[llvm] 70a5d8e - [PPC] Add support for tune-cpu attribute
Kai Nacke via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 6 10:02:07 PST 2023
Author: Kai Nacke
Date: 2023-01-06T18:01:48Z
New Revision: 70a5d8e4c469195e9302dba2c5a9518a69e0773e
URL: https://github.com/llvm/llvm-project/commit/70a5d8e4c469195e9302dba2c5a9518a69e0773e
DIFF: https://github.com/llvm/llvm-project/commit/70a5d8e4c469195e9302dba2c5a9518a69e0773e.diff
LOG: [PPC] Add support for tune-cpu attribute
clang (like gcc) has the -mtune= command line option. This option
adds the "tune-cpu" attribute to a function. The intended functionality
is that the scheduling model of that cpu is used. E.g. -mtune=pwr9 -march=pwr8
generates only instructions supported on pwr8 but uses the scheduling model
of pwr9 for it.
This PR adds the infrastructure to support this in LLVM.
clang support was added in https://reviews.llvm.org/D130526.
Reviewed By: amyk, qiucf
Differential Revision: https://reviews.llvm.org/D138317
Added:
Modified:
llvm/lib/Target/PowerPC/PPCSubtarget.cpp
llvm/lib/Target/PowerPC/PPCSubtarget.h
llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
index fb37bf4b3362f..e32a2ed9dee7c 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.cpp
@@ -48,18 +48,20 @@ static cl::opt<bool>
cl::init(false), cl::Hidden);
PPCSubtarget &PPCSubtarget::initializeSubtargetDependencies(StringRef CPU,
+ StringRef TuneCPU,
StringRef FS) {
initializeEnvironment();
- initSubtargetFeatures(CPU, FS);
+ initSubtargetFeatures(CPU, TuneCPU, FS);
return *this;
}
PPCSubtarget::PPCSubtarget(const Triple &TT, const std::string &CPU,
- const std::string &FS, const PPCTargetMachine &TM)
- : PPCGenSubtargetInfo(TT, CPU, /*TuneCPU*/ CPU, FS), TargetTriple(TT),
+ const std::string &TuneCPU, const std::string &FS,
+ const PPCTargetMachine &TM)
+ : PPCGenSubtargetInfo(TT, CPU, TuneCPU, FS), TargetTriple(TT),
IsPPC64(TargetTriple.getArch() == Triple::ppc64 ||
TargetTriple.getArch() == Triple::ppc64le),
- TM(TM), FrameLowering(initializeSubtargetDependencies(CPU, FS)),
+ TM(TM), FrameLowering(initializeSubtargetDependencies(CPU, TuneCPU, FS)),
InstrInfo(*this), TLInfo(TM, *this) {
CallLoweringInfo.reset(new PPCCallLowering(*getTargetLowering()));
Legalizer.reset(new PPCLegalizerInfo(*this));
@@ -76,7 +78,8 @@ void PPCSubtarget::initializeEnvironment() {
HasPOPCNTD = POPCNTD_Unavailable;
}
-void PPCSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
+void PPCSubtarget::initSubtargetFeatures(StringRef CPU, StringRef TuneCPU,
+ StringRef FS) {
// Determine default and user specified characteristics
std::string CPUName = std::string(CPU);
if (CPUName.empty() || CPU == "generic") {
@@ -89,11 +92,14 @@ void PPCSubtarget::initSubtargetFeatures(StringRef CPU, StringRef FS) {
CPUName = "generic";
}
+ // Determine the CPU to schedule for.
+ if (TuneCPU.empty()) TuneCPU = CPUName;
+
// Initialize scheduling itinerary for the specified CPU.
InstrItins = getInstrItineraryForCPU(CPUName);
// Parse features string.
- ParseSubtargetFeatures(CPUName, /*TuneCPU*/ CPUName, FS);
+ ParseSubtargetFeatures(CPUName, TuneCPU, FS);
// If the user requested use of 64-bit regs, but the cpu selected doesn't
// support it, ignore.
diff --git a/llvm/lib/Target/PowerPC/PPCSubtarget.h b/llvm/lib/Target/PowerPC/PPCSubtarget.h
index 007ffd5c0235e..05ab0d4d71989 100644
--- a/llvm/lib/Target/PowerPC/PPCSubtarget.h
+++ b/llvm/lib/Target/PowerPC/PPCSubtarget.h
@@ -116,7 +116,8 @@ class PPCSubtarget : public PPCGenSubtargetInfo {
/// This constructor initializes the data members to match that
/// of the specified triple.
///
- PPCSubtarget(const Triple &TT, const std::string &CPU, const std::string &FS,
+ PPCSubtarget(const Triple &TT, const std::string &CPU,
+ const std::string &TuneCPU, const std::string &FS,
const PPCTargetMachine &TM);
/// ParseSubtargetFeatures - Parses features string setting specified
@@ -153,13 +154,16 @@ class PPCSubtarget : public PPCGenSubtargetInfo {
}
const PPCTargetMachine &getTargetMachine() const { return TM; }
- /// initializeSubtargetDependencies - Initializes using a CPU and feature string
- /// so that we can use initializer lists for subtarget initialization.
- PPCSubtarget &initializeSubtargetDependencies(StringRef CPU, StringRef FS);
+ /// initializeSubtargetDependencies - Initializes using a CPU, a TuneCPU, and
+ /// feature string so that we can use initializer lists for subtarget
+ /// initialization.
+ PPCSubtarget &initializeSubtargetDependencies(StringRef CPU,
+ StringRef TuneCPU,
+ StringRef FS);
private:
void initializeEnvironment();
- void initSubtargetFeatures(StringRef CPU, StringRef FS);
+ void initSubtargetFeatures(StringRef CPU, StringRef TuneCPU, StringRef FS);
public:
/// isPPC64 - Return true if we are generating code for 64-bit pointer mode.
diff --git a/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp b/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
index 0a020b98d0e4d..9aea5af8a60a4 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -341,10 +341,13 @@ PPCTargetMachine::~PPCTargetMachine() = default;
const PPCSubtarget *
PPCTargetMachine::getSubtargetImpl(const Function &F) const {
Attribute CPUAttr = F.getFnAttribute("target-cpu");
+ Attribute TuneAttr = F.getFnAttribute("tune-cpu");
Attribute FSAttr = F.getFnAttribute("target-features");
std::string CPU =
CPUAttr.isValid() ? CPUAttr.getValueAsString().str() : TargetCPU;
+ std::string TuneCPU =
+ TuneAttr.isValid() ? TuneAttr.getValueAsString().str() : CPU;
std::string FS =
FSAttr.isValid() ? FSAttr.getValueAsString().str() : TargetFS;
@@ -359,14 +362,14 @@ PPCTargetMachine::getSubtargetImpl(const Function &F) const {
if (SoftFloat)
FS += FS.empty() ? "-hard-float" : ",-hard-float";
- auto &I = SubtargetMap[CPU + FS];
+ auto &I = SubtargetMap[CPU + TuneCPU + FS];
if (!I) {
// This needs to be done before we create a new subtarget since any
// creation will depend on the TM and the code generation flags on the
// function that reside in TargetOptions.
resetTargetOptions(F);
I = std::make_unique<PPCSubtarget>(
- TargetTriple, CPU,
+ TargetTriple, CPU, TuneCPU,
// FIXME: It would be good to have the subtarget additions here
// not necessary. Anything that turns them on/off (overrides) ends
// up being put at the end of the feature string, but the defaults
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