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!

! Fast SH memset

!

! by Toshiyasu Morita (tm@netcom.com)

!

! SH5 code by J"orn Rennecke (joern.rennecke@superh.com)

! Copyright 2002 SuperH Ltd.

!

#include "asm.h"

ENTRY(memset)

#if __SHMEDIA__

        pta/l multiquad, tr0

        ptabs r18, tr2

        andi r2, -8, r25

        add r2, r4, r5

        addi r5, -1, r20    // calculate end address.

        andi r20, -8, r20

        cmveq r4, r25, r20

        bne/u r25, r20, tr0 // multiquad

!       This sequence could clobber volatile objects that are in the same

!       quadword as a very short char array.

!       ldlo.q r2, 0, r7

!       shlli r4, 2, r4

!       movi -1, r8

!       SHHI r8, r4, r8

!       SHHI r8, r4, r8

!       mcmv r7, r8, r3

!       stlo.q r2, 0, r3

        pta/l setlongs, tr0

        movi 4, r8

        bgeu/u r4, r8, tr0

        pta/l endset, tr0

        beqi/u r4, 0, tr0

        st.b r2, 0, r3

        beqi/u r4, 1, tr0

        nop

        st.b r2, 1, r3

        beqi/l r4, 2, tr0

        st.b r2,2,r3

endset: blink tr2, r63

setlongs:

        mshflo.b r3, r3, r3

        mperm.w r3, r63, r3     // Fill pattern now in every byte of r3

        stlo.l r2, 0, r3

        nop

        nop

        sthi.l r5, -1, r3

        blink tr2, r63

multiquad:

        mshflo.b r3, r3, r3

        mperm.w r3, r63, r3     // Fill pattern now in every byte of r3

        pta/l lastquad, tr0

        stlo.q r2, 0, r3

        sub r20, r25, r24

        movi 64, r9

        beqi/u r24, 8, tr0 // lastquad

        pta/l loop, tr1

        addi r20, -7*8, r8 // loop end address; This might overflow, so we need

                           // to use a different test before we start the loop

        bgeu/u r24, r9, tr1// loop

        st.q r25, 8, r3

        shlri r24, 4, r24

        st.q r20, -8, r3

        beqi/u r24, 1, tr0 // lastquad

        st.q r25, 16, r3

        st.q r20, -16, r3

        beqi/u r24, 2, tr0 // lastquad

        st.q r25, 24, r3

        st.q r20, -24, r3

lastquad:

        sthi.q r5, -1, r3

        blink tr2,r63

loop:

        alloco r25, 32

        st.q r25, 8, r3

        st.q r25, 16, r3

        st.q r25, 24, r3

        st.q r25, 32, r3

        addi r25, 32, r25

        bgeu/l r8, r25, tr1 // loop

        st.q r20, -40, r3

        st.q r20, -32, r3

        st.q r20, -24, r3

        st.q r20, -16, r3

        st.q r20, -8, r3

        sthi.q r5, -1, r3

        blink tr2,r63

#else /* ! SHMEDIA, i.e. SH1 .. SH4 / SHcompact */

! Entry: r4: destination pointer

!        r5: fill value

!        r6: byte count

!

! Exit:  r0-r3: trashed

!

! This assumes that the first four bytes of the address space (0..3) are

! reserved - usually by the linker script.  Otherwise, we would had to check

! for the case of objects of the size 12..15 at address 0..3 .

#ifdef __SH5__

#define DST r2

#define VAL r3

#define CNT r4

#define TMP r5

#else

#define DST r4

#define VAL r5

#define CNT r6

#define TMP r2

#endif

        mov     #12,r0  ! Check for small number of bytes

        cmp/gt  CNT,r0

        mov     DST,r0

        SL(bt, L_store_byte_loop_check0, add DST,CNT)

        tst     #3,r0   ! Align destination

        SL(bt,  L_dup_bytes, extu.b r5,r5)

        .balignw 4,0x0009

L_align_loop:

        mov.b   VAL,@r0

        add     #1,r0

        tst     #3,r0

        bf      L_align_loop

L_dup_bytes:

        swap.b  VAL,TMP ! Duplicate bytes across longword

        or      TMP,VAL

        swap.w  VAL,TMP

        or      TMP,VAL

        add     #-16,CNT

        .balignw 4,0x0009

L_store_long_loop:

        mov.l   VAL,@r0 ! Store double longs to memory

        cmp/hs  CNT,r0

        mov.l   VAL,@(4,r0)

        SL(bf, L_store_long_loop, add #8,r0)

        add     #16,CNT

L_store_byte_loop_check0:

        cmp/eq  CNT,r0

        bt      L_exit

        .balignw 4,0x0009

L_store_byte_loop:

        mov.b   VAL,@r0 ! Store bytes to memory

        add     #1,r0

        cmp/eq  CNT,r0

        bf      L_store_byte_loop

L_exit:

        rts

        mov     r4,r0

#endif /* ! SHMEDIA */