https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=df7f55cb2ae550adeda339a57b657ebe1ad39367
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109473

From df7f55cb2ae550adeda339a57b657ebe1ad39367 Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Wed, 12 Apr 2023 10:22:08 +0200
Subject: [PATCH] tree-optimization/109473 - ICE with reduction epilog
 adjustment op

The following makes sure to carry out the reduction epilog adjustment
in the original computation type which for pointers is an unsigned
integer type.  There's a similar issue with signed vs. unsigned ops
and overflow which is fixed by this as well.

	PR tree-optimization/109473
	* tree-vect-loop.cc (vect_create_epilog_for_reduction):
	Convert scalar result to the computation type before performing
	the reduction adjustment.

	* gcc.dg/vect/pr109473.c: New testcase.
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr109473.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-O" } */
+
+struct spa_buffer {
+  __UINT32_TYPE__ *metas;
+};
+void do_port_use_buffers(struct spa_buffer **buffers, void *endptr, void *mem)
+{
+  for (int i = 0; i < 128; i++)
+    {
+      for (int j = 0; j < 128; j++)
+	endptr = (void *)((__UINTPTR_TYPE__)endptr + buffers[i]->metas[j]);
+      if (endptr > mem)
+	return;
+    }
+}
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -6297,9 +6297,12 @@ vect_create_epilog_for_reduction (loop_vec_info loop_vinfo,
 	{
           new_temp = scalar_results[0];
 	  gcc_assert (TREE_CODE (TREE_TYPE (adjustment_def)) != VECTOR_TYPE);
-	  adjustment_def = gimple_convert (&stmts, scalar_type, adjustment_def);
-	  new_temp = gimple_build (&stmts, code, scalar_type,
+	  adjustment_def = gimple_convert (&stmts, TREE_TYPE (vectype),
+					   adjustment_def);
+	  new_temp = gimple_convert (&stmts, TREE_TYPE (vectype), new_temp);
+	  new_temp = gimple_build (&stmts, code, TREE_TYPE (vectype),
 				   new_temp, adjustment_def);
+	  new_temp = gimple_convert (&stmts, scalar_type, new_temp);
 	}
 
       epilog_stmt = gimple_seq_last_stmt (stmts);
-- 
2.31.1