[PATCH] D28196: [X86] Tune bypassing of slow division for Intel CPUs

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added inline comments.


================
Comment at: test/CodeGen/X86/atom-bypass-slow-division-64.ll:3
+; RUN: llc < %s -mcpu=silvermont -march=x86-64 -asm-verbose=false | FileCheck %s
+; RUN: llc < %s -mcpu=skylake    -march=x86-64 -asm-verbose=false | FileCheck %s
 
----------------
n.bozhenov wrote:
> n.bozhenov wrote:
> > RKSimon wrote:
> > > spatel wrote:
> > > > Is there some reason to choose skylake here rather than sandybridge? If not, I'd prefer SNB because that's the oldest big core where the feature is applied?
> > > Drop the -march and move the triple in there instead.
> > > Is there some reason to choose skylake here rather than sandybridge?
> > It doesn't make much difference because in D28197 I change this into `-mattr=+idivq-to-divl`
> > Drop the -march and move the triple in there instead.
> Ok, I will. But what is the difference?
> >  Drop the -march and move the triple in there instead.
> 
> Ok, I will. But what is the difference?

Triple sets the arch and the abi for you, so just avoids duplication.


https://reviews.llvm.org/D28196