rules.386

# Rules to optimize BCC assembler output for 386

# Many of these rules are very broken, ho hum.

# Rules for loading a long constant

xor	ax,ax
xor	%[bx|si|di]1,%[bx|si|di]1
=
xor	eax,eax

xor	eax,eax
mov	%[ebx|ecx|edx]1,eax
=
xor	%1,%1

xor	ax,ax
mov	%[bx|si|di]*,%[*|#]0%1
=
mov	eax,%0%1<<16

mov	ax,%[*|#]0%1
xor	%[bx|si|di]2,%[bx|si|di]2
=
mov	eax,%0%1 & $0000FFFF

mov	ax,%0[%1]
xor	%[bx|si|di]2,%[bx|si|di]2
=
movzx	eax,word ptr %0[%1]

mov	ax,%[si|di]1
xor	bx,bx
=
movzx	eax,%1

%[movzx|movsx]5	eax,%1
mov	%[ebx|ecx|edx]2,eax
=
%5	%2,%1

%[movzx|movsx]5	%[ebx|ecx|edx]1,%2
mov	eax,%[#|*]0%3
%[add|and|xor|or]4	eax,%[ebx|ecx|edx]1
=
%5	eax,%2
%4	eax,%0%3

mov	ax,%0[%1]
cwde
=
movsx	eax,word ptr %0[%1]

mov	ax,%[si|di]1
cwde
=
movsx	eax,%1

mov	ax,%[#|*]3%1
mov	%[bx|si|di]*,%[#|*]4%2
=
mov	eax,%4%2<<16 + %1


# Rules for pushing variables and constants onto the stack

push	%![dword ptr]%1[%[bx|si|di|bp]3]
push	%![dword ptr]%(%1-2)[%[bx|si|di|bp]3]
=
push	dword ptr %(%1-2)[%3]

push	[%1+2]
push	[%1]
=
push	dword ptr [%1]

push	%[bx|si|di]*
push	ax
=
push	eax

mov	eax,%[#|*]0%1
push	eax
=
push	dword %0%1

mov	%1,%[eax|ebx|ecx|edx]2
push	dword ptr %1
=
mov	%1,%2
push	%2


# Rules for loading long variables

mov	ax,[%1]
mov	%[bx|si|di]*,[%1+2]
=
mov	eax,[%1]

mov	ax,%1[%[bx|si|di|bp]3]
mov	%[bx|si|di]*,%(%1+2)[%[bx|si|di|bp]3]
=
mov	eax,%1[%3]

mov	ax,#%1[bx]
mov	%[bx|si|di]*,#%1+2[bx]
=
mov	eax,#%1[bx]

mov	[%1],ax
mov	[%1+2],%[bx|si|di]*
=
mov	[%1],eax

mov	[%1+%3],ax
mov	[%1+%(%3+2)],%[bx|si|di]*
=
mov	[%1+%3],eax

mov	%1[%[si|di|bp]3],ax
mov	%(%1+2)[%[si|di|bp]3],%[bx|si|di]*
=
mov	%1[%3],eax

mov	#%1[bx],ax
mov	#%1+2[bx],%[bx|si|di]*
=
mov	#%1[bx],eax

mov	eax,%[#|*]0%1
mov	%![dword ptr]%3[%2],eax
=
mov	dword ptr %3[%2],%0%1

xor	ax,ax
xor	%[bx|si|di]3,%[bx|si|di]3
mov	%1[%[bx|bp]4],ax
mov	%(%1+2)[%[bx|bp]4],%[bx|si|di]3
=
mov	dword ptr %1[%4],#0

mov	ax,%1
mov	%[bx|si|di]5,%2
mov	%3[%[bx|bp]6],ax
mov	%(%3+2)[%[bx|bp]6],%[bx|si|di]5
=
mov	eax,dword ptr %1
mov	dword ptr %3[%6],eax


# Long return values are in EAX, so we can skip dx

mov	dx,bx
add	sp,*%1
=
add	sp,*%1


# Rules for manipulating long values

call	%1
mov	bx,dx
=
call	%1

call	l%[tstu|tst]*l
=
test	eax,eax

call	l%[comu|com]*l
=
not	eax

mov	eax,eax
%1
=
%1

mov	%2,%[eax|ebx|ecx|edx]1
mov	%[eax|ebx|ecx|edx]1,%2
=
mov	%2,%1

cwd
mov	bx,dx
=
cwde

mov	%[ebx|ecx|edx]0,%1
mov	eax,%2
%3	eax,%[ebc|ecx|edx]0
=
mov	eax,%2
%3	eax,%1

%[movzx|movsx|mov]0	%[eax|ebx|ecx|edx]2,%4
%[add|and|xor|sub|or]1	%[eax|ebx|ecx|edx]2,%6
mov	%6,%[eax|ebx|ecx|edx]2
=
%0	%2,%4
%1	%6,%2

