHECK-NEXT: ]
> +# CHECK-NEXT: EpilogueScopes [
> +# CHECK-NEXT: EpilogueScope {
> +# CHECK-NEXT: StartOffset: 16
> +# CHECK-NEXT: EpilogueStartIndex: 15
> +# CHECK-NEXT: Opcodes [
> +# CHECK-NEXT: 0xc80c ; ldp x19, x20, [sp, #96]
> +# CHECK-NEXT: 0xc88a ; ldp x21, x22, [sp, #80]
> +# CHECK-NEXT: 0xc908 ; ldp x23, x24, [sp, #64]
> +# CHECK-NEXT: 0xc986 ; ldp x25, x26, [sp, #48]
> +# CHECK-NEXT: 0xd802 ; ldp d8, d9, [sp, #16]
> +# CHECK-NEXT: 0xda8d ; ldp d10, d11, [sp], #112
> +# CHECK-NEXT: 0xe4 ; end
> +# CHECK-NEXT: ]
> +# CHECK-NEXT: }
> +# CHECK-NEXT: EpilogueScope {
> +# CHECK-NEXT: StartOffset: 32
> +# CHECK-NEXT: EpilogueStartIndex: 28
> +# CHECK-NEXT: Opcodes [
> +# CHECK-NEXT: 0xc80c ; ldp x19, x20, [sp, #96]
> +# CHECK-NEXT: 0xc88a ; ldp x21, x22, [sp, #80]
> +# CHECK-NEXT: 0xc908 ; ldp x23, x24, [sp, #64]
> +# CHECK-NEXT: 0xc986 ; ldp x25, x26, [sp, #48]
> +# CHECK-NEXT: 0xca04 ; ldp x27, x28, [sp, #32]
> +# CHECK-NEXT: 0xd802 ; ldp d8, d9, [sp, #16]
> +# CHECK-NEXT: 0xda8d ; ldp d10, d11, [sp], #112
> +# CHECK-NEXT: 0xe4 ; end
> +# CHECK-NEXT: ]
> +# CHECK-NEXT: }
> +# CHECK-NEXT: ]
> +# CHECK-NEXT: }
> +...
> +---
> +name: test
> +alignment: 2
> +exposesReturnsTwice: false
> +legalized: false
> +regBankSelected: false
> +selected: false
> +failedISel: false
> +tracksRegLiveness: true
> +hasWinCFI: true
> +registers:
> +liveins:
> + - { reg: '$w0', virtual-reg: '' }
> +frameInfo:
> + isFrameAddressTaken: false
> + isReturnAddressTaken: false
> + hasStackMap: false
> + hasPatchPoint: false
> + stackSize: 112
> + offsetAdjustment: 0
> + maxAlignment: 8
> + adjustsStack: false
> + hasCalls: false
> + stackProtector: ''
> + maxCallFrameSize: 0
> + hasOpaqueSPAdjustment: true
> + hasVAStart: false
> + hasMustTailInVarArgFunc: false
> + localFrameSize: 0
> + savePoint: ''
> + restorePoint: ''
> +fixedStack:
> +stack:
> + - { id: 0, name: '', type: spill-slot, offset: -8, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x19', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 1, name: '', type: spill-slot, offset: -16, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x20', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 2, name: '', type: spill-slot, offset: -24, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x21', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 3, name: '', type: spill-slot, offset: -32, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x22', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 4, name: '', type: spill-slot, offset: -40, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x23', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 5, name: '', type: spill-slot, offset: -48, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x24', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 6, name: '', type: spill-slot, offset: -56, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x25', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 7, name: '', type: spill-slot, offset: -64, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x26', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 8, name: '', type: spill-slot, offset: -72, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x27', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 9, name: '', type: spill-slot, offset: -80, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$x28', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 10, name: '', type: spill-slot, offset: -88, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$d8', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 11, name: '', type: spill-slot, offset: -96, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$d9', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 12, name: '', type: spill-slot, offset: -104, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$d10', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> + - { id: 13, name: '', type: spill-slot, offset: -112, size: 8, alignment: 8,
> + stack-id: 0, callee-saved-register: '$d11', callee-saved-restored: true,
> + debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
> +constants:
> +body: |
> + bb.0.entry:
> + successors: %bb.2(0x40000000), %bb.1(0x40000000)
> + liveins: $x0, $x1, $d0, $d1, $d10, $d11, $d8, $d9, $x27, $x28, $x25, $x26, $x23, $x24, $x21, $x22, $x19, $x20
> +
> + early-clobber $sp = frame-setup STPDpre killed $d10, killed $d11, $sp, -14 :: (store 8 into %stack.12), (store 8 into %stack.13)
> + frame-setup SEH_SaveFRegP_X 10, 11, -112
