[Bug middle-end/81558] New: Loop not vectorized

[kugan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81558

            Bug ID: 81558
           Summary: Loop not vectorized
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kugan at gcc dot gnu.org
  Target Milestone: ---

For the testcase:

struct I
{
  int opix_x;
  int opix_y;
};

//#define R 
#define R __restrict__
extern struct I * R img;
extern unsigned short ** R imgY_org;
extern unsigned short orig_blocks[256];

void foo1 (int n)
{
  int x = 1, y = 1;
  unsigned short *orgptr=orig_blocks;
  // Vectorized
  for (y = 0; y < img->opix_y; y++)
    for (x = 0; x < img->opix_x; x++)
      *orgptr++ = imgY_org [y][x];
}

void foo2 (int n)
{
  int x = 1, y = 1;
  unsigned short *orgptr=orig_blocks;
  // Not vectorized
  for (y = img->opix_y; y < img->opix_y+16; y++)
    for (x = img->opix_x; x < img->opix_x+16; x++)
      *orgptr++ = imgY_org [y][x];
}

Loop in foo2 is not vectorized.

In the *.156t.vect, I see:
Creating dr for *_40
analyze_innermost: failed: evolution of base is not affine.
        base_address: 
        offset from base address: 
        constant offset from base address: 
        step: 
        aligned to: 
        base_object: *_40


LLVM seems to be able to vectorize this.