[rfa:ppc] Fix PPC/NBSD struct return; Was: userdef.exp regression for ppc?

[Jason R Thorpe]

On Sun, Jun 02, 2002 at 09:20:43PM -0400, Kevin B. Hendricks wrote:

 > 1. How are you currently handling the case when you call a function with 
 > more than 8 floating point (not double) values so that floating point 
 > values must be created on the outgoing parameter stack in the frame making 
 > the call?
 > 
 > The sys v abi says these float parameters should be passed as double values 
 > on the outgoing stack with addresses aligned to 8.
 > 
 > Currently ppc Linux does NOT follow this part of the abi and instead 
 > passing float parameters (after the 8 which are passed in f1-f8) as 
 > floating point (single) values aligned to 4.
 > 
 > What does NetBSD ppc do here?

As far as I can tell, this is also what NetBSD does.  Attached is:

	float.c -- function which takes 10 float arguments, and
	consumes them all.

	float.s-2.95.3-native -- asm output from the 2.95.3-based
	native compiler.

	float.s-3.2 -- asm output from gcc-current.

Note the offsets used in the "lfs" insns.

 > 2. What about returning unions (which would probably be exactly 8 bytes in 
 > size?  Are they treated like small structures or something different?

Unions of <= 8 bytes are treated just like structures of <= 8 bytes,
in both the 2.95.3-based native compiler and in the fixed gcc 3.1/3.2
compiler.

-- 
        -- Jason R. Thorpe <thorpej@wasabisystems.com>
-------------- next part --------------
int
float_test(float f1, float f2, float f3, float f4, float f5,
   float f6, float f7, float f8, float f9, float f10)
{

	return f1 == f2 &&
	       f1 == f3 &&
	       f1 == f4 &&
	       f1 == f5 &&
	       f1 == f6 &&
	       f1 == f7 &&
	       f1 == f8 &&
	       f1 == f9 &&
	       f1 == f10;
}
-------------- next part --------------
	.file	"float.c"
gcc2_compiled.:
	.section	".text"
	.align 2
	.globl float_test
	.type	 float_test,@function
float_test:
	fcmpu 6,1,2
	fcmpu 7,1,3
	li 3,0
	mfcr 0
	rlwinm 9,0,27,1
	rlwinm 0,0,31,1
	and. 11,9,0
	bclr 12,2
	fcmpu 7,1,4
	fcmpu 6,1,5
	mfcr 0
	rlwinm 9,0,31,1
	rlwinm 0,0,27,1
	and. 11,9,0
	bclr 12,2
	fcmpu 7,1,6
	fcmpu 6,1,7
	mfcr 0
	rlwinm 9,0,31,1
	rlwinm 0,0,27,1
	and. 11,9,0
	bclr 12,2
	lfs 0,8(1)
	fcmpu 6,1,8
	fcmpu 7,1,0
	mfcr 0
	rlwinm 9,0,27,1
	rlwinm 0,0,31,1
	and. 11,9,0
	bclr 12,2
	lfs 0,12(1)
	fcmpu 7,1,0
	mfcr 3
	rlwinm 3,3,31,1
	blr
.Lfe1:
	.size	 float_test,.Lfe1-float_test
	.ident	"GCC: (GNU) 2.95.3 20010315 (release) (NetBSD nb1)"
-------------- next part --------------
	.file	"float.c"
	.section	".text"
	.align 2
	.globl float_test
	.type	float_test,@function
float_test:
	fcmpu 0,1,2
	li 3,0
	bnelr- 0
	fcmpu 0,1,3
	bnelr- 0
	fcmpu 0,1,4
	bnelr- 0
	fcmpu 0,1,5
	bnelr- 0
	fcmpu 0,1,6
	bnelr- 0
	fcmpu 0,1,7
	bnelr- 0
	fcmpu 0,1,8
	bnelr- 0
	lfs 0,8(1)
	fcmpu 0,1,0
	bnelr- 0
	lfs 0,12(1)
	fcmpu 0,1,0
	bnelr- 0
	li 3,1
	blr
.Lfe1:
	.size	float_test,.Lfe1-float_test
	.ident	"GCC: (GNU) 3.2 20020602 (experimental)"