VAX: Actually produce QImode and HImode `ctz' operations

The middle end does not refer to `ctzqi2'/`ctzhi2' or `ffsqi2'/`ffshi2'
patterns by name where `__builtin_ctz' or `__builtin_ffs' respectively
is invoked for an argument of the QImode or HImode type, and instead it
extends the data type before passing it to `ctzsi2' or `ffssi2'.

Avoid the redundant operation and use a peephole2 to convert it to the
right RTL expression that will collapse the two operations into a single
machine instruction instead unless we need the extended intermediate
result for another purpose.

	gcc/
	* config/vax/builtins.md: Add a peephole2 for QImode and HImode
	`ctz' operations.
	(any_extend): New code iterator.

	gcc/testsuite/
	* gcc.target/vax/ctzhi.c: New test.
	* gcc.target/vax/ctzqi.c: New test.
	* gcc.target/vax/ffshi.c: New test.
	* gcc.target/vax/ffsqi.c: New test.

1 files changed, 24 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/vax/ffshi.c b/gcc/testsuite/gcc.target/vax/ffshi.c
new file mode 100644
index 0000000..db592fb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/vax/ffshi.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-fdump-rtl-peephole2" } */
+/* { dg-skip-if "code quality test" { *-*-* } { "-O0" "-O1" } { "" } } */
+
+typedef int __attribute__ ((mode (HI))) int_t;
+
+int
+ffshi (int_t *x)
+{
+  return __builtin_ffs (*x);
+}
+
+/* Expect assembly like:
+
+	ffs $0,$16,*4(%ap),%r0
+	jneq .L2
+	mnegl $1,%r0
+.L2:
+	incl %r0
+
+ */
+
+/* { dg-final { scan-rtl-dump-times "Splitting with gen_peephole2" 1 "peephole2" } } */
+/* { dg-final { scan-assembler "\tffs \\\$0,\\\$16," } } */