[PATCH] Fix mult expansion ICE (PR middle-end/82875)

[Jakub Jelinek]

On Wed, Nov 22, 2017 at 10:41:19AM +0100, Richard Biener wrote:
> How much churn would it be to pass down a mode alongside the operands
> in expand_binop?  Can't find it right now but didn't we introduce
> some rtx_with_mode pair-like stuff somewhen?

We have rtx_mode_t for that.  But there are 240+ calls to expand_binop,
and even if we add an overload that will transform it, unless we forcefully
inline it wouldn't that slow down all the spots a little bit?
The thing is, for the vast majority of binary ops we don't need the operand
modes, it is mainly comparisons, second arg of shifts/rotates and this
widening case.

	Jakub