[Bug target/18503] _mm_move_ss SSE intrinsic causes erroneous

[uros at kss-loka dot si]

------- Additional Comments From uros at kss-loka dot si  2004-11-17 09:17 -------
The problem was that "sse_movss" pattern has wrong vec_merge constant, so it was
wrongly combined to "vmsubv4sf3" pattern. Instead of 0x1, "sse_movss" pattern
should have 0x14:

(define_insn "sse_movss"
  [(set (match_operand:V4SF 0 "register_operand" "=x")
	(vec_merge:V4SF
	 (match_operand:V4SF 1 "register_operand" "0")
	 (match_operand:V4SF 2 "register_operand" "x")
	 (const_int 14)))]                               <- here!
  "TARGET_SSE"
  "movss\t{%2, %0|%0, %2}"
  [(set_attr "type" "ssemov")
   (set_attr "mode" "SF")])

With this change, the result from your testcase is OK. ASM code looks like:

bug:
        movaps %xmm0, %xmm2
        subps %xmm1, %xmm2
        pushl %ebp
        movl %esp, %ebp
        movaps %xmm2, %xmm1
        movss %xmm0, %xmm1
        popl %ebp
        movaps %xmm1, %xmm0
        ret

BTW: "sse2_movsd" pattern has the same problem... And "sse_loadss_1",
"sse_storess" and their sse2 equivalents.

Bug is confirmed, a patch will follow soon...

Thanks,
Uros.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18503