Message ID | 20230510090758.3737162-1-hongtao.liu@intel.com |
---|---|
State | New |
Headers | show |
Series | x86: Add a new option -mdaz-ftz to enable FTZ and DAZ flags in MXCSR. | expand |
On Wed, May 10, 2023 at 5:10 PM liuhongt <hongtao.liu@intel.com> wrote: > > > The quoted patch shows -shared in context and you didn't post a > > backport version > > to look at. But yes, we shouldn't change -shared behavior on a > > branch, even less so make it > > inconsistent between targets. > Here's the patch. > > Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. > Ok for GCC 11/12 backport? I'm going to push the patch next week if there's no objection. > > if (mdaz-ftz) > link crtfastmath.o > else if ((Ofast || ffast-math || funsafe-math-optimizations) > && !mno-daz-ftz) > link crtfastmath.o > else > Don't link crtfastmath.o > > gcc/ChangeLog: > > * config/i386/cygwin.h (ENDFILE_SPEC): Link crtfastmath.o > whenever -mdaz-ftz is specified. Don't link crtfastmath.o > when -mno-daz-ftz is specified. > * config/i386/darwin.h (ENDFILE_SPEC): Ditto. > * config/i386/gnu-user-common.h > (GNU_USER_TARGET_MATHFILE_SPEC): Ditto. > * config/i386/mingw32.h (ENDFILE_SPEC): Ditto. > * config/i386/i386.opt (mdaz-ftz): New option. > * doc/invoke.texi (x86 options): Document mftz-daz. > --- > gcc/config/i386/cygwin.h | 2 +- > gcc/config/i386/darwin.h | 4 ++-- > gcc/config/i386/gnu-user-common.h | 2 +- > gcc/config/i386/i386.opt | 4 ++++ > gcc/config/i386/mingw32.h | 2 +- > gcc/doc/invoke.texi | 11 ++++++++++- > 6 files changed, 19 insertions(+), 6 deletions(-) > > diff --git a/gcc/config/i386/cygwin.h b/gcc/config/i386/cygwin.h > index d06eda369cf..5412c5d4479 100644 > --- a/gcc/config/i386/cygwin.h > +++ b/gcc/config/i386/cygwin.h > @@ -57,7 +57,7 @@ along with GCC; see the file COPYING3. If not see > > #undef ENDFILE_SPEC > #define ENDFILE_SPEC \ > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s}\ > + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > %{!shared:%:if-exists(default-manifest.o%s)}\ > %{fvtable-verify=none:%s; \ > fvtable-verify=preinit:vtv_end.o%s; \ > diff --git a/gcc/config/i386/darwin.h b/gcc/config/i386/darwin.h > index a55f6b2b874..2f773924d6e 100644 > --- a/gcc/config/i386/darwin.h > +++ b/gcc/config/i386/darwin.h > @@ -109,8 +109,8 @@ along with GCC; see the file COPYING3. If not see > "%{!force_cpusubtype_ALL:-force_cpusubtype_ALL} " > > #undef ENDFILE_SPEC > -#define ENDFILE_SPEC \ > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ > +#define ENDFILE_SPEC > +\ "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > %{mpc32:crtprec32.o%s} \ > %{mpc64:crtprec64.o%s} \ > %{mpc80:crtprec80.o%s}" TM_DESTRUCTOR > diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h > index 23b54c5be52..3d2a33f1714 100644 > --- a/gcc/config/i386/gnu-user-common.h > +++ b/gcc/config/i386/gnu-user-common.h > @@ -47,7 +47,7 @@ along with GCC; see the file COPYING3. If not see > > /* Similar to standard GNU userspace, but adding -ffast-math support. */ > #define GNU_USER_TARGET_MATHFILE_SPEC \ > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ > + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > %{mpc32:crtprec32.o%s} \ > %{mpc64:crtprec64.o%s} \ > %{mpc80:crtprec80.o%s}" > diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt > index a3675e515bc..5cfb7cdcbc2 