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[ARM] Restructure cpu handling in the driver to mostly use the triple
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Using the target cpu to determine some behaviour is sprinkled in
several places in the driver, but in almost all the information that
is needed can be found in the triple. Restructure things so that the
triple is used, and the cpu is only used if the exact cpu name is
needed.

Also add a check that the -mcpu argument is valid, and correct the
-march argument checking so that it handles -march=native correctly. I
would have liked to move these checks into the computation of the
triple, but the triple is calculated several times in several places
and that would lead to multiple error messages for the same thing.

Differential Revision: http://reviews.llvm.org/D9879

llvm-svn: 237894
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@john-brawn-arm
john-brawn-arm committed May 21, 2015
1 parent 0f90c86 commit 94fd963
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Showing 2 changed files with 96 additions and 44 deletions.
136 changes: 92 additions & 44 deletions clang/lib/Driver/Tools.cpp
View file
Expand Up @@ -617,6 +617,44 @@ static void getARMFPUFeatures(const Driver &D, const Arg *A,
}
}

// FIXME: Move to ARMTargetParser.
static int getARMSubArchVersionNumber(const llvm::Triple &Triple) {
switch (Triple.getSubArch()) {
case llvm::Triple::ARMSubArch_v8_1a:
case llvm::Triple::ARMSubArch_v8:
return 8;
case llvm::Triple::ARMSubArch_v7:
case llvm::Triple::ARMSubArch_v7em:
case llvm::Triple::ARMSubArch_v7m:
case llvm::Triple::ARMSubArch_v7s:
return 7;
case llvm::Triple::ARMSubArch_v6:
case llvm::Triple::ARMSubArch_v6m:
case llvm::Triple::ARMSubArch_v6k:
case llvm::Triple::ARMSubArch_v6t2:
return 6;
case llvm::Triple::ARMSubArch_v5:
case llvm::Triple::ARMSubArch_v5te:
return 5;
case llvm::Triple::ARMSubArch_v4t:
return 4;
default:
return 0;
}
}

// FIXME: Move to ARMTargetParser.
static bool isARMMProfile(const llvm::Triple &Triple) {
switch (Triple.getSubArch()) {
case llvm::Triple::ARMSubArch_v7em:
case llvm::Triple::ARMSubArch_v7m:
case llvm::Triple::ARMSubArch_v6m:
return true;
default:
return false;
}
}

// Select the float ABI as determined by -msoft-float, -mhard-float, and
// -mfloat-abi=.
StringRef tools::arm::getARMFloatABI(const Driver &D, const ArgList &Args,
Expand Down Expand Up @@ -647,12 +685,8 @@ StringRef tools::arm::getARMFloatABI(const Driver &D, const ArgList &Args,
case llvm::Triple::IOS: {
// Darwin defaults to "softfp" for v6 and v7.
//
// FIXME: Factor out an ARM class so we can cache the arch somewhere.
std::string ArchName =
arm::getLLVMArchSuffixForARM(arm::getARMTargetCPU(Args, Triple),
arm::getARMArch(Args, Triple));
if (StringRef(ArchName).startswith("v6") ||
StringRef(ArchName).startswith("v7"))
if (getARMSubArchVersionNumber(Triple) == 6 ||
getARMSubArchVersionNumber(Triple) == 7)
FloatABI = "softfp";
else
FloatABI = "soft";
Expand Down Expand Up @@ -692,10 +726,7 @@ StringRef tools::arm::getARMFloatABI(const Driver &D, const ArgList &Args,
FloatABI = "softfp";
break;
case llvm::Triple::Android: {
std::string ArchName =
arm::getLLVMArchSuffixForARM(arm::getARMTargetCPU(Args, Triple),
arm::getARMArch(Args, Triple));
if (StringRef(ArchName).startswith("v7"))
if (getARMSubArchVersionNumber(Triple) == 7)
FloatABI = "softfp";
else
FloatABI = "soft";
Expand Down Expand Up @@ -748,12 +779,24 @@ static void getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
if (const Arg *A = Args.getLastArg(options::OPT_mhwdiv_EQ))
getARMHWDivFeatures(D, A, Args, Features);

