[llvm] r175314 - Use the 'target-features' and 'target-cpu' attributes to reset the subtarget features.

Benjamin Kramer benny.kra at gmail.com
Tue Feb 26 13:49:36 PST 2013


On 26.02.2013, at 22:41, Bill Wendling <isanbard at gmail.com> wrote:

> Hi Ben,
> 
> I need the command line that generated the testcase. Please run the command line with -### and send it to me. Also, a .i file wouldn't go to waste either. :) Thanks.

clang "-cc1" "-triple" "i386-pc-linux-gnu" "-emit-obj" "-disable-free" "-main-file-name" "gcc.c" "-mrelocation-model" "static" "-fmath-errno" "-masm-verbose" "-mconstructor-aliases" "-target-cpu" "pentium4" "-momit-leaf-frame-pointer"  "-O3" "-ferror-limit" "19" "-fmessage-length" "110" "-mstackrealign" "-fobjc-runtime=gcc" "-fdiagnostics-show-option" "-fcolor-diagnostics" "-backend-option" "-vectorize-loops" "-o" "/tmp/gcc-7xgigf.o" "-x" "c" "gcc.c"

Preprocessed source: https://dl.dropbox.com/u/922851/gcc.i.bz2

hope that helps.

- Ben

> 
> -bw
> 
> On Feb 25, 2013, at 2:32 AM, Benjamin Kramer <benny.kra at gmail.com> wrote:
> 
>> 
>> On 25.02.2013, at 07:03, Bill Wendling <isanbard at gmail.com> wrote:
>> 
>>> Ben,
>>> 
>>> How did you generate the testcase? I need the command line and stuff.
>> 
>> This happened while compiling gcc.c from http://people.csail.mit.edu/smcc/projects/single-file-programs/ on i386-linux-gnu with clang -O3, so the vectorizer runs. Running bugpoint on the bitcode yielded the testcase I attached.
>> 
>> - Ben
>> 
>>> 
>>> -bw
>>> 
>>> On Feb 23, 2013, at 2:22 PM, Benjamin Kramer <benny.kra at gmail.com> wrote:
>>> 
>>>> 
>>>> On 15.02.2013, at 23:31, Bill Wendling <isanbard at gmail.com> wrote:
>>>> 
>>>>> Author: void
>>>>> Date: Fri Feb 15 16:31:27 2013
>>>>> New Revision: 175314
>>>>> 
>>>>> URL: http://llvm.org/viewvc/llvm-project?rev=175314&view=rev
>>>>> Log:
>>>>> Use the 'target-features' and 'target-cpu' attributes to reset the subtarget features.
>>>>> 
>>>>> If two functions require different features (e.g., `-mno-sse' vs. `-msse') then
>>>>> we want to honor that, especially during LTO. We can do that by resetting the
>>>>> subtarget's features depending upon the 'target-feature' attribute.
>>>> 
>>>> Something about this commit is incomplete, it looks like it's not reinitializing TLI's legality settings.
>>>> 
>>>> Take the attached testcase, it enables sse2 with the target-features attribute but doesn't compile with llc because sse2 suddenly went missing. It works when I remove the attribute.
>>>> 
>>>> $ llc < bugpoint-reduced-simplified.ll
>>>> 	.file	"<stdin>"
>>>> LLVM ERROR: Cannot select: 0x7f9fb383d510: v4i32 = mul 0x7f9fb383d410, 0x7f9fb3839810 [ID=12]
>>>> 0x7f9fb383d410: v4i32 = fp_to_sint 0x7f9fb383d110 [ID=11]
>>>> 0x7f9fb383d110: v4f32,ch = load 0x7f9fb34113e8, 0x7f9fb383d210, 0x7f9fb3839610<LD16[ConstantPool]> [ID=9]
>>>>   0x7f9fb383d210: i32 = X86ISD::Wrapper 0x7f9fb3839010 [ID=7]
