vect: Use original LHS type for gather pattern [PR118950].

In PR118950 we do not zero masked elements in a gather load.
While recognizing a gather/scatter pattern we do not use the original
type of the LHS.  This matters because the type can differ with bool
patterns (e.g. _Bool vs unsigned char) and we don't notice the need
for zeroing out the padding bytes.

This patch just uses the original LHS's type.

	PR middle-end/118950

gcc/ChangeLog:

	* tree-vect-patterns.cc (vect_recog_gather_scatter_pattern): Use
	original LHS's type.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/pr118950.c: New test.

1 files changed, 29 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr118950.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr118950.c
new file mode 100644
index 0000000..604d426
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/pr118950.c
@@ -0,0 +1,29 @@
+/* { dg-do run } */
+/* { dg-require-effective-target riscv_v_ok } */
+/* { dg-add-options riscv_v } */
+/* { dg-additional-options "-std=gnu99 -Wno-pedantic" } */
+
+unsigned char a;
+long long r;
+_Bool h = 1;
+short j[23];
+_Bool k[3][23];
+
+void b(_Bool h, short j[], _Bool k[][23]) {
+  for (int m = 0; m < 23; m += 3)
+    for (short n = 0; n < 22; n += 4)
+      a = ({
+        unsigned char o = a;
+        unsigned char p = j[n] ? h : k[m][n];
+        o > p ? o : p;
+      });
+}
+
+int main() {
+  for (int m = 0; m < 23; ++m)
+    j[m] = 10;
+  b(h, j, k);
+  r = a;
+  if (r != 1)
+    __builtin_abort ();
+}