[Bug target/112447] risc-v regression: FAIL: gcc.c-torture/execute/memset-3.c -O3

[vineetg at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112447

--- Comment #6 from Vineet Gupta <vineetg at gcc dot gnu.org> ---
I have debugged this by single stepped in qemu 

when the test fails (first loop for offset 0, iteration 8)

The last VSETVLI is this one, 

   0x10a3e   0d107057  vsetvli  zero,zero,e32,m2,ta,ma
   0x10a42   j  0x10666

We eventually hit a VMV.v.x. which creates invalid pattern due to e32.

   (gdb) info reg vtype
   vtype          0xd1  209     # SEW = 010’b / e32, LMUL = 001’b / m2
   (gdb) info reg vl
   vl             0x8   8
   (gdb) info reg a0
   a0             0x41  65

   vmv.v.x      v2,a0

  (gdb) info reg v2
  v2             {q = {0x41000000410000004100000041}     
  (gdb) info reg v3
  v2             {q = {0x41000000410000004100000041}