[PATCH] s390: Optimize vec_cmpge followed by vec_sel

[PATCH] s390: Optimize vec_cmpge followed by vec_sel

[Juergen Christ]

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.

Bootstrapped and regression tested on s390x.

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>
---
 gcc/config/s390/vx-builtins.md                 | 11 +++++++++++
 .../gcc.target/s390/vector/vec-cmpge.c         | 18 ++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/s390/vector/vec-cmpge.c

diff --git a/gcc/config/s390/vx-builtins.md b/gcc/config/s390/vx-builtins.md
index f4248c55d4ec..0ce3ff6ef4a6 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" } } */
-- 
2.39.3

Re: [PATCH] s390: Optimize vec_cmpge followed by vec_sel

[Andreas Krebbel]

On 7/17/23 17:09, Juergen Christ wrote:
> 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.
> 
> Bootstrapped and regression tested on s390x.
> 
> 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>

Committed to mainline. Thanks!

Bye,

Andreas