diff options
Diffstat (limited to 'arch/arm/lib/memzero.S')
| -rw-r--r-- | arch/arm/lib/memzero.S | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/lib/memzero.S b/arch/arm/lib/memzero.S index abf2508e822..b8f79d80ee9 100644 --- a/arch/arm/lib/memzero.S +++ b/arch/arm/lib/memzero.S @@ -39,6 +39,9 @@ ENTRY(__memzero) */ cmp r1, #16 @ 1 we can skip this chunk if we blt 4f @ 1 have < 16 bytes + +#if ! CALGN(1)+0 + /* * We need an extra register for this loop - save the return address and * use the LR @@ -64,6 +67,47 @@ ENTRY(__memzero) stmneia r0!, {r2, r3, ip, lr} @ 4 ldr lr, [sp], #4 @ 1 +#else + +/* + * This version aligns the destination pointer in order to write + * whole cache lines at once. + */ + + stmfd sp!, {r4-r7, lr} + mov r4, r2 + mov r5, r2 + mov r6, r2 + mov r7, r2 + mov ip, r2 + mov lr, r2 + + cmp r1, #96 + andgts ip, r0, #31 + ble 3f + + rsb ip, ip, #32 + sub r1, r1, ip + movs ip, ip, lsl #(32 - 4) + stmcsia r0!, {r4, r5, r6, r7} + stmmiia r0!, {r4, r5} + movs ip, ip, lsl #2 + strcs r2, [r0], #4 + +3: subs r1, r1, #64 + stmgeia r0!, {r2-r7, ip, lr} + stmgeia r0!, {r2-r7, ip, lr} + bgt 3b + ldmeqfd sp!, {r4-r7, pc} + + tst r1, #32 + stmneia r0!, {r2-r7, ip, lr} + tst r1, #16 + stmneia r0!, {r4-r7} + ldmfd sp!, {r4-r7, lr} + +#endif + 4: tst r1, #8 @ 1 8 bytes or more? stmneia r0!, {r2, r3} @ 2 tst r1, #4 @ 1 4 bytes or more? |