r240994 - Add support for the x86 builtin __builtin_cpu_supports.
Eric Christopher
echristo at gmail.com
Mon Jun 29 14:00:06 PDT 2015
Author: echristo
Date: Mon Jun 29 16:00:05 2015
New Revision: 240994
URL: http://llvm.org/viewvc/llvm-project?rev=240994&view=rev
Log:
Add support for the x86 builtin __builtin_cpu_supports.
This matches the implementation of the gcc support for the same
feature, including checking the values set up by libgcc at runtime.
The structure looks like this:
unsigned int __cpu_vendor;
unsigned int __cpu_type;
unsigned int __cpu_subtype;
unsigned int __cpu_features[1];
with a set of enums to match various fields that are field out after
parsing the output of the cpuid instruction.
This also adds a set of errors checking for valid input (and cpu).
compiler-rt support for this and the other builtins in this family
(__builtin_cpu_init and __builtin_cpu_is) are forthcoming.
Added:
cfe/trunk/test/CodeGen/builtin-cpu-supports.c
cfe/trunk/test/Sema/builtin-cpu-supports.c
Modified:
cfe/trunk/include/clang/Basic/BuiltinsX86.def
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/include/clang/Basic/TargetInfo.h
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Basic/Targets.cpp
cfe/trunk/lib/CodeGen/CGBuiltin.cpp
cfe/trunk/lib/Sema/SemaChecking.cpp
Modified: cfe/trunk/include/clang/Basic/BuiltinsX86.def
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/BuiltinsX86.def?rev=240994&r1=240993&r2=240994&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/BuiltinsX86.def (original)
+++ cfe/trunk/include/clang/Basic/BuiltinsX86.def Mon Jun 29 16:00:05 2015
@@ -24,6 +24,11 @@
// FIXME: Are these nothrow/const?
+// Miscellaneous builtin for checking x86 cpu features.
+// TODO: Make this somewhat generic so that other backends
+// can use it?
+BUILTIN(__builtin_cpu_supports, "bcC*", "nc")
+
// 3DNow!
//
BUILTIN(__builtin_ia32_femms, "v", "")
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=240994&r1=240993&r2=240994&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon Jun 29 16:00:05 2015
@@ -426,6 +426,7 @@ def warn_redecl_library_builtin : Warnin
InGroup<DiagGroup<"incompatible-library-redeclaration">>;
def err_builtin_definition : Error<"definition of builtin function %0">;
def err_arm_invalid_specialreg : Error<"invalid special register for builtin">;
+def err_invalid_cpu_supports : Error<"invalid cpu feature string for builtin">;
def warn_builtin_unknown : Warning<"use of unknown builtin %0">,
InGroup<ImplicitFunctionDeclare>, DefaultError;
def warn_dyn_class_memaccess : Warning<
Modified: cfe/trunk/include/clang/Basic/TargetInfo.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/TargetInfo.h?rev=240994&r1=240993&r2=240994&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/TargetInfo.h (original)
+++ cfe/trunk/include/clang/Basic/TargetInfo.h Mon Jun 29 16:00:05 2015
@@ -611,6 +611,9 @@ public:
}
};
+ // Validate the contents of the __builtin_cpu_supports(const char*) argument.
+ virtual bool validateCpuSupports(StringRef Name) const { return false; }
+
// validateOutputConstraint, validateInputConstraint - Checks that
// a constraint is valid and provides information about it.
// FIXME: These should return a real error instead of just true/false.
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=240994&r1=240993&r2=240994&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Mon Jun 29 16:00:05 2015
@@ -8734,6 +8734,7 @@ private:
bool SemaBuiltinARMSpecialReg(unsigned BuiltinID, CallExpr *TheCall,
int ArgNum, unsigned ExpectedFieldNum,
bool AllowName);
+ bool SemaBuiltinCpuSupports(CallExpr *TheCall);
public:
enum FormatStringType {
FST_Scanf,
Modified: cfe/trunk/lib/Basic/Targets.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=240994&r1=240993&r2=240994&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/Targets.cpp (original)
+++ cfe/trunk/lib/Basic/Targets.cpp Mon Jun 29 16:00:05 2015
@@ -2215,6 +2215,7 @@ public:
Names = AddlRegNames;
NumNames = llvm::array_lengthof(AddlRegNames);
}
+ bool validateCpuSupports(StringRef Name) const override;
bool validateAsmConstraint(const char *&Name,
TargetInfo::ConstraintInfo &info) const override;
@@ -3338,6 +3339,33 @@ bool X86TargetInfo::hasFeature(StringRef
.Default(false);
}
+// We can't use a generic validation scheme for the features accepted here
+// versus subtarget features accepted in the target attribute because the
+// bitfield structure that's initialized in the runtime only supports the
+// below currently rather than the full range of subtarget features. (See
+// X86TargetInfo::hasFeature for a somewhat comprehensive list).
