[PATCH] tree-optimization/101158 - adjust SLP call matching sequence

[Richard Biener <rguenther@suse.de>]

This moves the check for same operands after verifying we're
facing compatible calls.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

2021-06-22  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/101158
	* tree-vect-slp.c (vect_build_slp_tree_1): Move same operand
	checking after checking for matching operation.

	* gfortran.dg/pr101158.f90: New testcase.
---
 gcc/testsuite/gfortran.dg/pr101158.f90 | 25 +++++++++++++++++++++
 gcc/tree-vect-slp.c                    | 31 +++++++++++++-------------
 2 files changed, 41 insertions(+), 15 deletions(-)
 create mode 100644 gcc/testsuite/gfortran.dg/pr101158.f90

diff --git a/gcc/testsuite/gfortran.dg/pr101158.f90 b/gcc/testsuite/gfortran.dg/pr101158.f90
new file mode 100644
index 00000000000..9a4d9a2d7ae
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr101158.f90
@@ -0,0 +1,25 @@
+! { dg-do compile }
+! { dg-options "-O1 -ftree-slp-vectorize -fwrapv" }
+! { dg-additional-options "-march=armv8-a+sve" { target aarch64-*-* } }
+
+subroutine sprpl5 (left)
+  implicit none
+
+  integer :: left
+  integer :: avail1, avail2, delx1, delx2, i2, ic
+
+  ic = left
+  delx1 = ic / 2
+  delx2 = delx1 + 1
+  i2 = ic + delx2
+  avail1 = i2
+  avail2 = 1
+
+  do delx1 = 1, 2
+     ic = left + nint (real (left) / 2)
+     if (ic .ge. avail1) avail1 = ic + 1
+
+     i2 = ic + delx2
+     if (i2 .le. avail2) avail2 = i2 + 1
+  end do
+end subroutine sprpl5
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index b9f91e7c7ba..6c98acbe722 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -1177,21 +1177,6 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap,
 	      continue;
 	    }
 
-	  if (need_same_oprnds)
-	    {
-	      tree other_op1 = (call_stmt
-				? gimple_call_arg (call_stmt, 1)
-				: gimple_assign_rhs2 (stmt));
-	      if (!operand_equal_p (first_op1, other_op1, 0))
-		{
-		  if (dump_enabled_p ())
-		    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
-				     "Build SLP failed: different shift "
-				     "arguments in %G", stmt);
-		  /* Mismatch.  */
-		  continue;
-		}
-	    }
 	  if (!load_p
 	      && first_stmt_code == BIT_FIELD_REF
 	      && (TREE_OPERAND (gimple_assign_rhs1 (first_stmt_info->stmt), 0)
@@ -1231,6 +1216,22 @@ vect_build_slp_tree_1 (vec_info *vinfo, unsigned char *swap,
 	      continue;
 	    }
 
+	  if (need_same_oprnds)
+	    {
+	      tree other_op1 = (call_stmt
+				? gimple_call_arg (call_stmt, 1)
+				: gimple_assign_rhs2 (stmt));
+	      if (!operand_equal_p (first_op1, other_op1, 0))
+		{
+		  if (dump_enabled_p ())
+		    dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+				     "Build SLP failed: different shift "
+				     "arguments in %G", stmt);
+		  /* Mismatch.  */
+		  continue;
+		}
+	    }
+
 	  if (!types_compatible_p (vectype, *node_vectype))
 	    {
 	      if (dump_enabled_p ())
-- 
2.26.2