From: Richard Sandiford <rdsandif...@googlemail.com> Date: Wed, 02 May 2012 20:37:58 +0100
> I think the problem is in the way sparc.c:emit_soft_tfmode_libcall > reuses existing MEMs when passing arguments on the stack: > > if (GET_CODE (this_arg) == MEM > && ! force_stack_temp) > this_arg = XEXP (this_arg, 0); > > -ffloat-store forces "a" and "b" to be stored in their argument slots, > and emit_soft_tfmode_libcall then passes the address of these incoming > argument slots to the libcall. But "a" and "b" don't escape, so DSE > thinks that the call can't read them. I'm fine with adjusting how we emit libcalls to better show the compiler what's going on. Can you suggest a way that we can mark these MEMs so that the rest of the compiler will know that these values can in fact escape?