+bool X86TargetInfo::validateCpuSupports(StringRef FeatureStr) const {
+ return llvm::StringSwitch<bool>(FeatureStr)
+ .Case("cmov", true)
+ .Case("mmx", true)
+ .Case("popcnt", true)
+ .Case("sse", true)
+ .Case("sse2", true)
+ .Case("sse3", true)
+ .Case("sse4.1", true)
+ .Case("sse4.2", true)
+ .Case("avx", true)
+ .Case("avx2", true)
+ .Case("sse4a", true)
+ .Case("fma4", true)
+ .Case("xop", true)
+ .Case("fma", true)
+ .Case("avx512f", true)
+ .Case("bmi", true)
+ .Case("bmi2", true)
+ .Default(false);
+}
+
bool
X86TargetInfo::validateAsmConstraint(const char *&Name,
TargetInfo::ConstraintInfo &Info) const {
Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBuiltin.cpp?rev=240994&r1=240993&r2=240994&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGBuiltin.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp Mon Jun 29 16:00:05 2015
@@ -6101,6 +6101,83 @@ Value *CodeGenFunction::EmitX86BuiltinEx
switch (BuiltinID) {
default: return nullptr;
+ case X86::BI__builtin_cpu_supports: {
+ const Expr *FeatureExpr = E->getArg(0)->IgnoreParenCasts();
+ StringRef FeatureStr = cast<StringLiteral>(FeatureExpr)->getString();
+
+ // TODO: When/if this becomes more than x86 specific then use a TargetInfo
+ // based mapping.
+ // Processor features and mapping to processor feature value.
+ enum X86Features {
+ CMOV = 0,
+ MMX,
+ POPCNT,
+ SSE,
+ SSE2,
+ SSE3,
+ SSSE3,
+ SSE4_1,
+ SSE4_2,
+ AVX,
+ AVX2,
+ SSE4_A,
+ FMA4,
+ XOP,
+ FMA,
+ AVX512F,
+ BMI,
+ BMI2,
+ MAX
+ };
+
+ X86Features Feature = StringSwitch<X86Features>(FeatureStr)
+ .Case("cmov", X86Features::CMOV)
+ .Case("mmx", X86Features::MMX)
+ .Case("popcnt", X86Features::POPCNT)
+ .Case("sse", X86Features::SSE)
+ .Case("sse2", X86Features::SSE2)
+ .Case("sse3", X86Features::SSE3)
+ .Case("sse4.1", X86Features::SSE4_1)
+ .Case("sse4.2", X86Features::SSE4_2)
+ .Case("avx", X86Features::AVX)
+ .Case("avx2", X86Features::AVX2)
+ .Case("sse4a", X86Features::SSE4_A)
+ .Case("fma4", X86Features::FMA4)
+ .Case("xop", X86Features::XOP)
+ .Case("fma", X86Features::FMA)
+ .Case("avx512f", X86Features::AVX512F)
+ .Case("bmi", X86Features::BMI)
+ .Case("bmi2", X86Features::BMI2)
+ .Default(X86Features::MAX);
+ assert(Feature != X86Features::MAX && "Invalid feature!");
+
+ // Matching the struct layout from the compiler-rt/libgcc structure that is
+ // filled in:
+ // unsigned int __cpu_vendor;
+ // unsigned int __cpu_type;
+ // unsigned int __cpu_subtype;
+ // unsigned int __cpu_features[1];
+ llvm::Type *STy = llvm::StructType::get(
+ Int32Ty, Int32Ty, Int32Ty, llvm::ArrayType::get(Int32Ty, 1), nullptr);
+
+ // Grab the global __cpu_model.
+ llvm::Constant *CpuModel = CGM.CreateRuntimeVariable(STy, "__cpu_model");
+
+ // Grab the first (0th) element from the field __cpu_features off of the
+ // global in the struct STy.
+ Value *Idxs[] = {
+ ConstantInt::get(Int32Ty, 0),
+ ConstantInt::get(Int32Ty, 3),
+ ConstantInt::get(Int32Ty, 0)
+ };
+ Value *CpuFeatures = Builder.CreateGEP(STy, CpuModel, Idxs);
+ Value *Features = Builder.CreateLoad(CpuFeatures);
+
+ // Check the value of the bit corresponding to the feature requested.
