diff mbox

[rs6000] Document reserved use of "wc" constraint

Message ID 1393633411.3554.87.camel@gnopaine
State New
Headers show

Commit Message

Bill Schmidt March 1, 2014, 12:23 a.m. UTC 
Hi,

Hal Finkel requested that we define a constraint for representing
individual CR bits.  We agreed to reserve "wc" for this purpose to
maintain compatibility with LLVM.  This patch documents that use.

A pro-forma regstrap is in progress.  Assuming no problems, is this ok
for trunk?

Thanks,
Bill


2014-02-28  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	* config/rs6000/constraints.md: Document reserved use of "wc".

Comments

David Edelsohn March 1, 2014, 3:24 a.m. UTC | #1 
On Fri, Feb 28, 2014 at 7:23 PM, Bill Schmidt
<wschmidt@linux.vnet.ibm.com> wrote:
> Hi,
>
> Hal Finkel requested that we define a constraint for representing
> individual CR bits.  We agreed to reserve "wc" for this purpose to
> maintain compatibility with LLVM.  This patch documents that use.
>
> A pro-forma regstrap is in progress.  Assuming no problems, is this ok
> for trunk?

You're not going to implement the new register class?















Okay

Thanks, David
diff mbox

Patch

Index: gcc/config/rs6000/constraints.md
===================================================================
--- gcc/config/rs6000/constraints.md	(revision 208237)
+++ gcc/config/rs6000/constraints.md	(working copy)
@@ -56,6 +56,9 @@ 
 (define_register_constraint "wa" "rs6000_constraints[RS6000_CONSTRAINT_wa]"
   "Any VSX register if the -mvsx option was used or NO_REGS.")
 
+;; NOTE: For compatibility, "wc" is reserved to represent individual CR bits.
+;; It is currently used for that purpose in LLVM.
+
 (define_register_constraint "wd" "rs6000_constraints[RS6000_CONSTRAINT_wd]"
   "VSX vector register to hold vector double data or NO_REGS.")