From: liuhongt <hongtao.liu@intel.com>
Date: Thu, 27 Jul 2023 07:14:39 +0000 (+0800)
Subject: Add UNSPEC_MASKOP to vpbroadcastm pattern.
X-Git-Tag: basepoints/gcc-15~7306
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=54e54f77c1012ab53126314181c51eaee146ad5d;p=thirdparty%2Fgcc.git

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 35fd66ed4aa0..51961bbfc0b5 100644
--- 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
index 000000000000..4cf1676ccb69
--- /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.;
+}