| Message ID | CAAs8HmxZb_5ZYuwpPfwJ0DRDOnmRuGVj=h1SBBU9Pv-uF7P1Ng@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On 2012-11-16 14:55 , Sriraman Tallam wrote: > Hi, > > The previous patch was incomplete because the front-end strips off > invalid target attributes which I did not consider. The attached > updated patch handles this with updated test cases. > > Thanks, > -Sri. > > On Thu, Nov 15, 2012 at 2:08 PM, Sriraman Tallam <tmsriram@google.com> wrote: >> Hi, >> >> Currently, function multiversioning determines that two functions >> are different by comparing the arch type and isa flags that are set >> after the target string is processed. This leads to cases where the >> versions become identical when the command-line target options are >> altered. >> >> For example, these two versions: >> >> __attribute__ target (("sse4.2"))) >> int foo () >> { >> } >> >> __attribute__ target (("popcnt"))) >> int foo () >> { >> } >> >> become identical when -mpopcnt and -msse4.2 are used while building, >> leading to build errors. >> >> To avoid this, I have modified the function version determination to >> just compare the target string. >> Patch attached. Is this alright to submit? >> >> Thanks, >> -Sri. > > * doc/tm.texi.in (TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS): Document > new target hook. > * doc/tm.texi: Regenerate. > * c-family/c-common.c (handle_target_attribute): Retain target attribute > for targets that support versioning. > * target.def (supports_function_versions): New hook. > * config/i386/i386.c (ix86_function_versions): Use target string > to check for function versions instead of target flags. > * testsuite/g++.dg/mv1.C: Remove target options. > * testsuite/g++.dg/mv2.C: Ditto. > * testsuite/g++.dg/mv3.C: Ditto. > * testsuite/g++.dg/mv4.C: Ditto. > * testsuite/g++.dg/mv5.C: Ditto. > * cp/class.c (add_method): Remove calls > to DECL_FUNCTION_SPECIFIC_TARGET. > * config/i386/i386.c (ix86_function_versions): Use target string > to check for function versions instead of target flags. > * (ix86_supports_function_versions): New function. > * (is_function_default_version): Check target string. > * TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS: New macro. > Looks mostly OK. > Index: cp/class.c > =================================================================== > --- cp/class.c (revision 193486) > +++ cp/class.c (working copy) > @@ -1095,8 +1095,6 @@ add_method (tree type, tree method, tree using_dec > && TREE_CODE (method) == FUNCTION_DECL > && !DECL_EXTERN_C_P (fn) > && !DECL_EXTERN_C_P (method) > - && (DECL_FUNCTION_SPECIFIC_TARGET (fn) > - || DECL_FUNCTION_SPECIFIC_TARGET (method)) I don't follow. Given the new hook, why do you need to remove this check? > +/* This function returns true if FN1 and FN2 are versions of the same function, > + that is, the target strings of the function decls are different. This assumes > + that FN1 and FN2 have the same signature. */ > + > +static bool > +ix86_function_versions (tree fn1, tree fn2) > +{ Any particular reason why you moved this function down here? > + tree attr1, attr2; > + const char *attr_str1, *attr_str2; > + char *target1, *target2; > + bool result; > + > + if (TREE_CODE (fn1) != FUNCTION_DECL > + || TREE_CODE (fn2) != FUNCTION_DECL) > + return false; > + > + attr1 = lookup_attribute ("target", DECL_ATTRIBUTES (fn1)); > + attr2 = lookup_attribute ("target", DECL_ATTRIBUTES (fn2)); > + > + /* Atleast one function decl should have the target attribute specified. */ s/Atleast/At least/ Diego.
