r250473 - Add an error when calling a builtin that requires features that don't
Jim Grosbach via cfe-commits
cfe-commits at lists.llvm.org
Fri Oct 16 14:27:52 PDT 2015
Woot! Thanks!
> On Oct 15, 2015, at 4:47 PM, Eric Christopher via cfe-commits <cfe-commits at lists.llvm.org> wrote:
>
> Author: echristo
> Date: Thu Oct 15 18:47:11 2015
> New Revision: 250473
>
> URL: http://llvm.org/viewvc/llvm-project?rev=250473&view=rev
> Log:
> Add an error when calling a builtin that requires features that don't
> match the feature set of the function that they're being called from.
>
> This ensures that we can effectively diagnose some[1] code that would
> instead ICE in the backend with a failure to select message.
>
> Example:
>
> __m128d foo(__m128d a, __m128d b) {
> return __builtin_ia32_addsubps(b, a);
> }
>
> compiled for normal x86_64 via:
>
> clang -target x86_64-linux-gnu -c
>
> would fail to compile in the back end because the normal subtarget
> features for x86_64 only include sse2 and the builtin requires sse3.
>
> [1] We're still not erroring on:
>
> __m128i bar(__m128i const *p) { return _mm_lddqu_si128(p); }
>
> where we should fail and error on an always_inline function being
> inlined into a function that doesn't support the subtarget features
> required.
>
> Added:
> cfe/trunk/test/CodeGen/target-builtin-error-2.c
> cfe/trunk/test/CodeGen/target-builtin-error.c
> cfe/trunk/test/CodeGen/target-builtin-noerror.c
> Modified:
> cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> cfe/trunk/lib/CodeGen/CGBuiltin.cpp
> cfe/trunk/lib/CodeGen/CGCall.cpp
> cfe/trunk/lib/CodeGen/CodeGenFunction.h
>
> Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=250473&r1=250472&r2=250473&view=diff
> ==============================================================================
> --- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
> +++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Thu Oct 15 18:47:11 2015
> @@ -430,6 +430,7 @@ def warn_redecl_library_builtin : Warnin
> 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 err_builtin_needs_feature : Error<"%0 needs target feature %1">;
> def warn_builtin_unknown : Warning<"use of unknown builtin %0">,
> InGroup<ImplicitFunctionDeclare>, DefaultError;
> def warn_dyn_class_memaccess : Warning<
>
> Modified: cfe/trunk/lib/CodeGen/CGBuiltin.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGBuiltin.cpp?rev=250473&r1=250472&r2=250473&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/CGBuiltin.cpp (original)
> +++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp Thu Oct 15 18:47:11 2015
> @@ -21,6 +21,7 @@
> #include "clang/Basic/TargetBuiltins.h"
> #include "clang/Basic/TargetInfo.h"
> #include "clang/CodeGen/CGFunctionInfo.h"
> +#include "clang/Sema/SemaDiagnostic.h"
> #include "llvm/ADT/StringExtras.h"
> #include "llvm/IR/CallSite.h"
> #include "llvm/IR/DataLayout.h"
> @@ -288,6 +289,62 @@ Value *CodeGenFunction::EmitVAStartEnd(V
> return Builder.CreateCall(CGM.getIntrinsic(inst), ArgValue);
> }
>
> +// Returns true if we have a valid set of target features.
> +bool CodeGenFunction::checkBuiltinTargetFeatures(
> + const FunctionDecl *TargetDecl) {
> + // Early exit if this is an indirect call.
> + if (!TargetDecl)
> + return true;
> +
> + // Get the current enclosing function if it exists.
> + if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl)) {
> + unsigned BuiltinID = TargetDecl->getBuiltinID();
> + const char *FeatureList =
> + CGM.getContext().BuiltinInfo.getRequiredFeatures(BuiltinID);
> + if (FeatureList && StringRef(FeatureList) != "") {
> + StringRef TargetCPU = Target.getTargetOpts().CPU;
> + llvm::StringMap<bool> FeatureMap;
> +
> + if (const auto *TD = FD->getAttr<TargetAttr>()) {
> + // If we have a TargetAttr build up the feature map based on that.
> + TargetAttr::ParsedTargetAttr ParsedAttr = TD->parse();
> +
> + // Make a copy of the features as passed on the command line into the
> + // beginning of the additional features from the function to override.
> + ParsedAttr.first.insert(
> + ParsedAttr.first.begin(),
> + Target.getTargetOpts().FeaturesAsWritten.begin(),
> + Target.getTargetOpts().FeaturesAsWritten.end());
> +
> + if (ParsedAttr.second != "")
> + TargetCPU = ParsedAttr.second;
> +
> + // Now populate the feature map, first with the TargetCPU which is
> + // either
> + // the default or a new one from the target attribute string. Then we'll
> + // use the passed in features (FeaturesAsWritten) along with the new
> + // ones
> + // from the attribute.
> + Target.initFeatureMap(FeatureMap, CGM.getDiags(), TargetCPU,
> + ParsedAttr.first);
> + } else {
> + Target.initFeatureMap(FeatureMap, CGM.getDiags(), TargetCPU,
> + Target.getTargetOpts().Features);
> + }
> +
> + // If we have at least one of the features in the feature list return
> + // true, otherwise return false.
