[PATCH] D22064: [X86] Make some cast costs more precise

[Michael Kuperstein via llvm-commits]

mkuper added a comment.

Thanks, Simon!


================
Comment at: lib/Target/X86/X86TargetTransformInfo.cpp:540
@@ -539,3 +539,3 @@
     { ISD::UINT_TO_FP,  MVT::v8f32,  MVT::v8i64,  1 },    
     { ISD::UINT_TO_FP,  MVT::v8f64,  MVT::v8i64,  1 },
 
----------------
RKSimon wrote:
> mkuper wrote:
> > delena wrote:
> > > mkuper wrote:
> > > > RKSimon wrote:
> > > > > Depending on how thorough we need to be shouldn't there be AVX512DQ+AVX512VL UINT_TO_FP cases for 128/256 bit vectors?
> > > > Probably.
> > > > I'd rather leave that to the Intel folks, they can probably get more precise numbers for SKX.
> > > In this case, even if you have only DQ without VL, the conversion is in ZMM instead of YMM, but the cost is the same.
> > We don't do this right now, see below.
> OK - please add a TODO comment to the table for the AVX512DQ 128/256 entries.
Ack.

================
Comment at: lib/Target/X86/X86TargetTransformInfo.cpp:717
@@ -708,1 +716,3 @@
+    { ISD::FP_EXTEND,   MVT::v4f64,  MVT::v4f32,  1 },
+    { ISD::FP_ROUND,    MVT::v4f32,  MVT::v4f64,  1 },
   };
----------------
RKSimon wrote:
> Test?
Right, thanks.
Elena's original patch didn't have one, and I didn't notice. I'll add.


http://reviews.llvm.org/D22064