From 18eaea7f15cf89aa5e0c9c99c76b14dfc39563c5 Mon Sep 17 00:00:00 2001 From: Roger Sayle Date: Sat, 26 Nov 2005 04:06:57 +0000 Subject: [PATCH] re PR middle-end/21309 (internal compiler error: in expand_mult_const, at expmed.c:2884) PR middle-end/21309 * expmed.c (choose_mult_variant): Return immediately when mult_cost is less than zero. Limit mult_cost to a reasonable upper bound for the synthetic multiplication sequence. From-SVN: r107537 --- gcc/ChangeLog | 7 +++++++ gcc/expmed.c | 11 +++++++++++ 2 files changed, 18 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 654acf22846..c4ec10c521f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2005-11-25 Roger Sayle + + PR middle-end/21309 + * expmed.c (choose_mult_variant): Return immediately when mult_cost + is less than zero. Limit mult_cost to a reasonable upper bound for + the synthetic multiplication sequence. + 2005-11-25 Kaveh R. Ghazi PR middle-end/25022 diff --git a/gcc/expmed.c b/gcc/expmed.c index d591b6bc7c2..ec2758ec8ef 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -2836,6 +2836,17 @@ choose_mult_variant (enum machine_mode mode, HOST_WIDE_INT val, struct mult_cost limit; int op_cost; + /* Fail quickly for impossible bounds. */ + if (mult_cost < 0) + return false; + + /* Ensure that mult_cost provides a reasonable upper bound. + Any constant multiplication can be performed with less + than 2 * bits additions. */ + op_cost = 2 * GET_MODE_BITSIZE (mode) * add_cost[mode]; + if (mult_cost > op_cost) + mult_cost = op_cost; + *variant = basic_variant; limit.cost = mult_cost; limit.latency = mult_cost; -- 2.30.2