On Fri, Oct 09, 2020 at 12:35:44AM -0400, Michael Meissner wrote:
> This patch is revised from the first version of the patch posted.
In the future, please send a NEW series, in a NEW thread, when you have
a new series. I was waiting for a new series (because you needed
changes), and I missed that you posted it in the old thread.
If you do not want to because the patches are independent (and not
actually a series), you can send them as independent patches as well
(and that is easier to handle, independent things become much more
obviously independent!)
> Normally the mapping is done in the math.h and stdio.h files. However, not
> everybody uses these files, which means we also need to change the external
> name for the built-in function within the compiler.
Because those are *not* defined in those headers. So those headers are
completely irrelevant to this.
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -26897,56 +26897,156 @@ rs6000_globalize_decl_name (FILE * stream, tree
> decl)
> library before you can switch the real*16 type at compile time.
>
> We use the TARGET_MANGLE_DECL_ASSEMBLER_NAME hook to change this name. We
> - only do this if the default is that long double is IBM extended double,
> and
> - the user asked for IEEE 128-bit. */
> + only do this transformation if the __float128 type is enabled. This
> + prevents us from doing the transformation on older 32-bit ports that might
> + have enabled using IEEE 128-bit floating point as the default long double
> + type. */
But that is just as broken then?
> + default:
> + break;
Please don't invert the natural order, leave the default at the bottom.
Just like you should not write "0 == x".
> + case BUILT_IN_NEXTTOWARD:
> + newname = "__nexttoward_to_ieee128";
> + break;
> +
> + case BUILT_IN_NEXTTOWARDF:
> + newname = "__nexttowardf_to_ieee128";
> + break;
Why the "_to_" in those? How irregular.
> + case BUILT_IN_SCALBL:
> + newname = "__scalbnieee128";
> + break;
Should that be __scalbieee128?
> + /* Update the __builtin_*printf && __builtin_*scanf functions. */
> + if (!newname)
> + {
> + const size_t printf_len = sizeof ("printf") - 1;
The "const" here has no function; the compiler *knows* this is a
constant number.
Please use strlen, and no - 1.
> + if (len >= printf_len
> + && strcmp (name + len - printf_len, "printf") == 0)
Thew first test is unnecessary.
> + {
> + char *name2 = (char *) alloca (len + 1 + printf_extra);
> + strcpy (name2, "__");
> + memcpy (name2 + 2, name, len);
> + strcpy (name2 + 2 + len, "ieee128");
> + newname = (const char *) name2;
> + }
Maybe just use asprintf and simplify all of this massively? It's not
like a malloc here or there will be measurably slower (if it was, you
need to do all of this differently anyway, with some caching etc.)
> + /* See if the function passes a IEEE 128-bit floating point
> type
> + or complex type. */
> + FOREACH_FUNCTION_ARGS (type, arg, args_iter)
> {
> - uses_ieee128_p = true;
> - break;
> + machine_mode arg_mode = TYPE_MODE (arg);
> + if (arg_mode == TFmode || arg_mode == TCmode)
> + {
> + uses_ieee128_p = true;
> + break;
> + }
I don't see why TFmode would mean it is IEEE? TFmode can be IBM128 as
well?
Segher
