rs6000: unnecessary clear after vctzlsbb in vec_first_match_or_eos_index

For rs6000 target we dont need zero_extend after vctzlsbb as vctzlsbb
already zero extend.

2023-09-17  Ajit Kumar Agarwal  <aagarwa1@linux.ibm.com>

gcc/ChangeLog:

	* config/rs6000/vsx.md (*vctzlsbb_zext_<mode>): New define_insn.

gcc/testsuite/ChangeLog:

	* g++.target/powerpc/altivec-19.C: New testcase.

diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md
index 19abfeb565a6fe201b0ff431ca5c23575a22e80e..4de41e78d51b9d2309f5b65a9579a737dc7524f7 100644 (file)
--- a/gcc/config/rs6000/vsx.md
+++ b/gcc/config/rs6000/vsx.md
@@ -5846,11 +5846,22 @@
   [(set_attr "type" "vecsimple")])
 
 ;; Vector Count Trailing Zero Least-Significant Bits Byte
-(define_insn "vctzlsbb_<mode>"
-  [(set (match_operand:SI 0 "register_operand" "=r")
+(define_insn "*vctzlsbb_zext_<mode>"
+  [(set (match_operand:DI 0 "register_operand" "=r")
+       (zero_extend:DI
        (unspec:SI
         [(match_operand:VSX_EXTRACT_I 1 "altivec_register_operand" "v")]
-        UNSPEC_VCTZLSBB))]
+        UNSPEC_VCTZLSBB)))]
+  "TARGET_P9_VECTOR"
+  "vctzlsbb %0,%1"
+  [(set_attr "type" "vecsimple")])
+
+;; Vector Count Trailing Zero Least-Significant Bits Byte
+(define_insn "vctzlsbb_<mode>"
+  [(set (match_operand:SI 0 "register_operand" "=r")
+        (unspec:SI
+         [(match_operand:VSX_EXTRACT_I 1 "altivec_register_operand" "v")]
+         UNSPEC_VCTZLSBB))]
   "TARGET_P9_VECTOR"
   "vctzlsbb %0,%1"
   [(set_attr "type" "vecsimple")])

diff --git a/gcc/testsuite/g++.target/powerpc/altivec-19.C b/gcc/testsuite/g++.target/powerpc/altivec-19.C
new file mode 100644 (file)
index 0000000..5879e72
--- /dev/null
+++ b/gcc/testsuite/g++.target/powerpc/altivec-19.C
@@ -0,0 +1,10 @@
+/* { dg-do compile } */ 
+/* { dg-require-effective-target powerpc_p9vector_ok } */
+/* { dg-options "-mdejagnu-cpu=power9 -O2 " } */ 
+
+#include <altivec.h>
+
+unsigned int foo (vector unsigned char a, vector unsigned char b) {
+  return vec_first_match_or_eos_index (a, b);
+}
+/* { dg-final { scan-assembler-not {\mrldicl\M} } } */