From: notaz Date: Mon, 10 Jun 2013 23:36:32 +0000 (+0300) Subject: handle src buffer underflow corner cases X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=edd481ef690995dec3626f0f0c5580db9d2dd600;p=sdl_omap.git handle src buffer underflow corner cases --- diff --git a/src/video/SDL_blit_neon.S b/src/video/SDL_blit_neon.S index 344ae05..979bb2a 100644 --- a/src/video/SDL_blit_neon.S +++ b/src/video/SDL_blit_neon.S @@ -19,7 +19,12 @@ .macro do_argb bgr2rgb vdup.i8 d0, r3 0: + cmp r2, #8 + pld [r1, #64*2] + blt 3f +1: vld4.8 {d4-d7}, [r1]! +2: .if \bgr2rgb vswp d4, d6 @ BGR->RGB .endif @@ -30,6 +35,23 @@ bxeq lr nop b 0b + +3: + @ unaligned ending nastiness :( + add r12, r1, #8*4 + lsr r12, #12 + cmp r12, r1, lsr #12 @ crossing page? + beq 1b @ nope, overreading is safe + + @ _wb_'s bad luck, do some slow stuff here + push {r0-r2,lr} + sub sp, #8*4 + mov r0, sp + lsl r2, #2 + bl memcpy + vld4.8 {d4-d7}, [sp]! + pop {r0-r2,lr} + b 2b .endm @ void *dst, const void *src, int count, uint global_alpha @@ -39,11 +61,16 @@ vdup.16 q11, r3 .endif vdup.i16 q12, r12 + 0: pld [r1, #64*2] + cmp r2, #8 pld [r0, #64*2] + blt 3f +1: vld4.8 {d4-d7}, [r1]! vld4.8 {d0-d3}, [r0] +2: .if \bgr2rgb vswp d4, d6 @ BGR->RGB .endif @@ -69,6 +96,35 @@ bxeq lr nop b 0b + +3: + @ unaligned ending nastiness :( + add r3, r0, #8*4 + add r12, r1, #8*4 + lsr r3, #12 + lsr r12, #12 + cmp r3, r0, lsr #12 @ are we crossing + cmpeq r12, r1, lsr #12 @ the page boundary? + beq 1b @ nope, overreading is safe + + @ _wb_'s bad luck, do some slow stuff here + push {r0-r2, lr} + vpush {q11, q12} + sub sp, #8*4*2 + lsl r2, #2 + mov r1, r0 + mov r0, sp + bl memcpy + ldr r2, [sp, #8*4*2 + 16*2 + 8] @ stacked r2 + add r0, sp, #8*4 + ldr r1, [sp, #8*4*2 + 16*2 + 4] + lsl r2, #2 + bl memcpy + vld4.8 {d0-d3}, [sp]! + vld4.8 {d4-d7}, [sp]! + vpop {q11, q12} + pop {r0-r2, lr} + b 2b .endm @@ -109,7 +165,10 @@ do_argb_finish: vdup.i16 q12, r12 0: pld [r1, #64*2] + cmp r2, #8 pld [r0, #64*2] + blt 3f +1: vld4.8 {d4-d7}, [r1]! vld2.8 {d1-d2}, [r0] .if \bgr2rgb @@ -146,6 +205,19 @@ do_argb_finish: bxeq lr nop b 0b + +3: + @ unaligned ending nastiness :( + add r3, r0, #8*2 + add r12, r1, #8*4 + lsr r3, #12 + lsr r12, #12 + cmp r3, r0, lsr #12 @ are we crossing + cmpeq r12, r1, lsr #12 @ the page boundary? + beq 1b @ nope, overreading is safe + + nop + bx lr @ abandon ship! (until someone complains) .endm