On Thu, Apr 07, 2022 at 06:09:52AM -0500, Segher Boessenkool wrote:
> Hi!
>
> On Thu, Mar 03, 2022 at 10:11:32AM +0800, Kewen.Lin wrote:
> > As PR103623 shows, it's a regression failure due to new built-in
> > function framework, previously we guard __builtin_{un,}pack_{longdouble,
> > ibm128} built-in functions under hard float, so they are unavailable
> > with the given configuration. While with new bif infrastructure, it
> > becomes available and gets ICE due to incomplete supports.
> >
> > Segher and Peter pointed out that we should make them available with
> > soft float, I agree we can extend them to cover both soft and hard
> > float. But considering it's stage 4 now and this regression is
> > classified as P1, also the previous behavior requiring hard float
> > aligns with what document [1] says, I guess it may be a good idea to
> > fix it with the attached small patch to be consistent with the previous
> > behavior. Then we can extend the functionality in upcoming stage 1.
>
> Or you could just not take away the existing functionality.
Have those builtins ever worked with 64-bit soft-float?
When I try e.g. gcc 11 on the #c0 testcase from the PR, I get:
./cc1.r11-1 -quiet -nostdinc pr103623.c -m64 -mlong-double-128 -msoft-float
pr103623.c: In function ‘main’:
pr103623.c:2:16: error: ‘__builtin_unpack_longdouble’ requires the
‘-mhard-float’ option
2 | #define UNPACK __builtin_unpack_longdouble
| ^
pr103623.c:11:15: note: in expansion of macro ‘UNPACK’
11 | double x0 = UNPACK (a, 0);
| ^~~~~~
>From what I can see, those builtins were using:
/* 128-bit long double floating point builtins. */
#define BU_LDBL128_2(ENUM, NAME, ATTR, ICODE) \
RS6000_BUILTIN_2 (MISC_BUILTIN_ ## ENUM, /* ENUM */ \
"__builtin_" NAME, /* NAME */ \
(RS6000_BTM_HARD_FLOAT /* MASK */ \
| RS6000_BTM_LDBL128), \
(RS6000_BTC_ ## ATTR /* ATTR */ \
| RS6000_BTC_BINARY), \
CODE_FOR_ ## ICODE) /* ICODE */
/* 128-bit __ibm128 floating point builtins (use -mfloat128 to indicate that
__ibm128 is available). */
#define BU_IBM128_2(ENUM, NAME, ATTR, ICODE) \
RS6000_BUILTIN_2 (MISC_BUILTIN_ ## ENUM, /* ENUM */ \
"__builtin_" NAME, /* NAME */ \
(RS6000_BTM_HARD_FLOAT /* MASK */ \
| RS6000_BTM_FLOAT128), \
(RS6000_BTC_ ## ATTR /* ATTR */ \
| RS6000_BTC_BINARY), \
CODE_FOR_ ## ICODE) /* ICODE */
macros and rs6000_builtin_is_supported_p was checking whether
all the bits in the mask are set:
HOST_WIDE_INT fnmask = rs6000_builtin_info[fncode].mask;
if ((fnmask & rs6000_builtin_mask) != fnmask)
return false;
else
return true;
(so logical and of all of them).
Jakub
