From: Juergen Christ <jchrist@linux.ibm.com>
Date: Tue, 18 Jul 2023 06:30:14 +0000 (+0200)
Subject: IBM zSystems: Optimize vec_cmpge followed by vec_sel
X-Git-Tag: basepoints/gcc-15~7541
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=615c2e555d34c2b17513c869b309b8f398376874;p=thirdparty%2Fgcc.git

IBM zSystems: Optimize vec_cmpge followed by vec_sel

A vec_cmpge produces a negation.  Replace this negation by swapping the two
selection choices of a vec_sel based on the result of the vec_cmpge.

gcc/ChangeLog:

	* config/s390/vx-builtins.md: New vsel pattern.

gcc/testsuite/ChangeLog:

	* gcc.target/s390/vector/vec-cmpge.c: New test.

Signed-off-by: Juergen Christ <jchrist@linux.ibm.com>
---

diff --git a/gcc/config/s390/vx-builtins.md b/gcc/config/s390/vx-builtins.md
index f4248c55d4ec..10eae76777f4 100644
--- a/gcc/config/s390/vx-builtins.md
+++ b/gcc/config/s390/vx-builtins.md
@@ -530,6 +530,17 @@
   "vsel\t%v0,%1,%2,%3"
   [(set_attr "op_type" "VRR")])
 
+(define_insn "*vsel<mode>_swapped"
+  [(set (match_operand:V_HW_FT               0 "register_operand" "=v")
+	(ior:V_HW_FT
+	 (and:V_HW_FT (not:V_HW_FT (match_operand:V_HW_FT 3 "register_operand"  "v"))
+		      (match_operand:V_HW_FT 1 "register_operand"  "v"))
+	 (and:V_HW_FT (match_dup 3)
+		      (match_operand:V_HW_FT 2 "register_operand"  "v"))))]
+  "TARGET_VX"
+  "vsel\t%v0,%2,%1,%3"
+  [(set_attr "op_type" "VRR")])
+
 
 ; Vector sign extend to doubleword
 
diff --git a/gcc/testsuite/gcc.target/s390/vector/vec-cmpge.c b/gcc/testsuite/gcc.target/s390/vector/vec-cmpge.c
new file mode 100644
index 000000000000..eb188690ae41
--- /dev/null
+++ b/gcc/testsuite/gcc.target/s390/vector/vec-cmpge.c
@@ -0,0 +1,18 @@
+/* Check that vec_sel absorbs a negation generated by vec_cmpge.  */
+
+/* { dg-do compile } */
+/* { dg-options "-O3 -mzarch -march=z13" } */
+
+typedef __attribute__((vector_size(16))) unsigned char uv16qi;
+
+#include <vecintrin.h>
+
+void f(char *res, uv16qi ctrl)
+{
+  uv16qi a = vec_splat_u8(0xfe);
+  uv16qi b = vec_splat_u8(0x80);
+  uv16qi mask = vec_cmpge(ctrl, b);
+  *(uv16qi *)res = vec_sel(a, b, mask);
+}
+
+/* { dg-final { scan-assembler-not "vno\t" } } */