[Bug target/70322] New: STV doesn't optimize andn

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70322

            Bug ID: 70322
           Summary: STV doesn't optimize andn
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
                CC: enkovich.gnu at gmail dot com
  Target Milestone: ---
            Target: i386

i386.md has

(define_insn_and_split "*andndi3_doubleword"
  [(set (match_operand:DI 0 "register_operand" "=r,r")
        (and:DI
          (not:DI (match_operand:DI 1 "register_operand" "r,r"))
          (match_operand:DI 2 "nonimmediate_operand" "r,m")))
   (clobber (reg:CC FLAGS_REG))]
  "TARGET_BMI && !TARGET_64BIT && TARGET_STV && TARGET_SSE"
  "#"

But it is never used:

[hjl@gnu-tools-1 bitwise-1]$ cat andn.i
extern long long z;

void
foo (long long x, long long y)
{
  z = ~x & y;
}
[hjl@gnu-tools-1 bitwise-1]$ /export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -m32 -S  andn.i
-fno-asynchronous-unwind-tables
[hjl@gnu-tools-1 bitwise-1]$ cat andn.s
        .file   "andn.i"
        .text
        .p2align 4,,15
        .globl  foo
        .type   foo, @function
foo:
        movl    4(%esp), %ecx
        notl    %ecx
        movl    %ecx, %eax
        movl    8(%esp), %ecx
        andl    12(%esp), %eax
        notl    %ecx
        movl    %ecx, %edx
        andl    16(%esp), %edx
        movl    %eax, z
        movl    %edx, z+4
        ret
        .size   foo, .-foo
        .ident  "GCC: (GNU) 6.0.0 20160318 (experimental)"
        .section        .note.GNU-stack,"",@progbits
[hjl@gnu-tools-1 bitwise-1]$