MATCH: Optimize `VEC_SHL_INSERT (dup (A), A)` to just `dup (A) [PR116075]

It was noticed if we have `.VEC_SHL_INSERT ({ 0, ... }, 0)` it was not being
simplified to just `{ 0, ... }`. This was generated from the autovectorizer
(maybe even on accident, see PR tree-optmization/116081).

This adds a few SVE testcases to see if this is optimized since the
auto-vectorizer or intrinsics are the only two ways of getting this
produced.

Changes since:
* v1: Move the constant case over to fold-const-call.cc.
      Simplify match pattern to use handle vec_duplicate.

Build and tested for aarch64-linux-gnu with no regressions.

	PR target/116075

gcc/ChangeLog:

	* fold-const-call.cc (fold_const_vec_shl_insert): New function.
	(fold_const_call): Call fold_const_vec_shl_insert for CFN_VEC_SHL_INSERT.
	* match.pd (`VEC_SHL_INSERT (dup (A), A)`): New pattern.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/sve/dup-insr-1.c: New test.
	* gcc.target/aarch64/sve/dup-insr-2.c: New test.

Signed-off-by: Andrew Pinski <andrew.pinski@oss.qualcomm.com>

diff --git a/gcc/fold-const-call.cc b/gcc/fold-const-call.cc
index 439bf8044f5e1202a82ce4f049a9a9117cd0cdb0..89c1c28b60d685edcf076ba16f01f9703a3b2254 100644 (file)
--- a/gcc/fold-const-call.cc
+++ b/gcc/fold-const-call.cc
@@ -1440,6 +1440,25 @@ fold_const_fold_left (tree type, tree arg0, tree arg1, tree_code code)
   return arg0;
 }
 
+/* Fold a call to IFN_VEC_SHL_INSERT (ARG0, ARG1), returning a value
+   of type TYPE.  */
+
+static tree
+fold_const_vec_shl_insert (tree, tree arg0, tree arg1)
+{
+  if (TREE_CODE (arg0) != VECTOR_CST)
+    return NULL_TREE;
+
+  /* vec_shl_insert ( dup(CST), CST) -> dup (CST). */
+  if (tree elem = uniform_vector_p (arg0))
+    {
+      if (operand_equal_p (elem, arg1))
+       return arg0;
+    }
+
+  return NULL_TREE;
+}
+
 /* Try to evaluate:
 
       *RESULT = FN (*ARG0, *ARG1)
@@ -1843,6 +1862,9 @@ fold_const_call (combined_fn fn, tree type, tree arg0, tree arg1)
     case CFN_FOLD_LEFT_PLUS:
       return fold_const_fold_left (type, arg0, arg1, PLUS_EXPR);
 
+    case CFN_VEC_SHL_INSERT:
+      return fold_const_vec_shl_insert (type, arg0, arg1);
+
     case CFN_UBSAN_CHECK_ADD:
     case CFN_ADD_OVERFLOW:
       subcode = PLUS_EXPR;

diff --git a/gcc/match.pd b/gcc/match.pd
index b65adece8dc666cee9625489602ea7a64f4308e3..6aaf80eee7d5b42dbb2be2452904bd6c89623b1f 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -12023,3 +12023,8 @@ and,
       && direct_internal_fn_supported_p (IFN_AVG_CEIL, type, OPTIMIZE_FOR_BOTH))
       (IFN_AVG_CEIL @0 @2)))
 #endif
+
+/* vec shift left insert (dup (A), A) -> dup(A) */
+(simplify
+ (IFN_VEC_SHL_INSERT (vec_duplicate@1 @0) @0)
+  @1)

diff --git a/gcc/testsuite/gcc.target/aarch64/sve/dup-insr-1.c b/gcc/testsuite/gcc.target/aarch64/sve/dup-insr-1.c
new file mode 100644 (file)
index 0000000..41dcbba
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/dup-insr-1.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+/* PR target/116075 */
+
+#include <arm_sve.h>
+
+svint8_t f(void)
+{
+  svint8_t tt;
+  tt = svdup_s8 (0);
+  tt = svinsr (tt, 0);
+  return tt;
+}
+
+svint8_t f1(int8_t t)
+{
+  svint8_t tt;
+  tt = svdup_s8 (t);
+  tt = svinsr (tt, t);
+  return tt;
+}
+
+/* The above 2 functions should have removed the VEC_SHL_INSERT. */
+
+/* { dg-final { scan-tree-dump-not ".VEC_SHL_INSERT " "optimized" } } */
+

diff --git a/gcc/testsuite/gcc.target/aarch64/sve/dup-insr-2.c b/gcc/testsuite/gcc.target/aarch64/sve/dup-insr-2.c
new file mode 100644 (file)
index 0000000..8eafe97
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/dup-insr-2.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+/* PR target/116075 */
+
+#include <arm_sve.h>
+
+svint8_t f(int8_t t)
+{
+  svint8_t tt;
+  tt = svdup_s8 (0);
+  tt = svinsr (tt, t);
+  return tt;
+}
+
+svint8_t f1(int8_t t)
+{
+  svint8_t tt;
+  tt = svdup_s8 (t);
+  tt = svinsr (tt, 0);
+  return tt;
+}
+
+/* The above 2 functions should not have removed the VEC_SHL_INSERT. */
+
+/* { dg-final { scan-tree-dump-times ".VEC_SHL_INSERT " 2 "optimized" } } */
+