/* libs/pixelflinger/t32cb16blend.S
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
.text
.syntax unified
.balign 4
.global scanline_t32cb16blend_arm
/*
* .macro pixel
*
* \DREG is a 32-bit register containing *two* original destination RGB565
* pixels, with the even one in the low-16 bits, and the odd one in the
* high 16 bits.
*
* \SRC is a 32-bit 0xAABBGGRR pixel value, with pre-multiplied colors.
*
* \FB is a target register that will contain the blended pixel values.
*
* \ODD is either 0 or 1 and indicates if we're blending the lower or
* upper 16-bit pixels in DREG into FB
*
*
* clobbered: r6, r7, lr
*
*/
.macro pixel, DREG, SRC, FB, ODD
// SRC = 0xAABBGGRR
mov r7, \SRC, lsr #24 // sA
add r7, r7, r7, lsr #7 // sA + (sA >> 7)
rsb r7, r7, #0x100 // sA = 0x100 - (sA+(sA>>7))
1:
.if \ODD
// red
mov lr, \DREG, lsr #(16 + 11)
smulbb lr, r7, lr
mov r6, \SRC, lsr #3
and r6, r6, #0x1F
add lr, r6, lr, lsr #8
cmp lr, #0x1F
orrhs \FB, \FB, #(0x1F<<(16 + 11))
orrlo \FB, \FB, lr, lsl #(16 + 11)
// green
and r6, \DREG, #(0x3F<<(16 + 5))
smulbt r6, r7, r6
mov lr, \SRC, lsr #(8+2)
and lr, lr, #0x3F
add r6, lr, r6, lsr #(5+8)
cmp r6, #0x3F
orrhs \FB, \FB, #(0x3F<<(16 + 5))
orrlo \FB, \FB, r6, lsl #(16 + 5)
// blue
and lr, \DREG, #(0x1F << 16)
smulbt lr, r7, lr
mov r6, \SRC, lsr #(8+8+3)
and r6, r6, #0x1F
add lr, r6, lr, lsr #8
cmp lr, #0x1F
orrhs \FB, \FB, #(0x1F << 16)
orrlo \FB, \FB, lr, lsl #16
.else
// red
mov lr, \DREG, lsr #11
and lr, lr, #0x1F
smulbb lr, r7, lr
mov r6, \SRC, lsr #3
and r6, r6, #0x1F
add lr, r6, lr, lsr #8
cmp lr, #0x1F
movhs \FB, #(0x1F<<11)
movlo \FB, lr, lsl #11
// green
and r6, \DREG, #(0x3F<<5)
smulbb r6, r7, r6
mov lr, \SRC, lsr #(8+2)
and lr, lr, #0x3F
add r6, lr, r6, lsr #(5+8)
cmp r6, #0x3F
orrhs \FB, \FB, #(0x3F<<5)
orrlo \FB, \FB, r6, lsl #5
// blue
and lr, \DREG, #0x1F
smulbb lr, r7, lr
mov r6, \SRC, lsr #(8+8+3)
and r6, r6, #0x1F
add lr, r6, lr, lsr #8
cmp lr, #0x1F
orrhs \FB, \FB, #0x1F
orrlo \FB, \FB, lr
.endif
.endm
// r0: dst ptr
// r1: src ptr
// r2: count
// r3: d
// r4: s0
// r5: s1
// r6: pixel
// r7: pixel
// r8: free
// r9: free
// r10: free
// r11: free
// r12: scratch
// r14: pixel
scanline_t32cb16blend_arm:
stmfd sp!, {r4-r7, lr}
pld [r0]
pld [r1]
// align DST to 32 bits
tst r0, #0x3
beq aligned
subs r2, r2, #1
ldmfdlo sp!, {r4-r7, lr} // return
bxlo lr
last:
ldr r4, [r1], #4
ldrh r3, [r0]
pixel r3, r4, r12, 0
strh r12, [r0], #2
aligned:
subs r2, r2, #2
blo 9f
// The main loop is unrolled twice and processes 4 pixels
8: ldmia r1!, {r4, r5}
// stream the source
pld [r1, #32]
add r0, r0, #4
// it's all zero, skip this pixel
orrs r3, r4, r5
beq 7f
// load the destination
ldr r3, [r0, #-4]
// stream the destination
pld [r0, #32]
pixel r3, r4, r12, 0
pixel r3, r5, r12, 1
// effectively, we're getting write-combining by virtue of the
// cpu's write-back cache.
str r12, [r0, #-4]
// 2nd iterration of the loop, don't stream anything
subs r2, r2, #2
movlt r4, r5
blt 9f
ldmia r1!, {r4, r5}
add r0, r0, #4
orrs r3, r4, r5
beq 7f
ldr r3, [r0, #-4]
pixel r3, r4, r12, 0
pixel r3, r5, r12, 16
str r12, [r0, #-4]
7: subs r2, r2, #2
bhs 8b
mov r4, r5
9: adds r2, r2, #1
ldmfdlo sp!, {r4-r7, lr} // return
bxlo lr
b last
