Re: [PATCH] rs6000: Replace UNSPECS with ss_plus/us_plus and ss_minus/us_minus

2021-12-20 Thread Xionghu Luo via Gcc-patches
On 2021/12/21 09:32, David Edelsohn wrote: > Explicit clobbers like this help one side of the issue. For vscr, other > than the sat bit there is only the nj bit, and we just ignore that :-) > >> This patch is okay. Thanks for updating the machine description and >> for cleaning up the formatt

Re: [PATCH] rs6000: Replace UNSPECS with ss_plus/us_plus and ss_minus/us_minus

2021-12-20 Thread Xionghu Luo via Gcc-patches
On 2021/12/21 10:19, Xionghu Luo via Gcc-patches wrote: > > > On 2021/12/21 09:32, David Edelsohn wrote: >> On Mon, Dec 20, 2021 at 6:55 PM Segher Boessenkool >> wrote: >>> >>> On Mon, Dec 20, 2021 at 11:45:45AM -0500, David Edelsohn wrote: On Mon, Dec 20, 2021 at 3:24 AM Xionghu Luo wr

Re: [PATCH] rs6000: Replace UNSPECS with ss_plus/us_plus and ss_minus/us_minus

2021-12-20 Thread Xionghu Luo via Gcc-patches
On 2021/12/21 09:32, David Edelsohn wrote: > On Mon, Dec 20, 2021 at 6:55 PM Segher Boessenkool > wrote: >> >> On Mon, Dec 20, 2021 at 11:45:45AM -0500, David Edelsohn wrote: >>> On Mon, Dec 20, 2021 at 3:24 AM Xionghu Luo wrote: These four UNSPECS seems could be replaced with native RTL,

Re: [PATCH] rs6000: Replace UNSPECS with ss_plus/us_plus and ss_minus/us_minus

2021-12-20 Thread David Edelsohn via Gcc-patches
On Mon, Dec 20, 2021 at 6:55 PM Segher Boessenkool wrote: > > On Mon, Dec 20, 2021 at 11:45:45AM -0500, David Edelsohn wrote: > > On Mon, Dec 20, 2021 at 3:24 AM Xionghu Luo wrote: > > > These four UNSPECS seems could be replaced with native RTL, and why > > > "(set (reg:SI VSCR_REGNO) (unspec:SI

Re: [PATCH] rs6000: Replace UNSPECS with ss_plus/us_plus and ss_minus/us_minus

2021-12-20 Thread Segher Boessenkool
On Mon, Dec 20, 2021 at 11:45:45AM -0500, David Edelsohn wrote: > On Mon, Dec 20, 2021 at 3:24 AM Xionghu Luo wrote: > > These four UNSPECS seems could be replaced with native RTL, and why > > "(set (reg:SI VSCR_REGNO) (unspec:SI [(const_int 0)] UNSPEC_SET_VSCR))" > > in the RTL pattern, per ISA o

Re: [PATCH] rs6000: Replace UNSPECS with ss_plus/us_plus and ss_minus/us_minus

2021-12-20 Thread David Edelsohn via Gcc-patches
On Mon, Dec 20, 2021 at 3:24 AM Xionghu Luo wrote: > > These four UNSPECS seems could be replaced with native RTL, and why > "(set (reg:SI VSCR_REGNO) (unspec:SI [(const_int 0)] UNSPEC_SET_VSCR))" > in the RTL pattern, per ISA of VSCR bit 127(VECTOR Saturation, SAT): > > This bit is sticky; that

[PATCH] rs6000: Replace UNSPECS with ss_plus/us_plus and ss_minus/us_minus

2021-12-20 Thread Xionghu Luo via Gcc-patches
These four UNSPECS seems could be replaced with native RTL, and why "(set (reg:SI VSCR_REGNO) (unspec:SI [(const_int 0)] UNSPEC_SET_VSCR))" in the RTL pattern, per ISA of VSCR bit 127(VECTOR Saturation, SAT): This bit is sticky; that is, once set to 1 it remains set to 1 until it is set to 0 b