[Qemu-devel] tcg problem running SPARC program on x86

[Vince Weaver <vince@csl.cornell.edu>]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 757 bytes --]

Hello

I'm continuing on my quest to get the SPEC2000 benchmarks running under 
sparc32-linux-user (so far 8 out of 48 work).

Many of the benchmarks die early on with the following error:

     /fusion/research4/vince/qemu/svn/tcg/tcg.c:1455: tcg fatal error

This error is caused when tcg_reg_alloc_mov() is called but ts->val_type
is equal to 0 (which is TEMP_VAL_DEAD). So maybe the optimizer is 
optimizing away something that it shouldn't?

This happens in a block with multiple calls to the SPARC "mulscc"
instruction which is a complicated instruction, so maybe this is finding 
an obscure corner case.

I've attached a very small sample program that exhibits the bug when 
run with ./sparc32-linux-user/qemu-sparc32plus

Thanks for any help

Vince

[-- Attachment #2: Type: TEXT/PLAIN, Size: 549 bytes --]

! as -o mulscc.o mulscc.s ; ld -o mulscc mulscc.o

.equ SYSCALL_EXIT,1	

	.globl _start
_start:	
        wr  	%g0, %o3, %y
        sra 	%o5, 0x1f, %g2
        and  	%o3, %g2, %g2
        andcc	%g1, 0, %g1

	mulscc  %g1, %o5, %g1
	mulscc  %g1, %o5, %g1
	mulscc  %g1, %o5, %g1
	mulscc  %g1, %o5, %g1
		
	!================================
	! Exit
	!================================
exit:		
        mov	0,%o0			! exit value
        mov	SYSCALL_EXIT,%g1        ! put the exit syscall number in g1
        ta      0x10			! and exit

[-- Attachment #3: Type: APPLICATION/octet-stream, Size: 542 bytes --]