r255337 - in /branches/gcc-7-branch/gcc: Change...

[segher@gcc.gnu.org]

Author: segher
Date: Fri Dec  1 20:35:52 2017
New Revision: 255337

URL: https://gcc.gnu.org/viewcvs?rev=255337&root=gcc&view=rev
Log:
rs6000: Improve comparison rtx_cost (PR81288)

The current rs6000 rtx_cost for comparisons against 0 is very high if
TARGET_ISEL && !TARGET_MFCRF, much higher than for reg-reg comparisons,
much higher than a load of 0 and such a reg-reg-comparison.  This leads
to infinite recursion in CSE (see PR81288).

This patch removes the too-high cost, also simplifying this code.


	PR 81288/target
	* config/rs6000/rs6000.c (rs6000_rtx_costs): Do not handle
	TARGET_ISEL && !TARGET_MFCRF differently.  Simplify code.

Modified:
    branches/gcc-7-branch/gcc/ChangeLog
    branches/gcc-7-branch/gcc/config/rs6000/rs6000.c