Re: Regressions on native/master at commit r16-29 vs commit r16-21 on Linux/x86_64

[Sam James via Gcc-regression]

This builder uses --with-arch=native. The (a) difference starts at x86-64-v3:

 $ diff -u <(gcc -O2 -fdump-tree-forwprop1-details=- -O2 gcc.dg/pr78408-3.c -c 
-march=x86-64-v2) <(gcc -O2 -fdump-tree-forwprop1-details=- -O2 
gcc.dg/pr78408-3.c -c -march=x86-64-v3)
--- /dev/fd/63  2025-04-19 01:27:31.676852279 +0100
+++ /dev/fd/62  2025-04-19 01:27:31.651851999 +0100
@@ -1,15 +1,17 @@

-;; Function bbb (bbb, funcdef_no=0, decl_uid=2939, cgraph_uid=1, 
symbol_order=0)
+;; Function bbb (bbb, funcdef_no=0, decl_uid=3312, cgraph_uid=1, 
symbol_order=0)

 void * bbb ()
 {
   char buf[32];
   void * ret;
+  vector(32) unsigned char _5;

   <bb 2> :
   ret_3 = aaa ();
   buf = "";
-  MEM <unsigned char[32]> [(char * {ref-all})ret_3] = MEM <unsigned char[32]> 
[(char * {ref-all})&buf];
+  _5 = MEM <vector(32) unsigned char> [(char * {ref-all})&buf];
+  MEM <vector(32) unsigned char> [(char * {ref-all})ret_3] = _5;
   buf ={v} {CLOBBER(eos)};
   return ret_3;