Fixed SVP64 implentation

diff --git a/media/video/libvpx/variance_svp64_real.s b/media/video/libvpx/variance_svp64_real.s
index 4242f68e9c3922f0f56ac0d111da8029696db2e4..046f68beb6d5197d5e7b220746af7ed503697a56 100644 (file)
--- a/media/video/libvpx/variance_svp64_real.s
+++ b/media/video/libvpx/variance_svp64_real.s
@@ -13,9 +13,9 @@
 .set ref_col, 15
 .set row, 16
 .set src, 20
-.set ref, 36
-.set diff, 52
-.set prod, 68
+.set ref, 24
+.set diff, 28
+.set prod, 32
 
        .machine libresoc
        .file   "variance_svp64_real.c"
@@ -27,45 +27,44 @@
 variance_svp64_real:
 .LFB0:
        .cfi_startproc
-       # Set sum to zero
-       li sum, 0                               # Set sum to zero
-       li sse, 0                               # Set sse to zero
-       mr row, height                          # Set row to height
+       li      sum, 0                          # Set sum to zero
+       li      sse, 0                          # Set sse to zero
+       li      row, 0                          # Set row to zero
        sldi    src_stride, src_stride, 1       # strides are for 16-bit elements
        sldi    ref_stride, ref_stride, 1       # we need to increase by bytes
-       srdi    ctr, width, 2
-       mtctr   ctr
+       srdi    width, width, 2                 # We load groups of 4
        setvl   0,0,4,0,1,1                     # Set VL to 4 elements
 
 .L1:   # outer loop: for (r=0; r < h; r++)
-
-.L2:   # inner loop: for (c=0; c < w; c += 4)
-       # Load 4 elements from src_ptr and ref_ptr, at groups of 4
        mr      src_col, src_ptr                # Temporary variables
        mr      ref_col, ref_ptr
+       mr      ctr, width                      # Set up CTR to width/4 -1 on each row
+       mtctr   ctr                             # Set up counter
+.L2:   # inner loop: for (c=0; c < w; c += 4)
+       # Load 4 elements from src_ptr and ref_ptr
        sv.lha  *src, 0(src_col)                # Load 4 ints from (src_ptr)
        sv.lha  *ref, 0(ref_col)                # Load 4 ints from (ref_ptr)
-       addi    src_col, src_col, 8             # Increment src, ref by 8 bytes
-       addi    ref_col, ref_col, 8
 
        # equivalent to: for (i = 0; i < 4; i++) diff[i] = src[i] - ref[i];
-       sv.subf         *diff, *src, *ref
+       sv.subf         *diff, *ref, *src
        # equivalent to: for (i = 0; i < 4; i++) prod[i] = diff[i] * diff[i];
        sv.mulld        *prod, *diff, *diff
        # equivalent to: for (i = 0; i < 4; i++) sum += diff[i];
        sv.add/mr       sum, *diff, sum
-       # equivalent to: for (i = 0; i < 4; i++) sum += diff[i];
+       # equivalent to: for (i = 0; i < 4; i++) sse += diff[i]*diff[i];
        sv.add/mr       sse, *prod, sse
 
-       bdnz .L2                                # Loop until CTR is zero
+       addi    src_col, src_col, 8             # Increment src, ref by 8 bytes
+       addi    ref_col, ref_col, 8
+       bdnz    .L2                             # Loop until CTR is zero
+
        add     src_ptr, src_ptr, src_stride    # Advance src_ptr by src_stride
        add     ref_ptr, ref_ptr, ref_stride    # Advance ref_ptr by ref_stride
-
-       subi row, row, 1                        # Subtract 1 from row
-       cmpwi cr1, row, 0                       # Is row zero?
-       bne cr1, .L1                            # Go back to L1 if not done
-       std sum, 0(sum_ptr)                     # Set (sum_ptr) to sum
-       std sse, 0(sse_ptr)                     # Set (sum_ptr) to sum
+       addi    row, row, 1                     # Add 1 to row
+       cmpw    cr1, row, height                # Is row equal to height?
+       bne     cr1, .L1                        # Go back to L1 if not done
+       std     sum, 0(sum_ptr)                 # Set (sum_ptr) to sum
+       std     sse, 0(sse_ptr)                 # Set (sum_ptr) to sum
        blr
        .long 0
        .byte 0,0,0,0,0,3,0,0