On Fri, Mar 11, 2016 at 3:01 PM, Richard Biener <[email protected]> wrote: > > The following teaches phiprop to handle the case of aggregate copies > where the aggregate has non-BLKmode which means it is very likely > expanded as reg-reg moves (any better test for that apart from > checking for non-BLKmode?). This improves code for the testcase > from > > _Z14struct_ternary1SS_b: > .LFB2: > .cfi_startproc > leaq -40(%rsp), %rcx > leaq -24(%rsp), %rax > testb %dl, %dl > movl %edi, -24(%rsp) > movl %esi, -40(%rsp) > cmove %rcx, %rax > movl (%rax), %eax > ret > > to > > _Z14struct_ternary1SS_b: > .LFB2: > .cfi_startproc > testb %dl, %dl > movl %edi, %eax > cmove %esi, %eax > ret > > Bootstrapped and tested on x86_64-unknown-linux-gnu, queued for stage1.
Re-bootstrapped and tested on x86_64-unknown-linux-gnu, applied as r235208. Richard. > Richard. > > 2016-03-11 Richard Biener <[email protected]> > > PR tree-optimization/70171 > * tree-ssa-phiprop.c: Include stor-layout.h. > (phiprop_insert_phi): Handle the aggregate copy case. > (propagate_with_phi): Likewise. > > * g++.dg/tree-ssa/pr70171.C: New testcase. > > Index: gcc/tree-ssa-phiprop.c > =================================================================== > *** gcc/tree-ssa-phiprop.c (revision 234134) > --- gcc/tree-ssa-phiprop.c (working copy) > *************** along with GCC; see the file COPYING3. > *** 31,36 **** > --- 31,37 ---- > #include "tree-eh.h" > #include "gimplify.h" > #include "gimple-iterator.h" > + #include "stor-layout.h" > > /* This pass propagates indirect loads through the PHI node for its > address to make the load source possibly non-addressable and to > *************** phiprop_insert_phi (basic_block bb, gphi > *** 132,138 **** > struct phiprop_d *phivn, size_t n) > { > tree res; > ! gphi *new_phi; > edge_iterator ei; > edge e; > > --- 133,139 ---- > struct phiprop_d *phivn, size_t n) > { > tree res; > ! gphi *new_phi = NULL; > edge_iterator ei; > edge e; > > *************** phiprop_insert_phi (basic_block bb, gphi > *** 142,148 **** > /* Build a new PHI node to replace the definition of > the indirect reference lhs. */ > res = gimple_assign_lhs (use_stmt); > ! new_phi = create_phi_node (res, bb); > > if (dump_file && (dump_flags & TDF_DETAILS)) > { > --- 143,150 ---- > /* Build a new PHI node to replace the definition of > the indirect reference lhs. */ > res = gimple_assign_lhs (use_stmt); > ! if (TREE_CODE (res) == SSA_NAME) > ! new_phi = create_phi_node (res, bb); > > if (dump_file && (dump_flags & TDF_DETAILS)) > { > *************** phiprop_insert_phi (basic_block bb, gphi > *** 187,193 **** > { > tree rhs = gimple_assign_rhs1 (use_stmt); > gcc_assert (TREE_CODE (old_arg) == ADDR_EXPR); > ! new_var = make_ssa_name (TREE_TYPE (rhs)); > if (!is_gimple_min_invariant (old_arg)) > old_arg = PHI_ARG_DEF_FROM_EDGE (phi, e); > else > --- 189,198 ---- > { > tree rhs = gimple_assign_rhs1 (use_stmt); > gcc_assert (TREE_CODE (old_arg) == ADDR_EXPR); > ! if (TREE_CODE (res) == SSA_NAME) > ! new_var = make_ssa_name (TREE_TYPE (rhs)); > ! else > ! new_var = unshare_expr (res); > if (!is_gimple_min_invariant (old_arg)) > old_arg = PHI_ARG_DEF_FROM_EDGE (phi, e); > else > *************** phiprop_insert_phi (basic_block bb, gphi > *** 210,222 **** > } > } > > ! add_phi_arg (new_phi, new_var, e, locus); > } > > ! update_stmt (new_phi); > > ! if (dump_file && (dump_flags & TDF_DETAILS)) > ! print_gimple_stmt (dump_file, new_phi, 0, 0); > > return