Author: myatsina
Date: Mon Dec 26 06:23:42 2016
New Revision: 290539
URL: http://llvm.org/viewvc/llvm-project?rev=290539&view=rev
Log:
[inline-asm]No error for conflict between inputs\outputs and clobber list
According to extended asm syntax, a case where the clobber list includes a
variable from the inputs or outputs should be an error - conflict.
for example:
const long double a = 0.0;
int main()
{
char b;
double t1 = a;
__asm__ ("fucompp": "=a" (b) : "u" (t1), "t" (t1) : "cc", "st", "st(1)");
return 0;
}
This should conflict with the output - t1 which is st, and st which is st
aswell.
The patch fixes it.
Commit on behald of Ziv Izhar.
Differential Revision: https://reviews.llvm.org/D15075
Modified:
cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
cfe/trunk/include/clang/Basic/TargetInfo.h
cfe/trunk/lib/Basic/TargetInfo.cpp
cfe/trunk/lib/Basic/Targets.cpp
cfe/trunk/lib/Headers/intrin.h
cfe/trunk/lib/Sema/SemaStmtAsm.cpp
cfe/trunk/test/Sema/asm.c
Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=290539&r1=290538&r2=290539&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Mon Dec 26 06:23:42
2016
@@ -7069,6 +7069,10 @@ let CategoryName = "Inline Assembly Issu
"constraint '%0' is already present here">;
}
+ def error_inoutput_conflict_with_clobber : Error<
+ "asm-specifier for input or output variable conflicts with asm"
+ " clobber list">;
+
let CategoryName = "Semantic Issue" in {
def err_invalid_conversion_between_vectors : Error<
Modified: cfe/trunk/include/clang/Basic/TargetInfo.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/TargetInfo.h?rev=290539&r1=290538&r2=290539&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/TargetInfo.h (original)
+++ cfe/trunk/include/clang/Basic/TargetInfo.h Mon Dec 26 06:23:42 2016
@@ -605,8 +605,16 @@ public:
/// \brief Returns the "normalized" GCC register name.
///
- /// For example, on x86 it will return "ax" when "eax" is passed in.
- StringRef getNormalizedGCCRegisterName(StringRef Name) const;
+ /// ReturnCannonical true will return the register name without any additions
+ /// such as "{}" or "%" in it's canonical form, for example:
+ /// ReturnCanonical = true and Name = "rax", will return "ax".
+ StringRef getNormalizedGCCRegisterName(StringRef Name,
+ bool ReturnCanonical = false) const;
+
+ virtual StringRef getConstraintRegister(const StringRef &Constraint,
+ const StringRef &Expression) const {
+ return "";
+ }
struct ConstraintInfo {
enum {
Modified: cfe/trunk/lib/Basic/TargetInfo.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/TargetInfo.cpp?rev=290539&r1=290538&r2=290539&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/TargetInfo.cpp (original)
+++ cfe/trunk/lib/Basic/TargetInfo.cpp Mon Dec 26 06:23:42 2016
@@ -410,8 +410,8 @@ bool TargetInfo::isValidGCCRegisterName(
return false;
}
-StringRef
-TargetInfo::getNormalizedGCCRegisterName(StringRef Name) const {
+StringRef TargetInfo::getNormalizedGCCRegisterName(StringRef Name,
+ bool ReturnCanonical) const
{
assert(isValidGCCRegisterName(Name) && "Invalid register passed in");
// Get rid of any register prefix.
@@ -436,7 +436,7 @@ TargetInfo::getNormalizedGCCRegisterName
// Make sure the register that the additional name is for is within
// the bounds of the register names from above.
if (AN == Name && ARN.RegNum < Names.size())
- return Name;
+ return ReturnCanonical ? Names[ARN.RegNum] : Name;
}
// Now check aliases.
