This handles the case of CSEing part of an SSA name that is stored
to memory and defined with a composition like COMPLEX_EXPR or
CONSTRUCTOR. This fixes the remaining pieces of PR38884 and
PR38885.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2011-10-06 Richard Guenther <rguent...@suse.de>
PR tree-optimization/38884
* tree-ssa-sccvn.c (vn_reference_lookup_3): Handle partial
reads from aggregate SSA names.
* gcc.dg/tree-ssa/ssa-fre-34.c: New testcase.
* gcc.dg/tree-ssa/ssa-fre-35.c: Likewise.
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 179556)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** vn_reference_lookup_3 (ao_ref *ref, tree
*** 1489,1495 ****
}
}
! /* 4) For aggregate copies translate the reference through them if
the copy kills ref. */
else if (vn_walk_kind == VN_WALKREWRITE
&& gimple_assign_single_p (def_stmt)
--- 1489,1554 ----
}
}
! /* 4) Assignment from an SSA name which definition we may be able
! to access pieces from. */
! else if (ref->size == maxsize
! && is_gimple_reg_type (vr->type)
! && gimple_assign_single_p (def_stmt)
! && TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME)
! {
! tree rhs1 = gimple_assign_rhs1 (def_stmt);
! gimple def_stmt2 = SSA_NAME_DEF_STMT (rhs1);
! if (is_gimple_assign (def_stmt2)
! && (gimple_assign_rhs_code (def_stmt2) == COMPLEX_EXPR
! || gimple_assign_rhs_code (def_stmt2) == CONSTRUCTOR)
! && types_compatible_p (vr->type, TREE_TYPE (TREE_TYPE (rhs1))))
! {
! tree base2;
! HOST_WIDE_INT offset2, size2, maxsize2, off;
! base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
! &offset2, &size2, &maxsize2);
! off = offset - offset2;
! if (maxsize2 != -1
! && maxsize2 == size2
! && operand_equal_p (base, base2, 0)
! && offset2 <= offset
! && offset2 + size2 >= offset + maxsize)
! {
! tree val = NULL_TREE;
! HOST_WIDE_INT elsz
! = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (TREE_TYPE (rhs1))));
! if (gimple_assign_rhs_code (def_stmt2) == COMPLEX_EXPR)
! {
! if (off == 0)
! val = gimple_assign_rhs1 (def_stmt2);
! else if (off == elsz)
! val = gimple_assign_rhs2 (def_stmt2);
! }
! else if (gimple_assign_rhs_code (def_stmt2) == CONSTRUCTOR
! && off % elsz == 0)
! {
! tree ctor = gimple_assign_rhs1 (def_stmt2);
! unsigned i = off / elsz;
! if (i < CONSTRUCTOR_NELTS (ctor))
! {
! constructor_elt *elt = CONSTRUCTOR_ELT (ctor, i);
! if (compare_tree_int (elt->index, i) == 0)
! val = elt->value;
! }
! }
! if (val)
! {
! unsigned int value_id = get_or_alloc_constant_value_id (val);
! return vn_reference_insert_pieces
! (vuse, vr->set, vr->type,
! VEC_copy (vn_reference_op_s, heap, vr->operands),
! val, value_id);
! }
! }
! }
! }
!
! /* 5) For aggregate copies translate the reference through them if
the copy kills ref. */
else if (vn_walk_kind == VN_WALKREWRITE
&& gimple_assign_single_p (def_stmt)
*************** vn_reference_lookup_3 (ao_ref *ref, tree
*** 1587,1593 ****
return NULL;
}
! /* 5) For memcpy copies translate the reference through them if
the copy kills ref. */
else if (vn_walk_kind == VN_WALKREWRITE
&& is_gimple_reg_type (vr->type)
--- 1646,1652 ----
return NULL;
}
! /* 6) For memcpy copies translate the reference through them if
the copy kills ref. */
else if (vn_walk_kind == VN_WALKREWRITE
&& is_gimple_reg_type (vr->type)
Index: gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-34.c
===================================================================
*** gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-34.c (revision 0)
--- gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-34.c (revision 0)
***************
*** 0 ****
--- 1,18 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O -fdump-tree-fre1-details" } */
+
+ #define vector __attribute__((vector_size(16) ))
+
+ struct {
+ float i;
+ vector float global_res;
+ } s;
+ float foo(float f)
+ {
+ vector float res = (vector float){0.0f,f,0.0f,1.0f};
+ s.global_res = res;
+ return *((float*)&s.global_res + 1);
+ }
+
+ /* { dg-final { scan-tree-dump "Replaced BIT_FIELD_REF.*with f" "fre1" } } */
+ /* { dg-final { cleanup-tree-dump "fre1" } } */
Index: gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-35.c
===================================================================
*** gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-35.c (revision 0)
--- gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-35.c (revision 0)
***************
*** 0 ****
--- 1,17 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O -fdump-tree-fre1-details" } */
+
+ struct s { _Complex float i; };
+ void g(struct s *);
+
+ float a1 (float dd)
+ {
+ struct s sv;
+ sv.i = dd;
+ float d = __real__ sv.i;
+ g(&sv);
+ return d;
+ }
+
+ /* { dg-final { scan-tree-dump "Replaced REALPART_EXPR.*with dd" "fre1" } } */
+ /* { dg-final { cleanup-tree-dump "fre1" } } */
