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[SYCL]Use llvm-link's only-needed option to link device libs #2783

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Merged
merged 12 commits into from
Dec 10, 2020
Merged

[SYCL]Use llvm-link's only-needed option to link device libs #2783

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af48e23
Use llvm-link's only-needed option to link device libs
jinge90 Nov 17, 2020
ee8a959
Fix clang-format issue
jinge90 Nov 17, 2020
668c1c7
Merge remote-tracking branch 'origin/sycl' into SyclDeviceLibsLinkOnl…
jinge90 Dec 1, 2020
702d25e
Merge remote-tracking branch 'origin/sycl' into SyclDeviceLibsLinkOnl…
jinge90 Dec 4, 2020
a3c7066
Enable libm-fp64 default link
jinge90 Dec 4, 2020
31133b6
Revert link all device libraries by default, plan to do this in a sep…
jinge90 Dec 8, 2020
cffb9fe
Fix clang-format issue
jinge90 Dec 8, 2020
ebc68a8
Fix sycl-device-lib lit failure
jinge90 Dec 8, 2020
b4bce03
Fix sycl devicelib check issue on Windows
jinge90 Dec 8, 2020
37ffa4b
Using std::find_if to replace for-loop when checking input SYCL devic…
jinge90 Dec 9, 2020
9dc7070
Fix minor defect and issues for sycl-device-lib-win
jinge90 Dec 9, 2020
865b50e
add test to check only-needed is not used when fno-sycl-device-only=all
jinge90 Dec 9, 2020
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69 changes: 47 additions & 22 deletions clang/lib/Driver/Driver.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3772,16 +3772,6 @@ class OffloadingActionBuilder final {
for (auto SDA : SYCLDeviceActions)
SYCLLinkBinaryList.push_back(SDA);
if (WrapDeviceOnlyBinary) {
// If used without -fintelfpga, -fsycl-link is used to wrap device
// objects for future host link. Device libraries should be linked
// by default to resolve any undefined reference.
if (!Args.hasArg(options::OPT_fintelfpga)) {
const auto *TC = ToolChains.front();
addSYCLDeviceLibs(TC, SYCLLinkBinaryList, true,
C.getDefaultToolChain()
.getTriple()
.isWindowsMSVCEnvironment());
}
// -fsycl-link behavior does the following to the unbundled device
// binaries:
// 1) Link them together using llvm-link
Expand All @@ -3791,8 +3781,29 @@ class OffloadingActionBuilder final {
// by any compilation link step.
auto *DeviceLinkAction = C.MakeAction<LinkJobAction>(
SYCLLinkBinaryList, types::TY_Image);
ActionList FullSYCLLinkBinaryList;
bool SYCLDeviceLibLinked = false;
FullSYCLLinkBinaryList.push_back(DeviceLinkAction);
// If used without -fintelfpga, -fsycl-link is used to wrap device
// objects for future host link. Device libraries should be linked
// by default to resolve any undefined reference.
if (!Args.hasArg(options::OPT_fintelfpga)) {
const auto *TC = ToolChains.front();
SYCLDeviceLibLinked =
addSYCLDeviceLibs(TC, FullSYCLLinkBinaryList, true,
C.getDefaultToolChain()
.getTriple()
.isWindowsMSVCEnvironment());
}

Action *FullDeviceLinkAction = nullptr;
if (SYCLDeviceLibLinked)
FullDeviceLinkAction = C.MakeAction<LinkJobAction>(
FullSYCLLinkBinaryList, types::TY_LLVM_BC);
else
FullDeviceLinkAction = DeviceLinkAction;
auto *PostLinkAction = C.MakeAction<SYCLPostLinkJobAction>(
DeviceLinkAction, types::TY_LLVM_BC);
FullDeviceLinkAction, types::TY_LLVM_BC);
auto *TranslateAction = C.MakeAction<SPIRVTranslatorJobAction>(
PostLinkAction, types::TY_Image);
SYCLLinkBinary = C.MakeAction<OffloadWrapperJobAction>(
Expand Down Expand Up @@ -3948,7 +3959,7 @@ class OffloadingActionBuilder final {
SYCLDeviceActions.clear();
}

void addSYCLDeviceLibs(const ToolChain *TC, ActionList &DeviceLinkObjects,
bool addSYCLDeviceLibs(const ToolChain *TC, ActionList &DeviceLinkObjects,
bool isSpirvAOT, bool isMSVCEnv) {
enum SYCLDeviceLibType {
sycl_devicelib_wrapper,
Expand All @@ -3960,6 +3971,7 @@ class OffloadingActionBuilder final {
};

