16 bit load generated in z80 mode

[hansake]

When compiling a very simple test program for z80 an incorrect 16 bit indexed load is generated by the compiler.
This was correct in earlier version.

The test program:

/* Very very simple test program: testz80.c
 */
int main() {
    int a , b, c;

    b = 1;
    c = 2;
    a = b + c;
    return (a);
}

Compiled with:

$ ez80-clang --target=z80 -S testz80.c

gave in a previous release this output:

        section	.text,"ax",@progbits
	section	.text,"ax",@progbits
	public	_main
_main:
	push	ix
	ld	ix, 0
	add	ix, sp
	ld	hl, -8
	add	hl, sp
	ld	sp, hl
	ld	hl, 0
	ld	de, 1
	ld	bc, 2
	ld	(ix + -2), l
	ld	(ix + -1), h
	ld	(ix + -6), e
	ld	(ix + -5), d
	ld	(ix + -8), c
	ld	(ix + -7), b
	ld	l, (ix + -6)
	ld	h, (ix + -5)
	ld	e, (ix + -8)
	ld	d, (ix + -7)
	add	hl, de
	ld	(ix + -4), l
	ld	(ix + -3), h
	ld	l, (ix + -4)
	ld	h, (ix + -3)
	ld	iy, 8
	add	iy, sp
	ld	sp, iy
	pop	ix
	ret
	section	.text,"ax",@progbits

	ident	"clang version 13.0.0 (https://github.com/jacobly0/llvm-project.git d270916c9cf31e630cc9ef215671a0d1c56280f8)"
	extern	__Unwind_SjLj_Register
	extern	__Unwind_SjLj_Unregister

and in the latest release I cloned and compiled, the following assembler output is generated.

	section	.text,"ax",@progbits
	section	.text,"ax",@progbits
	public	_main
_main:
	push	ix
	ld	ix, 0
	add	ix, sp
	ld	hl, -8
	add	hl, sp
	ld	sp, hl
	ld	hl, 0
	ld	de, 1
	ld	bc, 2
	ld	(ix - 2), l
	ld	(ix - 1), h
	ld	(ix - 6), e
	ld	(ix - 5), d
	ld	(ix - 8), c
	ld	(ix - 7), b
	ld	l, (ix - 6)
	ld	h, (ix - 5)
	ld	e, (ix - 8)
	ld	d, (ix - 7)
	add	hl, de
	ld	(ix - 4), l
	ld	(ix - 3), h
	ld	hl, (ix - 4) <--- incorrect instruction
	ld	iy, 8
	add	iy, sp
	ld	sp, iy
	pop	ix
	ret
	section	.text,"ax",@progbits

	ident	"clang version 13.0.0 (https://github.com/jacobly0/llvm-project.git a25003f240988428e2fad6f77f25d9b600c59b5e)"
	extern	__Unwind_SjLj_Register
	extern	__Unwind_SjLj_Unregister

The instruction that upsets the assembler (z80-elf-as) is:

	ld	hl, (ix - 4)

which is correctly generated in an earlier release as:

	ld	l, (ix + -4)
	ld	h, (ix + -3)

Unfortunately Z80 and Z180 can't make a 16 bit indexed load.

Another thing that z80-elf-as don't understand is:

	public	_main

but that was fixed with a sed script used by the Makefile:

...Makefile
# Define a pattern rule that compiles every .c file into a .o file
%.o : %.c
	ez80-clang --target=z180 -S -o $<.is $<
	sed -f asmscript.sed $<.is >  $<.s
	z80-elf-as -march=z180 -o $@ $<.s
	rm $<.is $<.s
...asmscript.sed
s/\tpublic/\tglobal/

[jacobly0]

Sorry, I was in the middle of moving and forgot to fix this.

[hansake]

Works good now. Thanks.