From 9fb87eb0bb346faced57e1f7ea0f9d7f4b9dd472 Mon Sep 17 00:00:00 2001 From: Eric Botcazou Date: Fri, 6 Feb 2015 11:17:46 +0000 Subject: [PATCH] re PR target/62631 (gcc.dg/tree-ssa/ivopts-lt-2.c FAILs) PR target/62631 * tree-ssa-loop-ivopts.c (get_shiftadd_cost): Use the mininum of costs of shift-add and (add + shift) operations. Rename local variable. From-SVN: r220473 --- gcc/ChangeLog | 6 ++++++ gcc/tree-ssa-loop-ivopts.c | 18 +++++++++++------- 2 files changed, 17 insertions(+), 7 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4d84df7..7cf5049 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2015-02-06 Eric Botcazou + + PR target/62631 + * tree-ssa-loop-ivopts.c (get_shiftadd_cost): Use the mininum of costs + of shift-add and (add + shift) operations. Rename local variable. + 2015-02-05 Jeff Law PR target/17306 diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c index bde68e7..a701636 100644 --- a/gcc/tree-ssa-loop-ivopts.c +++ b/gcc/tree-ssa-loop-ivopts.c @@ -3597,22 +3597,26 @@ get_shiftadd_cost (tree expr, machine_mode mode, comp_cost cost0, tree multop = TREE_OPERAND (mult, 0); int m = exact_log2 (int_cst_value (cst)); int maxm = MIN (BITS_PER_WORD, GET_MODE_BITSIZE (mode)); - int sa_cost; - bool equal_p = false; + int as_cost, sa_cost; + bool mult_in_op1; if (!(m >= 0 && m < maxm)) return false; - if (operand_equal_p (op1, mult, 0)) - equal_p = true; + mult_in_op1 = operand_equal_p (op1, mult, 0); + as_cost = add_cost (speed, mode) + shift_cost (speed, mode, m); + + /* If the target has a cheap shift-and-add or shift-and-sub instruction, + use that in preference to a shift insn followed by an add insn. */ sa_cost = (TREE_CODE (expr) != MINUS_EXPR ? shiftadd_cost (speed, mode, m) - : (equal_p + : (mult_in_op1 ? shiftsub1_cost (speed, mode, m) : shiftsub0_cost (speed, mode, m))); - res = new_cost (sa_cost, 0); - res = add_costs (res, equal_p ? cost0 : cost1); + + res = new_cost (MIN (as_cost, sa_cost), 0); + res = add_costs (res, mult_in_op1 ? cost0 : cost1); STRIP_NOPS (multop); if (!is_gimple_val (multop)) -- 2.7.4