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Re: [PATCH] Improve folding of bitwise ops on booleans
- From: Richard Henderson <rth at redhat dot com>
- To: Kai Tietz <ktietz70 at googlemail dot com>
- Cc: Jeff Law <law at redhat dot com>, Richard Biener <richard dot guenther at gmail dot com>, gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 03 Jun 2013 10:00:19 -0700
- Subject: Re: [PATCH] Improve folding of bitwise ops on booleans
- References: <51A90588 dot 5080807 at redhat dot com> <CAFiYyc3yxAs0vV8qS830ubnprJSs5o4RCD+S9Pzkink_VPRzGw at mail dot gmail dot com> <51ACBEB8 dot 70005 at redhat dot com> <CAEwic4YMPzpEbjoX8moMOdVPPr7p6e6uhjZgy-=daQzgdZAy-g at mail dot gmail dot com>
On 06/03/2013 09:37 AM, Kai Tietz wrote:
> foo:
> .seh_endprologue
> cmpb %cl, %dl
> seta %al
> ret
> .seh_endproc
> .p2align 4,,15
> .globl boo
> .def boo; .scl 2; .type 32; .endef
> .seh_proc boo
> boo:
> .seh_endprologue
> movl %ecx, %eax
> notl %eax
> andl %edx, %eax
> andl $1, %eax
> ret
Try arm or s390 or ppc for significantly different results.
r~