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.
llvm-svn: 250473
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index bcc6ac9..6dff363 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -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 @@
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 @@
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;
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index 60770b1..bb7fdca 100644
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -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"
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 390e346..d67e6f6 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -2633,6 +2633,8 @@
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,