[PATCH] match.pd: Use element_mode instead of TYPE_MODE.

[Robin Dapp <rdapp.gcc@gmail.com>]

Hi,

this patch changes TYPE_MODE into element_mode in a match.pd
simplification.  As the simplification can be called with vector types
real_can_shorten_arithmetic would ICE in REAL_MODE_FORMAT which
expects a scalar mode.  Therefore, use element_mode instead of
TYPE_MODE.

Additionally, check if the target supports the resulting operation in the
new mode.  One target that supports e.g. a float addition but not a
_Float16 addition is the RISC-V vector Float16 extension Zvfhmin.

Bootstrap on x86_64 succeeded, testsuite is currently running.  Is this OK
if the testsuite is clean?

Regards
 Robin

gcc/ChangeLog:

	* match.pd: Use element_mode and check if target supports
	operation with new type.
---
 gcc/match.pd | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/gcc/match.pd b/gcc/match.pd
index 33ccda3e7b6..4a200f221f6 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -7454,10 +7454,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 		  values representable in the TYPE to be within the
 		  range of normal values of ITYPE.  */
 	      (if (element_precision (newtype) < element_precision (itype)
+		   && target_supports_op_p (newtype, op, optab_default)
 		   && (flag_unsafe_math_optimizations
 		       || (element_precision (newtype) == element_precision (type)
-			   && real_can_shorten_arithmetic (TYPE_MODE (itype),
-							   TYPE_MODE (type))
+			   && real_can_shorten_arithmetic (element_mode (itype),
+							   element_mode (type))
 			   && !excess_precision_type (newtype)))
 		   && !types_match (itype, newtype))
 		 (convert:type (op (convert:newtype @1)
-- 
2.41.0