This patch fixes PR52678 - re-computing the evolution of a loop
PHI node after updating it during prologue loop peeling is fragile
(and I remember several cases in the past where we ICEd here and
adjusted the code). So, instead of re-computing the evolution
this patch saves the evolution part at analysis time and re-uses
it at this place.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2012-03-23 Richard Guenther <rguent...@suse.de>
PR tree-optimization/52678
* tree-vectorizer.h (struct _stmt_vec_info): Add
loop_phi_evolution_part member.
(STMT_VINFO_LOOP_PHI_EVOLUTION_PART): New define.
* tree-vect-loop.c (vect_analyze_scalar_cycles_1): Initialize
STMT_VINFO_LOOP_PHI_EVOLUTION_PART.
* tree-vect-loop-manip.c (vect_update_ivs_after_vectorizer):
Use the cached evolution part and the PHI nodes value from
the loop preheader edge instead of re-analyzing the evolution.
* gfortran.dg/pr52678.f: New testcase.
Index: gcc/tree-vectorizer.h
===================================================================
*** gcc/tree-vectorizer.h (revision 185724)
--- gcc/tree-vectorizer.h (working copy)
*************** typedef struct _stmt_vec_info {
*** 476,481 ****
--- 476,488 ----
tree dr_step;
tree dr_aligned_to;
+ /* For loop PHI nodes, the evolution part of it. This makes sure
+ this information is still available in vect_update_ivs_after_vectorizer
+ where we may not be able to re-analyze the PHI nodes evolution as
+ peeling for the prologue loop can make it unanalyzable. The evolution
+ part is still correct though. */
+ tree loop_phi_evolution_part;
+
/* Used for various bookkeeping purposes, generally holding a pointer to
some other stmt S that is in some way "related" to this stmt.
Current use of this field is:
*************** typedef struct _stmt_vec_info {
*** 572,577 ****
--- 579,585 ----
#define STMT_VINFO_GROUP_SAME_DR_STMT(S) (S)->same_dr_stmt
#define STMT_VINFO_GROUP_READ_WRITE_DEPENDENCE(S) (S)->read_write_dep
#define STMT_VINFO_STRIDED_ACCESS(S) ((S)->first_element != NULL &&
(S)->data_ref_info)
+ #define STMT_VINFO_LOOP_PHI_EVOLUTION_PART(S) (S)->loop_phi_evolution_part
#define GROUP_FIRST_ELEMENT(S) (S)->first_element
#define GROUP_NEXT_ELEMENT(S) (S)->next_element
Index: gcc/tree-vect-loop.c
===================================================================
*** gcc/tree-vect-loop.c (revision 185724)
--- gcc/tree-vect-loop.c (working copy)
*************** vect_analyze_scalar_cycles_1 (loop_vec_i
*** 579,584 ****
--- 579,588 ----
continue;
}
+ STMT_VINFO_LOOP_PHI_EVOLUTION_PART (stmt_vinfo)
+ = evolution_part_in_loop_num (access_fn, loop->num);
+ gcc_assert (STMT_VINFO_LOOP_PHI_EVOLUTION_PART (stmt_vinfo) !=
NULL_TREE);
+
if (vect_print_dump_info (REPORT_DETAILS))
fprintf (vect_dump, "Detected induction.");
STMT_VINFO_DEF_TYPE (stmt_vinfo) = vect_induction_def;
Index: gcc/tree-vect-loop-manip.c
===================================================================
*** gcc/tree-vect-loop-manip.c (revision 185724)
--- gcc/tree-vect-loop-manip.c (working copy)
*************** vect_update_ivs_after_vectorizer (loop_v
*** 1797,1809 ****
!gsi_end_p (gsi) && !gsi_end_p (gsi1);
gsi_next (&gsi), gsi_next (&gsi1))
{
- tree access_fn = NULL;
- tree evolution_part;
tree init_expr;
tree step_expr, off;
tree type;
tree var, ni, ni_name;
gimple_stmt_iterator last_gsi;
phi = gsi_stmt (gsi);
phi1 = gsi_stmt (gsi1);
--- 1797,1808 ----
!gsi_end_p (gsi) && !gsi_end_p (gsi1);
gsi_next (&gsi), gsi_next (&gsi1))
{
tree init_expr;
tree step_expr, off;
