Re: Improve things for PR71724, in combine/if_then_else_cond

On Thu, Jan 26, 2017 at 01:57:02PM +0100, Bernd Schmidt wrote: > On 01/25/2017 08:46 PM, Segher Boessenkool wrote: > > > >It turns out my patch (see the PR) causes (or at least triggers) > >miscompilations on tilegx. I will drop it for now. > > Curious, it looked very reasonable. What's needed

Re: Improve things for PR71724, in combine/if_then_else_cond

On 01/25/2017 08:46 PM, Segher Boessenkool wrote: It turns out my patch (see the PR) causes (or at least triggers) miscompilations on tilegx. I will drop it for now. Curious, it looked very reasonable. What's needed to reproduce this? Bernd

Re: Improve things for PR71724, in combine/if_then_else_cond

On Fri, Jan 20, 2017 at 01:24:15PM -0600, Segher Boessenkool wrote: > On Fri, Jan 20, 2017 at 01:33:59PM +0100, Bernd Schmidt wrote: > > So, when looking for situations where we have only one condition, we can > > try to undo the conversion of a plain REG into a condition, on the > > grounds

Re: Improve things for PR71724, in combine/if_then_else_cond

On 25/01/17 15:20, Christophe Lyon wrote: On 25 January 2017 at 15:55, Bernd Schmidt wrote: On 01/25/2017 10:18 AM, Kyrill Tkachov wrote: The test is supposed to test the generation of the vsel instruction. I believe adding an -mcpu=cortex-a57 to the testcases would be

Re: Improve things for PR71724, in combine/if_then_else_cond

On 25 January 2017 at 15:55, Bernd Schmidt wrote: > On 01/25/2017 10:18 AM, Kyrill Tkachov wrote: >> >> The test is supposed to test the generation of the vsel instruction. >> I believe adding an -mcpu=cortex-a57 to the testcases would be best, as >> VSEL isn't actually

Re: Improve things for PR71724, in combine/if_then_else_cond

On 01/25/2017 10:18 AM, Kyrill Tkachov wrote: The test is supposed to test the generation of the vsel instruction. I believe adding an -mcpu=cortex-a57 to the testcases would be best, as VSEL isn't actually available on Cortex-A5, it's just enabled by the -mfpu=fp-armv8 option. A more realistic

Re: Improve things for PR71724, in combine/if_then_else_cond

On 25/01/17 09:29, Christophe Lyon wrote: > On 25 January 2017 at 10:18, Kyrill Tkachov > wrote: >> >> On 25/01/17 08:53, Christophe Lyon wrote: >>> >>> On 24 January 2017 at 18:15, Bernd Schmidt wrote: On 01/24/2017 06:03 PM,

Re: Improve things for PR71724, in combine/if_then_else_cond

On 25 January 2017 at 10:18, Kyrill Tkachov wrote: > > On 25/01/17 08:53, Christophe Lyon wrote: >> >> On 24 January 2017 at 18:15, Bernd Schmidt wrote: >>> >>> On 01/24/2017 06:03 PM, Christophe Lyon wrote: Ha... the regression

Re: Improve things for PR71724, in combine/if_then_else_cond

On 25/01/17 08:53, Christophe Lyon wrote: On 24 January 2017 at 18:15, Bernd Schmidt wrote: On 01/24/2017 06:03 PM, Christophe Lyon wrote: Ha... the regression occurred between r 244818 and r 244816, and I read r 244816 ChangeLog too quickly and did not notice it was

Re: Improve things for PR71724, in combine/if_then_else_cond

On 24 January 2017 at 18:15, Bernd Schmidt wrote: > On 01/24/2017 06:03 PM, Christophe Lyon wrote: >> >> Ha... the regression occurred between r 244818 and r 244816, >> and I read r 244816 ChangeLog too quickly and did not notice >> it was modifying ifcvt.c in addition to

Re: Improve things for PR71724, in combine/if_then_else_cond

On 01/24/2017 06:03 PM, Christophe Lyon wrote: Ha... the regression occurred between r 244818 and r 244816, and I read r 244816 ChangeLog too quickly and did not notice it was modifying ifcvt.c in addition to x86-only files. So it's likely that it's your other patch for pr78634 that caused the

Re: Improve things for PR71724, in combine/if_then_else_cond

On 24 January 2017 at 17:55, Bernd Schmidt wrote: > On 01/24/2017 05:50 PM, Kyrill Tkachov wrote: >> >> >> Actually trying it out with an explicit -mcpu=cortex-a5 (so -O2 -S >> -mfpu=fp-armv8 -mcpu=cortex-a57 -mfloat-abi=hard) I get >> the test failing before and after the

