[PATCH] D144565: dwp check overflow

[Alexander Yermolovich via Phabricator via llvm-commits]

ayermolo added inline comments.


================
Comment at: llvm/tools/llvm-dwp/llvm-dwp.cpp:470
       bool Overflow = false;
       APInt NewOffset = Offset.uadd_ov(NewLength, Overflow);
       if (Overflow) {
----------------
ayermolo wrote:
> I think this will break the overflow behavior that llvm patch I references relies on.
> 
> 
> ```
> APInt APInt::uadd_sat(const APInt &RHS) const {
>   bool Overflow;
>   APInt Res = uadd_ov(RHS, Overflow);
>   if (!Overflow)
>     return Res;
>  
>   return APInt::getMaxValue(BitWidth);
> }
> ```
> I think this will break the overflow behavior that llvm patch I references relies on.
> 
> 
> ```
> APInt APInt::uadd_sat(const APInt &RHS) const {
>   bool Overflow;
>   APInt Res = uadd_ov(RHS, Overflow);
>   if (!Overflow)
>     return Res;
>  
>   return APInt::getMaxValue(BitWidth);
> }
> ```




================
Comment at: llvm/tools/llvm-dwp/llvm-dwp.cpp:470
       bool Overflow = false;
       APInt NewOffset = Offset.uadd_ov(NewLength, Overflow);
       if (Overflow) {
----------------
ayermolo wrote:
> ayermolo wrote:
> > I think this will break the overflow behavior that llvm patch I references relies on.
> > 
> > 
> > ```
> > APInt APInt::uadd_sat(const APInt &RHS) const {
> >   bool Overflow;
> >   APInt Res = uadd_ov(RHS, Overflow);
> >   if (!Overflow)
> >     return Res;
> >  
> >   return APInt::getMaxValue(BitWidth);
> > }
> > ```
> > I think this will break the overflow behavior that llvm patch I references relies on.
> > 
> > 
> > ```
> > APInt APInt::uadd_sat(const APInt &RHS) const {
> >   bool Overflow;
> >   APInt Res = uadd_ov(RHS, Overflow);
> >   if (!Overflow)
> >     return Res;
> >  
> >   return APInt::getMaxValue(BitWidth);
> > }
> > ```
> 
> 
> I think this will break the overflow behavior that llvm patch I references relies on.
> 
> 
> ```
> APInt APInt::uadd_sat(const APInt &RHS) const {
>   bool Overflow;
>   APInt Res = uadd_ov(RHS, Overflow);
>   if (!Overflow)
>     return Res;
>  
>   return APInt::getMaxValue(BitWidth);
> }
> ```

errr, messeed up APIs. never mind. 


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D144565/new/

https://reviews.llvm.org/D144565