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| author | Roger Sayle <roger@eyesopen.com> | 2005-11-26 04:06:57 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2005-11-26 04:06:57 +0000 |
| commit | 18eaea7f15cf89aa5e0c9c99c76b14dfc39563c5 (patch) | |
| tree | c16de2a90743698ed3aced9ff6b2d3d645393e96 /gcc/expmed.c | |
| parent | 7e7b53aa73f8b47b73e924289204eac5d84723cf (diff) | |
| download | gcc-18eaea7f15cf89aa5e0c9c99c76b14dfc39563c5.zip gcc-18eaea7f15cf89aa5e0c9c99c76b14dfc39563c5.tar.gz gcc-18eaea7f15cf89aa5e0c9c99c76b14dfc39563c5.tar.bz2 | |
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
Diffstat (limited to 'gcc/expmed.c')
| -rw-r--r-- | gcc/expmed.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index d591b6b..ec2758e 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; |