Rail Shafigulin via llvm-dev
2016-Mar-05 01:25 UTC
[llvm-dev] Enable / Disable a processor feature
I'm trying to enable/disable a target feature through clang.
Here is how my target looks like
// Esencia subtarget features
//===----------------------------------------------------------------------===//
def FeatureMul : SubtargetFeature<"mul", "HasMul",
"true",
"Enable hardware multiplier">;
def FeatureDiv : SubtargetFeature<"div", "HasDiv",
"true",
"Enable hardware divider">;
def FeatureCmov : SubtargetFeature<"cmov", "HasCmov",
"true",
"Enable conditional move
instruction">;
def FeatureAddc : SubtargetFeature<"addc", "HasAddc",
"true",
"Enable add with carry
instruction">;
//===----------------------------------------------------------------------===//
// Esencia processors supported.
//===----------------------------------------------------------------------===//
class Proc<string Name, SchedMachineModel Model,
list<SubtargetFeature> Features>
: ProcessorModel<Name, Model, Features>;
def : Proc<"esencia", EsenciaModel, [FeatureMul,
FeatureDiv,
FeatureCmov,
FeatureAddc
]>;
This is what I have in EsenciaTargetInfo::setFeatureEnabled(...) in
clang/lib/Basic/Targets.cpp
virtual void setFeatureEnabled(llvm::StringMap<bool> &Features,
StringRef Name,
bool Enabled) const {
if (Name == "mul" ||
Name == "div" ||
Name == "cmov" ||
Name == "addc") {
Features[Name] = Enabled;
}
}
Is there a way to enable/disable a given feature through clang? Any flags I
need to pass?
Any help is appreciated.
--
Rail Shafigulin
Software Engineer
Esencia Technologies
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.llvm.org/pipermail/llvm-dev/attachments/20160304/3a562bf8/attachment-0001.html>
Eric Christopher via llvm-dev
2016-Mar-07 21:34 UTC
[llvm-dev] Enable / Disable a processor feature
The easiest way here is to take a look at an existing target, say x86, and do what it does :) For specific guidance within x86, take a look at how -msse3 works. -eric On Fri, Mar 4, 2016 at 5:25 PM Rail Shafigulin via llvm-dev < llvm-dev at lists.llvm.org> wrote:> I'm trying to enable/disable a target feature through clang. > > Here is how my target looks like > > // Esencia subtarget features > > //===----------------------------------------------------------------------===// > def FeatureMul : SubtargetFeature<"mul", "HasMul", "true", > "Enable hardware multiplier">; > def FeatureDiv : SubtargetFeature<"div", "HasDiv", "true", > "Enable hardware divider">; > def FeatureCmov : SubtargetFeature<"cmov", "HasCmov", "true", > "Enable conditional move instruction">; > def FeatureAddc : SubtargetFeature<"addc", "HasAddc", "true", > "Enable add with carry instruction">; > > > //===----------------------------------------------------------------------===// > // Esencia processors supported. > > //===----------------------------------------------------------------------===// > class Proc<string Name, SchedMachineModel Model, > list<SubtargetFeature> Features> > : ProcessorModel<Name, Model, Features>; > > def : Proc<"esencia", EsenciaModel, [FeatureMul, > FeatureDiv, > FeatureCmov, > FeatureAddc > ]>; > > This is what I have in EsenciaTargetInfo::setFeatureEnabled(...) in > clang/lib/Basic/Targets.cpp > > virtual void setFeatureEnabled(llvm::StringMap<bool> &Features, > StringRef Name, > bool Enabled) const { > if (Name == "mul" || > Name == "div" || > Name == "cmov" || > Name == "addc") { > Features[Name] = Enabled; > } > } > > Is there a way to enable/disable a given feature through clang? Any flags > I need to pass? > > Any help is appreciated. > > -- > Rail Shafigulin > Software Engineer > Esencia Technologies > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160307/a3d0f984/attachment.html>
Rail Shafigulin via llvm-dev
2016-Mar-08 23:37 UTC
[llvm-dev] Enable / Disable a processor feature
Thanks for the reply. The issue was that I did look at an existing target, but wasn't able to figure it out, at least initially. I figured it right now (with llc use -mattr=+feature1,-feature2,+feature3 to enable feature1, disable feature2 and enable feature3 respectively), but still have questions. For example, clang has this -target-feature=+feature1,-feature2,+feature3, but for some reason it didn't work for my target. I'm wondering why it didn't. I would really like to know why it didn't work. I can post more code if you are interested in helping out. On Mon, Mar 7, 2016 at 1:34 PM, Eric Christopher <echristo at gmail.com> wrote:> The easiest way here is to take a look at an existing target, say x86, and > do what it does :) > > For specific guidance within x86, take a look at how -msse3 works. > > -eric > > On Fri, Mar 4, 2016 at 5:25 PM Rail Shafigulin via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> I'm trying to enable/disable a target feature through clang. >> >> Here is how my target looks like >> >> // Esencia subtarget features >> >> //===----------------------------------------------------------------------===// >> def FeatureMul : SubtargetFeature<"mul", "HasMul", "true", >> "Enable hardware multiplier">; >> def FeatureDiv : SubtargetFeature<"div", "HasDiv", "true", >> "Enable hardware divider">; >> def FeatureCmov : SubtargetFeature<"cmov", "HasCmov", "true", >> "Enable conditional move >> instruction">; >> def FeatureAddc : SubtargetFeature<"addc", "HasAddc", "true", >> "Enable add with carry instruction">; >> >> >> //===----------------------------------------------------------------------===// >> // Esencia processors supported. >> >> //===----------------------------------------------------------------------===// >> class Proc<string Name, SchedMachineModel Model, >> list<SubtargetFeature> Features> >> : ProcessorModel<Name, Model, Features>; >> >> def : Proc<"esencia", EsenciaModel, [FeatureMul, >> FeatureDiv, >> FeatureCmov, >> FeatureAddc >> ]>; >> >> This is what I have in EsenciaTargetInfo::setFeatureEnabled(...) in >> clang/lib/Basic/Targets.cpp >> >> virtual void setFeatureEnabled(llvm::StringMap<bool> &Features, >> StringRef Name, >> bool Enabled) const { >> if (Name == "mul" || >> Name == "div" || >> Name == "cmov" || >> Name == "addc") { >> Features[Name] = Enabled; >> } >> } >> >> Is there a way to enable/disable a given feature through clang? Any flags >> I need to pass? >> >> Any help is appreciated. >> >> -- >> Rail Shafigulin >> Software Engineer >> Esencia Technologies >> _______________________________________________ >> LLVM Developers mailing list >> llvm-dev at lists.llvm.org >> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev >> >-- Rail Shafigulin Software Engineer Esencia Technologies -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160308/67d24a62/attachment.html>