MIPS floating point problem

[Ken Faiczak]

We are compiling our code for MIPS R5K -mips3
using -mfp32 (since the exception handling code for 
 some instructions that can't be handled in hardware
 assumes fp32) - but otherwise its mips64 calling convention

Target is mips-vxworks-elf

Using builtin specs.
gcc version egcs-2.93.08 19990219 (gcc2 ss-980929 experimental)

-EL -mips3 -mcpu=r4000 -non_shared -G 0 -mfp32 -ansi -nostdinc -O2
-funroll-loops -fno-for-scope -fno-builtin -DMIPSEL -fsjlj-exceptions

The calling convention gets completely messed up
it looks like it is using the mips64 flag to generate the floating
point calls but fp32 in other places.


0000000000007f40 <testf1__Fv>:
    7f40:	27bdffd0 	addiu	$sp,$sp,-48
    7f44:	f7b40028 	sdc1	$f20,40($sp)
    7f48:	3c010000 	lui	$at,0x0
    7f4c:	d4340f30 	ldc1	$f20,3888($at)
    7f50:	ffbf0020 	sd	$ra,32($sp)
    7f54:	4620a306 	mov.d	$f12,$f20
    7f58:	0c001fe0 	jal	7f80 <testf2__Fdd>
    7f5c:	4620a346 	mov.d	$f13,$f20			-->
should be moved to $f14 (overwrites f12/f13)
	
(and with fp32 the SR_FR bit is clear and this
	
is illegal)
    7f60:	4404a000 	mfc1	$a0,$f20
    7f64:	4405a800 	mfc1	$a1,$f21
    7f68:	0c001ff2 	jal	7fc8 <testf3__Fde>
    7f6c:	0080282d 	move	$a1,$a0			--> should
fill in a2/a3 with other arg
	
this is overwriting part of the first arg
    7f70:	dfbf0020 	ld	$ra,32($sp)
    7f74:	d7b40028 	ldc1	$f20,40($sp)
    7f78:	03e00008 	jr	$ra
    7f7c:	27bd0030 	addiu	$sp,$sp,48

0000000000007f80 <testf2__Fdd>:
    7f80:	27bdffd0 	addiu	$sp,$sp,-48
    7f84:	44056000 	mfc1	$a1,$f12		-> first arg
pulled off ok (f12/f13)
    7f88:	44066800 	mfc1	$a2,$f13
    7f8c:	3c040000 	lui	$a0,0x0
    7f90:	64840f38 	daddiu	$a0,$a0,3896
    7f94:	f7b40028 	sdc1	$f20,40($sp)
    7f98:	ffbf0020 	sd	$ra,32($sp)
    7f9c:	0c000000 	jal	0
<_pdbPCIEncInstanceAddNodes__FUiPCcN21>
    7fa0:	46206d06 	mov.d	$f20,$f13		-> second
arg pulled off wrong (should be in f14/f15)
    7fa4:	4405a000 	mfc1	$a1,$f20
    7fa8:	4406a800 	mfc1	$a2,$f21
    7fac:	3c040000 	lui	$a0,0x0
    7fb0:	0c000000 	jal	0
<_pdbPCIEncInstanceAddNodes__FUiPCcN21>
    7fb4:	64840f48 	daddiu	$a0,$a0,3912
    7fb8:	dfbf0020 	ld	$ra,32($sp)
    7fbc:	d7b40028 	ldc1	$f20,40($sp)
    7fc0:	03e00008 	jr	$ra
    7fc4:	27bd0030 	addiu	$sp,$sp,48

0000000000007fc8 <testf3__Fde>:				--> other errors are
in this as well
    7fc8:	ffa50008 	sd	$a1,8($sp)
    7fcc:	ffa60010 	sd	$a2,16($sp)
    7fd0:	ffa70018 	sd	$a3,24($sp)
    7fd4:	27bdffd0 	addiu	$sp,$sp,-48
    7fd8:	27a2003f 	addiu	$v0,$sp,63
    7fdc:	2403fff8 	li	$v1,-8
    7fe0:	00431024 	and	$v0,$v0,$v1
    7fe4:	ffbf0020 	sd	$ra,32($sp)
    7fe8:	f7b40028 	sdc1	$f20,40($sp)
    7fec:	ffa40030 	sd	$a0,48($sp)
    7ff0:	d4540000 	ldc1	$f20,0($v0)
    7ff4:	44840000 	mtc1	$a0,$f0
    7ff8:	44850800 	mtc1	$a1,$f1
    7ffc:	00000000 	nop
    8000:	44050000 	mfc1	$a1,$f0
    8004:	44060800 	mfc1	$a2,$f1
    8008:	3c040000 	lui	$a0,0x0
    800c:	0c000000 	jal	0
<_pdbPCIEncInstanceAddNodes__FUiPCcN21>
    8010:	64840f38 	daddiu	$a0,$a0,3896
    8014:	4405a000 	mfc1	$a1,$f20
    8018:	4406a800 	mfc1	$a2,$f21
    801c:	3c040000 	lui	$a0,0x0
    8020:	0c000000 	jal	0
<_pdbPCIEncInstanceAddNodes__FUiPCcN21>
    8024:	64840f48 	daddiu	$a0,$a0,3912
    8028:	dfbf0020 	ld	$ra,32($sp)
    802c:	d7b40028 	ldc1	$f20,40($sp)
    8030:	03e00008 	jr	$ra
    8034:	27bd0030 	addiu	$sp,$sp,48

------------------------------------



void testf2(double d, double e);
void testf3(double d,...);
int testf1(void)
{
    double d;
    d = 99.88;
    testf2(d,d);
    testf3(d,d);
}

void testf2(double d, double e)
{
    printf("testf2 d = %e\n", d);
    printf("testf2 e = %e\n", e);
}
void testf3(double d,...)
{
    va_list  p;
    double   e;
    va_start(p, d);

    e = va_arg(p, double);
    printf("testf2 d = %e\n", d);
    printf("testf2 e = %e\n", e);
    va_end(p);
}

_______________________________________________________________
Ken Faiczak                        PixStream Incorporated
ken@pixstream.com                  180 Columbia St. West
(519) 884-4196 x2234               Waterloo Ontario, Canada
fax:(519) 884-5949                 N2L 3L3