>>>>     0x7f9fb3839010: i32 = TargetConstantPool<<4 x i32> <i32 1065353216, i32 1056964608, i32 1048576000, i32 1040187392>> 0 [ID=5]
>>>>   0x7f9fb3839610: i32 = undef [ID=3]
>>>> 0x7f9fb3839810: v4i32 = bitcast 0x7f9fb3839210 [ID=10]
>>>> 0x7f9fb3839210: v2i64,ch = load 0x7f9fb34113e8, 0x7f9fb383d010, 0x7f9fb3839610<LD16[ConstantPool]> [ID=8]
>>>>   0x7f9fb383d010: i32 = X86ISD::Wrapper 0x7f9fb383cf10 [ID=6]
>>>>     0x7f9fb383cf10: i32 = TargetConstantPool<<4 x i32> <i32 1, i32 1, i32 1, i32 1>> 0 [ID=4]
>>>>   0x7f9fb3839610: i32 = undef [ID=3]
>>>> In function: widen_bitfield
>>>> 
>>>> - Ben
>>>> 
>>>> <bugpoint-reduced-simplified.ll>
>>>>> 
>>>>> Modified:
>>>>> llvm/trunk/include/llvm/Target/TargetSubtargetInfo.h
>>>>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
>>>>> llvm/trunk/lib/Target/X86/X86Subtarget.cpp
>>>>> llvm/trunk/lib/Target/X86/X86Subtarget.h
>>>>> 
>>>>> Modified: llvm/trunk/include/llvm/Target/TargetSubtargetInfo.h
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetSubtargetInfo.h?rev=175314&r1=175313&r2=175314&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/include/llvm/Target/TargetSubtargetInfo.h (original)
>>>>> +++ llvm/trunk/include/llvm/Target/TargetSubtargetInfo.h Fri Feb 15 16:31:27 2013
>>>>> @@ -19,6 +19,7 @@
>>>>> 
>>>>> namespace llvm {
>>>>> 
>>>>> +class MachineFunction;
>>>>> class MachineInstr;
>>>>> class SDep;
>>>>> class SUnit;
>>>>> @@ -73,6 +74,9 @@ public:
>>>>> // the latency of a schedule dependency.
>>>>> virtual void adjustSchedDependency(SUnit *def, SUnit *use,
>>>>>                                  SDep& dep) const { }
>>>>> +
>>>>> +  /// \brief Reset the features for the subtarget.
>>>>> +  virtual void resetSubtargetFeatures(const MachineFunction *MF) { }
>>>>> };
>>>>> 
>>>>> } // End llvm namespace
>>>>> 
>>>>> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp?rev=175314&r1=175313&r2=175314&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp (original)
>>>>> +++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Fri Feb 15 16:31:27 2013
>>>>> @@ -354,6 +354,10 @@ bool SelectionDAGISel::runOnMachineFunct
>>>>> TTI = getAnalysisIfAvailable<TargetTransformInfo>();
>>>>> GFI = Fn.hasGC() ? &getAnalysis<GCModuleInfo>().getFunctionInfo(Fn) : 0;
>>>>> 
>>>>> +  TargetSubtargetInfo &ST =
>>>>> +    const_cast<TargetSubtargetInfo&>(TM.getSubtarget<TargetSubtargetInfo>());
>>>>> +  ST.resetSubtargetFeatures(MF);
>>>>> +
>>>>> DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
>>>>> 
>>>>> SplitCriticalSideEffectEdges(const_cast<Function&>(Fn), this);
>>>>> 
>>>>> Modified: llvm/trunk/lib/Target/X86/X86Subtarget.cpp
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.cpp?rev=175314&r1=175313&r2=175314&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/lib/Target/X86/X86Subtarget.cpp (original)
>>>>> +++ llvm/trunk/lib/Target/X86/X86Subtarget.cpp Fri Feb 15 16:31:27 2013
>>>>> @@ -14,6 +14,8 @@
>>>>> #define DEBUG_TYPE "subtarget"
>>>>> #include "X86Subtarget.h"