Re: Improve things for PR71724, in combine/if_then_else_cond

On 01/24/2017 05:50 PM, Kyrill Tkachov wrote: Actually trying it out with an explicit -mcpu=cortex-a5 (so -O2 -S -mfpu=fp-armv8 -mcpu=cortex-a57 -mfloat-abi=hard) I get the test failing before and after the patch. The code generated is vcmp.f64d0, d1 vmrsAPSR_nzcv,

Re: Improve things for PR71724, in combine/if_then_else_cond

On 24/01/17 16:36, Bernd Schmidt wrote: On 01/24/2017 05:30 PM, Kyrill Tkachov wrote: The -mfpu is overridden in the testcase to add the ARMv8 instructions. So to reproduce the compilation in that testcase you'd want -mfpu=fp-armv8 or something equivalent rather than vfpv3-d16-fp16. Exact

Re: Improve things for PR71724, in combine/if_then_else_cond

On 01/24/2017 05:30 PM, Kyrill Tkachov wrote: The -mfpu is overridden in the testcase to add the ARMv8 instructions. So to reproduce the compilation in that testcase you'd want -mfpu=fp-armv8 or something equivalent rather than vfpv3-d16-fp16. Exact steps please. No one who's not well-versed

Re: Improve things for PR71724, in combine/if_then_else_cond

On 24/01/17 16:28, Christophe Lyon wrote: On 24 January 2017 at 17:02, Kyrill Tkachov wrote: On 24/01/17 15:21, Segher Boessenkool wrote: On Tue, Jan 24, 2017 at 01:40:46PM +0100, Bernd Schmidt wrote: On 01/24/2017 09:38 AM, Christophe Lyon wrote: It seems that

Re: Improve things for PR71724, in combine/if_then_else_cond

On 24 January 2017 at 17:02, Kyrill Tkachov wrote: > > On 24/01/17 15:21, Segher Boessenkool wrote: >> >> On Tue, Jan 24, 2017 at 01:40:46PM +0100, Bernd Schmidt wrote: >>> >>> On 01/24/2017 09:38 AM, Christophe Lyon wrote: It seems that Bernd's patch causes

Re: Improve things for PR71724, in combine/if_then_else_cond

On 24/01/17 15:21, Segher Boessenkool wrote: On Tue, Jan 24, 2017 at 01:40:46PM +0100, Bernd Schmidt wrote: On 01/24/2017 09:38 AM, Christophe Lyon wrote: It seems that Bernd's patch causes regressions on arm-linux-gnueabihf --with-cpu=cortex-a5 --with-fpu=vfpv3-d16-fp16:

Re: Improve things for PR71724, in combine/if_then_else_cond

On Tue, Jan 24, 2017 at 01:40:46PM +0100, Bernd Schmidt wrote: > On 01/24/2017 09:38 AM, Christophe Lyon wrote: > >It seems that Bernd's patch causes regressions on arm-linux-gnueabihf > >--with-cpu=cortex-a5 --with-fpu=vfpv3-d16-fp16: > > > > gcc.target/arm/vselvcdf.c scan-assembler-times

Re: Improve things for PR71724, in combine/if_then_else_cond

On 01/24/2017 09:38 AM, Christophe Lyon wrote: It seems that Bernd's patch causes regressions on arm-linux-gnueabihf --with-cpu=cortex-a5 --with-fpu=vfpv3-d16-fp16: gcc.target/arm/vselvcdf.c scan-assembler-times vselvs.f64\td[0-9]+ 1 gcc.target/arm/vselvcsf.c scan-assembler-times

Re: Improve things for PR71724, in combine/if_then_else_cond

On 20 January 2017 at 20:24, Segher Boessenkool wrote: > Hi Bernd, > > On Fri, Jan 20, 2017 at 01:33:59PM +0100, Bernd Schmidt wrote: >> So, when looking for situations where we have only one condition, we can >> try to undo the conversion of a plain REG into a

Re: Improve things for PR71724, in combine/if_then_else_cond

Hi Bernd, On Fri, Jan 20, 2017 at 01:33:59PM +0100, Bernd Schmidt wrote: > So, when looking for situations where we have only one condition, we can > try to undo the conversion of a plain REG into a condition, on the > grounds that this is probably less helpful. > > This seems to cure the

Improve things for PR71724, in combine/if_then_else_cond

The PR is about infinite recursion in combine_simplify_rtx, because if_then_else_cond does strange things to an expression, and we end up simplifying something to itself. The patch below tries to address this by improving that function a little. As stated in the PR, the situation is that we