rjmccall added inline comments.
================
Comment at: include/clang/AST/ASTContext.h:1954
+ llvm::APInt getFixedPointMin(QualType Ty) const;
+ llvm::APInt getFixedPointOne(QualType Ty) const;
----------------
Are these opaque bit-patterns? I think there should be a type which abstracts
over constant fixed-point values, something `APSInt`-like that also carries the
signedness and scale. For now that type can live in Clang; if LLVM wants to
add intrinsic support for fixed-point, it'll be easy enough to move it there.
================
Comment at: lib/CodeGen/CGExprScalar.cpp:768
+ if (CGF.getContext().getTargetInfo().unsignedFixedPointTypesHavePadding()
&&
+ Ty->isUnsignedFixedPointType()) {
+ unsigned NumBits = CGF.getContext().getTypeSize(Ty);
----------------
Can you explain the padding thing? Why is padding uniformly present or absent
on all unsigned fixed point types on a target, and never on signed types? Is
this "low bits set" thing endian-specific?
================
Comment at: lib/CodeGen/CGExprScalar.cpp:1801
+ return Builder.CreateLShr(
+ EmitScalarConversion(Val, SrcTy, DestTy, CE->getExprLoc()), scale);
+ }
----------------
Please abstract functions for doing this kind of arithmetic instead of inlining
them into scalar emission. Feel free to make a new CGFixedPoint.h header and
corresponding implementation file.
Also, it looks like you're assuming that the output type is the same size as
the input type. I don't think that's actually a language restriction, right?
Repository:
rC Clang
https://reviews.llvm.org/D48456
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