Hi Diego, Thanks for the review. On Tue, Dec 18, 2012 at 8:04 AM, Diego Novillo <dnovillo@google.com> wrote: > On 2012-11-16 14:55 , Sriraman Tallam wrote: >> >> Hi, >> >> The previous patch was incomplete because the front-end strips off >> invalid target attributes which I did not consider. The attached >> updated patch handles this with updated test cases. >> >> Thanks, >> -Sri. >> >> On Thu, Nov 15, 2012 at 2:08 PM, Sriraman Tallam <tmsriram@google.com> >> wrote: >>> >>> Hi, >>> >>> Currently, function multiversioning determines that two functions >>> are different by comparing the arch type and isa flags that are set >>> after the target string is processed. This leads to cases where the >>> versions become identical when the command-line target options are >>> altered. >>> >>> For example, these two versions: >>> >>> __attribute__ target (("sse4.2"))) >>> int foo () >>> { >>> } >>> >>> __attribute__ target (("popcnt"))) >>> int foo () >>> { >>> } >>> >>> become identical when -mpopcnt and -msse4.2 are used while building, >>> leading to build errors. >>> >>> To avoid this, I have modified the function version determination to >>> just compare the target string. >>> Patch attached. Is this alright to submit? >>> >>> Thanks, >>> -Sri. >> >> >> * doc/tm.texi.in (TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS): >> Document >> new target hook. >> * doc/tm.texi: Regenerate. >> * c-family/c-common.c (handle_target_attribute): Retain target >> attribute >> for targets that support versioning. >> * target.def (supports_function_versions): New hook. >> * config/i386/i386.c (ix86_function_versions): Use target string >> to check for function versions instead of target flags. >> * testsuite/g++.dg/mv1.C: Remove target options. >> * testsuite/g++.dg/mv2.C: Ditto. >> * testsuite/g++.dg/mv3.C: Ditto. >> * testsuite/g++.dg/mv4.C: Ditto. >> * testsuite/g++.dg/mv5.C: Ditto. >> * cp/class.c (add_method): Remove calls >> to DECL_FUNCTION_SPECIFIC_TARGET. >> * config/i386/i386.c (ix86_function_versions): Use target string >> to check for function versions instead of target flags. >> * (ix86_supports_function_versions): New function. >> * (is_function_default_version): Check target string. >> * TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS: New macro. >> > > > Looks mostly OK. > >> Index: cp/class.c >> =================================================================== >> --- cp/class.c (revision 193486) >> +++ cp/class.c (working copy) >> @@ -1095,8 +1095,6 @@ add_method (tree type, tree method, tree using_dec >> && TREE_CODE (method) == FUNCTION_DECL >> && !DECL_EXTERN_C_P (fn) >> && !DECL_EXTERN_C_P (method) >> - && (DECL_FUNCTION_SPECIFIC_TARGET (fn) >> - || DECL_FUNCTION_SPECIFIC_TARGET (method)) > > > I don't follow. Given the new hook, why do you need to remove this check? The function versions are now determined purely based on the string value and not on DECL_FUNCTION_SPECIFIC_TARGET fields. So, this check is not necessary. > >> +/* This function returns true if FN1 and FN2 are versions of the same >> function, >> + that is, the target strings of the function decls are different. This >> assumes >> + that FN1 and FN2 have the same signature. */ >> + >> +static bool >> +ix86_function_versions (tree fn1, tree fn2) >> +{ > > > Any particular reason why you moved this function down here? Just refactoring, keeping functions that are related to ix86_dispatch_versions together. > >> + tree attr1, attr2; >> + const char *attr_str1, *attr_str2; >> + char *target1, *target2; >> + bool result; >> + >> + if (TREE_CODE (fn1) != FUNCTION_DECL >> + || TREE_CODE (fn2) != FUNCTION_DECL) >> + return false; >> + >> + attr1 = lookup_attribute ("target", DECL_ATTRIBUTES (fn1)); >> + attr2 = lookup_attribute ("target", DECL_ATTRIBUTES (fn2)); >> + >> + /* Atleast one function decl should have the target attribute >> specified. */ > > > s/Atleast/At least/ I will make this change. Thanks, -Sri. > > > Diego.
On Tue, Dec 18, 2012 at 6:38 PM, Sriraman Tallam <tmsriram@google.com> wrote: > The function versions are now determined purely based on the string > value and not on DECL_FUNCTION_SPECIFIC_TARGET fields. So, this check > is not necessary. Ah, OK. Thanks. The patch is OK with that minor fix then. Diego.
I committed this patch with the fix. Thanks, -Sri. On Tue, Dec 18, 2012 at 4:13 PM, Diego Novillo <dnovillo@google.com> wrote: > On Tue, Dec 18, 2012 at 6:38 PM, Sriraman Tallam <tmsriram@google.com> wrote: > >> The function versions are now determined purely based on the string >> value and not on DECL_FUNCTION_SPECIFIC_TARGET fields. So, this check >> is not necessary. > > Ah, OK. Thanks. > > The patch is OK with that minor fix then. > > > Diego.