mov	eax,%[#|*]0%1
cmp	eax,%2
%[jbe |jae |jne |jge |jle ]3	%4
=
cmp	dword ptr %2,%0%1
%=[jbe |jae |jne |jge |jle ][jae |jbe |jne |jle |jge ]3	%4

mov	eax,%[#|*]0%1
cmp	eax,%2
%[jb  |ja  |je  |jg  |jl  ]3	%4
=
cmp	dword ptr %2,%0%1
%=[jb  |ja  |je  |jg  |jl  ][ja  |jb  |je  |jl  |jg  ]3	%4

mov	eax,%1[%3]
cmp	eax,dword %[#|*]0%2
=
cmp	dword ptr %1[%3],%0%2


# Rules for calling the bcc library routines.

push	%1
push	%2
mov	eax,%3[bp]
%4	eax,%(%3-4)[bp]
add	sp,*8
=
mov	edx,%2
mov	eax,%1
%4	eax,edx

push	%1
mov	eax,%2
push	eax
mov	eax,%3[bp]
%4	eax,%(%3-4)[bp]
add	sp,*8
=
mov	edx,%2
mov	eax,%1
%4	eax,edx

push	%1
xor	eax,eax
push	eax
mov	eax,%2[bp]
%3	eax,%(%2-4)[bp]
add	sp,*8
=
mov	eax,%1
%3	eax,#0

push	%1
mov	eax,%2
%3	eax,%4[bp]
add	sp,*4
=
mov	edx,%1
mov	eax,%2
%3	eax,edx

push	%1
mov	eax,%2
%3	eax,%4[bp]
mov	%2,eax
add	sp,*4
=
mov	edx,%1
%3	%2,edx


push	%1
push	%2
mov	eax,%3[bp]
%4	eax,%(%3-4)[bp]
lea	sp,%(%3+4)[bp]
=
mov	edx,%2
mov	eax,%1
%4	eax,edx

push	%1
mov	eax,%2
push	eax
mov	eax,%3[bp]
%4	eax,%(%3-4)[bp]
lea	sp,%(%3+4)[bp]
=
mov	edx,%2
mov	eax,%1
%4	eax,edx

push	%1
xor	eax,eax
push	eax
mov	eax,%2[bp]
%3	eax,%(%2-4)[bp]
lea	sp,%(%2+4)[bp]
=
mov	eax,%1
%3	eax,#0

push	%1
mov	eax,%2
%3	eax,%4[bp]
lea	sp,%(%4+4)[bp]
=
mov	edx,%1
mov	eax,%2
%3	eax,edx


# Rules for calling the basic bcc library routines.

mov	di,#%2
call	l%3%[ul|l]*
=
%3	eax,[%2]

mov	di,*%2
call	lsll
=
lsl	eax,*%2

lea	di,%2
call	l%3%[ul|l]*
=
%3	eax,%2

mov	di,%[si|di]1
call	l%3%[ul|l]*
=
%3	eax,[%1]

mov	di,%[ax|bx|cx|dx]1
call	l%3%[ul|l]*
=
mov	di,%[ax|bx|cx|dx]1
%3	eax,[di]


# Rules for pushing short values

mov	%[ax|bx|cx|dx|si|di]2,%0[%1]
push	%[ax|bx|cx|dx|si|di]2
=
push	word ptr %0[%1]

mov	%[ax|bx|cx|dx|si|di]2,%[#|*]0%1
push	%[ax|bx|cx|dx|si|di]2
=
push	%0%1


# Shifting rules

%[shl|shr]2	%1,*1
%[shl|shr]2	%1,*1
=
%2	%1,*2

mov	cl,*%1
%[shl|shr]2	%3,cl
=
%2	%3,*%1

mov	dx,ax
shl	ax,*%1
add	ax,dx
shl	ax,*%2
=
mov	dx,ax
imul	ax,*%(1<%1+1<%2)

mov	dx,ax
imul	ax,*%1
add	ax,dx
=
mov	dx,ax
imul	ax,*%(%1+1)

mov	dx,ax
imul	ax,*%1
shl	ax,*%2
=
mov	dx,ax
imul	ax,*%(%1<%2)

mov	ax,%![#|*]%4
mov	dx,ax
imul	ax,*%1
%[add|and|xor|sub|or]2	ax,%![dx]%3
=
imul	ax,%4,*%1
%2	ax,%3

mov	ax,%![#|*]%4
mov	dx,ax
imul	ax,*%1
push	ax
=
imul	ax,%4,*%1
push	ax

imul	ax,%2,%[#|*]0%1
add	ax,%3
mov	bx,ax
=
imul	bx,%2,%0%1
add	bx,%3


# Different rules

%1	dword ptr %[eax|ebx|ecx|edx]3,*%2
=
%1	%3,*%2

%1	dword ptr %[eax|ebx|ecx|edx]3,#%2
=
%1	%3,#%2

eor	%1,%2
=
xor	%1,%2

com	%1
=
not	%1

xor	bx,bx
=
and	eax,#$0000FFFF