I'm testing a pair of patches to fix PR38885 (for constants)
and PR38884 (for non-constants) stores to complex/vector memory
and CSE of component accesses from SCCVN.
This is the piece that handles stores from constants and partial
reads of it. We can conveniently re-use fold-const native
encode/interpret code for this.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2011-10-05 Richard Guenther <rguent...@suse.de>
PR tree-optimization/38885
* tree-ssa-sccvn.c (vn_reference_lookup_3): Handle partial reads
from constants.
* gcc.dg/tree-ssa/ssa-fre-33.c: New testcase.
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 179549)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** vn_reference_lookup_3 (ao_ref *ref, tree
*** 1442,1448 ****
}
}
! /* 3) 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)
--- 1442,1495 ----
}
}
! /* 3) Assignment from a constant. We can use folds native encode/interpret
! routines to extract the assigned bits. */
! else if (CHAR_BIT == 8 && BITS_PER_UNIT == 8
! && ref->size == maxsize
! && maxsize % BITS_PER_UNIT == 0
! && offset % BITS_PER_UNIT == 0
! && is_gimple_reg_type (vr->type)
! && gimple_assign_single_p (def_stmt)
! && is_gimple_min_invariant (gimple_assign_rhs1 (def_stmt)))
! {
! tree base2;
! HOST_WIDE_INT offset2, size2, maxsize2;
! base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
! &offset2, &size2, &maxsize2);
! if (maxsize2 != -1
! && maxsize2 == size2
! && size2 % BITS_PER_UNIT == 0
! && offset2 % BITS_PER_UNIT == 0
! && operand_equal_p (base, base2, 0)
! && offset2 <= offset
! && offset2 + size2 >= offset + maxsize)
! {
! /* We support up to 512-bit values (for V8DFmode). */
! unsigned char buffer[64];
! int len;
!
! len = native_encode_expr (gimple_assign_rhs1 (def_stmt),
! buffer, sizeof (buffer));
! if (len > 0)
! {
! tree val = native_interpret_expr (vr->type,
! buffer
! + ((offset - offset2)
! / BITS_PER_UNIT),
! ref->size / BITS_PER_UNIT);
! 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);
! }
! }
! }
! }
!
! /* 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)
*************** vn_reference_lookup_3 (ao_ref *ref, tree
*** 1540,1546 ****
return NULL;
}
! /* 4) 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)
--- 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)
Index: gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-33.c
===================================================================
*** gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-33.c (revision 0)
--- gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-33.c (revision 0)
***************
*** 0 ****
--- 1,21 ----
+ /* { 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 x;
+ int main(int argc)
+ {
+ vector float res = (vector float){0.0f,0.0f,0.0f,1.0f};
+ res += (vector float){1.0f,2.0f,3.0f,4.0f};
+ s.global_res = res;
+ x = *((float*)&s.global_res + 1);
+ return 0;
+ }
+
+ /* { dg-final { scan-tree-dump "Replaced BIT_FIELD_REF.*with 2" "fre1" } } */
+ /* { dg-final { cleanup-tree-dump "fre1" } } */
