[PATCH] Fix DAG fold that didn't check legal ops

[Hal Finkel]

Hi Escha,

In the future, please post patches like this using phabricator. Although trivial, it is much easier to see the full context of the patch using the web interface (because, when uploading a patch, you upload with full context and let the web interface reduce it dynamically). Please see: http://llvm.org/docs/Phabricator.html#requesting-a-review-via-the-web-interface

> + (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT)) &&

I'd prefer that we use TLI.isOperationLegalOrCustom here; otherwise, LGTM.

 -Hal

----- Original Message -----
> From: "escha" <escha at apple.com>
> To: "llvm-commits" <llvm-commits at cs.uiuc.edu>
> Sent: Sunday, May 17, 2015 9:51:43 PM
> Subject: [PATCH] Fix DAG fold that didn't check legal ops
> 
> 
> 
> This should be straightforward: an out-of-tree target has legal
> ZERO_EXTEND for a type which is not legal for AND, which causes
> breakage.
> 
> 
> —escha
> 
> 
> Index: lib/CodeGen/SelectionDAG/DAGCombiner.cpp
> ===================================================================
> --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp (revision 237549)
> +++ lib/CodeGen/SelectionDAG/DAGCombiner.cpp (working copy)
> @@ -6100,6 +6100,7 @@
> // Fold (zext (and (trunc x), cst)) -> (and x, cst),
> // if either of the casts is not free.
> if (N0.getOpcode() == ISD::AND &&
> + (!LegalOperations || TLI.isOperationLegal(ISD::AND, VT)) &&
> N0.getOperand(0).getOpcode() == ISD::TRUNCATE &&
> N0.getOperand(1).getOpcode() == ISD::Constant &&
> (!TLI.isTruncateFree(N0.getOperand(0).getOperand(0).getValueType(),
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory