[Bug 710652] Re: ARM neon vld1q_lane_u8 & co. don't accept lanes >= 8

[Andrew Stubbs]

** Tags added: 46merge

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Title:
  ARM neon vld1q_lane_u8 & co. don't accept lanes >= 8

Status in The GNU Compiler Collection:
  Fix Released
Status in Linaro GCC:
  Fix Released
Status in Linaro GCC Tracking:
  Fix Released
Status in “gcc-4.5” package in Ubuntu:
  Fix Released

Bug description:
  The testcase:

  #include <arm_neon.h>

  uint8x16_t
  foo (uint8_t *a, uint8x16_t b)
  {
    vst1q_lane_u8 (a, b, 14);
    return vld1q_lane_u8 (a + 0x100, b, 15);
  }

  fails with:

  error: argument must be a constant

  The v{ld,st}1q_lane_{u,s,p}8 intrinsic functions are supposed to take a range
  between 0 and 15.  The function is then converted to a vld1 or vst1 of one half
  of the quad value.  The problem is that the lane predicate doesn't account for
  this, and only accepts the 0..7 range that are supported by vld1 and vst1.

  The error could be a bit friendlier too; maybe "argument out of range" or
  something.  That's a problem in a separate piece of code though, so I'm not
  treating it as part of this bug.

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