Index: doc/tm.texi =================================================================== --- doc/tm.texi (revision 193485) +++ doc/tm.texi (working copy) @@ -9937,6 +9937,11 @@ different target specific attributes, that is, the different target machines. @end deftypefn +@deftypefn {Target Hook} bool TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS (void) +This target hook returns @code{true} if the target supports function +multiversioning. +@end deftypefn + @deftypefn {Target Hook} bool TARGET_CAN_INLINE_P (tree @var{caller}, tree @var{callee}) This target hook returns @code{false} if the @var{caller} function cannot inline @var{callee}, based on target specific information. By Index: doc/tm.texi.in =================================================================== --- doc/tm.texi.in (revision 193485) +++ doc/tm.texi.in (working copy) @@ -9798,6 +9798,11 @@ different target specific attributes, that is, the different target machines. @end deftypefn +@hook TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS +This target hook returns @code{true} if the target supports function +multiversioning. +@end deftypefn + @hook TARGET_CAN_INLINE_P This target hook returns @code{false} if the @var{caller} function cannot inline @var{callee}, based on target specific information. By Index: c-family/c-common.c =================================================================== --- c-family/c-common.c (revision 193485) +++ c-family/c-common.c (working copy) @@ -8720,8 +8720,12 @@ handle_target_attribute (tree *node, tree name, tr warning (OPT_Wattributes, "%qE attribute ignored", name); *no_add_attrs = true; } + /* Do not strip invalid target attributes for targets which support function + multiversioning as the target string is used to determine versioned + functions. */ else if (! targetm.target_option.valid_attribute_p (*node, name, args, - flags)) + flags) + && ! targetm.target_option.supports_function_versions ()) *no_add_attrs = true; return NULL_TREE; Index: target.def =================================================================== --- target.def (revision 193485) +++ target.def (working copy) @@ -2826,6 +2826,14 @@ DEFHOOK bool, (tree decl1, tree decl2), hook_bool_tree_tree_false) +/* This function returns true if the target supports function + multiversioning. */ +DEFHOOK +(supports_function_versions, + "", + bool, (void), + hool_bool_void_false) + /* Function to determine if one function can inline another function. */ #undef HOOK_PREFIX #define HOOK_PREFIX "TARGET_" Index: testsuite/g++.dg/mv2.C =================================================================== --- testsuite/g++.dg/mv2.C (revision 193485) +++ testsuite/g++.dg/mv2.C (working copy) @@ -2,7 +2,7 @@ dispatching order when versions are for various ISAs. */ /* { dg-do run { target i?86-*-* x86_64-*-* } } */ /* { dg-require-ifunc "" } */ -/* { dg-options "-O2 -mno-sse -mno-mmx -mno-popcnt -mno-avx" } */ +/* { dg-options "-O2" } */ #include <assert.h> Index: testsuite/g++.dg/mv4.C =================================================================== --- testsuite/g++.dg/mv4.C (revision 193486) +++ testsuite/g++.dg/mv4.C (working copy) @@ -4,7 +4,7 @@ /* { dg-do compile { target i?86-*-* x86_64-*-* } } */ /* { dg-require-ifunc "" } */ -/* { dg-options "-O2 -mno-sse -mno-popcnt" } */ +/* { dg-options "-O2" } */ int __attribute__ ((target ("sse"))) foo () Index: testsuite/g++.dg/mv1.C =================================================================== --- testsuite/g++.dg/mv1.C (revision 193485) +++ testsuite/g++.dg/mv1.C (working copy) @@ -1,7 +1,7 @@ /* Test case to check if Multiversioning works. */ /* { dg-do run { target i?86-*-* x86_64-*-* } } */ /* { dg-require-ifunc "" } */ -/* { dg-options "-O2 -fPIC -mno-avx -mno-popcnt" } */ +/* { dg-options "-O2 -fPIC" } */ #include <assert.h> Index: testsuite/g++.dg/mv3.C =================================================================== --- testsuite/g++.dg/mv3.C (revision 193485) +++ testsuite/g++.dg/mv3.C (working copy) @@ -10,7 +10,7 @@ test should pass. */ /* { dg-do run { target i?86-*-* x86_64-*-* } } */ -/* { dg-options "-O2 -mno-sse -mno-popcnt" } */ +/* { dg-options "-O2" } */ int __attribute__ ((target ("sse"))) Index: testsuite/g++.dg/mv5.C =================================================================== --- testsuite/g++.dg/mv5.C (revision 193486) +++ testsuite/g++.dg/mv5.C (working copy) @@ -3,7 +3,7 @@ /* { dg-do run { target i?86-*-* x86_64-*-* } } */ /* { dg-require-ifunc "" } */ -/* { dg-options "-O2 -mno-popcnt" } */ +/* { dg-options "-O2" } */ /* Default