>>>>> #include "X86InstrInfo.h"
>>>>> +#include "llvm/IR/Attributes.h"
>>>>> +#include "llvm/IR/Function.h"
>>>>> #include "llvm/IR/GlobalValue.h"
>>>>> #include "llvm/Support/Debug.h"
>>>>> #include "llvm/Support/ErrorHandling.h"
>>>>> @@ -324,46 +326,21 @@ void X86Subtarget::AutoDetectSubtargetFe
>>>>> }
>>>>> }
>>>>> 
>>>>> -X86Subtarget::X86Subtarget(const std::string &TT, const std::string &CPU,
>>>>> -                           const std::string &FS,
>>>>> -                           unsigned StackAlignOverride, bool is64Bit)
>>>>> -  : X86GenSubtargetInfo(TT, CPU, FS)
>>>>> -  , X86ProcFamily(Others)
>>>>> -  , PICStyle(PICStyles::None)
>>>>> -  , X86SSELevel(NoMMXSSE)
>>>>> -  , X863DNowLevel(NoThreeDNow)
>>>>> -  , HasCMov(false)
>>>>> -  , HasX86_64(false)
>>>>> -  , HasPOPCNT(false)
>>>>> -  , HasSSE4A(false)
>>>>> -  , HasAES(false)
>>>>> -  , HasPCLMUL(false)
>>>>> -  , HasFMA(false)
>>>>> -  , HasFMA4(false)
>>>>> -  , HasXOP(false)
>>>>> -  , HasMOVBE(false)
>>>>> -  , HasRDRAND(false)
>>>>> -  , HasF16C(false)
>>>>> -  , HasFSGSBase(false)
>>>>> -  , HasLZCNT(false)
>>>>> -  , HasBMI(false)
>>>>> -  , HasBMI2(false)
>>>>> -  , HasRTM(false)
>>>>> -  , HasADX(false)
>>>>> -  , IsBTMemSlow(false)
>>>>> -  , IsUAMemFast(false)
>>>>> -  , HasVectorUAMem(false)
>>>>> -  , HasCmpxchg16b(false)
>>>>> -  , UseLeaForSP(false)
>>>>> -  , HasSlowDivide(false)
>>>>> -  , PostRAScheduler(false)
>>>>> -  , PadShortFunctions(false)
>>>>> -  , stackAlignment(4)
>>>>> -  // FIXME: this is a known good value for Yonah. How about others?
>>>>> -  , MaxInlineSizeThreshold(128)
>>>>> -  , TargetTriple(TT)
>>>>> -  , In64BitMode(is64Bit) {
>>>>> -  // Determine default and user specified characteristics
>>>>> +void X86Subtarget::resetSubtargetFeatures(const MachineFunction *MF) {
>>>>> +  AttributeSet FnAttrs = MF->getFunction()->getAttributes();
>>>>> +  Attribute CPUAttr = FnAttrs.getAttribute(AttributeSet::FunctionIndex,
>>>>> +                                           "target-cpu");
>>>>> +  Attribute FSAttr = FnAttrs.getAttribute(AttributeSet::FunctionIndex,
>>>>> +                                          "target-features");
>>>>> +  std::string CPU =
>>>>> +    !CPUAttr.hasAttribute(Attribute::None) ?CPUAttr.getValueAsString() : "";
>>>>> +  std::string FS =
>>>>> +    !FSAttr.hasAttribute(Attribute::None) ? FSAttr.getValueAsString() : "";
>>>>> +  if (!FS.empty())
>>>>> +    resetSubtargetFeatures(CPU, FS);
>>>>> +}
>>>>> +
>>>>> +void X86Subtarget::resetSubtargetFeatures(StringRef CPU, StringRef FS) {
>>>>> std::string CPUName = CPU;
>>>>> if (!FS.empty() || !CPU.empty()) {
>>>>> if (CPUName.empty()) {
>>>>> @@ -440,6 +417,49 @@ X86Subtarget::X86Subtarget(const std::st
>>>>> stackAlignment = 16;
>>>>> }
>>>>> 
>>>>> +X86Subtarget::X86Subtarget(const std::string &TT, const std::string &CPU,
>>>>> +                           const std::string &FS,
