Enhance NARROW FLOAT_EXPR vectorization by truncating integer to lower precision.

Similar like WIDEN FLOAT_EXPR, when direct_optab is not existed, try
intermediate integer type whenever gimple ranger can tell it's safe.

.i.e.
When there's no direct optab for vector long long -> vector float, but
the value range of integer can be represented as int, try vector int
-> vector float if availble.

gcc/ChangeLog:

	PR tree-optimization/108804
	* tree-vect-patterns.cc (vect_get_range_info): Remove static.
	* tree-vect-stmts.cc (vect_create_vectorized_demotion_stmts):
	Add new parameter narrow_src_p.
	(vectorizable_conversion): Enhance NARROW FLOAT_EXPR
	vectorization by truncating to lower precision.
	* tree-vectorizer.h (vect_get_range_info): New declare.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/pr108804.c: New test.

1 files changed, 1 insertions, 1 deletions

diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index 33a8b2b..917f7bc 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -61,7 +61,7 @@ along with GCC; see the file COPYING3.  If not see
 /* Return true if we have a useful VR_RANGE range for VAR, storing it
    in *MIN_VALUE and *MAX_VALUE if so.  Note the range in the dump files.  */
 
-static bool
+bool
 vect_get_range_info (tree var, wide_int *min_value, wide_int *max_value)
 {
   value_range vr;