Modified: cfe/trunk/lib/Basic/Targets.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=290539&r1=290538&r2=290539&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/Targets.cpp (original)
+++ cfe/trunk/lib/Basic/Targets.cpp Mon Dec 26 06:23:42 2016
@@ -2789,6 +2789,40 @@ public:
const char *getClobbers() const override {
return "~{dirflag},~{fpsr},~{flags}";
}
+
+ StringRef getConstraintRegister(const StringRef &Constraint,
+ const StringRef &Expression) const override {
+ StringRef::iterator I, E;
+ for (I = Constraint.begin(), E = Constraint.end(); I != E; ++I) {
+ if (isalpha(*I))
+ break;
+ }
+ if (I == E)
+ return "";
+ switch (*I) {
+ // For the register constraints, return the matching register name
+ case 'a':
+ return "ax";
+ case 'b':
+ return "bx";
+ case 'c':
+ return "cx";
+ case 'd':
+ return "dx";
+ case 'S':
+ return "si";
+ case 'D':
+ return "di";
+ // In case the constraint is 'r' we need to return Expression
+ case 'r':
+ return Expression;
+ default:
+ // Default value if there is no constraint for the register
+ return "";
+ }
+ return "";
+ }
+
void getTargetDefines(const LangOptions &Opts,
MacroBuilder &Builder) const override;
static void setSSELevel(llvm::StringMap<bool> &Features, X86SSEEnum Level,
Modified: cfe/trunk/lib/Headers/intrin.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Headers/intrin.h?rev=290539&r1=290538&r2=290539&view=diff
==============================================================================
--- cfe/trunk/lib/Headers/intrin.h (original)
+++ cfe/trunk/lib/Headers/intrin.h Mon Dec 26 06:23:42 2016
@@ -1010,40 +1010,33 @@ __readgsqword(unsigned long __offset) {
#if defined(__i386__) || defined(__x86_64__)
static __inline__ void __DEFAULT_FN_ATTRS
__movsb(unsigned char *__dst, unsigned char const *__src, size_t __n) {
- __asm__("rep movsb" : : "D"(__dst), "S"(__src), "c"(__n)
- : "%edi", "%esi", "%ecx");
+ __asm__("rep movsb" : : "D"(__dst), "S"(__src), "c"(__n));
}
static __inline__ void __DEFAULT_FN_ATTRS
__movsd(unsigned long *__dst, unsigned long const *__src, size_t __n) {
- __asm__("rep movsl" : : "D"(__dst), "S"(__src), "c"(__n)
- : "%edi", "%esi", "%ecx");
+ __asm__("rep movsl" : : "D"(__dst), "S"(__src), "c"(__n));
}
static __inline__ void __DEFAULT_FN_ATTRS
__movsw(unsigned short *__dst, unsigned short const *__src, size_t __n) {
- __asm__("rep movsw" : : "D"(__dst), "S"(__src), "c"(__n)
- : "%edi", "%esi", "%ecx");
+ __asm__("rep movsw" : : "D"(__dst), "S"(__src), "c"(__n));
}
static __inline__ void __DEFAULT_FN_ATTRS
__stosd(unsigned long *__dst, unsigned long __x, size_t __n) {
- __asm__("rep stosl" : : "D"(__dst), "a"(__x), "c"(__n)
- : "%edi", "%ecx");
+ __asm__("rep stosl" : : "D"(__dst), "a"(__x), "c"(__n));
}
static __inline__ void __DEFAULT_FN_ATTRS
__stosw(unsigned short *__dst, unsigned short __x, size_t __n) {
- __asm__("rep stosw" : : "D"(__dst), "a"(__x), "c"(__n)
- : "%edi", "%ecx");
+ __asm__("rep stosw" : : "D"(__dst), "a"(__x), "c"(__n));
}
#endif
#ifdef __x86_64__
static __inline__ void __DEFAULT_FN_ATTRS
__movsq(unsigned long long *__dst, unsigned long long const *__src, size_t
__n) {
- __asm__("rep movsq" : : "D"(__dst), "S"(__src), "c"(__n)
- : "%edi", "%esi", "%ecx");
+ __asm__("rep movsq" : : "D"(__dst), "S"(__src), "c"(__n));
}
static __inline__ void __DEFAULT_FN_ATTRS
__stosq(unsigned __int64 *__dst, unsigned __int64 __x, size_t __n) {
- __asm__("rep stosq" : : "D"(__dst), "a"(__x), "c"(__n)
- : "%edi", "%ecx");
+ __asm__("rep stosq" : : "D"(__dst), "a"(__x), "c"(__n));
}
#endif
Modified: cfe/trunk/lib/Sema/SemaStmtAsm.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmtAsm.cpp?rev=290539&r1=290538&r2=290539&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaStmtAsm.cpp (original)
+++ cfe/trunk/lib/Sema/SemaStmtAsm.cpp Mon Dec 26 06:23:42 2016
@@ -22,6 +22,7 @@
#include "clang/Sema/ScopeInfo.h"
#include "clang/Sema/SemaInternal.h"
#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringSet.h"
#include "llvm/MC/MCParser/MCAsmParser.h"
using namespace clang;
using namespace sema;
@@ -137,6 +138,57 @@ static bool checkExprMemoryConstraintCom
return false;
}
+// Extracting the register name from the Expression value,
+// if there is no register name to extract, returns ""
+static StringRef extractRegisterName(const Expr *Expression,
+ const TargetInfo &Target) {