version. */ Index: cp/class.c =================================================================== --- cp/class.c (revision 193486) +++ cp/class.c (working copy) @@ -1095,8 +1095,6 @@ add_method (tree type, tree method, tree using_dec && TREE_CODE (method) == FUNCTION_DECL && !DECL_EXTERN_C_P (fn) && !DECL_EXTERN_C_P (method) - && (DECL_FUNCTION_SPECIFIC_TARGET (fn) - || DECL_FUNCTION_SPECIFIC_TARGET (method)) && targetm.target_option.function_versions (fn, method)) { /* Mark functions as versions if necessary. Modify the mangled Index: config/i386/i386.c =================================================================== --- config/i386/i386.c (revision 193486) +++ config/i386/i386.c (working copy) @@ -28646,47 +28646,6 @@ dispatch_function_versions (tree dispatch_decl, return 0; } -/* This function returns true if FN1 and FN2 are versions of the same function, - that is, the targets of the function decls are different. This assumes - that FN1 and FN2 have the same signature. */ - -static bool -ix86_function_versions (tree fn1, tree fn2) -{ - tree attr1, attr2; - struct cl_target_option *target1, *target2; - - if (TREE_CODE (fn1) != FUNCTION_DECL - || TREE_CODE (fn2) != FUNCTION_DECL) - return false; - - attr1 = DECL_FUNCTION_SPECIFIC_TARGET (fn1); - attr2 = DECL_FUNCTION_SPECIFIC_TARGET (fn2); - - /* Atleast one function decl should have target attribute specified. */ - if (attr1 == NULL_TREE && attr2 == NULL_TREE) - return false; - - if (attr1 == NULL_TREE) - attr1 = target_option_default_node; - else if (attr2 == NULL_TREE) - attr2 = target_option_default_node; - - target1 = TREE_TARGET_OPTION (attr1); - target2 = TREE_TARGET_OPTION (attr2); - - /* target1 and target2 must be different in some way. */ - if (target1->x_ix86_isa_flags == target2->x_ix86_isa_flags - && target1->x_target_flags == target2->x_target_flags - && target1->arch == target2->arch - && target1->tune == target2->tune - && target1->x_ix86_fpmath == target2->x_ix86_fpmath - && target1->branch_cost == target2->branch_cost) - return false; - - return true; -} - /* Comparator function to be used in qsort routine to sort attribute specification strings to "target". */ @@ -28799,6 +28758,60 @@ ix86_mangle_function_version_assembler_name (tree return get_identifier (assembler_name); } +/* This function returns true if FN1 and FN2 are versions of the same function, + that is, the target strings of the function decls are different. This assumes + that FN1 and FN2 have the same signature. */ + +static bool +ix86_function_versions (tree fn1, tree fn2) +{ + tree attr1, attr2; + const char *attr_str1, *attr_str2; + char *target1, *target2; + bool result; + + if (TREE_CODE (fn1) != FUNCTION_DECL + || TREE_CODE (fn2) != FUNCTION_DECL) + return false; + + attr1 = lookup_attribute ("target", DECL_ATTRIBUTES (fn1)); + attr2 = lookup_attribute ("target", DECL_ATTRIBUTES (fn2)); + + /* Atleast one function decl should have the target attribute specified. */ + if (attr1 == NULL_TREE && attr2 == NULL_TREE) + return false; + + /* If one function does not have a target attribute, these are versions. */ + if (attr1 == NULL_TREE || attr2 == NULL_TREE) + return true; + + attr_str1 = TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr1))); + attr_str2 = TREE_STRING_POINTER (TREE_VALUE (TREE_VALUE (attr2))); + + target1 = sorted_attr_string (attr_str1); + target2 = sorted_attr_string (attr_str2); + + /* The sorted target strings must be different for fn1 and fn2 + to be versions. */ + if (strcmp (target1, target2) == 0) + result = false; + else + result = true; + + free (target1); + free (target2); + + return result; +} + +/* This target supports function multiversioning. */ + +static bool +ix86_supports_function_versions (void) +{ + return true; +} + static tree ix86_mangle_decl_assembler_name (tree decl, tree id) { @@ -28893,7 +28906,7 @@ is_function_default_version (const tree decl) { return (TREE_CODE (decl) == FUNCTION_DECL && DECL_FUNCTION_VERSIONED (decl) - && DECL_FUNCTION_SPECIFIC_TARGET (decl) == NULL_TREE); + && lookup_attribute ("target", DECL_ATTRIBUTES (decl)) == NULL_TREE); } /* Make a dispatcher declaration for the multi-versioned function DECL. @@ -42154,6 +42167,10 @@ ix86_memmodel_check (unsigned HOST_WIDE_INT val) #undef TARGET_OPTION_FUNCTION_VERSIONS #define TARGET_OPTION_FUNCTION_VERSIONS ix86_function_versions +#undef TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS +#define TARGET_OPTION_SUPPORTS_FUNCTION_VERSIONS \ + ix86_supports_function_versions + #undef TARGET_CAN_INLINE_P #define TARGET_CAN_INLINE_P ix86_can_inline_p