tree type;
tree var, ni, ni_name;
gimple_stmt_iterator last_gsi;
+ stmt_vec_info stmt_info;
phi = gsi_stmt (gsi);
phi1 = gsi_stmt (gsi1);
*************** vect_update_ivs_after_vectorizer (loop_v
*** 1822,1866 ****
}
/* Skip reduction phis. */
! if (STMT_VINFO_DEF_TYPE (vinfo_for_stmt (phi)) == vect_reduction_def)
{
if (vect_print_dump_info (REPORT_DETAILS))
fprintf (vect_dump, "reduc phi. skip.");
continue;
}
! access_fn = analyze_scalar_evolution (loop, PHI_RESULT (phi));
! gcc_assert (access_fn);
! /* We can end up with an access_fn like
! (short int) {(short unsigned int) i_49, +, 1}_1
! for further analysis we need to strip the outer cast but we
! need to preserve the original type. */
! type = TREE_TYPE (access_fn);
! STRIP_NOPS (access_fn);
! evolution_part =
! unshare_expr (evolution_part_in_loop_num (access_fn, loop->num));
! gcc_assert (evolution_part != NULL_TREE);
/* FORNOW: We do not support IVs whose evolution function is a
polynomial
of degree >= 2 or exponential. */
! gcc_assert (!tree_is_chrec (evolution_part));
! step_expr = evolution_part;
! init_expr = unshare_expr (initial_condition_in_loop_num (access_fn,
! loop->num));
! init_expr = fold_convert (type, init_expr);
off = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr),
fold_convert (TREE_TYPE (step_expr), niters),
step_expr);
! if (POINTER_TYPE_P (TREE_TYPE (init_expr)))
ni = fold_build_pointer_plus (init_expr, off);
else
! ni = fold_build2 (PLUS_EXPR, TREE_TYPE (init_expr),
! init_expr,
! fold_convert (TREE_TYPE (init_expr), off));
! var = create_tmp_var (TREE_TYPE (init_expr), "tmp");
add_referenced_var (var);
last_gsi = gsi_last_bb (exit_bb);
--- 1821,1854 ----
}
/* Skip reduction phis. */
! stmt_info = vinfo_for_stmt (phi);
! if (STMT_VINFO_DEF_TYPE (stmt_info) == vect_reduction_def)
{
if (vect_print_dump_info (REPORT_DETAILS))
fprintf (vect_dump, "reduc phi. skip.");
continue;
}
! type = TREE_TYPE (gimple_phi_result (phi));
! step_expr = STMT_VINFO_LOOP_PHI_EVOLUTION_PART (stmt_info);
! step_expr = unshare_expr (step_expr);
/* FORNOW: We do not support IVs whose evolution function is a
polynomial
of degree >= 2 or exponential. */
! gcc_assert (!tree_is_chrec (step_expr));
! init_expr = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop));
off = fold_build2 (MULT_EXPR, TREE_TYPE (step_expr),
fold_convert (TREE_TYPE (step_expr), niters),
step_expr);
! if (POINTER_TYPE_P (type))
ni = fold_build_pointer_plus (init_expr, off);
else
! ni = fold_build2 (PLUS_EXPR, type,
! init_expr, fold_convert (type, off));
! var = create_tmp_var (type, "tmp");
add_referenced_var (var);
last_gsi = gsi_last_bb (exit_bb);
Index: gcc/testsuite/gfortran.dg/pr52678.f
===================================================================
*** gcc/testsuite/gfortran.dg/pr52678.f (revision 0)
--- gcc/testsuite/gfortran.dg/pr52678.f (revision 0)
***************
*** 0 ****
--- 1,18 ----
+ ! { dg-do compile }
+ ! { dg-options "-O -ftree-vectorize" }
+ SUBROUTINE OpenAD_set_ref_state(DRF, RHOFACF, RHOFACC)
+ real(8) DRF(1 : 15)
+ real(8) RHOFACF(1 : 16)
+ real(8) RHOFACC(1 : 15)
+ integer, dimension(:), allocatable :: oad_it
+ integer :: oad_it_ptr
+ INTEGER(8) OpenAD_Symbol_188
+ INTEGER(4) K
+ OpenAD_Symbol_188 = 0
+ DO K = 2, 15, 1
+ RHOFACF(INT(K)) = ((RHOFACC(K) * DRF(K + (-1)) + RHOFACC(K +
+ + (-1)) * DRF(K)) /(DRF(K) + DRF(K + (-1))))
+ OpenAD_Symbol_188 = (INT(OpenAD_Symbol_188) + INT(1))
+ END DO
+ oad_it(oad_it_ptr) = OpenAD_Symbol_188
+ end subroutine OpenAD_set_ref_state