// -march is handled in getARMCPUForMarch by translating it into a CPU name,
// but it needs to return an empty string on invalid arguments. We therefore
// check and give an error here if the -march is invalid.
if (const Arg *A = Args.getLastArg(options::OPT_march_EQ))
if (!Triple.getARMCPUForArch(A->getValue()))
// Check if -march is valid by checking if it can be canonicalised. getARMArch
// is used here instead of just checking the -march value in order to handle
// -march=native correctly.
if (const Arg *A = Args.getLastArg(options::OPT_march_EQ)) {
StringRef Arch = arm::getARMArch(Args, Triple);
if (llvm::ARMTargetParser::getCanonicalArchName(Arch).empty())
D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
}

// We do a similar thing with -mcpu, but here things are complicated because
// the only function we have to check if a cpu is valid is
// getLLVMArchSuffixForARM which also needs an architecture.
if (const Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
StringRef CPU = arm::getARMTargetCPU(Args, Triple);
StringRef Arch = arm::getARMArch(Args, Triple);
if (strcmp(arm::getLLVMArchSuffixForARM(CPU, Arch), "") == 0)
D.Diag(diag::err_drv_clang_unsupported) << A->getAsString(Args);
}

// Setting -msoft-float effectively disables NEON because of the GCC
// implementation, although the same isn't true of VFP or VFP3.
Expand Down Expand Up @@ -783,7 +826,6 @@ void Clang::AddARMTargetArgs(const ArgList &Args,
// Get the effective triple, which takes into account the deployment target.
std::string TripleStr = getToolChain().ComputeEffectiveClangTriple(Args);
llvm::Triple Triple(TripleStr);
std::string CPUName = arm::getARMTargetCPU(Args, Triple);

// Select the ABI to use.
//
Expand All @@ -797,7 +839,7 @@ void Clang::AddARMTargetArgs(const ArgList &Args,
// the frontend matches that.
if (Triple.getEnvironment() == llvm::Triple::EABI ||
Triple.getOS() == llvm::Triple::UnknownOS ||
StringRef(CPUName).startswith("cortex-m")) {
isARMMProfile(Triple)) {
ABIName = "aapcs";
} else {
ABIName = "apcs-gnu";
Expand Down Expand Up @@ -3209,9 +3251,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
}

// Add the target cpu
std::string ETripleStr = getToolChain().ComputeEffectiveClangTriple(Args);
llvm::Triple ETriple(ETripleStr);
std::string CPU = getCPUName(Args, ETriple);
std::string CPU = getCPUName(Args, Triple);
if (!CPU.empty()) {
CmdArgs.push_back("-target-cpu");
CmdArgs.push_back(Args.MakeArgString(CPU));
Expand All @@ -3223,7 +3263,7 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
}

// Add the target features
getTargetFeatures(D, ETriple, Args, CmdArgs, false);
getTargetFeatures(D, Triple, Args, CmdArgs, false);

// Add target specific flags.
switch(getToolChain().getArch()) {
Expand Down Expand Up @@ -5105,7 +5145,7 @@ void ClangAs::ConstructJob(Compilation &C, const JobAction &JA,
CmdArgs.push_back(Clang::getBaseInputName(Args, Input));

// Add the target cpu
const llvm::Triple &Triple = getToolChain().getTriple();
const llvm::Triple Triple(TripleStr);
std::string CPU = getCPUName(Args, Triple);
if (!CPU.empty()) {
CmdArgs.push_back("-target-cpu");
Expand Down Expand Up @@ -5630,24 +5670,33 @@ const StringRef arm::getARMArch(const ArgList &Args,
// Otherwise, use the Arch from the triple.
MArch = Triple.getArchName();
}
return MArch;
}
/// Get the (LLVM) name of the minimum ARM CPU for the arch we are targeting.
const char *arm::getARMCPUForMArch(const ArgList &Args,
const llvm::Triple &Triple) {
StringRef MArch = getARMArch(Args, Triple);

// Handle -march=native.
if (MArch == "native") {
std::string CPU = llvm::sys::getHostCPUName();
if (CPU != "generic") {
// Translate the native cpu into the architecture. The switch below will
// then chose the minimum cpu for that arch.
MArch = std::string("arm") +
arm::getLLVMArchSuffixForARM(CPU, arm::getARMArch(Args, Triple));
// Translate the native cpu into the architecture suffix for that CPU.
const char *Suffix = arm::getLLVMArchSuffixForARM(CPU, MArch);
// If there is no valid architecture suffix for this CPU we don't know how
// to handle it, so return no architecture.
if (strcmp(Suffix,"") == 0)
MArch = "";
else
MArch = std::string("arm") + Suffix;
}
}

return MArch;
}
/// Get the (LLVM) name of the minimum ARM CPU for the arch we are targeting.
const char *arm::getARMCPUForMArch(const ArgList &Args,
const llvm::Triple &Triple) {
StringRef MArch = getARMArch(Args, Triple);
// getARMCPUForArch defaults to the triple if MArch is empty, but empty MArch
// here means an -march=native that we can't handle, so instead return no CPU.
if (MArch.empty())
return "";