> + frame-setup STPDi killed $d8, killed $d9, $sp, 2 :: (store 8 into %stack.10), (store 8 into %stack.11)
> + frame-setup SEH_SaveFRegP 8, 9, 16
> + frame-setup STPXi killed $x27, killed $x28, $sp, 4 :: (store 8 into %stack.8), (store 8 into %stack.9)
> + frame-setup SEH_SaveRegP 27, 28, 32
> + frame-setup STPXi killed $x25, killed $x26, $sp, 6 :: (store 8 into %stack.6), (store 8 into %stack.7)
> + frame-setup SEH_SaveRegP 25, 26, 48
> + frame-setup STPXi killed $x23, killed $x24, $sp, 8 :: (store 8 into %stack.4), (store 8 into %stack.5)
> + frame-setup SEH_SaveRegP 23, 24, 64
> + frame-setup STPXi killed $x21, killed $x22, $sp, 10 :: (store 8 into %stack.2), (store 8 into %stack.3)
> + frame-setup SEH_SaveRegP 21, 22, 80
> + frame-setup STPXi killed $x19, killed $x20, $sp, 12 :: (store 8 into %stack.0), (store 8 into %stack.1)
> + frame-setup SEH_SaveRegP 19, 20, 96
> + frame-setup SEH_PrologEnd
> + frame-setup CFI_INSTRUCTION def_cfa_offset 112
> + frame-setup CFI_INSTRUCTION offset $w19, -8
> + frame-setup CFI_INSTRUCTION offset $w20, -16
> + frame-setup CFI_INSTRUCTION offset $w21, -24
> + frame-setup CFI_INSTRUCTION offset $w22, -32
> + frame-setup CFI_INSTRUCTION offset $w23, -40
> + frame-setup CFI_INSTRUCTION offset $w24, -48
> + frame-setup CFI_INSTRUCTION offset $w25, -56
> + frame-setup CFI_INSTRUCTION offset $w26, -64
> + frame-setup CFI_INSTRUCTION offset $w27, -72
> + frame-setup CFI_INSTRUCTION offset $w28, -80
> + frame-setup CFI_INSTRUCTION offset $b8, -88
> + frame-setup CFI_INSTRUCTION offset $b9, -96
> + frame-setup CFI_INSTRUCTION offset $b10, -104
> + frame-setup CFI_INSTRUCTION offset $b11, -112
> + $x19 = ADDXrr $x0, killed $x1
> + $d8 = FADDDrr killed $d0, $d1
> + $d9 = FADDDrr $d8, $d1
> + $d10 = FADDDrr $d9, $d8
> + $d11 = FADDDrr killed $d9, $d10
> + $x20 = SUBSXrr $x19, killed $x0, implicit-def $nzcv
> + Bcc 1, %bb.2, implicit killed $nzcv
> + B %bb.1
> +
> + bb.1:
> + liveins: $x19, $x20
> +
> + $x21 = ADDXrr $x20, killed $x19
> + $x22 = ADDXrr $x21, killed $x20
> + $x23 = ADDXrr $x22, killed $x21
> + $x24 = ADDXrr $x23, killed $x22
> + $x25 = ADDXrr $x24, killed $x23
> + $x26 = ADDXrr $x25, killed $x24
> + $x27 = ADDXrr $x26, killed $x25
> + $x28 = ADDXrr $x27, killed $x26
> + $x0 = COPY $x28
> + frame-destroy SEH_EpilogStart
> + $x19, $x20 = frame-destroy LDPXi $sp, 12 :: (load 8 from %stack.0), (load 8 from %stack.1)
> + frame-destroy SEH_SaveRegP 19, 20, 96
> + $x21, $x22 = frame-destroy LDPXi $sp, 10 :: (load 8 from %stack.2), (load 8 from %stack.3)
> + frame-destroy SEH_SaveRegP 21, 22, 80
> + $x23, $x24 = frame-destroy LDPXi $sp, 8 :: (load 8 from %stack.4), (load 8 from %stack.5)
> + frame-destroy SEH_SaveRegP 23, 24, 64
> + $x25, $x26 = frame-destroy LDPXi $sp, 6 :: (load 8 from %stack.6), (load 8 from %stack.7)
> + frame-destroy SEH_SaveRegP 25, 26, 48
> + $x27, $x28 = frame-destroy LDPXi $sp, 4 :: (load 8 from %stack.8), (load 8 from %stack.9)
> + frame-destroy SEH_SaveRegP 27, 28, 32
> + $d8, $d9 = frame-destroy LDPDi $sp, 2 :: (load 8 from %stack.10), (load 8 from %stack.11)
> + frame-destroy SEH_SaveFRegP 8, 9, 16
> + early-clobber $sp, $d10, $d11 = frame-destroy LDPDpost $sp, 14 :: (load 8 from %stack.12), (load 8 from %stack.13)
> + frame-destroy SEH_SaveFRegP_X 10, 11, -112
> + frame-destroy SEH_EpilogEnd
> + RET_ReallyLR implicit $x0
> +
> + bb.2:
> + liveins: $x28, $d11
> +
> + $x0 = COPY $d11
> + $x0 = ADDXrr $x0, killed $x28
> + frame-destroy SEH_EpilogStart
> + $x19, $x20 = frame-destroy LDPXi $sp, 12 :: (load 8 from %stack.0), (load 8 from %stack.1)
> + frame-destroy SEH_SaveRegP 19, 20, 96
> + $x21, $x22 = frame-destroy LDPXi $sp, 10 :: (load 8 from %stack.2), (load 8 from %stack.3)
> + frame-destroy SEH_SaveRegP 21, 22, 80
> + $x23, $x24 = frame-destroy LDPXi $sp, 8 :: (load 8 from %stack.4), (load 8 from %stack.5)
> + frame-destroy SEH_SaveRegP 23, 24, 64
> + $x25, $x26 = frame-destroy LDPXi $sp, 6 :: (load 8 from %stack.6), (load 8 from %stack.7)
> + frame-destroy SEH_SaveRegP 25, 26, 48
> + $d8, $d9 = frame-destroy LDPDi $sp, 2 :: (load 8 from %stack.10), (load 8 from %stack.11)
> + frame-destroy SEH_SaveFRegP 8, 9, 16
> + early-clobber $sp, $d10, $d11 = frame-destroy LDPDpost $sp, 14 :: (load 8 from %stack.12), (load 8 from %stack.13)
> + frame-destroy SEH_SaveFRegP_X 10, 11, -112
> + frame-destroy SEH_EpilogEnd
> + RET_ReallyLR implicit $x0
> +
> +...
>
>
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