RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Thanks. All the best, Peixin -Original Message- From: Richard Sandiford [mailto:richard.sandif...@arm.com] Sent: Wednesday, August 19, 2020 5:56 PM To: qiaopeixin Cc: Christophe Lyon ; gcc-patches@gcc.gnu.org Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479] qiaopeixin writes: > Hi Richard, > > Thanks for the example. > > I remove the whole line "&&fndecl && TREE_PUBLIC (fndecl)" and passed > bootstrap and deja tests. I add your provided example under > /gcc.target/aarch64, and the patch is attached. Thanks, pushed to master. Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
qiaopeixin writes: > Hi Richard, > > Thanks for the example. > > I remove the whole line "&&fndecl && TREE_PUBLIC (fndecl)" and passed > bootstrap and deja tests. I add your provided example under > /gcc.target/aarch64, and the patch is attached. Thanks, pushed to master. Richard
RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Hi Richard, Thanks for the example. I remove the whole line "&&fndecl && TREE_PUBLIC (fndecl)" and passed bootstrap and deja tests. I add your provided example under /gcc.target/aarch64, and the patch is attached. By the way, the new example also passed deja tests. All the best, Peixin -Original Message- From: Richard Sandiford [mailto:richard.sandif...@arm.com] Sent: Wednesday, August 19, 2020 1:01 AM To: qiaopeixin Cc: Christophe Lyon ; gcc-patches@gcc.gnu.org Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479] qiaopeixin writes: > Hi Richard, > > Thanks for the review and explanation. > > The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29. > > I checked the past log of writing the function aarch64_init_cumulative_args, > and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as > one condition for entering the function type check. Maybe Alan could clarify? > I tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the > glibc problem and the previous ICE problem. A new fix is made as following, > passed bootstrap and deja test. I believe this fix is reasonable, since the > function type should be checked no matter if it has external linkage or not. > > The function aarch64_init_cumulative_args checks the function types and > should catch the error that "-mgeneral-regs-only" is incompatible with the > use of SIMD/FP registers. In the test case on PR96479, the function myfunc2 > returns one vector of 4 integers, while it is defined static type. > TREE_PUBLIC (fndecl) is set as false and it prevents from entering if > statement and checking function types. I delete "TREE_PUBLIC (fndecl)" so > that gcc can catch the error through the function > aarch64_init_cumulative_args now. The ICE on PR96479 can report the > diagnostic error with this fix. The patch for the fix is attached as > following: > > diff --git a/gcc/config/aarch64/aarch64.c > b/gcc/config/aarch64/aarch64.c index b7f5bc76f1b..9ce83dce131 100644 > --- a/gcc/config/aarch64/aarch64.c > +++ b/gcc/config/aarch64/aarch64.c > @@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS > *pcum, > >if (!silent_p >&& !TARGET_FLOAT > - && fndecl && TREE_PUBLIC (fndecl) > + && fndecl >&& fntype && fntype != error_mark_node) > { >const_tree type = TREE_TYPE (fntype); I think the fndecl test is problematic too though. E.g. consider: typedef int v4si __attribute__((vector_size(16))); v4si (*foo) (); void f (v4si *ptr) { *ptr = foo (); } which ICEs for me even with the above. I suggest we just remove the line and see whether anything breaks. Thanks, Richard 0001-AArch64-Remove-fndecl-TREE_PUBLIC-fndecl-in-aarch64_.patch Description: 0001-AArch64-Remove-fndecl-TREE_PUBLIC-fndecl-in-aarch64_.patch
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
qiaopeixin writes: > Hi Richard, > > Thanks for the review and explanation. > > The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29. > > I checked the past log of writing the function aarch64_init_cumulative_args, > and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as > one condition for entering the function type check. Maybe Alan could clarify? > I tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the > glibc problem and the previous ICE problem. A new fix is made as following, > passed bootstrap and deja test. I believe this fix is reasonable, since the > function type should be checked no matter if it has external linkage or not. > > The function aarch64_init_cumulative_args checks the function types and > should catch the error that "-mgeneral-regs-only" is