+ Expression = Expression->IgnoreImpCasts();
+ if (const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(Expression)) {
+ // Handle cases where the expression is a variable
+ const VarDecl *Variable = dyn_cast<VarDecl>(AsmDeclRef->getDecl());
+ if (Variable && Variable->getStorageClass() == SC_Register) {
+ if (AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>())
+ if (Target.isValidGCCRegisterName(Attr->getLabel()))
+ return Target.getNormalizedGCCRegisterName(Attr->getLabel(), true);
+ }
+ }
+ return "";
+}
+
+// Checks if there is a conflict between the input and output lists with the
+// clobbers list. If there's a conflict, returns the location of the
+// conflicted clobber, else returns nullptr
+static SourceLocation
+getClobberConflictLocation(MultiExprArg Exprs, StringLiteral **Constraints,
+ StringLiteral **Clobbers, int NumClobbers,
+ const TargetInfo &Target, ASTContext &Cont) {
+ llvm::StringSet<> InOutVars;
+ // Collect all the input and output registers from the extended asm
+ // statement
+ // in order to check for conflicts with the clobber list
+ for (int i = 0; i < Exprs.size(); ++i) {
+ StringRef Constraint = Constraints[i]->getString();
+ StringRef InOutReg = Target.getConstraintRegister(
+ Constraint, extractRegisterName(Exprs[i], Target));
+ if (InOutReg != "")
+ InOutVars.insert(InOutReg);
+ }
+ // Check for each item in the clobber list if it conflicts with the input
+ // or output
+ for (int i = 0; i < NumClobbers; ++i) {
+ StringRef Clobber = Clobbers[i]->getString();
+ // We only check registers, therefore we don't check cc and memory
+ // clobbers
+ if (Clobber == "cc" || Clobber == "memory")
+ continue;
+ Clobber = Target.getNormalizedGCCRegisterName(Clobber, true);
+ // Go over the output's registers we collected
+ if (InOutVars.count(Clobber))
+ return Clobbers[i]->getLocStart();
+ }
+ return SourceLocation();
+}
+
StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
bool IsVolatile, unsigned NumOutputs,
unsigned NumInputs, IdentifierInfo **Names,
@@ -543,6 +595,13 @@ StmtResult Sema::ActOnGCCAsmStmt(SourceL
return StmtError();
}
+ // Check for conflicts between clobber list and input or output lists
+ SourceLocation ConstraintLoc =
+ getClobberConflictLocation(Exprs, Constraints, Clobbers, NumClobbers,
+ Context.getTargetInfo(), Context);
+ if (ConstraintLoc.isValid())
+ return Diag(ConstraintLoc, diag::error_inoutput_conflict_with_clobber);
+
return NS;
}
Modified: cfe/trunk/test/Sema/asm.c
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/asm.c?rev=290539&r1=290538&r2=290539&view=diff
==============================================================================
--- cfe/trunk/test/Sema/asm.c (original)
+++ cfe/trunk/test/Sema/asm.c Mon Dec 26 06:23:42 2016
@@ -28,6 +28,16 @@ void clobbers() {
asm ("nop" : : : "204"); // expected-error {{unknown register name '204' in
asm}}
asm ("nop" : : : "-1"); // expected-error {{unknown register name '-1' in
asm}}
asm ("nop" : : : "+1"); // expected-error {{unknown register name '+1' in
asm}}
+ register void *clobber_conflict asm ("%rcx");
+ register void *no_clobber_conflict asm ("%rax");
+ int a,b,c;
+ asm ("nop" : "=r" (no_clobber_conflict) : "r" (clobber_conflict) : "%rcx");
// expected-error {{asm-specifier for input or output variable conflicts with
asm clobber list}}
+ asm ("nop" : "=r" (clobber_conflict) : "r" (no_clobber_conflict) : "%rcx");
// expected-error {{asm-specifier for input or output variable conflicts with
asm clobber list}}
+ asm ("nop" : "=r" (clobber_conflict) : "r" (clobber_conflict) : "%rcx"); //
expected-error {{asm-specifier for input or output variable conflicts with asm
clobber list}}
+ asm ("nop" : "=c" (a) : "r" (no_clobber_conflict) : "%rcx"); //
expected-error {{asm-specifier for input or output variable conflicts with asm
clobber list}}
+ asm ("nop" : "=r" (no_clobber_conflict) : "c" (c) : "%rcx"); //
expected-error {{asm-specifier for input or output variable conflicts with asm
clobber list}}
+ asm ("nop" : "=r" (clobber_conflict) : "c" (c) : "%rcx"); // expected-error
{{asm-specifier for input or output variable conflicts with asm clobber list}}
+ asm ("nop" : "=a" (a) : "b" (b) : "%rcx", "%rbx"); // expected-error
{{asm-specifier for input or output variable conflicts with asm clobber list}}
}
// rdar://6094010
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