C++ PATCH: multiple inheritance optimization

[Richard Henderson]

On Mon, Jan 17, 2000 at 02:55:15PM -0800, Mark Mitchell wrote:
> ========== OLD ABI =========
> 
> 	xorl	%eax, %eax
> 	testl	%ecx, %ecx
> 	leal	8(%ecx), %edx
> 	sete	%al
> 	decl	%eax
> 	andl	%edx, %eax
> 	movl	4(%eax), %ebx
> 	xorl	%eax, %eax
> 	testl	%ecx, %ecx
> 	sete	%al
> 	decl	%eax
> 	andl	%eax, %edx
> 	pushl	%edx
> 	movl	8(%ebx), %ebx
> .LCFI6:
> 	call	*%ebx

This calculates (u ? u+8 : u) twice, and due to the if-conversion,
it's too complicated for cse to grovel it's way through.

Any chance you could help the code generator out here and save the
first copy and reuse it?  Or are the two COND_EXPRs coming from 
different parts of the front end?


r~