[Bug middle-end/87256] hppa spends huge amount of time in synth_mult()

[danglin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87256

--- Comment #11 from John David Anglin <danglin at gcc dot gnu.org> ---
I tend to think there may be an issue with costs.  There is no pattern
for muldi3 on 32-bit hppa, so we use the generic code from libgcc.  How
do we know the cost for this routine?

If synth_mult is disabled, the testcase takes a fraction of a second to
compile.  The only difference in the generated code is for "case 6" where
the multiplication by 13 is done using shift add.