--- /dev/null
+/*
+ * Copyright © 2008 Mozilla Corporation
+ * Copyright © 2010 Nokia Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of Mozilla Corporation not be used in
+ * advertising or publicity pertaining to distribution of the software without
+ * specific, written prior permission. Mozilla Corporation makes no
+ * representations about the suitability of this software for any purpose. It
+ * is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ *
+ * Author: Jeff Muizelaar (jeff@infidigm.net)
+ *
+ */
+
+/* Prevent the stack from becoming executable */
+#if defined(__linux__) && defined(__ELF__)
+.section .note.GNU-stack,"",%progbits
+#endif
+
+ .text
+ .arch armv6
+ .object_arch armv4
+ .arm
+ .altmacro
+ .p2align 2
+
+/* Supplementary macro for setting function attributes */
+.macro pixman_asm_function fname
+ .func fname
+ .global fname
+#ifdef __ELF__
+ .hidden fname
+ .type fname, %function
+#endif
+fname:
+.endm
+
+/*
+ * Note: This code is only using armv5te instructions (not even armv6),
+ * but is scheduled for ARM Cortex-A8 pipeline. So it might need to
+ * be split into a few variants, tuned for each microarchitecture.
+ *
+ * TODO: In order to get good performance on ARM9/ARM11 cores (which don't
+ * have efficient write combining), it needs to be changed to use 16-byte
+ * aligned writes using STM instruction.
+ *
+ * Nearest scanline scaler macro template uses the following arguments:
+ * fname - name of the function to generate
+ * bpp_shift - (1 << bpp_shift) is the size of pixel in bytes
+ * t - type suffix for LDR/STR instructions
+ * prefetch_distance - prefetch in the source image by that many
+ * pixels ahead
+ * prefetch_braking_distance - stop prefetching when that many pixels are
+ * remaining before the end of scanline
+ */
+
+.macro generate_nearest_scanline_func fname, bpp_shift, t, \
+ prefetch_distance, \
+ prefetch_braking_distance
+
+pixman_asm_function fname
+ W .req r0
+ DST .req r1
+ SRC .req r2
+ VX .req r3
+ UNIT_X .req ip
+ TMP1 .req r4
+ TMP2 .req r5
+ VXMASK .req r6
+ PF_OFFS .req r7
+ SRC_WIDTH_FIXED .req r8
+
+ ldr UNIT_X, [sp]
+ push {r4, r5, r6, r7, r8, r10}
+ mvn VXMASK, #((1 << bpp_shift) - 1)
+ ldr SRC_WIDTH_FIXED, [sp, #28]
+
+ /* define helper macro */
+ .macro scale_2_pixels
+ ldr&t TMP1, [SRC, TMP1]
+ and TMP2, VXMASK, VX, asr #(16 - bpp_shift)
+ adds VX, VX, UNIT_X
+ str&t TMP1, [DST], #(1 << bpp_shift)
+9: subpls VX, VX, SRC_WIDTH_FIXED
+ bpl 9b
+
+ ldr&t TMP2, [SRC, TMP2]
+ and TMP1, VXMASK, VX, asr #(16 - bpp_shift)
+ adds VX, VX, UNIT_X
+ str&t TMP2, [DST], #(1 << bpp_shift)
+9: subpls VX, VX, SRC_WIDTH_FIXED
+ bpl 9b
+ .endm
+
+ /* now do the scaling */
+ and TMP1, VXMASK, VX, asr #(16 - bpp_shift)
+ adds VX, VX, UNIT_X
+9: subpls VX, VX, SRC_WIDTH_FIXED
+ bpl 9b
+ subs W, W, #(8 + prefetch_braking_distance)
+ blt 2f
+ /* calculate prefetch offset */
+ mov PF_OFFS, #prefetch_distance
+ mla PF_OFFS, UNIT_X, PF_OFFS, VX
+1: /* main loop, process 8 pixels per iteration with prefetch */
+ pld [SRC, PF_OFFS, asr #(16 - bpp_shift)]
+ add PF_OFFS, UNIT_X, lsl #3
+ scale_2_pixels
+ scale_2_pixels
+ scale_2_pixels
+ scale_2_pixels
+ subs W, W, #8
+ bge 1b
+2:
+ subs W, W, #(4 - 8 - prefetch_braking_distance)
+ blt 2f
+1: /* process the remaining pixels */
+ scale_2_pixels
+ scale_2_pixels
+ subs W, W, #4
+ bge 1b
+2:
+ tst W, #2
+ beq 2f
+ scale_2_pixels
+2:
+ tst W, #1
+ ldrne&t TMP1, [SRC, TMP1]
+ strne&t TMP1, [DST]
+ /* cleanup helper macro */
+ .purgem scale_2_pixels
+ .unreq DST
+ .unreq SRC
+ .unreq W
+ .unreq VX
+ .unreq UNIT_X
+ .unreq TMP1
+ .unreq TMP2
+ .unreq VXMASK
+ .unreq PF_OFFS
+ .unreq SRC_WIDTH_FIXED
+ /* return */
+ pop {r4, r5, r6, r7, r8, r10}
+ bx lr
+.endfunc
+.endm
+
+generate_nearest_scanline_func \
+ pixman_scaled_nearest_scanline_0565_0565_SRC_asm_armv6, 1, h, 80, 32
+
+generate_nearest_scanline_func \
+ pixman_scaled_nearest_scanline_8888_8888_SRC_asm_armv6, 2, , 48, 32
Code Review / kvmfornfv.git / blobdiff