Add UNSPEC_MASKOP to vpbroadcastm pattern.

Prevent rtl optimization of vec_duplicate + zero_extend to
vpbroadcastm since there could be an extra kmov after RA.

gcc/ChangeLog:

	PR target/110788
	* config/i386/sse.md (avx512cd_maskb_vec_dup<mode>): Add
	UNSPEC_MASKOP.
	(avx512cd_maskw_vec_dup<mode>): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/pr110788.c: New test.

diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 35fd66ed4aa0bcda35fe54888eb8a9da06a2d55a..51961bbfc0b535b80e772bcd2ded9578862e39fd 100644 (file)
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -26778,11 +26778,14 @@
    (set_attr "prefix" "evex")
    (set_attr "mode" "<sseinsnmode>")])
 
+;; Use unspec to prevent rtl optimizer to optimize zero_extend + vec_duplicate
+;; to pbroadcastm, there could be an extra kmov after RA.
 (define_insn "avx512cd_maskb_vec_dup<mode>"
   [(set (match_operand:VI8_AVX512VL 0 "register_operand" "=v")
        (vec_duplicate:VI8_AVX512VL
          (zero_extend:DI
-           (match_operand:QI 1 "register_operand" "k"))))]
+           (match_operand:QI 1 "register_operand" "k"))))
+   (unspec [(const_int 0)] UNSPEC_MASKOP)]
   "TARGET_AVX512CD"
   "vpbroadcastmb2q\t{%1, %0|%0, %1}"
   [(set_attr "type" "mskmov")
@@ -26793,7 +26796,8 @@
   [(set (match_operand:VI4_AVX512VL 0 "register_operand" "=v")
        (vec_duplicate:VI4_AVX512VL
          (zero_extend:SI
-           (match_operand:HI 1 "register_operand" "k"))))]
+           (match_operand:HI 1 "register_operand" "k"))))
+   (unspec [(const_int 0)] UNSPEC_MASKOP)]
   "TARGET_AVX512CD"
   "vpbroadcastmw2d\t{%1, %0|%0, %1}"
   [(set_attr "type" "mskmov")

diff --git a/gcc/testsuite/gcc.target/i386/pr110788.c b/gcc/testsuite/gcc.target/i386/pr110788.c
new file mode 100644 (file)
index 0000000..4cf1676
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr110788.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=cascadelake --param vect-partial-vector-usage=2" } */
+/* { dg-final { scan-assembler-not "vpbroadcastm" } } */
+
+double a[1024], b[1024];
+
+void foo (int n)
+{
+  for (int i = 0; i < n; ++i)
+    a[i] = b[i] * 3.;
+}