res; > } > --- 215,231 ---- > } > } > > ! if (new_phi) > ! add_phi_arg (new_phi, new_var, e, locus); > } > > ! if (new_phi) > ! { > ! update_stmt (new_phi); > > ! if (dump_file && (dump_flags & TDF_DETAILS)) > ! print_gimple_stmt (dump_file, new_phi, 0, 0); > ! } > > return res; > } > *************** propagate_with_phi (basic_block bb, gphi > *** 250,256 **** > tree type = NULL_TREE; > > if (!POINTER_TYPE_P (TREE_TYPE (ptr)) > ! || !is_gimple_reg_type (TREE_TYPE (TREE_TYPE (ptr)))) > return false; > > /* Check if we can "cheaply" dereference all phi arguments. */ > --- 259,266 ---- > tree type = NULL_TREE; > > if (!POINTER_TYPE_P (TREE_TYPE (ptr)) > ! || (!is_gimple_reg_type (TREE_TYPE (TREE_TYPE (ptr))) > ! && TYPE_MODE (TREE_TYPE (TREE_TYPE (ptr))) == BLKmode)) > return false; > > /* Check if we can "cheaply" dereference all phi arguments. */ > *************** propagate_with_phi (basic_block bb, gphi > *** 306,312 **** > > /* Check whether this is a load of *ptr. */ > if (!(is_gimple_assign (use_stmt) > - && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME > && gimple_assign_rhs_code (use_stmt) == MEM_REF > && TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 0) == ptr > && integer_zerop (TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 1)) > --- 316,321 ---- > *************** propagate_with_phi (basic_block bb, gphi > *** 327,335 **** > bb, gimple_bb (def_stmt)))) > goto next; > > /* Found a proper dereference. Insert a phi node if this > is the first load transformation. */ > ! if (!phi_inserted) > { > res = phiprop_insert_phi (bb, phi, use_stmt, phivn, n); > type = TREE_TYPE (res); > --- 336,366 ---- > bb, gimple_bb (def_stmt)))) > goto next; > > + /* Found a proper dereference with an aggregate copy. Just > + insert aggregate copies on the edges instead. */ > + if (!is_gimple_reg_type (TREE_TYPE (TREE_TYPE (ptr)))) > + { > + phiprop_insert_phi (bb, phi, use_stmt, phivn, n); > + > + /* Remove old stmt. The phi is taken care of by DCE. */ > + gsi = gsi_for_stmt (use_stmt); > + /* Unlinking the VDEF here is fine as we are sure that we process > + stmts in execution order due to aggregate copies having VDEFs > + and we emit loads on the edges in the very same order. > + We get multiple copies (or intermediate register loads) handled > + only by walking PHIs or immediate uses in a lucky order though, > + so we could signal the caller to re-start iterating over PHIs > + when we come here which would make it quadratic in the number > + of PHIs. */ > + unlink_stmt_vdef (use_stmt); > + gsi_remove (&gsi, true); > + > + phi_inserted = true; > + } > + > /* Found a proper dereference. Insert a phi node if this > is the first load transformation. */ > ! else if (!phi_inserted) > { > res = phiprop_insert_phi (bb, phi, use_stmt, phivn, n); > type = TREE_TYPE (res); > Index: gcc/testsuite/g++.dg/tree-ssa/pr70171.C > =================================================================== > *** gcc/testsuite/g++.dg/tree-ssa/pr70171.C (revision 0) > --- gcc/testsuite/g++.dg/tree-ssa/pr70171.C (working copy) > *************** > *** 0 **** > --- 1,8 ---- > + /* { dg-do compile } */ > + /* { dg-options "-O2 -fdump-tree-optimized" } */ > + > + struct S { int i; }; > + S struct_ternary (S a, S b, bool select) { return select ? a : b; } > + > + /* { dg-final { scan-tree-dump-not "&\[ab\]" "optimized" } } */ > + /* { dg-final { scan-assembler-not "\[er\]sp" { target { { i?86-*-* > x86_64-*-* } && { ! ia32 } } } } } */
