Am 08.04.19 um 22:45 schrieb Klaus Brandl:
> Hi,
>
> i think i found two bugs in the z80 port:
>
> buggy.c:
> __sfr __banked __at 0xf500 SPI_PORT_IN;
>
> struct {
> unsigned char SDHC : 1;
> unsigned char FAT32 : 1;
> } SDFlags;
>
> int main () {
> SDFlags.SDHC = (SPI_PORT_IN & 0x40) ? 1 : 0;
> return(SDFlags.SDHC);
> }
>
> compiles to:
> 53 ;buggy.c:9: SDFlags.SDHC = (SPI_PORT_IN
> & 0x40) ? 1 : 0;
> 0000 3E F5 [ 7] 54 ld a,#>(_SPI_PORT_IN)
> 0002 DB 00 [11] 55 in a,(#<(_SPI_PORT_IN))
>
> SPI_PORT_IN should be:
> ld bc,#SPI_PORT_IN
> in a,(c)The generated code here looks correct to me. From the Zilog Z80 user manual, description of in a,(n): "The operand n is placed on the bottom half (A0 through A7) of the address bus to select the I/O device at one of 256 possible ports. The contents of the Accumulator also appear on the top half (A8 through A15) of the address bus at this time." > > 0004 E6 40 [ 7] 56 and a, #0x40 > 0006 21r00r00 [10] 57 ld hl,#_SDFlags > 0009 E6 01 [ 7] 58 and a,#0x01 > > What is this? It makes "a" broken. > > 000B 4F [ 4] 59 ld c,a > 000C 7E [ 7] 60 ld a,(hl) > 000D E6 FE [ 7] 61 and a,#0xFE > 000F B1 [ 4] 62 or a,c > 0010 77 [ 7] 63 ld (hl),a > > I think, it should be: > ld hl,#_SDFlags > ld c,a > ld a,(hl) > bit 6,c > jr z,zero > or a,#0x01 > jr save > zero: and a,#0xFE > save: ld (hl),a > > (or so...) > I cannot reproduce this issue. Using SDCC 3.8.7 #11188 I get: 0000 3E F5 [ 7] 53 ld a, #>(_SPI_PORT_IN) 0002 DB 00 [11] 54 in a, (#<(_SPI_PORT_IN)) 0004 CB 77 [ 8] 55 bit 6, a 0006 28 05 [12] 56 jr Z,00103$ 0008 01 01 00 [10] 57 ld bc, #0x0001 000B 18 03 [12] 58 jr 00104$ 000D 59 00103$: 000D 01 00 00 [10] 60 ld bc, #0x0000 0010 61 00104$: 0010 79 [ 4] 62 ld a, c 0011 21r00r00 [10] 63 ld hl, #_SDFlags 0014 E6 01 [ 7] 64 and a, #0x01 0016 4F [ 4] 65 ld c, a 0017 7E [ 7] 66 ld a, (hl) 0018 E6 FE [ 7] 67 and a, #0xfe 001A B1 [ 4] 68 or a, c 001B 77 [ 7] 69 ld (hl), a 001C 3Ar00r00 [13] 71 ld a,(#_SDFlags + 0) 001F E6 01 [ 7] 72 and a, #0x01 0021 6F [ 4] 73 ld l, a 0022 26 00 [ 7] 74 ld h, #0x00 0024 C9 [10] 76 ret Which looks correct, though not particularly efficient. Philipp
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