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Diffstat (limited to 'gcc/doc/tm.texi')
| -rw-r--r-- | gcc/doc/tm.texi | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index a89d0ec..7351e83 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -4277,6 +4277,34 @@ insns involving vector mode @var{mode}. At the very least, it must have move patterns for this mode. @end deftypefn +@deftypefn {Target Hook} bool TARGET_ARRAY_MODE_SUPPORTED_P (enum machine_mode @var{mode}, unsigned HOST_WIDE_INT @var{nelems}) +Return true if GCC should try to use a scalar mode to store an array +of @var{nelems} elements, given that each element has mode @var{mode}. +Returning true here overrides the usual @code{MAX_FIXED_MODE} limit +and allows GCC to use any defined integer mode. + +One use of this hook is to support vector load and store operations +that operate on several homogeneous vectors. For example, ARM NEON +has operations like: + +@smallexample +int8x8x3_t vld3_s8 (const int8_t *) +@end smallexample + +where the return type is defined as: + +@smallexample +typedef struct int8x8x3_t +@{ + int8x8_t val[3]; +@} int8x8x3_t; +@end smallexample + +If this hook allows @code{val} to have a scalar mode, then +@code{int8x8x3_t} can have the same mode. GCC can then store +@code{int8x8x3_t}s in registers rather than forcing them onto the stack. +@end deftypefn + @deftypefn {Target Hook} bool TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P (enum machine_mode @var{mode}) Define this to return nonzero for machine modes for which the port has small register classes. If this target hook returns nonzero for a given |