On November 21, 2014 8:04:39 PM CET, Jakub Jelinek <ja...@redhat.com> wrote:
>Hi!
>
>As discussed on IRC and in the PR, these internal calls are quite
>unique for VRP in that they return _Complex integer result,
>which VRP doesn't track, but then extract using
>REALPART_EXPR/IMAGPART_EXPR
>the two results from that _Complex int and to generate good code
>it is desirable to get proper ranges of those two results.
>The problem is that right now this works only on the first VRP
>iteration,
>the REALPART_EXPR/IMAGPART_EXPR statements are handled if their operand
>is set by {ADD,SUB,MUL}_OVERFLOW. If we iterate because a VR of one
>of the internal call arguments changes, nothing in the propagator marks
>the REALPART_EXPR/IMAGPART_EXPR statements for reconsideration.
>
>The following patch handles this, by making the internal calls
>interesting
>to the propagator and returning the right SSA_PROP_* for it (depending
>on
>whether any of the value ranges of the REALPART_EXPR/IMAGPART_EXPR
>immediate
>uses would change or not).
>
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Thanks,
Richard.
>2014-11-21 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/64006
> * tree-vrp.c (stmt_interesting_for_vrp): Return true
> for {ADD,SUB,MUL}_OVERFLOW internal calls.
> (vrp_visit_assignment_or_call): For {ADD,SUB,MUL}_OVERFLOW
> internal calls, check if any REALPART_EXPR/IMAGPART_EXPR
> immediate uses would change their value ranges and return
> SSA_PROP_INTERESTING if so, or SSA_PROP_NOT_INTERESTING
> if there are some REALPART_EXPR/IMAGPART_EXPR immediate uses
> interesting for vrp.
>
> * gcc.c-torture/execute/pr64006.c: New test.
>
>--- gcc/tree-vrp.c.jj 2014-11-21 10:17:05.000000000 +0100
>+++ gcc/tree-vrp.c 2014-11-21 13:12:09.895013334 +0100
>@@ -6949,6 +6949,20 @@ stmt_interesting_for_vrp (gimple stmt)
> && (is_gimple_call (stmt)
> || !gimple_vuse (stmt)))
> return true;
>+ else if (is_gimple_call (stmt) && gimple_call_internal_p (stmt))
>+ switch (gimple_call_internal_fn (stmt))
>+ {
>+ case IFN_ADD_OVERFLOW:
>+ case IFN_SUB_OVERFLOW:
>+ case IFN_MUL_OVERFLOW:
>+ /* These internal calls return _Complex integer type,
>+ but are interesting to VRP nevertheless. */
>+ if (lhs && TREE_CODE (lhs) == SSA_NAME)
>+ return true;
>+ break;
>+ default:
>+ break;
>+ }
> }
> else if (gimple_code (stmt) == GIMPLE_COND
> || gimple_code (stmt) == GIMPLE_SWITCH)
>@@ -7101,6 +7115,74 @@ vrp_visit_assignment_or_call (gimple stm
>
> return SSA_PROP_NOT_INTERESTING;
> }
>+ else if (is_gimple_call (stmt) && gimple_call_internal_p (stmt))
>+ switch (gimple_call_internal_fn (stmt))
>+ {
>+ case IFN_ADD_OVERFLOW:
>+ case IFN_SUB_OVERFLOW:
>+ case IFN_MUL_OVERFLOW:
>+ /* These internal calls return _Complex integer type,
>+ which VRP does not track, but the immediate uses
>+ thereof might be interesting. */
>+ if (lhs && TREE_CODE (lhs) == SSA_NAME)
>+ {
>+ imm_use_iterator iter;
>+ use_operand_p use_p;
>+ enum ssa_prop_result res = SSA_PROP_VARYING;
>+
>+ set_value_range_to_varying (get_value_range (lhs));
>+
>+ FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
>+ {
>+ gimple use_stmt = USE_STMT (use_p);
>+ if (!is_gimple_assign (use_stmt))
>+ continue;
>+ enum tree_code rhs_code = gimple_assign_rhs_code (use_stmt);
>+ if (rhs_code != REALPART_EXPR && rhs_code != IMAGPART_EXPR)
>+ continue;
>+ tree rhs1 = gimple_assign_rhs1 (use_stmt);
>+ tree use_lhs = gimple_assign_lhs (use_stmt);
>+ if (TREE_CODE (rhs1) != rhs_code
>+ || TREE_OPERAND (rhs1, 0) != lhs
>+ || TREE_CODE (use_lhs) != SSA_NAME
>+ || !stmt_interesting_for_vrp (use_stmt)
>+ || (!INTEGRAL_TYPE_P (TREE_TYPE (use_lhs))
>+ || !TYPE_MIN_VALUE (TREE_TYPE (use_lhs))
>+ || !TYPE_MAX_VALUE (TREE_TYPE (use_lhs))))
>+ continue;
>+
>+ /* If there is a change in the value range for any of the
>+ REALPART_EXPR/IMAGPART_EXPR immediate uses, return
>+ SSA_PROP_INTERESTING. If there are any REALPART_EXPR
>+ or IMAGPART_EXPR immediate uses, but none of them have
>+ a change in their value ranges, return
>+ SSA_PROP_NOT_INTERESTING. If there are no
>+ {REAL,IMAG}PART_EXPR uses at all,
>+ return SSA_PROP_VARYING. */
>+ value_range_t new_vr = VR_INITIALIZER;
>+ extract_range_basic (&new_vr, use_stmt);
>+ value_range_t *old_vr = get_value_range (use_lhs);
>+ if (old_vr->type != new_vr.type
>+ || !vrp_operand_equal_p (old_vr->min, new_vr.min)
>+ || !vrp_operand_equal_p (old_vr->max, new_vr.max)
>+ || !vrp_bitmap_equal_p (old_vr->equiv, new_vr.equiv))
>+ res = SSA_PROP_INTERESTING;
>+ else
>+ res = SSA_PROP_NOT_INTERESTING;
>+ BITMAP_FREE (new_vr.equiv);
>+ if (res == SSA_PROP_INTERESTING)
>+ {
>+ *output_p = lhs;
>+ return res;
>+ }
>+ }
>+
>+ return res;
>+ }
>+ break;
>+ default:
>+ break;
>+ }
>
> /* Every other statement produces no useful ranges. */
> FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF)
>--- gcc/testsuite/gcc.c-torture/execute/pr64006.c.jj 2014-11-21
>13:22:08.185160990 +0100
>+++ gcc/testsuite/gcc.c-torture/execute/pr64006.c 2014-11-21
>13:29:28.259119733 +0100
>@@ -0,0 +1,26 @@
>+/* PR tree-optimization/64006 */
>+
>+int v;
>+
>+long __attribute__ ((noinline, noclone))
>+test (long *x, int y)
>+{
>+ int i;
>+ long s = 1;
>+ for (i = 0; i < y; i++)
>+ if (__builtin_mul_overflow (s, x[i], &s))
>+ v++;
>+ return s;
>+}
>+
>+int
>+main ()
>+{
>+ long d[7] = { 975, 975, 975, 975, 975, 975, 975 };
>+ long r = test (d, 7);
>+ if (sizeof (long) * __CHAR_BIT__ == 64 && v != 1)
>+ __builtin_abort ();
>+ else if (sizeof (long) * __CHAR_BIT__ == 32 && v != 4)
>+ __builtin_abort ();
>+ return 0;
>+}
>
> Jakub
