Fix PR92162

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.

Richard.

2019-10-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/92162
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Lookup
	STMT_VINFO_REDUC_IDX in reduc_info.
	* tree-vect-stmts.c (vectorizable_condition): Likewise.

	* gcc.dg/pr92162.c: New testcase.

Richard Biener <rguenther@suse.de> writes:
> Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
>
> Richard.
>
> 2019-10-21  Richard Biener  <rguenther@suse.de>
>
> 	PR tree-optimization/92162
> 	* tree-vect-loop.c (vect_create_epilog_for_reduction): Lookup
> 	STMT_VINFO_REDUC_IDX in reduc_info.
> 	* tree-vect-stmts.c (vectorizable_condition): Likewise.
>
> 	* gcc.dg/pr92162.c: New testcase.
>
> Index: gcc/testsuite/gcc.dg/pr92162.c
> ===================================================================
> --- gcc/testsuite/gcc.dg/pr92162.c	(nonexistent)
> +++ gcc/testsuite/gcc.dg/pr92162.c	(working copy)
> @@ -0,0 +1,10 @@
> +/* { dg-do compile } */
> +/* { dg-options "-Ofast" } */
> +
> +short int s8;
> +
> +void __attribute__ ((simd))
> +gn (void)
> +{
> +  s8 = 0;
> +}
> Index: gcc/tree-vect-loop.c
> ===================================================================
> --- gcc/tree-vect-loop.c	(revision 277242)
> +++ gcc/tree-vect-loop.c	(working copy)
> @@ -4259,9 +4259,9 @@ vect_create_epilog_for_reduction (stmt_v
>  	 (CCOMPARE).  The then and else values mirror the main VEC_COND_EXPR:
>  	 the reduction phi corresponds to NEW_PHI_TREE and the new values
>  	 correspond to INDEX_BEFORE_INCR.  */
> -      gcc_assert (STMT_VINFO_REDUC_IDX (stmt_info) >= 1);
> +      gcc_assert (STMT_VINFO_REDUC_IDX (reduc_info) >= 1);
>        tree index_cond_expr;
> -      if (STMT_VINFO_REDUC_IDX (stmt_info) == 2)
> +      if (STMT_VINFO_REDUC_IDX (reduc_info) == 2)
>  	index_cond_expr = build3 (VEC_COND_EXPR, cr_index_vector_type,
>  				  ccompare, indx_before_incr, new_phi_tree);
>        else
> Index: gcc/tree-vect-stmts.c
> ===================================================================
> --- gcc/tree-vect-stmts.c	(revision 277242)
> +++ gcc/tree-vect-stmts.c	(working copy)
> @@ -9818,7 +9818,7 @@ vectorizable_condition (stmt_vec_info st
>  	return false;
>        reduc_info = info_for_reduction (stmt_info);
>        reduction_type = STMT_VINFO_REDUC_TYPE (reduc_info);
> -      reduc_index = STMT_VINFO_REDUC_IDX (stmt_info);
> +      reduc_index = STMT_VINFO_REDUC_IDX (reduc_info);
>        gcc_assert (reduction_type != EXTRACT_LAST_REDUCTION
>  		  || reduc_index != -1);
>      }

After recent changes, do we still want this last bit?  reduc_index
is only used by EXTRACT_LAST_REDUCTION, which wants to know which
arm of the COND_EXPR is the reduction phi and which is the "new" value.
AIUI this what the REDUC_IDX on the COND_EXPR now tells us.

Reverting that fixes ICEs in gcc.target/aarch64/sve/clastb*.  Tested on
aarch64-linux-gnu (with and without SVE) and x86_64-linux-gnu.

Thanks,
Richard


2019-10-29  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-vect-stmts.c (vectorizable_condition): Get the reduction
	index for the COND_EXPR from stmt_info rather than reduc_info.

Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c	2019-10-29 08:29:12.000000000 +0000
+++ gcc/tree-vect-stmts.c	2019-10-29 10:01:43.180808257 +0000
@@ -9903,7 +9903,7 @@ vectorizable_condition (stmt_vec_info st
 	return false;
       reduc_info = info_for_reduction (stmt_info);
       reduction_type = STMT_VINFO_REDUC_TYPE (reduc_info);
-      reduc_index = STMT_VINFO_REDUC_IDX (reduc_info);
+      reduc_index = STMT_VINFO_REDUC_IDX (stmt_info);
       gcc_assert (reduction_type != EXTRACT_LAST_REDUCTION
 		  || reduc_index != -1);
     }

On Tue, 29 Oct 2019, Richard Sandiford wrote:

> Richard Biener <rguenther@suse.de> writes:
> > Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
> >
> > Richard.
> >
> > 2019-10-21  Richard Biener  <rguenther@suse.de>
> >
> > 	PR tree-optimization/92162
> > 	* tree-vect-loop.c (vect_create_epilog_for_reduction): Lookup
> > 	STMT_VINFO_REDUC_IDX in reduc_info.
> > 	* tree-vect-stmts.c (vectorizable_condition): Likewise.
> >
> > 	* gcc.dg/pr92162.c: New testcase.
> >
> > Index: gcc/testsuite/gcc.dg/pr92162.c
> > ===================================================================
> > --- gcc/testsuite/gcc.dg/pr92162.c	(nonexistent)
> > +++ gcc/testsuite/gcc.dg/pr92162.c	(working copy)
> > @@ -0,0 +1,10 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-Ofast" } */
> > +
> > +short int s8;
> > +
> > +void __attribute__ ((simd))
> > +gn (void)
> > +{
> > +  s8 = 0;
> > +}
> > Index: gcc/tree-vect-loop.c
> > ===================================================================
> > --- gcc/tree-vect-loop.c	(revision 277242)
> > +++ gcc/tree-vect-loop.c	(working copy)
> > @@ -4259,9 +4259,9 @@ vect_create_epilog_for_reduction (stmt_v
> >  	 (CCOMPARE).  The then and else values mirror the main VEC_COND_EXPR:
> >  	 the reduction phi corresponds to NEW_PHI_TREE and the new values
> >  	 correspond to INDEX_BEFORE_INCR.  */
> > -      gcc_assert (STMT_VINFO_REDUC_IDX (stmt_info) >= 1);
> > +      gcc_assert (STMT_VINFO_REDUC_IDX (reduc_info) >= 1);
> >        tree index_cond_expr;
> > -      if (STMT_VINFO_REDUC_IDX (stmt_info) == 2)
> > +      if (STMT_VINFO_REDUC_IDX (reduc_info) == 2)
> >  	index_cond_expr = build3 (VEC_COND_EXPR, cr_index_vector_type,
> >  				  ccompare, indx_before_incr, new_phi_tree);
> >        else
> > Index: gcc/tree-vect-stmts.c
> > ===================================================================
> > --- gcc/tree-vect-stmts.c	(revision 277242)
> > +++ gcc/tree-vect-stmts.c	(working copy)
> > @@ -9818,7 +9818,7 @@ vectorizable_condition (stmt_vec_info st
> >  	return false;
> >        reduc_info = info_for_reduction (stmt_info);
> >        reduction_type = STMT_VINFO_REDUC_TYPE (reduc_info);
> > -      reduc_index = STMT_VINFO_REDUC_IDX (stmt_info);
> > +      reduc_index = STMT_VINFO_REDUC_IDX (reduc_info);
> >        gcc_assert (reduction_type != EXTRACT_LAST_REDUCTION
> >  		  || reduc_index != -1);
> >      }
> 
> After recent changes, do we still want this last bit?  reduc_index
> is only used by EXTRACT_LAST_REDUCTION, which wants to know which
> arm of the COND_EXPR is the reduction phi and which is the "new" value.
> AIUI this what the REDUC_IDX on the COND_EXPR now tells us.
> 
> Reverting that fixes ICEs in gcc.target/aarch64/sve/clastb*.  Tested on
> aarch64-linux-gnu (with and without SVE) and x86_64-linux-gnu.

Hum, I thought I have done this with r277513 already but appearantly
it somehow got lost.

So, OK.

Thanks,
Richard.

> Thanks,
> Richard
> 
> 
> 2019-10-29  Richard Sandiford  <richard.sandiford@arm.com>
> 
> gcc/
> 	* tree-vect-stmts.c (vectorizable_condition): Get the reduction
> 	index for the COND_EXPR from stmt_info rather than reduc_info.
> 
> Index: gcc/tree-vect-stmts.c
> ===================================================================
> --- gcc/tree-vect-stmts.c	2019-10-29 08:29:12.000000000 +0000
> +++ gcc/tree-vect-stmts.c	2019-10-29 10:01:43.180808257 +0000
> @@ -9903,7 +9903,7 @@ vectorizable_condition (stmt_vec_info st
>  	return false;
>        reduc_info = info_for_reduction (stmt_info);
>        reduction_type = STMT_VINFO_REDUC_TYPE (reduc_info);
> -      reduc_index = STMT_VINFO_REDUC_IDX (reduc_info);
> +      reduc_index = STMT_VINFO_REDUC_IDX (stmt_info);
>        gcc_assert (reduction_type != EXTRACT_LAST_REDUCTION
>  		  || reduc_index != -1);
>      }