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Fix inline assembler constraint validation 

The current constraint logic is both too lax and too strict. It fails
for input outside the [INT_MIN..INT_MAX] range, but it also implicitly
accepts 0 as value when it should not. Adjust logic to handle both
correctly.

Differential Revision: https://reviews.llvm.org/D58649

llvm-svn: 354937
This commit is contained in:
Joerg Sonnenberger 2019-02-27 00:40:59 +00:00
parent 7ad06a9319
commit 49ef2a4acd
2 changed files with 10 additions and 4 deletions
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10
clang/include/clang/Basic/TargetInfo.h
View File

@ -816,6 +816,7 @@ public:
struct {
int Min;
int Max;
bool isConstrained;
} ImmRange;
llvm::SmallSet<int, 4> ImmSet;
@ -826,6 +827,7 @@ public:
: Flags(0), TiedOperand(-1), ConstraintStr(ConstraintStr.str()),
Name(Name.str()) {
ImmRange.Min = ImmRange.Max = 0;
ImmRange.isConstrained = false;
}
const std::string &getConstraintStr() const { return ConstraintStr; }
@ -854,8 +856,9 @@ public:
return (Flags & CI_ImmediateConstant) != 0;
}
bool isValidAsmImmediate(const llvm::APInt &Value) const {
return (Value.sge(ImmRange.Min) && Value.sle(ImmRange.Max)) ||
ImmSet.count(Value.getZExtValue()) != 0;
if (!ImmSet.empty())
return ImmSet.count(Value.getZExtValue()) != 0;
return !ImmRange.isConstrained || (Value.sge(ImmRange.Min) && Value.sle(ImmRange.Max));
}
void setIsReadWrite() { Flags |= CI_ReadWrite; }
@ -867,6 +870,7 @@ public:
Flags |= CI_ImmediateConstant;
ImmRange.Min = Min;
ImmRange.Max = Max;
ImmRange.isConstrained = true;
}
void setRequiresImmediate(llvm::ArrayRef<int> Exacts) {
Flags |= CI_ImmediateConstant;
@ -879,8 +883,6 @@ public:
}
void setRequiresImmediate() {
Flags |= CI_ImmediateConstant;
ImmRange.Min = INT_MIN;
ImmRange.Max = INT_MAX;
}
/// Indicate that this is an input operand that is tied to

4
clang/test/Sema/inline-asm-validate-x86.c
View File

@ -55,6 +55,7 @@ void K(int i, int j) {
void L(int i, int j) {
static const int Invalid1 = 1;
static const int Invalid2 = 42;
static const int Invalid3 = 0;
static const int Valid1 = 0xff;
static const int Valid2 = 0xffff;
static const int Valid3 = 0xffffffff;
@ -67,6 +68,9 @@ void L(int i, int j) {
__asm__("xorl %0,%2"
: "=r"(i)
: "0"(i), "L"(Invalid2)); // expected-error{{value '42' out of range for constraint 'L'}}
__asm__("xorl %0,%2"
: "=r"(i)
: "0"(i), "L"(Invalid3)); // expected-error{{value '0' out of range for constraint 'L'}}
__asm__("xorl %0,%2"
: "=r"(i)
: "0"(i), "L"(Valid1)); // expected-no-error