🚀 go-pugleaf

I'm using GCC version 2.3.1 on a Next computer, configured with
"./configure next".

When MISSING_OPTIMIZATION is not defined, the GCC optimizes away code that
calls first_computation, third_computation, and fourth_computation().  When
the macro MISSING_OPTIMIZATION is defined, all the extra code is not optimized
away, even though GCC realizes that (1 % 0) evaluates to 1.


% cat wow2.c
============

void
foo()
{
    long temp;
    
    temp = 1;
    
#ifdef MISSING_OPTIMIZATION
    temp = temp % 33;
#else
    temp = temp + 0;
#endif
    
    
    if (temp == 0)
	first_computation();
    else if (temp == 1)
	second_computation();
    else if (temp == 32)
	third_computation();
    else
	fourth_computation();
}


% gcc -v -S -O wow2.c
=====================

Reading specs from /usr/local/lib/gcc-lib/next/2.3.1/specs
gcc version 2.3.1
 /usr/local/lib/gcc-lib/next/2.3.1/cpp -lang-c -v -undef -D__GNUC__=2 -Dmc68000 -Dm68k -DNeXT -Dunix -D__MACH__ -D__ARCHITECTURE__="m68k" -D__mc68000__ -D__m68k__ -D__NeXT__ -D__unix__ -D__MACH__ -D__ARCHITECTURE__="m68k" -D__mc68000 -D__m68k -D__NeXT -D__unix -D__MACH__ -D__ARCHITECTURE__="m68k" -D__OPTIMIZE__ wow2.c /usr/tmp/cc011547.i
GNU CPP version 2.3.1 (68k, MIT syntax)
 /usr/local/lib/gcc-lib/next/2.3.1/cc1 /usr/tmp/cc011547.i -quiet -dumpbase wow2.c -O -version -o wow2.s
GNU C version 2.3.1 (68k, MIT syntax) compiled by GNU C version 2.3.1.


% cat wow2.s
============

#NO_APP
.text
	.align 1
.globl _foo
_foo:
	link a6,#0
	jbsr _second_computation
	unlk a6
	rts


% gcc -v -S -O wow2.c -DMISSING_OPTIMIZATION
============================================

Reading specs from /usr/local/lib/gcc-lib/next/2.3.1/specs
gcc version 2.3.1
 /usr/local/lib/gcc-lib/next/2.3.1/cpp -lang-c -v -DMISSING_OPTIMIZATION -undef -D__GNUC__=2 -Dmc68000 -Dm68k -DNeXT -Dunix -D__MACH__ -D__ARCHITECTURE__="m68k" -D__mc68000__ -D__m68k__ -D__NeXT__ -D__unix__ -D__MACH__ -D__ARCHITECTURE__="m68k" -D__mc68000 -D__m68k -D__NeXT -D__unix -D__MACH__ -D__ARCHITECTURE__="m68k" -D__OPTIMIZE__ wow2.c /usr/tmp/cc011551.i
GNU CPP version 2.3.1 (68k, MIT syntax)
 /usr/local/lib/gcc-lib/next/2.3.1/cc1 /usr/tmp/cc011551.i -quiet -dumpbase wow2.c -O -version -o wow2.s
GNU C version 2.3.1 (68k, MIT syntax) compiled by GNU C version 2.3.1.


% cat wow2.s
============

#NO_APP
.text
	.align 1
.globl _foo
_foo:
	link a6,#0
	moveq #1,d0
	moveq #1,d1
	cmpl d0,d1
	jne L4
	jbsr _second_computation
	jra L3
L4:
	moveq #32,d1
	cmpl d0,d1
	jne L6
	jbsr _third_computation
	jra L3
L6:
	jbsr _fourth_computation
L3:
	unlk a6
	rts