bool NoDeviceLibs = false;
int NumOfDeviceLibLinked = 0;
// Currently, libc, libm-fp32 will be linked in by default. In order
// to use libm-fp64, -fsycl-device-lib=libm-fp64/all should be used.
llvm::StringMap<bool> devicelib_link_info = {
Expand Down Expand Up @@ -4017,6 +4029,7 @@ class OffloadingActionBuilder final {
llvm::sys::path::append(LibName, Lib.devicelib_name);
llvm::sys::path::replace_extension(LibName, LibSuffix);
if (llvm::sys::fs::exists(LibName)) {
++NumOfDeviceLibLinked;
Arg *InputArg = MakeInputArg(Args, C.getDriver().getOpts(),
Args.MakeArgString(LibName));
auto *SYCLDeviceLibsInputAction =
Expand All @@ -4032,6 +4045,7 @@ class OffloadingActionBuilder final {
addInputs(sycl_devicelib_wrapper);
if (isSpirvAOT)
addInputs(sycl_devicelib_fallback);
return NumOfDeviceLibLinked != 0;
}

void appendLinkDependences(OffloadAction::DeviceDependences &DA) override {
Expand Down Expand Up @@ -4125,15 +4139,6 @@ class OffloadingActionBuilder final {
else
LinkObjects.push_back(Input);
}
// FIXME: Link all wrapper and fallback device libraries as default,
// When spv online link is supported by all backends, the fallback
// device libraries are only needed when current toolchain is using
// AOT compilation.
if (!isNVPTX) {
addSYCLDeviceLibs(
*TC, LinkObjects, true,
C.getDefaultToolChain().getTriple().isWindowsMSVCEnvironment());
}
// The linkage actions subgraph leading to the offload wrapper.
// [cond] Means incoming/outgoing dependence is created only when cond
// is true. A function of:
Expand Down Expand Up @@ -4187,6 +4192,26 @@ class OffloadingActionBuilder final {
//
Action *DeviceLinkAction =
C.MakeAction<LinkJobAction>(LinkObjects, types::TY_LLVM_BC);
ActionList FullLinkObjects;
bool SYCLDeviceLibLinked = false;
FullLinkObjects.push_back(DeviceLinkAction);

// FIXME: Link all wrapper and fallback device libraries as default,
// When spv online link is supported by all backends, the fallback
// device libraries are only needed when current toolchain is using
// AOT compilation.
if (!isNVPTX) {
SYCLDeviceLibLinked = addSYCLDeviceLibs(
*TC, FullLinkObjects, true,
C.getDefaultToolChain().getTriple().isWindowsMSVCEnvironment());
}

Action *FullDeviceLinkAction = nullptr;
if (SYCLDeviceLibLinked)
FullDeviceLinkAction =
C.MakeAction<LinkJobAction>(FullLinkObjects, types::TY_LLVM_BC);
else
FullDeviceLinkAction = DeviceLinkAction;
// setup some flags upfront

if (isNVPTX && DeviceCodeSplit) {
Expand All @@ -4212,7 +4237,7 @@ class OffloadingActionBuilder final {
? types::TY_LLVM_BC
: types::TY_Tempfiletable;
auto *PostLinkAction = C.MakeAction<SYCLPostLinkJobAction>(
DeviceLinkAction, PostLinkOutType);
FullDeviceLinkAction, PostLinkOutType);
PostLinkAction->setRTSetsSpecConstants(!isAOT);

if (isNVPTX) {
Expand Down
13 changes: 12 additions & 1 deletion clang/lib/Driver/ToolChains/SYCL.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,6 @@
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "SYCL.h"
#include "CommonArgs.h"
#include "InputInfo.h"
Expand Down Expand Up @@ -107,8 +106,20 @@ const char *SYCL::Linker::constructLLVMLinkCommand(Compilation &C,
// an actual object/archive. Take that list and pass those to the linker
// instead of the original object.
if (JA.isDeviceOffloading(Action::OFK_SYCL)) {
auto SYCLDeviceLibIter =
std::find_if(InputFiles.begin(), InputFiles.end(), [](const auto &II) {
StringRef InputFilename =
llvm::sys::path::filename(StringRef(II.getFilename()));
if (InputFilename.startswith("libsycl-") &&
InputFilename.endswith(".o"))
return true;
return false;
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Using file name for deciding if --only-needed option is required looks very fragile.

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Hi, @sndmitriev
I agree, we need some enhancement here .

});
bool LinkSYCLDeviceLibs = (SYCLDeviceLibIter != InputFiles.end());
// Go through the Inputs to the link. When a listfile is encountered, we
// know it is an unbundled generated list.
if (LinkSYCLDeviceLibs)
CmdArgs.push_back("-only-needed");
for (const auto &II : InputFiles) {
if (II.getType() == types::TY_Tempfilelist) {
// Pass the unbundled list with '@' to be processed.
Expand Down
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