🚀 go-pugleaf

The following program (a simplified version of code in the file
lib/Xaw/Command.c in X11R3), when compiled with -O, causes GCC 1.31 to
crash with a segmentation violation in equiv_constant (running on a
Sun-2, Sun OS 4.0).

typedef struct _XRegion *Region; 

typedef struct {
    short x, y;
    unsigned short width, height;
} XRectangle;

static Region HighlightRegion()
{
    static Region outerRegion = 0, innerRegion, emptyRegion;
    XRectangle rect;

    rect.x = rect.y = 0;
    XUnionRectWithRegion( &rect, emptyRegion, innerRegion );
    XSubtractRegion( outerRegion, innerRegion, outerRegion );
    return outerRegion;
}

Here is a stack trace of the crashed gcc:

% adb /usr/local/lib/gcc-cc1 core
core file = core -- program ``gcc-cc1''
SIGSEGV	11: segmentation violation
$c
_equiv_constant(0x8c6fa) + 86
_fold_rtx() + 17a
_cse_insn(0x8c77e) + 26c
_cse_basic_block(0x8c4b8,0x0) +	68
_cse_main() + 146
_rest_of_compilation(0x8ef22) +	208
_finish_function() + 68
_yyparse() + 638
_compile_file(0xefffe88) + 604
_main(0x8,0xefffe2c,0xefffe50) + 65a
$r
d0    0x232238
d1    0x21	__DYNAMIC+0x21
d2    0x0	__DYNAMIC
d3    0x8c6fa	_end+0x52ba
d4    0x1	__DYNAMIC+0x1
d5    0x4c	__DYNAMIC+0x4c
d6    0x0	__DYNAMIC
d7    0x2	__DYNAMIC+0x2
a0    0xeffe02c
a1    0xeffd708
a2    0x8c6fa	_end+0x52ba
a3    0x8c6b2	_end+0x5272
a4    0x0	__DYNAMIC
a5    0x0	__DYNAMIC
a6    0xeffd450
sp    0xeffd440
pc    0x3a98e	_equiv_constant+0x86
ps    0x0	__DYNAMIC
      0x0	__DYNAMIC
_equiv_constant+0x86:			movl	a0@(0,d0:l),d0