From d5f6f04c914e2742aae068bcc4872af694200681 Mon Sep 17 00:00:00 2001 From: Bill Schmidt Date: Thu, 14 Dec 2017 20:40:21 +0000 Subject: [PATCH] gimple-ssa-strength-reduction.c (analyze_increments): Distinguish replacement costs for constant strides from those for unknown strides. 2017-12-14 Bill Schmidt * gimple-ssa-strength-reduction.c (analyze_increments): Distinguish replacement costs for constant strides from those for unknown strides. From-SVN: r255664 --- gcc/ChangeLog | 6 ++++++ gcc/gimple-ssa-strength-reduction.c | 12 +++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d20a1b4e3ef..2e079fa4b60 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-12-14 Bill Schmidt + + * gimple-ssa-strength-reduction.c (analyze_increments): + Distinguish replacement costs for constant strides from those for + unknown strides. + 2017-12-14 Jakub Jelinek * var-tracking.c (variable_tracking_main_1): Formatting fix. diff --git a/gcc/gimple-ssa-strength-reduction.c b/gcc/gimple-ssa-strength-reduction.c index b51239b94d0..0f90232cca3 100644 --- a/gcc/gimple-ssa-strength-reduction.c +++ b/gcc/gimple-ssa-strength-reduction.c @@ -3083,7 +3083,17 @@ analyze_increments (slsr_cand_t first_dep, machine_mode mode, bool speed) else if (first_dep->kind == CAND_MULT) { int cost = mult_by_coeff_cost (incr, mode, speed); - int repl_savings = mul_cost (speed, mode) - add_cost (speed, mode); + int repl_savings; + + if (tree_fits_shwi_p (first_dep->stride)) + { + HOST_WIDE_INT hwi_stride = tree_to_shwi (first_dep->stride); + repl_savings = mult_by_coeff_cost (hwi_stride, mode, speed); + } + else + repl_savings = mul_cost (speed, mode); + repl_savings -= add_cost (speed, mode); + if (speed) cost = lowest_cost_path (cost, repl_savings, first_dep, incr_vec[i].incr, COUNT_PHIS); -- 2.30.2