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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