[PATCH 1/5] Unify ARRAY_REF/INDIRECT_REF stripping code in extract_base_bit_offset

[Julian Brown]

For historical reasons, it seems that extract_base_bit_offset
unnecessarily used two different ways to strip ARRAY_REF/INDIRECT_REF
nodes from component accesses. I verified that the two ways of performing
the operation gave the same results across the whole testsuite (and
several additional benchmarks).

The code was like this since an earlier "mechanical" refactoring by me,
first posted here:

  https://gcc.gnu.org/pipermail/gcc-patches/2018-November/510503.html

It was never clear to me if there was an important semantic
difference between the two ways of stripping the base before calling
get_inner_reference, but it appears that there is not, so one can go away.

OK for trunk?

Thanks,

Julian

2021-05-14  Julian Brown  <julian@codesourcery.com>

gcc/
	* gimplify.c (extract_base_bit_offset): Unify ARRAY_REF/INDIRECT_REF
	stripping code in first call/subsequent call cases.
---
 gcc/gimplify.c | 32 +++++++++++---------------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index e790f08b23f..90bd3341fd3 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -8368,31 +8368,21 @@ extract_base_bit_offset (tree base, tree *base_ref, poly_int64 *bitposp,
   poly_offset_int poffset;
 
   if (base_ref)
-    {
-      *base_ref = NULL_TREE;
-
-      while (TREE_CODE (base) == ARRAY_REF)
-	base = TREE_OPERAND (base, 0);
+    *base_ref = NULL_TREE;
 
-      if (TREE_CODE (base) == INDIRECT_REF)
-	base = TREE_OPERAND (base, 0);
-    }
-  else
+  if (TREE_CODE (base) == ARRAY_REF)
     {
-      if (TREE_CODE (base) == ARRAY_REF)
-	{
-	  while (TREE_CODE (base) == ARRAY_REF)
-	    base = TREE_OPERAND (base, 0);
-	  if (TREE_CODE (base) != COMPONENT_REF
-	      || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE)
-	    return NULL_TREE;
-	}
-      else if (TREE_CODE (base) == INDIRECT_REF
-	       && TREE_CODE (TREE_OPERAND (base, 0)) == COMPONENT_REF
-	       && (TREE_CODE (TREE_TYPE (TREE_OPERAND (base, 0)))
-		   == REFERENCE_TYPE))
+      while (TREE_CODE (base) == ARRAY_REF)
 	base = TREE_OPERAND (base, 0);
+      if (TREE_CODE (base) != COMPONENT_REF
+	  || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE)
+	return NULL_TREE;
     }
+  else if (TREE_CODE (base) == INDIRECT_REF
+	   && TREE_CODE (TREE_OPERAND (base, 0)) == COMPONENT_REF
+	   && (TREE_CODE (TREE_TYPE (TREE_OPERAND (base, 0)))
+	       == REFERENCE_TYPE))
+    base = TREE_OPERAND (base, 0);
 
   base = get_inner_reference (base, &bitsize, &bitpos, &offset, &mode,
 			      &unsignedp, &reversep, &volatilep);
-- 
2.29.2