> + SmallVector<StringRef, 1> AttrFeatures;
> + StringRef(FeatureList).split(AttrFeatures, ",");
> + for (const auto &Feature : AttrFeatures)
> + if (FeatureMap[Feature])
> + return true;
> + return false;
> + }
> + }
> + return true;
> +}
> +
> RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
> unsigned BuiltinID, const CallExpr *E,
> ReturnValueSlot ReturnValue) {
> @@ -1789,6 +1846,16 @@ RValue CodeGenFunction::EmitBuiltinExpr(
> if (getContext().BuiltinInfo.isPredefinedLibFunction(BuiltinID))
> return emitLibraryCall(*this, FD, E, EmitScalarExpr(E->getCallee()));
>
> + // Check that a call to a target specific builtin has the correct target
> + // features.
> + // This is down here to avoid non-target specific builtins, however, if
> + // generic builtins start to require generic target features then we
> + // can move this up to the beginning of the function.
> + if (!checkBuiltinTargetFeatures(FD))
> + CGM.getDiags().Report(E->getLocStart(), diag::err_builtin_needs_feature)
> + << FD->getDeclName()
> + << CGM.getContext().BuiltinInfo.getRequiredFeatures(BuiltinID);
> +
> // See if we have a target specific intrinsic.
> const char *Name = getContext().BuiltinInfo.getName(BuiltinID);
> Intrinsic::ID IntrinsicID = Intrinsic::not_intrinsic;
>
> Modified: cfe/trunk/lib/CodeGen/CGCall.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCall.cpp?rev=250473&r1=250472&r2=250473&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/CGCall.cpp (original)
> +++ cfe/trunk/lib/CodeGen/CGCall.cpp Thu Oct 15 18:47:11 2015
> @@ -21,6 +21,7 @@
> #include "clang/AST/Decl.h"
> #include "clang/AST/DeclCXX.h"
> #include "clang/AST/DeclObjC.h"
> +#include "clang/Basic/TargetBuiltins.h"
> #include "clang/Basic/TargetInfo.h"
> #include "clang/CodeGen/CGFunctionInfo.h"
> #include "clang/Frontend/CodeGenOptions.h"
>
> Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=250473&r1=250472&r2=250473&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
> +++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Thu Oct 15 18:47:11 2015
> @@ -2633,6 +2633,8 @@ public:
> RValue EmitCallExpr(const CallExpr *E,
> ReturnValueSlot ReturnValue = ReturnValueSlot());
>
> + bool checkBuiltinTargetFeatures(const FunctionDecl *TargetDecl);
> +
> llvm::CallInst *EmitRuntimeCall(llvm::Value *callee,
> const Twine &name = "");
> llvm::CallInst *EmitRuntimeCall(llvm::Value *callee,
>
> Added: cfe/trunk/test/CodeGen/target-builtin-error-2.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/target-builtin-error-2.c?rev=250473&view=auto
> ==============================================================================
> --- cfe/trunk/test/CodeGen/target-builtin-error-2.c (added)
> +++ cfe/trunk/test/CodeGen/target-builtin-error-2.c Thu Oct 15 18:47:11 2015
> @@ -0,0 +1,13 @@
> +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -S -verify -o -
> +#define __MM_MALLOC_H
> +
> +#include <x86intrin.h>
> +
> +// Since we do code generation on a function level this needs to error out since
> +// the subtarget feature won't be available.
> +__m256d wombat(__m128i a) {
> + if (__builtin_cpu_supports("avx"))
> + return __builtin_ia32_cvtdq2pd256((__v4si)a); // expected-error {{'__builtin_ia32_cvtdq2pd256' needs target feature avx}}
> + else
> + return (__m256d){0, 0, 0, 0};
> +}
>
> Added: cfe/trunk/test/CodeGen/target-builtin-error.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/target-builtin-error.c?rev=250473&view=auto
> ==============================================================================
> --- cfe/trunk/test/CodeGen/target-builtin-error.c (added)
> +++ cfe/trunk/test/CodeGen/target-builtin-error.c Thu Oct 15 18:47:11 2015
> @@ -0,0 +1,8 @@
> +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -S -verify -o -
> +#define __MM_MALLOC_H
> +
> +#include <x86intrin.h>
> +
> +__m128d foo(__m128d a, __m128d b) {
> + return __builtin_ia32_addsubps(b, a); // expected-error {{'__builtin_ia32_addsubps' needs target feature sse3}}
> +}
>
> Added: cfe/trunk/test/CodeGen/target-builtin-noerror.c
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/target-builtin-noerror.c?rev=250473&view=auto
> ==============================================================================
> --- cfe/trunk/test/CodeGen/target-builtin-noerror.c (added)
> +++ cfe/trunk/test/CodeGen/target-builtin-noerror.c Thu Oct 15 18:47:11 2015
> @@ -0,0 +1,30 @@
> +// RUN: %clang_cc1 %s -triple=x86_64-linux-gnu -S -o -
> +#define __MM_MALLOC_H
> +
> +#include <x86intrin.h>
> +
> +// No warnings.
> +extern __m256i a;
> +int __attribute__((target("avx"))) bar(__m256i a) {
> + return _mm256_extract_epi32(a, 3);
> +}
> +
> +int baz() {
> + return bar(a);
> +}
> +
> +int __attribute__((target("avx"))) qq_avx(__m256i a) {
> + return _mm256_extract_epi32(a, 3);
> +}
> +
> +int qq_noavx() {
> + return 0;
> +}
> +
> +extern __m256i a;
> +int qq() {
> + if (__builtin_cpu_supports("avx"))
> + return qq_avx(a);
> + else
> + return qq_noavx();
> +}
>
>
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