Hi, This patch introduces TARGET_C_EXCESS_PRECISION. This hook takes a tri-state argument, one of EXCESS_PRECISION_TYPE_IMPLICIT, EXCESS_PRECISION_TYPE_STANDARD, EXCESS_PRECISION_TYPE_FAST. Which relate to the implicit extra precision added by the target, the excess precision that should be guaranteed for -fexcess-precision=standard, and the excess precision that should be added for performance under -fexcess-precision=fast .
Bootstrapped and tested in sequence with the other patches in this series on Arch64, and as a standalone patch on x86_64. OK? Thanks James --- gcc/ 2016-09-30 James Greenhalgh <james.greenha...@arm.com> * target.def (excess_precision): New hook. * target.h (flt_eval_method): New. (excess_precision_type): Likewise. * targhooks.c (default_excess_precision): New. * targhooks.h (default_excess_precision): New. * doc/tm.texi.in (TARGET_EXCESS_PRECISION): New. * doc/tm.texi: Regenerate.
diff --git a/gcc/coretypes.h b/gcc/coretypes.h index fe1e984..26b0fa3 100644 --- a/gcc/coretypes.h +++ b/gcc/coretypes.h @@ -359,6 +359,24 @@ enum memmodel MEMMODEL_SYNC_SEQ_CST = MEMMODEL_SEQ_CST | MEMMODEL_SYNC }; +/* enums used by the targetm.excess_precision hook. */ + +enum flt_eval_method +{ + FLT_EVAL_METHOD_UNPREDICTABLE = -1, + FLT_EVAL_METHOD_PROMOTE_TO_FLOAT = 0, + FLT_EVAL_METHOD_PROMOTE_TO_DOUBLE = 1, + FLT_EVAL_METHOD_PROMOTE_TO_LONG_DOUBLE = 2, + FLT_EVAL_METHOD_PROMOTE_TO_FLOAT16 = 16 +}; + +enum excess_precision_type +{ + EXCESS_PRECISION_TYPE_IMPLICIT, + EXCESS_PRECISION_TYPE_STANDARD, + EXCESS_PRECISION_TYPE_FAST +}; + /* Support for user-provided GGC and PCH markers. The first parameter is a pointer to a pointer, the second a cookie. */ typedef void (*gt_pointer_operator) (void *, void *); diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 8a98ba4..0bdae58 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -947,6 +947,10 @@ sign-extend the result to 64 bits. On such machines, set Do not define this macro if it would never modify @var{m}. @end defmac +@deftypefn {Target Hook} {enum flt_eval_method} TARGET_C_EXCESS_PRECISION (enum excess_precision_type @var{type}) +Return a value, with the same meaning as @code{FLT_EVAL_METHOD} C that describes which excess precision should be applied. @var{type} is either @code{EXCESS_PRECISION_TYPE_IMPLICIT}, @code{EXCESS_PRECISION_TYPE_FAST}, or @code{EXCESS_PRECISION_TYPE_STANDARD}. For @code{EXCESS_PRECISION_TYPE_IMPLICIT}, the target should return which precision and range operations will be implictly evaluated in regardless of the excess precision explicitly added. For @code{EXCESS_PRECISION_TYPE_STANDARD} and @code{EXCESS_PRECISION_TYPE_FAST}, the target should return the explicit excess precision that should be added depending on the value set for @code{-fexcess-precision=[standard|fast]}. +@end deftypefn + @deftypefn {Target Hook} machine_mode TARGET_PROMOTE_FUNCTION_MODE (const_tree @var{type}, machine_mode @var{mode}, int *@var{punsignedp}, const_tree @var{funtype}, int @var{for_return}) Like @code{PROMOTE_MODE}, but it is applied to outgoing function arguments or function return values. The target hook should return the new mode diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in index f1cfc86..7c7af33 100644 --- a/gcc/doc/tm.texi.in +++ b/gcc/doc/tm.texi.in @@ -921,6 +921,8 @@ sign-extend the result to 64 bits. On such machines, set Do not define this macro if it would never modify @var{m}. @end defmac +@hook TARGET_C_EXCESS_PRECISION + @hook TARGET_PROMOTE_FUNCTION_MODE @defmac PARM_BOUNDARY diff --git a/gcc/target.def b/gcc/target.def index 83373a5..1542692 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -5402,6 +5402,23 @@ DEFHOOK_UNDOC machine_mode, (char c), default_mode_for_suffix) +DEFHOOK +(excess_precision, + "Return a value, with the same meaning as @code{FLT_EVAL_METHOD} C that\ + describes which excess precision should be applied. @var{type} is\ + either @code{EXCESS_PRECISION_TYPE_IMPLICIT},\ + @code{EXCESS_PRECISION_TYPE_FAST}, or\ + @code{EXCESS_PRECISION_TYPE_STANDARD}. For\ + @code{EXCESS_PRECISION_TYPE_IMPLICIT}, the target should return which\ + precision and range operations will be implictly evaluated in regardless\ + of the excess precision explicitly added. For\ + @code{EXCESS_PRECISION_TYPE_STANDARD} and\ + @code{EXCESS_PRECISION_TYPE_FAST}, the target should return the\ + explicit excess precision that should be added depending on the\ + value set for @code{-fexcess-precision=[standard|fast]}.", + enum flt_eval_method, (enum excess_precision_type type), + default_excess_precision) + HOOK_VECTOR_END (c) /* Functions specific to the C++ frontend. */ diff --git a/gcc/targhooks.c b/gcc/targhooks.c index d75650f..08d0b35 100644 --- a/gcc/targhooks.c +++ b/gcc/targhooks.c @@ -2110,4 +2110,12 @@ default_max_noce_ifcvt_seq_cost (edge e) return BRANCH_COST (true, predictable_p) * COSTS_N_INSNS (3); } +/* Default implementation of TARGET_EXCESS_PRECISION. */ + +enum flt_eval_method +default_excess_precision (enum excess_precision_type ATTRIBUTE_UNUSED) +{ + return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT; +} + #include "gt-targhooks.h" diff --git a/gcc/targhooks.h b/gcc/targhooks.h index 3356f0a..3fabde7 100644 --- a/gcc/targhooks.h +++ b/gcc/targhooks.h @@ -263,4 +263,7 @@ extern bool default_optab_supported_p (int, machine_mode, machine_mode, extern unsigned int default_max_noce_ifcvt_seq_cost (edge); +extern enum flt_eval_method +default_excess_precision (enum excess_precision_type ATTRIBUTE_UNUSED); + #endif /* GCC_TARGHOOKS_H */