sepavloff added inline comments.
================
Comment at: clang/lib/AST/Interp/ByteCodeExprGen.cpp:152
+ case CK_FloatingToIntegral: {
+ llvm::RoundingMode RM = getRoundingMode(CE);
+ Optional<PrimType> ToT = classify(CE->getType());
----------------
tbaeder wrote:
> sepavloff wrote:
> > According to C standard (6.3.1.4p1):
> > ```
> > When a finite value of real floating type is converted to an integer
> > type other than _Bool, the fractional part is discarded (i.e., the value is
> > truncated toward zero).
> > ```
> > So the conversion should not depend on rounding mode. The same applies to
> > the conversion to boolean (6.3.1.2p1):
> > ```
> > When any scalar value is converted to _Bool, the result is 0 if the
> > value compares equal to 0; otherwise, the result is 1.
> > ```
> >
> So this is a difference between C and C++?
No, C++ behaves similarly ([conv.fpint]):
```
A prvalue of a floating-point type can be converted to a prvalue of an integer
type. The conversion truncates;
that is, the fractional part is discarded.
```
and [conv.bool]:
```
A prvalue of arithmetic, unscoped enumeration, pointer, or pointer-to-member
type can be converted to a
prvalue of type bool. A zero value, null pointer value, or null member pointer
value is converted to false;
any other value is converted to true.
```
Theses conversions do not depend on rounding mode.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D134859/new/
https://reviews.llvm.org/D134859
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