incompatible with the > use of SIMD/FP registers. In the test case on PR96479, the function myfunc2 > returns one vector of 4 integers, while it is defined static type. > TREE_PUBLIC (fndecl) is set as false and it prevents from entering if > statement and checking function types. I delete "TREE_PUBLIC (fndecl)" so > that gcc can catch the error through the function > aarch64_init_cumulative_args now. The ICE on PR96479 can report the > diagnostic error with this fix. The patch for the fix is attached as > following: > > diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c > index b7f5bc76f1b..9ce83dce131 100644 > --- a/gcc/config/aarch64/aarch64.c > +++ b/gcc/config/aarch64/aarch64.c > @@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS *pcum, > >if (!silent_p >&& !TARGET_FLOAT > - && fndecl && TREE_PUBLIC (fndecl) > + && fndecl >&& fntype && fntype != error_mark_node) > { >const_tree type = TREE_TYPE (fntype); I think the fndecl test is problematic too though. E.g. consider: typedef int v4si __attribute__((vector_size(16))); v4si (*foo) (); void f (v4si *ptr) { *ptr = foo (); } which ICEs for me even with the above. I suggest we just remove the line and see whether anything breaks. Thanks, Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
On Tue, 18 Aug 2020 at 05:38, qiaopeixin wrote: > > Hi Richard, > > Thanks for the review and explanation. > > The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29. > > I checked the past log of writing the function aarch64_init_cumulative_args, > and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as > one condition for entering the function type check. Maybe Alan could clarify? > I tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the > glibc problem and the previous ICE problem. A new fix is made as following, > passed bootstrap and deja test. I believe this fix is reasonable, since the > function type should be checked no matter if it has external linkage or not. > > The function aarch64_init_cumulative_args checks the function types and > should catch the error that "-mgeneral-regs-only" is incompatible with the > use of SIMD/FP registers. In the test case on PR96479, the function myfunc2 > returns one vector of 4 integers, while it is defined static type. > TREE_PUBLIC (fndecl) is set as false and it prevents from entering if > statement and checking function types. I delete "TREE_PUBLIC (fndecl)" so > that gcc can catch the error through the function > aarch64_init_cumulative_args now. The ICE on PR96479 can report the > diagnostic error with this fix. The patch for the fix is attached as > following: > > diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c > index b7f5bc76f1b..9ce83dce131 100644 > --- a/gcc/config/aarch64/aarch64.c > +++ b/gcc/config/aarch64/aarch64.c > @@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS *pcum, > >if (!silent_p >&& !TARGET_FLOAT > - && fndecl && TREE_PUBLIC (fndecl) > + && fndecl >&& fntype && fntype != error_mark_node) > { >const_tree type = TREE_TYPE (fntype); > > Christophe, thanks for your tests on glibc-2.29. With the above fix, I built > glibc-2.29, and the previous error does not show up now. Could you please > check if this fix works? Hi, I confirm this works OK for my testing (aarch64-linux-gnu and aarch64-elf) Thanks, Christophe > > Do you have any suggestions on this fix? > > All the best, > Peixin > > > -Original Message----- > From: Richard Sandiford [mailto:richard.sandif...@arm.com] > Sent: Thursday, August 13, 2020 8:19 PM > To: Christophe Lyon > Cc: qiaopeixin ; gcc-patches@gcc.gnu.org > Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value > [PR96479] > > Christophe Lyon writes: > > On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote: > >> > >> Thanks for the review and commit. > >> > >> All the best, > >> Peixin > >> > >> -Original Message- > >> From: Richard Sandiford [mailto:richard.sandif...