Created attachment 25694 [details] benchmark file Revision 180450 (along with 180567 to fix the ICE) causes a large degradation in cpu2000 benchmark wupwise. Additional loops are now being vectorized but result in worse performance, not sure it that means a cost issue or what. Based on prior observations the degradation is most likely due to the permute instructions being used which are restricted to a single VSU pipe, so two of them can't be executed in parallel. Attatched file zaxpy.f is just one of the files containing a function that degraded (zscal.f is another). The second loop is where the time is spent in the function. Following degradations (compared to revision 180449) were observed with oprofile. -m64 -O3 -mcpu=power7 zaxpy : -24% zscal : -79% -m64 -O3 -mcpu=power7 -funroll-loops zaxpy : -65% zscal : -61%
I swapped the numbers, should be: -m64 -O3 -mcpu=power7 zaxpy : -79% zscal : -24% -m64 -O3 -mcpu=power7 -funroll-loops zaxpy : -61% zscal : -65%
Yes, sounds like a cost model issue.
Author: wschmidt Date: Mon Feb 6 21:39:34 2012 New Revision: 183944 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183944 Log: 2012-02-06 Bill Schmidt <wschmidt@linux.vnet.ibm.com> PR tree-optimization/50969 * tree-vect-stmts.c (vect_model_store_cost): Correct statement cost to use vec_perm rather than vector_stmt. (vect_model_load_cost): Likewise. * config/i386/i386.c (ix86_builtin_vectorization_cost): Change cost of vec_perm to be the same as other vector statements. * config/rs6000/rs6000.c (rs6000_builtin_vectorization_cost): Revise cost of vec_perm for TARGET_VSX. Modified: trunk/gcc/ChangeLog trunk/gcc/config/i386/i386.c trunk/gcc/config/rs6000/rs6000.c trunk/gcc/tree-vect-stmts.c
Fixed with simple permute cost change for now. A better analysis of permutes will be considered in 4.8.
Author: wschmidt Date: Tue Feb 14 19:40:13 2012 New Revision: 184225 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=184225 Log: 2012-02-14 Bill Schmidt <wschmidt@linux.vnet.ibm.com> Ira Rosen <irar@il.ibm.com> PR tree-optimization/50031 PR tree-optimization/50969 * targhooks.c (default_builtin_vectorization_cost): Handle vec_promote_demote. * target.h (enum vect_cost_for_stmt): Add vec_promote_demote. * tree-vect-loop.c (vect_get_single_scalar_iteraion_cost): Handle all types of reduction and pattern statements. (vect_estimate_min_profitable_iters): Likewise. * tree-vect-stmts.c (vect_model_promotion_demotion_cost): New function. (vect_model_store_cost): Use vec_perm rather than vector_stmt for statement cost. (vect_model_load_cost): Likewise. (vect_get_load_cost): Likewise; add dump logic for explicit realigns. (vectorizable_type_demotion): Call vect_model_promotion_demotion_cost. (vectorizable_type_promotion): Likewise. * config/spu/spu.c (spu_builtin_vectorization_cost): Handle vec_promote_demote. * config/i386/i386.c (ix86_builtin_vectorization_cost): Likewise. * config/rs6000/rs6000.c (rs6000_builtin_vectorization_cost): Update vec_perm for VSX and handle vec_promote_demote. Modified: branches/ibm/gcc-4_6-branch/gcc/ChangeLog.ibm branches/ibm/gcc-4_6-branch/gcc/config/i386/i386.c branches/ibm/gcc-4_6-branch/gcc/config/rs6000/rs6000.c branches/ibm/gcc-4_6-branch/gcc/config/spu/spu.c branches/ibm/gcc-4_6-branch/gcc/target.h branches/ibm/gcc-4_6-branch/gcc/targhooks.c branches/ibm/gcc-4_6-branch/gcc/tree-vect-loop.c branches/ibm/gcc-4_6-branch/gcc/tree-vect-stmts.c
Author: wschmidt Date: Fri Mar 2 14:51:58 2012 New Revision: 184787 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=184787 Log: 2012-03-02 Bill Schmidt <wschmidt@linux.vnet.ibm.com> Ira Rosen <irar@il.ibm.com> PR tree-optimization/50031 PR tree-optimization/50969 * targhooks.c (default_builtin_vectorization_cost): Handle vec_promote_demote. * target.h (enum vect_cost_for_stmt): Add vec_promote_demote. * tree-vect-loop.c (vect_get_single_scalar_iteraion_cost): Handle all types of reduction and pattern statements. (vect_estimate_min_profitable_iters): Likewise. * tree-vect-stmts.c (vect_model_promotion_demotion_cost): New function. (vect_model_store_cost): Use vec_perm rather than vector_stmt for statement cost. (vect_model_load_cost): Likewise. (vect_get_load_cost): Likewise; add dump logic for explicit realigns. (vectorizable_type_demotion): Call vect_model_promotion_demotion_cost. (vectorizable_type_promotion): Likewise. * config/spu/spu.c (spu_builtin_vectorization_cost): Handle vec_promote_demote. * config/i386/i386.c (ix86_builtin_vectorization_cost): Likewise. * config/rs6000/rs6000.c (rs6000_builtin_vectorization_cost): Update vec_perm for VSX and handle vec_promote_demote. Modified: branches/gcc-4_6-branch/gcc/ChangeLog branches/gcc-4_6-branch/gcc/config/i386/i386.c branches/gcc-4_6-branch/gcc/config/rs6000/rs6000.c branches/gcc-4_6-branch/gcc/config/spu/spu.c branches/gcc-4_6-branch/gcc/target.h branches/gcc-4_6-branch/gcc/targhooks.c branches/gcc-4_6-branch/gcc/tree-vect-loop.c branches/gcc-4_6-branch/gcc/tree-vect-stmts.c