SVE intrinsics: Fold constant operands for svdiv.

This patch implements constant folding for svdiv:
The new function aarch64_const_binop was created, which - in contrast to
int_const_binop - does not treat operations as overflowing. This function is
passed as callback to vector_const_binop from the new gimple_folder
method fold_const_binary, if the predicate is ptrue or predication is _x.
From svdiv_impl::fold, fold_const_binary is called with TRUNC_DIV_EXPR as
tree_code.
In aarch64_const_binop, a case was added for TRUNC_DIV_EXPR to return 0
for division by 0, as defined in the semantics for svdiv.
Tests were added to check the produced assembly for different
predicates, signed and unsigned integers, and the svdiv_n_* case.

The patch was bootstrapped and regtested on aarch64-linux-gnu, no regression.
OK for mainline?

Signed-off-by: Jennifer Schmitz <jschmitz@nvidia.com>

gcc/
	* config/aarch64/aarch64-sve-builtins-base.cc (svdiv_impl::fold):
	Try constant folding.
	* config/aarch64/aarch64-sve-builtins.h: Declare
	gimple_folder::fold_const_binary.
	* config/aarch64/aarch64-sve-builtins.cc (aarch64_const_binop):
	New function to fold binary SVE intrinsics without overflow.
	(gimple_folder::fold_const_binary): New helper function for
	constant folding of SVE intrinsics.

gcc/testsuite/
	* gcc.target/aarch64/sve/const_fold_div_1.c: New test.

0 files changed, 0 insertions, 0 deletions