@arm.com] > >> Sent: 2020年8月13日 0:25 > >> To: qiaopeixin > >> Cc: gcc-patches@gcc.gnu.org > >> Subject: Re: [PATCH] AArch64: Add if condition in > >> aarch64_function_value [PR96479] > >> > >> qiaopeixin writes: > >> > Hi, > >> > > >> > The test case vector-subscript-2.c in the gcc testsuit will report an > >> > ICE in the expand pass since '-mgeneral-regs-only' is incompatible with > >> > the use of V4SI mode. I propose to report the diagnostic information > >> > instead of ICE, and the problem has been discussed on PR 96479. > >> > > >> > I attached the patch to solve the problem. Bootstrapped and tested on > >> > aarch64-linux-gnu. Any suggestions? > >> > >> Thanks, pushed. I was initially sceptical because raising an error here > >> and in aarch64_layout_arg is a hack. Both functions are just query > >> functions and shouldn't have any side effects. > >> > >> The approach we took for FP modes seemed better: we define the FP move > >> patterns unconditionally, and raise an error if we try to emit an FP move > >> with !TARGET_FLOAT. This defers any error reporting until we actually try > >> to generate code that depends on TARGET_FLOAT. > >> > >> But I guess SIMD stuff is different. There's no reason in principle why > >> you can't use: > >> > >> unsigned short __attribute__((vector_size(8))) > >> > >> *within* a function with -mgeneral-regs-only. It would just need to be > >> emulated, in the same way as for: > >> > >> unsigned short __attribute__((vector_size
RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Hi Richard, Thanks for the review and explanation. The previous fix adding if condition of TARGET_FLOAT does crash glibc-2.29. I checked the past log of writing the function aarch64_init_cumulative_args, and did not find the reason why Alan Lawrence added TREE_PUBLIC (fndecl) as one condition for entering the function type check. Maybe Alan could clarify? I tried to delete TREE_PUBLIC (fndecl), which turns out could solve both the glibc problem and the previous ICE problem. A new fix is made as following, passed bootstrap and deja test. I believe this fix is reasonable, since the function type should be checked no matter if it has external linkage or not. The function aarch64_init_cumulative_args checks the function types and should catch the error that "-mgeneral-regs-only" is incompatible with the use of SIMD/FP registers. In the test case on PR96479, the function myfunc2 returns one vector of 4 integers, while it is defined static type. TREE_PUBLIC (fndecl) is set as false and it prevents from entering if statement and checking function types. I delete "TREE_PUBLIC (fndecl)" so that gcc can catch the error through the function aarch64_init_cumulative_args now. The ICE on PR96479 can report the diagnostic error with this fix. The patch for the fix is attached as following: diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index b7f5bc76f1b..9ce83dce131 100644 --- a/gcc/config/aarch64/aarch64.c +++ b/gcc/config/aarch64/aarch64.c @@ -6017,7 +6017,7 @@ aarch64_init_cumulative_args (CUMULATIVE_ARGS *pcum, if (!silent_p && !TARGET_FLOAT - && fndecl && TREE_PUBLIC (fndecl) + && fndecl && fntype && fntype != error_mark_node) { const_tree type = TREE_TYPE (fntype); Christophe, thanks for your tests on glibc-2.29. With the above fix, I built glibc-2.29, and the previous error does not show up now. Could you please check if this fix works? Do you have any suggestions on this fix? All the best, Peixin -Original Message- From: Richard Sandiford [mailto:richard.sandif...@arm.com] Sent: Thursday, August 13, 2020 8:19 PM To: Christophe Lyon Cc: qiaopeixin ; gcc-patches@gcc.gnu.org Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479] Christophe Lyon writes: > On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote: >> >> Thanks for the review and commit. >> >> All the best, >> Peixin >> >> -Original Message- >> From: Richard Sandiford [mailto:richard.sandif...@arm.com] >> Sent: 2020年8月13日 0:25 >> To: qiaopeixin >> Cc: gcc-patches@gcc.gnu.org >> Subject: Re: [PATCH] AArch64: Add if condition in >> aarch64_function_value [PR96479] >> >> qiaopeixin writes: >> > Hi, >> > >> > The test case vector-subscript-2.c in the gcc testsuit will report an ICE >> > in the expand pass since '-mgeneral-regs-only' is incompatible with the >> > use of V4SI mode. I propose to report the diagnostic information instead >> > of ICE, and the problem has been discussed on PR 96479. >> > >> > I attached the patch to solve the problem. Bootstrapped and tested on >> > aarch64-linux-gnu. Any suggestions? >> >> Thanks, pushed. I was initially sceptical because raising an error here and >> in aarch64_layout_arg is a hack. Both functions are just query functions >> and shouldn't have any side effects. >> >> The approach we took for FP modes seemed better: we define the FP move >> patterns unconditionally, and raise an error if we try to emit an FP move >> with !TARGET_FLOAT. This defers any error reporting until we actually try >> to generate code that depends on TARGET_FLOAT. >> >> But I guess SIMD stuff is different. There's no reason in principle why you >> can't use: >> >> unsigned short __attribute__((vector_size(8))) >> >> *within* a function with -mgeneral-regs-only. It would just need to be >> emulated, in the same way as for: >> >> unsigned short __attribute__((vector_size(4))) >> >> So it would be wrong to define the SIMD move patterns unconditionally and >> raise an error there. >> >> So all in all, I agree this is the best we can do given the current >> infrastructure. >> > > Since this patch was committed my buildbot is broken for > aarch64-linux-gnu because it now fails to build glibc-2.29: > ../stdlib/bits/stdlib-float.h: In function 'atof': > ../stdlib/bits/stdlib-float.h:26:1: error: '-mgeneral-regs-only' is > incompatible with the use of floating-point types Thanks for the heads-up. I've reve
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Christophe Lyon writes: > On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote: >> >> Thanks for the review and commit. >> >> All the best, >> Peixin >> >> -Original Message- >> From: Richard Sandiford [mailto:richard.sandif...@arm.com] >> Sent: 2020年8月13日 0:25 >> To: qiaopeixin >> Cc: gcc-patches@gcc.gnu.org >> Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value >> [PR96479] >> >> qiaopeixin writes: >> > Hi, >> > >> > The test case vector-subscript-2.c in the gcc testsuit will report an ICE >> > in the expand pass since '-mgeneral-regs-only' is incompatible with the >> > use of V4SI mode. I propose to report the diagnostic information instead >> > of ICE, and the problem has been discussed on PR 96479. >> > >> > I attached the patch to solve the problem. Bootstrapped and tested on >> > aarch64-linux-gnu. Any suggestions? >> >> Thanks, pushed. I was initially sceptical because raising an error here and >> in aarch64_layout_arg is a hack. Both functions are just query functions >> and shouldn't have any side effects. >> >> The approach we took for FP modes seemed better: we define the FP move >> patterns unconditionally, and raise an error if we try to emit an FP move >> with !TARGET_FLOAT. This defers any error reporting until we actually try >> to generate code that depends on TARGET_FLOAT. >> >> But I guess SIMD stuff is different. There's no reason in principle why you >> can't use: >> >> unsigned short __attribute__((vector_size(8))) >> >> *within* a function with -mgeneral-regs-only. It would just need to be >> emulated, in the same way as for: >> >> unsigned short __attribute__((vector_size(4))) >> >> So it would be wrong to define the SIMD move patterns unconditionally and >> raise an error there. >> >> So all in all, I agree this is the best we can do given the current >> infrastructure. >> > > Since this patch was committed my buildbot is broken for > aarch64-linux-gnu because it now fails to build glibc-2.29: > ../stdlib/bits/stdlib-float.h: In function 'atof': > ../stdlib/bits/stdlib-float.h:26:1: error: '-mgeneral-regs-only' is > incompatible with the use of floating-point types Thanks for the heads-up. I've reverted the patch for now. Looking more closely, it seems like aarch64_init_cumulative_args already tries to catch the problem that the patch was fixing: if (!silent_p && !TARGET_FLOAT && fndecl && TREE_PUBLIC (fndecl) && fntype && fntype != error_mark_node) { const_tree type = TREE_TYPE (fntype); machine_mode mode ATTRIBUTE_UNUSED; /* To pass pointer as argument. */ int nregs ATTRIBUTE_UNUSED; /* Likewise. */ if (aarch64_vfp_is_call_or_return_candidate (TYPE_MODE (type), type, &mode, &nregs, NULL, false)) aarch64_err_no_fpadvsimd (TYPE_MODE (type)); } The only reason it doesn't work for the testcase is that TREE_PUBLIC condition. TBH I'm not sure why it or the fndecl test is there: this is just as problematic when calling via a function pointer or when calling a static function. Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Hi, On Thu, 13 Aug 2020 at 03:54, qiaopeixin wrote: > > Thanks for the review and commit. > > All the best, > Peixin > > -Original Message- > From: Richard Sandiford [mailto:richard.sandif...