From: Ben Avison <bavi...@riscosopen.org>
This knocks off one instruction per row. The effect is probably too small to
be measurable, but might as well be included. The second occurrence of this
sequence doesn't actually benefit at all, but is changed for consistency.
The saved instruction comes from combining the "and" inside the .if
statement with an earlier "tst". The "and" was normally needed, except
for in one special case, where bits 4-31 were all shifted off the top of
the register later on in preload_leading_step2, so we didn't care about
their values.
v4, Pekka Paalanen <pekka.paala...@collabora.co.uk> :
Remove "bits 0-3" from the comments, update patch summary, and
augment message with Ben's suggestion.
---
pixman/pixman-arm-simd-asm.h | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/pixman/pixman-arm-simd-asm.h b/pixman/pixman-arm-simd-asm.h
index 74400c1..24b1ad2 100644
--- a/pixman/pixman-arm-simd-asm.h
+++ b/pixman/pixman-arm-simd-asm.h
@@ -741,12 +741,9 @@ fname:
preload_leading_step1 mask_bpp, WK2, MASK
preload_leading_step1 dst_r_bpp, WK3, DST
- tst DST, #15
+ ands WK0, DST, #15
beq 154f
- rsb WK0, DST, #0 /* bits 0-3 = number of leading bytes until
destination aligned */
- .if (src_bpp != 0 && src_bpp != 2*dst_w_bpp) || (mask_bpp != 0 && mask_bpp
!= 2*dst_w_bpp)
- PF and, WK0, WK0, #15
- .endif
+ rsb WK0, WK0, #16 /* number of leading bytes until destination
aligned */
preload_leading_step2 src_bpp, src_bpp_shift, WK1, SRC
preload_leading_step2 mask_bpp, mask_bpp_shift, WK2, MASK
@@ -787,9 +784,9 @@ fname:
preload_line 0, dst_r_bpp, dst_bpp_shift, DST
sub X, X, #128/dst_w_bpp /* simplifies inner loop termination
*/
- tst DST, #15
+ ands WK0, DST, #15
beq 164f
- rsb WK0, DST, #0 /* bits 0-3 = number of leading bytes until
destination aligned */
+ rsb WK0, WK0, #16 /* number of leading bytes until destination
aligned */
leading_15bytes process_head, process_tail
--
1.8.3.2
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