// We need to return an empty string here on invalid MArch values as the
// various places that call this function can't cope with a null result.
const char *result = Triple.getARMCPUForArch(MArch);
Expand Down Expand Up @@ -5689,8 +5738,10 @@ const char *arm::getLLVMArchSuffixForARM(StringRef CPU, StringRef Arch) {
}
}

// FIXME: Use ARMTargetParser
return llvm::StringSwitch<const char *>(CPU)
.Case("strongarm", "v4")
.Cases("arm8", "arm810", "v4")
.Cases("strongarm", "strongarm110", "strongarm1100", "strongarm1110", "v4")
.Cases("arm7tdmi", "arm7tdmi-s", "arm710t", "v4t")
.Cases("arm720t", "arm9", "arm9tdmi", "v4t")
.Cases("arm920", "arm920t", "arm922t", "v4t")
Expand Down Expand Up @@ -5720,15 +5771,10 @@ void arm::appendEBLinkFlags(const ArgList &Args, ArgStringList &CmdArgs,
if (Args.hasArg(options::OPT_r))
return;

StringRef Suffix = getLLVMArchSuffixForARM(getARMCPUForMArch(Args, Triple),
getARMArch(Args, Triple));
const char *LinkFlag = llvm::StringSwitch<const char *>(Suffix)
.Cases("v4", "v4t", "v5", "v5e", nullptr)
.Cases("v6", "v6k", "v6t2", nullptr)
.Default("--be8");

if (LinkFlag)
CmdArgs.push_back(LinkFlag);
// ARMv7 (and later) and ARMv6-M do not support BE-32, so instruct the linker
// to generate BE-8 executables.
if (getARMSubArchVersionNumber(Triple) >= 7 || isARMMProfile(Triple))
CmdArgs.push_back("--be8");
}

mips::NanEncoding mips::getSupportedNanEncoding(StringRef &CPU) {
Expand Down Expand Up @@ -7329,7 +7375,8 @@ void netbsd::Link::ConstructJob(Compilation &C, const JobAction &JA,
break;
case llvm::Triple::armeb:
case llvm::Triple::thumbeb:
arm::appendEBLinkFlags(Args, CmdArgs, getToolChain().getTriple());
arm::appendEBLinkFlags(Args, CmdArgs,
llvm::Triple(getToolChain().ComputeEffectiveClangTriple(Args)));
CmdArgs.push_back("-m");
switch (getToolChain().getTriple().getEnvironment()) {
case llvm::Triple::EABI:
Expand Down Expand Up @@ -7905,7 +7952,8 @@ void gnutools::Link::ConstructJob(Compilation &C, const JobAction &JA,

if (ToolChain.getArch() == llvm::Triple::armeb ||
ToolChain.getArch() == llvm::Triple::thumbeb)
arm::appendEBLinkFlags(Args, CmdArgs, getToolChain().getTriple());
arm::appendEBLinkFlags(Args, CmdArgs,
llvm::Triple(getToolChain().ComputeEffectiveClangTriple(Args)));

for (const auto &Opt : ToolChain.ExtraOpts)
CmdArgs.push_back(Opt.c_str());
Expand Down
4 changes: 4 additions & 0 deletions clang/test/Driver/arm-cortex-cpus.c
View file
Expand Up @@ -205,6 +205,10 @@
// RUN: %clang -target arm---eabihf -march=armbogusv7 -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BOGUS-HF %s
// CHECK-BOGUS-HF: error: the clang compiler does not support '-march=armbogusv7'

// ================== Check that a bogus CPU gives an error
// RUN: %clang -target arm -mcpu=bogus -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-BOGUS-CPU %s
// CHECK-BOGUS-CPU: error: the clang compiler does not support '-mcpu=bogus'

// ================== Check default Architecture on each ARM11 CPU
// RUN: %clang -target arm-linux-gnueabi -mcpu=arm1136j-s -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV6 %s
// RUN: %clang -target arm-linux-gnueabi -mcpu=arm1136jf-s -### -c %s 2>&1 | FileCheck -check-prefix=CHECK-CPUV6 %s
Expand Down

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