Frederic Riss <frederic.r...@gmail.com> writes: > I tried to limit the lower-subreg pass to splitting integral types by > constraining MODES_TIEABLE_P. This works for my simple test cases, but > I get some testsuite regressions of the form: > > ../gcc/testsuite/gcc.c-torture/execute/ieee/930529-1.c:27:1: error: > unrecognizable insn: > (insn 45 2 46 2 > ../gcc/testsuite/gcc.c-torture/execute/ieee/930529-1.c:2 (set > (subreg:SI (subreg:DF (reg/v:DI 136 [ d ]) 0) 0) > (const_int 2454267026 [0x92492492])) -1 (nil)) > > My other option is to disable subreg-splitting on my port, but I > wonder what adverse effects it could have on 64bits integral code. > > What is the correct way to deal with this?
Setting MODES_TIEABLE_P is the right way to control lower-subreg. Your problem lies elsewhere. gcc requires that all simple moves be handled by the backend one way or another, and the above insn is a simple move. Why is it not recognized? Is register 136 a pseudo or a hard register? If a hard floating point register, how do you load a constant into a floating point register? Ian