>>>>> +                           unsigned StackAlignOverride, bool is64Bit)
>>>>> +  : X86GenSubtargetInfo(TT, CPU, FS)
>>>>> +  , X86ProcFamily(Others)
>>>>> +  , PICStyle(PICStyles::None)
>>>>> +  , X86SSELevel(NoMMXSSE)
>>>>> +  , X863DNowLevel(NoThreeDNow)
>>>>> +  , HasCMov(false)
>>>>> +  , HasX86_64(false)
>>>>> +  , HasPOPCNT(false)
>>>>> +  , HasSSE4A(false)
>>>>> +  , HasAES(false)
>>>>> +  , HasPCLMUL(false)
>>>>> +  , HasFMA(false)
>>>>> +  , HasFMA4(false)
>>>>> +  , HasXOP(false)
>>>>> +  , HasMOVBE(false)
>>>>> +  , HasRDRAND(false)
>>>>> +  , HasF16C(false)
>>>>> +  , HasFSGSBase(false)
>>>>> +  , HasLZCNT(false)
>>>>> +  , HasBMI(false)
>>>>> +  , HasBMI2(false)
>>>>> +  , HasRTM(false)
>>>>> +  , HasADX(false)
>>>>> +  , IsBTMemSlow(false)
>>>>> +  , IsUAMemFast(false)
>>>>> +  , HasVectorUAMem(false)
>>>>> +  , HasCmpxchg16b(false)
>>>>> +  , UseLeaForSP(false)
>>>>> +  , HasSlowDivide(false)
>>>>> +  , PostRAScheduler(false)
>>>>> +  , PadShortFunctions(false)
>>>>> +  , stackAlignment(4)
>>>>> +  // FIXME: this is a known good value for Yonah. How about others?
>>>>> +  , MaxInlineSizeThreshold(128)
>>>>> +  , TargetTriple(TT)
>>>>> +  , StackAlignOverride(StackAlignOverride)
>>>>> +  , In64BitMode(is64Bit) {
>>>>> +  resetSubtargetFeatures(CPU, FS);
>>>>> +}
>>>>> +
>>>>> bool X86Subtarget::enablePostRAScheduler(
>>>>>        CodeGenOpt::Level OptLevel,
>>>>>        TargetSubtargetInfo::AntiDepBreakMode& Mode,
>>>>> 
>>>>> Modified: llvm/trunk/lib/Target/X86/X86Subtarget.h
>>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.h?rev=175314&r1=175313&r2=175314&view=diff
>>>>> ==============================================================================
>>>>> --- llvm/trunk/lib/Target/X86/X86Subtarget.h (original)
>>>>> +++ llvm/trunk/lib/Target/X86/X86Subtarget.h Fri Feb 15 16:31:27 2013
>>>>> @@ -168,11 +168,13 @@ protected:
>>>>> InstrItineraryData InstrItins;
>>>>> 
>>>>> private:
>>>>> +  /// StackAlignOverride - Override the stack alignment.
>>>>> +  unsigned StackAlignOverride;
>>>>> +
>>>>> /// In64BitMode - True if compiling for 64-bit, false for 32-bit.
>>>>> bool In64BitMode;
>>>>> 
>>>>> public:
>>>>> -
>>>>> /// This constructor initializes the data members to match that
>>>>> /// of the specified triple.
>>>>> ///
>>>>> @@ -197,6 +199,10 @@ public:
>>>>> /// instruction.
>>>>> void AutoDetectSubtargetFeatures();
>>>>> 
>>>>> +  /// \brief Reset the features for the X86 target.
>>>>> +  virtual void resetSubtargetFeatures(const MachineFunction *MF);
>>>>> +  void resetSubtargetFeatures(StringRef CPU, StringRef FS);
>>>>> +
>>>>> /// Is this x86_64? (disregarding specific ABI / programming model)
>>>>> bool is64Bit() const {
>>>>> return In64BitMode;
>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> llvm-commits mailing list
>>>>> llvm-commits at cs.uiuc.edu
>>>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>>> 
>>> 
>> 
> 





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