@arm.com] > Sent: 2020年8月13日 0:25 > To: qiaopeixin > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value > [PR96479] > > qiaopeixin writes: > > Hi, > > > > The test case vector-subscript-2.c in the gcc testsuit will report an ICE > > in the expand pass since '-mgeneral-regs-only' is incompatible with the use > > of V4SI mode. I propose to report the diagnostic information instead of > > ICE, and the problem has been discussed on PR 96479. > > > > I attached the patch to solve the problem. Bootstrapped and tested on > > aarch64-linux-gnu. Any suggestions? > > Thanks, pushed. I was initially sceptical because raising an error here and > in aarch64_layout_arg is a hack. Both functions are just query functions and > shouldn't have any side effects. > > The approach we took for FP modes seemed better: we define the FP move > patterns unconditionally, and raise an error if we try to emit an FP move > with !TARGET_FLOAT. This defers any error reporting until we actually try to > generate code that depends on TARGET_FLOAT. > > But I guess SIMD stuff is different. There's no reason in principle why you > can't use: > > unsigned short __attribute__((vector_size(8))) > > *within* a function with -mgeneral-regs-only. It would just need to be > emulated, in the same way as for: > > unsigned short __attribute__((vector_size(4))) > > So it would be wrong to define the SIMD move patterns unconditionally and > raise an error there. > > So all in all, I agree this is the best we can do given the current > infrastructure. > Since this patch was committed my buildbot is broken for aarch64-linux-gnu because it now fails to build glibc-2.29: ../stdlib/bits/stdlib-float.h: In function 'atof': ../stdlib/bits/stdlib-float.h:26:1: error: '-mgeneral-regs-only' is incompatible with the use of floating-point types I haven't yet tried a more recent glibc version, not sure if 2.29 is considered obsolete? Christophe > Thanks, > Richard >
RE: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
Thanks for the review and commit. All the best, Peixin -Original Message- From: Richard Sandiford [mailto:richard.sandif...@arm.com] Sent: 2020年8月13日 0:25 To: qiaopeixin Cc: gcc-patches@gcc.gnu.org Subject: Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479] qiaopeixin writes: > Hi, > > The test case vector-subscript-2.c in the gcc testsuit will report an ICE in > the expand pass since '-mgeneral-regs-only' is incompatible with the use of > V4SI mode. I propose to report the diagnostic information instead of ICE, and > the problem has been discussed on PR 96479. > > I attached the patch to solve the problem. Bootstrapped and tested on > aarch64-linux-gnu. Any suggestions? Thanks, pushed. I was initially sceptical because raising an error here and in aarch64_layout_arg is a hack. Both functions are just query functions and shouldn't have any side effects. The approach we took for FP modes seemed better: we define the FP move patterns unconditionally, and raise an error if we try to emit an FP move with !TARGET_FLOAT. This defers any error reporting until we actually try to generate code that depends on TARGET_FLOAT. But I guess SIMD stuff is different. There's no reason in principle why you can't use: unsigned short __attribute__((vector_size(8))) *within* a function with -mgeneral-regs-only. It would just need to be emulated, in the same way as for: unsigned short __attribute__((vector_size(4))) So it would be wrong to define the SIMD move patterns unconditionally and raise an error there. So all in all, I agree this is the best we can do given the current infrastructure. Thanks, Richard
Re: [PATCH] AArch64: Add if condition in aarch64_function_value [PR96479]
qiaopeixin writes: > Hi, > > The test case vector-subscript-2.c in the gcc testsuit will report an ICE in > the expand pass since '-mgeneral-regs-only' is incompatible with the use of > V4SI mode. I propose to report the diagnostic information instead of ICE, and > the problem has been discussed on PR 96479. > > I attached the patch to solve the problem. Bootstrapped and tested on > aarch64-linux-gnu. Any suggestions? Thanks, pushed. I was initially sceptical because raising an error here and in aarch64_layout_arg is a hack. Both functions are just query functions and shouldn't have any side effects. The approach we took for FP modes seemed better: we define the FP move patterns unconditionally, and raise an error if we try to emit an FP move with !TARGET_FLOAT. This defers any error reporting until we actually try to generate code that depends on TARGET_FLOAT. But I guess SIMD stuff is different. There's no reason in principle why you can't use: unsigned short __attribute__((vector_size(8))) *within* a function with -mgeneral-regs-only. It would just need to be emulated, in the same way as for: unsigned short __attribute__((vector_size(4))) So it would be wrong to define the SIMD move patterns unconditionally and raise an error there. So all in all, I agree this is the best we can do given the current infrastructure. Thanks, Richard