Peter Bergner <[email protected]> writes:
> On 4/28/20 11:57 AM, Richard Sandiford wrote:
>> I was just quoting code from simplify_replace_fn_rtx as an example of
>> something that handles a similar situation. The recursive calls would
>> be different for cse_process_notes_1.
>
> Ok, how about the following which adds the (const:P ...) as well, which
> fixes the ICE? The FOR loop which now follows this switch statement is
> what used to modify the PLUS's operands without adding the (const:P ).
>
> This is still in the middle of bootstrap and regtesting.
>
> Peter
>
>
> gcc/
> PR rtl-optimization/94740
> * cse.c (cse_process_notes_1):
>
> gcc/testsuite/
> PR rtl-optimization/94740
> * gcc.target/powerpc/pr94740.c: New test.
>
> diff --git a/gcc/cse.c b/gcc/cse.c
> index 5aaba8d80e0..4592820c04c 100644
> --- a/gcc/cse.c
> +++ b/gcc/cse.c
> @@ -6314,6 +6314,21 @@ cse_process_notes_1 (rtx x, rtx object, bool *changed)
> break;
> }
>
> + switch (GET_RTX_CLASS (code))
> + {
> + case RTX_BIN_ARITH:
> + case RTX_COMM_ARITH:
> + /* Call simplify_gen_binary with our updated operands in case they
> + are now constant and need to be wrapped with a (const:P ...). */
> + validate_change (object, &XEXP (x, 0),
> + cse_process_notes (XEXP (x, 0), object, changed), false);
> + validate_change (object, &XEXP (x, 1),
> + cse_process_notes (XEXP (x, 1), object, changed), false);
> + return simplify_gen_binary (code, GET_MODE (x), XEXP (x, 0), XEXP (x,
> 1));
If we use simplify_gen_binary then I don't think we need to validate
each change individually. It should be enough to do something like:
x0 = cse_process_notes (XEXP (x, 0), object, changed);
x1 = cse_process_notes (XEXP (x, 1), object, changed);
if (x0 == XEXP (x, 0) && x1 == XEXP (x, 1))
return x;
return simplify_gen_binary (code, GET_MODE (x), x0, x1);
Alternatively, in the hope of reducing redundant rtl, I guess we could
add the switch statement after the format walk and do:
switch (GET_RTX_CLASS (code))
{
case RTX_BIN_ARITH:
case RTX_COMM_ARITH:
if (rtx new_rtx = simplify_binary (code, GET_MODE (x),
XEXP (x, 0), XEXP (x, 1)))
return new_rtx;
break;
default:
break;
}
Thanks,
Richard
