Re: [RFC] Implementing detection of saturation and rounding arithmetic

在 5/12/21 5:13 PM, Tamar Christina via Gcc 写道: int f (int a, int b) { int res; if (__builtin_add_overflow (a, b, &res)) { if (res >= 0) return INT_MAX; else return INT_MIN; } return res; } Should be recognized as satur

Re: [RFC] Implementing detection of saturation and rounding arithmetic

On Wed, May 12, 2021 at 09:13:38AM +, Tamar Christina wrote: > > From: Segher Boessenkool > > On Tue, May 11, 2021 at 05:37:34AM +, Tamar Christina via Gcc wrote: > > > 2. Saturating abs: > > >char sat (char a) > > >{ > > > int tmp = abs (a); > > > return tmp > 127 ? 12

RE: [RFC] Implementing detection of saturation and rounding arithmetic

On Wed, 12 May 2021, Tamar Christina wrote: > > > > -Original Message- > > From: Richard Biener > > Sent: Tuesday, May 11, 2021 12:45 PM > > To: Tamar Christina > > Cc: gcc@gcc.gnu.org; Richard Sandiford ; > > Jakub Jelinek > > Subject

Re: [RFC] Implementing detection of saturation and rounding arithmetic

On Wed, 12 May 2021, Richard Sandiford wrote: > Tamar Christina writes: > > Hi All, > > > > We are looking to implement saturation support in the compiler. The aim is > > to > > recognize both Scalar and Vector variant of typical saturating expressions. > > > > As an example: > > > > 1. Saturat

RE: [RFC] Implementing detection of saturation and rounding arithmetic

> -Original Message- > From: Richard Sandiford > Sent: Wednesday, May 12, 2021 9:48 AM > To: Tamar Christina > Cc: gcc@gcc.gnu.org; Richard Biener > Subject: Re: [RFC] Implementing detection of saturation and rounding > arithmetic > > Tamar Christina wri

RE: [RFC] Implementing detection of saturation and rounding arithmetic

> -Original Message- > From: Joseph Myers > Sent: Tuesday, May 11, 2021 6:01 PM > To: David Brown > Cc: Tamar Christina ; gcc@gcc.gnu.org; Richard > Sandiford ; Richard Biener > > Subject: Re: [RFC] Implementing detection of saturation and rounding > ari

RE: [RFC] Implementing detection of saturation and rounding arithmetic

Hi, > -Original Message- > From: Segher Boessenkool > Sent: Tuesday, May 11, 2021 4:43 PM > To: Tamar Christina > Cc: gcc@gcc.gnu.org; Richard Sandiford ; > Richard Biener > Subject: Re: [RFC] Implementing detection of saturation and rounding > arithmetic >

RE: [RFC] Implementing detection of saturation and rounding arithmetic

> -Original Message- > From: Richard Biener > Sent: Tuesday, May 11, 2021 12:45 PM > To: Tamar Christina > Cc: gcc@gcc.gnu.org; Richard Sandiford ; > Jakub Jelinek > Subject: Re: [RFC] Implementing detection of saturation and rounding > arithmetic > &

Re: [RFC] Implementing detection of saturation and rounding arithmetic

Tamar Christina writes: > Hi All, > > We are looking to implement saturation support in the compiler. The aim is to > recognize both Scalar and Vector variant of typical saturating expressions. > > As an example: > > 1. Saturating addition: >char sat (char a, char b) >{ > int tmp =

Re: [RFC] Implementing detection of saturation and rounding arithmetic

On 12/05/2021 10:00, Tamar Christina wrote: > Hi David, > >> -Original Message- >> From: David Brown >> Sent: Tuesday, May 11, 2021 11:04 AM >> To: Tamar Christina ; gcc@gcc.gnu.org >> Cc: Richard Sandiford ; Richard Biener >> >> Subject

RE: [RFC] Implementing detection of saturation and rounding arithmetic

Hi David, > -Original Message- > From: David Brown > Sent: Tuesday, May 11, 2021 11:04 AM > To: Tamar Christina ; gcc@gcc.gnu.org > Cc: Richard Sandiford ; Richard Biener > > Subject: Re: [RFC] Implementing detection of saturation and rounding > arithmetic

Re: [RFC] Implementing detection of saturation and rounding arithmetic

On 11/05/2021 19:00, Joseph Myers wrote: > On Tue, 11 May 2021, David Brown wrote: > >> It is also worth noting that gcc already has support for saturating >> types on some targets: >> >> >> >> My testing of these (quite a long time ago) left m

Re: [RFC] Implementing detection of saturation and rounding arithmetic

On Tue, 11 May 2021, David Brown wrote: > It is also worth noting that gcc already has support for saturating > types on some targets: > > > > My testing of these (quite a long time ago) left me with a feeling that > it was not a feature anyo

Re: [RFC] Implementing detection of saturation and rounding arithmetic

Hi! On Tue, May 11, 2021 at 05:37:34AM +, Tamar Christina via Gcc wrote: > 2. Saturating abs: >char sat (char a) >{ > int tmp = abs (a); > return tmp > 127 ? 127 : ((tmp < -128) ? -128 : tmp); >} That can be done quite a bit better, branchless at least. Same for all e

Re: [RFC] Implementing detection of saturation and rounding arithmetic

On Tue, 11 May 2021, Tamar Christina wrote: > Hi All, > > We are looking to implement saturation support in the compiler. The aim is to > recognize both Scalar and Vector variant of typical saturating expressions. > > As an example: > > 1. Saturating addition: >char sat (char a, char b) >

Re: [RFC] Implementing detection of saturation and rounding arithmetic

On 11/05/2021 07:37, Tamar Christina via Gcc wrote: > Hi All, > > We are looking to implement saturation support in the compiler. The aim is to > recognize both Scalar and Vector variant of typical saturating expressions. > > As an example: > > 1. Saturating addition: >char sat (char a, cha

[RFC] Implementing detection of saturation and rounding arithmetic

Hi All, We are looking to implement saturation support in the compiler. The aim is to recognize both Scalar and Vector variant of typical saturating expressions. As an example: 1. Saturating addition: char sat (char a, char b) { int tmp = a + b; return tmp > 127 ? 127 : ((tmp