Re: [Patch]Simplify SUBREG with operand whose target bits are cleared by AND operation

2014-04-24 Thread Terry Guo
On Mon, Apr 14, 2014 at 6:13 PM, Terry Guo wrote: > On Thu, Apr 3, 2014 at 10:11 PM, Eric Botcazou wrote: >>> I find the GCC function simplify_subreg fails to simplify rtx (subreg:SI >>> (and:DI (reg/v:DI 115 [ a ]) (const_int 4294967295 [0x])) 4) to zero >>> during the fwprop1 pass, cons

Re: [Patch]Simplify SUBREG with operand whose target bits are cleared by AND operation

2014-04-14 Thread Terry Guo
On Thu, Apr 3, 2014 at 10:11 PM, Eric Botcazou wrote: >> I find the GCC function simplify_subreg fails to simplify rtx (subreg:SI >> (and:DI (reg/v:DI 115 [ a ]) (const_int 4294967295 [0x])) 4) to zero >> during the fwprop1 pass, considering the fact that the high 32-bit part of >> (a & 0x

Re: [Patch]Simplify SUBREG with operand whose target bits are cleared by AND operation

2014-04-03 Thread Eric Botcazou
> I find the GCC function simplify_subreg fails to simplify rtx (subreg:SI > (and:DI (reg/v:DI 115 [ a ]) (const_int 4294967295 [0x])) 4) to zero > during the fwprop1 pass, considering the fact that the high 32-bit part of > (a & 0x) is zero. This leads to some unnecessary multiplic

RE: [Patch]Simplify SUBREG with operand whose target bits are cleared by AND operation

2014-03-28 Thread Terry Guo
> -Original Message- > From: gcc-patches-ow...@gcc.gnu.org [mailto:gcc-patches- > ow...@gcc.gnu.org] On Behalf Of Terry Guo > Sent: Friday, March 28, 2014 3:48 PM > To: gcc-patches@gcc.gnu.org > Subject: [Patch]Simplify SUBREG with operand whose target bits are cleared > by AND operation