🚀 go-pugleaf

This is not a bug report, only a hint that "long long" performance on
i386 may be improved.

I'm working with gcc 2.2.2, configured as i386-linux.

Input file:

============================== lltest.c =====================================
unsigned long foo (unsigned long long x)
{ return x & 0x00000000FFFFFFFFULL; }

unsigned long foo2 (unsigned long long x, unsigned long long y)
{ unsigned long long z = x + y;
  z &= 0x00000000FFFFFFFFULL;
  return z;
}

unsigned long long bar (void* addr)
{ return (unsigned long long)(unsigned long)(addr) + 0x0000000D00000000ULL; }

==============================================================================

Output from "gcc -O6 -S lltest.c", with comments:

================================= lltest.s ===================================
	.file	"lltest.c"
gcc2_compiled.:
.text
	.align 2
.globl _foo
_foo:
	pushl %ebp
	movl %esp,%ebp
	movl 8(%ebp),%eax
	movl 12(%ebp),%edx              ! superfluous
	leave
	ret
	.align 2,0x90
	.align 2
.globl _foo2
_foo2:
	pushl %ebp
	movl %esp,%ebp
	pushl %ebx
	movl 8(%ebp),%ecx
	movl 12(%ebp),%ebx
	addl 16(%ebp),%ecx
	adcl 20(%ebp),%ebx
	movl %ecx,%eax
	xorl %edx,%edx                   ! superfluous
	movl -4(%ebp),%ebx
	leave
	ret
	.align 2
.globl _bar
_bar:
	pushl %ebp
	movl %esp,%ebp
	movl 8(%ebp),%eax
	movl %eax,%edx                    !
	xorl %ecx,%ecx                    ! may be replaced by
	movl %edx,%eax                    ! a simple
	movl %ecx,%edx                    !
	addl $0,%eax                      !    movl $13,%edx
	adcl $13,%edx                     !
	leave
	ret
	.align 2,0x90
==============================================================================

Note further that gcc (even without -O) aborts like this on some bigger
functions that use many "long long" variables. I can provide examples.
   gcc: Internal compiler error: program cc1 got fatal signal 6

Bruno Haible
haible@ma2s2.mathematik.uni-karlsruhe.de