+ Value *Bitset = Builder.CreateAnd(
+ Features, llvm::ConstantInt::get(Int32Ty, 1 << Feature));
+ return Builder.CreateICmpNE(Bitset, llvm::ConstantInt::get(Int32Ty, 0));
+ }
case X86::BI_mm_prefetch: {
Value *Address = EmitScalarExpr(E->getArg(0));
Value *RW = ConstantInt::get(Int32Ty, 0);
Modified: cfe/trunk/lib/Sema/SemaChecking.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaChecking.cpp?rev=240994&r1=240993&r2=240994&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaChecking.cpp (original)
+++ cfe/trunk/lib/Sema/SemaChecking.cpp Mon Jun 29 16:00:05 2015
@@ -1031,6 +1031,8 @@ bool Sema::CheckX86BuiltinFunctionCall(u
unsigned i = 0, l = 0, u = 0;
switch (BuiltinID) {
default: return false;
+ case X86::BI__builtin_cpu_supports:
+ return SemaBuiltinCpuSupports(TheCall);
case X86::BI_mm_prefetch: i = 1; l = 0; u = 3; break;
case X86::BI__builtin_ia32_sha1rnds4: i = 2, l = 0; u = 3; break;
case X86::BI__builtin_ia32_vpermil2pd:
@@ -2782,6 +2784,26 @@ bool Sema::SemaBuiltinARMSpecialReg(unsi
return false;
}
+/// SemaBuiltinCpuSupports - Handle __builtin_cpu_supports(char *).
+/// This checks that the target supports __builtin_cpu_supports and
+/// that the string argument is constant and valid.
+bool Sema::SemaBuiltinCpuSupports(CallExpr *TheCall) {
+ Expr *Arg = TheCall->getArg(0);
+
+ // Check if the argument is a string literal.
+ if (!isa<StringLiteral>(Arg->IgnoreParenImpCasts()))
+ return Diag(TheCall->getLocStart(), diag::err_expr_not_string_literal)
+ << Arg->getSourceRange();
+
+ // Check the contents of the string.
+ StringRef Feature =
+ cast<StringLiteral>(Arg->IgnoreParenImpCasts())->getString();
+ if (!Context.getTargetInfo().validateCpuSupports(Feature))
+ return Diag(TheCall->getLocStart(), diag::err_invalid_cpu_supports)
+ << Arg->getSourceRange();
+ return false;
+}
+
/// SemaBuiltinLongjmp - Handle __builtin_longjmp(void *env[5], int val).
/// This checks that the target supports __builtin_longjmp and
/// that val is a constant 1.
Added: cfe/trunk/test/CodeGen/builtin-cpu-supports.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/builtin-cpu-supports.c?rev=240994&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/builtin-cpu-supports.c (added)
+++ cfe/trunk/test/CodeGen/builtin-cpu-supports.c Mon Jun 29 16:00:05 2015
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -emit-llvm < %s| FileCheck %s
+
+// Test that we have the structure definition, the gep offsets, the name of the
+// global, the bit grab, and the icmp correct.
+extern void a(const char *);
+
+int main() {
+ if (__builtin_cpu_supports("sse4.2"))
+ a("sse4.2");
+
+ // CHECK: [[LOAD:%[^ ]+]] = load i32, i32* getelementptr inbounds ({ i32, i32, i32, [1 x i32] }, { i32, i32, i32, [1 x i32] }* @__cpu_model, i32 0, i32 3, i32 0)
+ // CHECK: [[AND:%[^ ]+]] = and i32 [[LOAD]], 256
+ // CHECK = icmp ne i32 [[AND]], 0
+
+ return 0;
+}
Added: cfe/trunk/test/Sema/builtin-cpu-supports.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/builtin-cpu-supports.c?rev=240994&view=auto
==============================================================================
--- cfe/trunk/test/Sema/builtin-cpu-supports.c (added)
+++ cfe/trunk/test/Sema/builtin-cpu-supports.c Mon Jun 29 16:00:05 2015
@@ -0,0 +1,21 @@
+// RUN: %clang_cc1 -fsyntax-only -triple x86_64-pc-linux-gnu -verify %s
+// RUN: %clang_cc1 -fsyntax-only -triple powerpc64le-linux-gnu -verify %s
+
+extern void a(const char *);
+
+extern const char *str;
+
+int main() {
+#ifdef __x86_64__
+ if (__builtin_cpu_supports("ss")) // expected-error {{invalid cpu feature string}}
+ a("sse4.2");
+
+ if (__builtin_cpu_supports(str)) // expected-error {{expression is not a string literal}}
+ a(str);
+#else
+ if (__builtin_cpu_supports("vsx")) // expected-error {{use of unknown builtin}}
+ a("vsx");
+#endif
+
+ return 0;
+}
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