100644 > --- a/gcc/config/i386/i386.opt > +++ b/gcc/config/i386/i386.opt > @@ -420,6 +420,10 @@ mpc80 > Target RejectNegative > Set 80387 floating-point precision to 80-bit. > > +mdaz-ftz > +Target > +Set the FTZ and DAZ Flags. > + > mpreferred-stack-boundary= > Target RejectNegative Joined UInteger Var(ix86_preferred_stack_boundary_arg) > Attempt to keep stack aligned to this power of 2. > diff --git a/gcc/config/i386/mingw32.h b/gcc/config/i386/mingw32.h > index d3ca0cd0279..ddbe6a4054b 100644 > --- a/gcc/config/i386/mingw32.h > +++ b/gcc/config/i386/mingw32.h > @@ -197,7 +197,7 @@ along with GCC; see the file COPYING3. If not see > > #undef ENDFILE_SPEC > #define ENDFILE_SPEC \ > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ > + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > %{!shared:%:if-exists(default-manifest.o%s)}\ > %{fvtable-verify=none:%s; \ > fvtable-verify=preinit:vtv_end.o%s; \ > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > index cb83dd8a1cc..87eedfffa6c 100644 > --- a/gcc/doc/invoke.texi > +++ b/gcc/doc/invoke.texi > @@ -1434,7 +1434,7 @@ See RS/6000 and PowerPC Options. > -m96bit-long-double -mlong-double-64 -mlong-double-80 -mlong-double-128 @gol > -mregparm=@var{num} -msseregparm @gol > -mveclibabi=@var{type} -mvect8-ret-in-mem @gol > --mpc32 -mpc64 -mpc80 -mstackrealign @gol > +-mpc32 -mpc64 -mpc80 -mdaz-ftz -mstackrealign @gol > -momit-leaf-frame-pointer -mno-red-zone -mno-tls-direct-seg-refs @gol > -mcmodel=@var{code-model} -mabi=@var{name} -maddress-mode=@var{mode} @gol > -m32 -m64 -mx32 -m16 -miamcu -mlarge-data-threshold=@var{num} @gol > @@ -32078,6 +32078,15 @@ are enabled by default; routines in such libraries could suffer significant > loss of accuracy, typically through so-called ``catastrophic cancellation'', > when this option is used to set the precision to less than extended precision. > > +@item -mdaz-ftz > +@opindex mdaz-ftz > + > +The flush-to-zero (FTZ) and denormals-are-zero (DAZ) flags in the MXCSR register > +are used to control floating-point calculations.SSE and AVX instructions > +including scalar and vector instructions could benefit from enabling the FTZ > +and DAZ flags when @option{-mdaz-ftz} is specified. Don't set FTZ/DAZ flags > +when @option{-mno-daz-ftz} is specified. > + > @item -mstackrealign > @opindex mstackrealign > Realign the stack at entry. On the x86, the @option{-mstackrealign} > -- > 2.39.1.388.g2fc9e9ca3c >
On Fri, May 12, 2023 at 1:43 PM Hongtao Liu <crazylht@gmail.com> wrote: > > On Wed, May 10, 2023 at 5:10 PM liuhongt <hongtao.liu@intel.com> wrote: > > > > > The quoted patch shows -shared in context and you didn't post a > > > backport version > > > to look at. But yes, we shouldn't change -shared behavior on a > > > branch, even less so make it > > > inconsistent between targets. > > Here's the patch. > > > > Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}. > > Ok for GCC 11/12 backport? > I'm going to push the patch next week if there's no objection. pushed to gcc-11/gcc-12 branch. > > > > if (mdaz-ftz) > > link crtfastmath.o > > else if ((Ofast || ffast-math || funsafe-math-optimizations) > > && !mno-daz-ftz) > > link crtfastmath.o > > else > > Don't link crtfastmath.o > > > > gcc/ChangeLog: > > > > * config/i386/cygwin.h (ENDFILE_SPEC): Link crtfastmath.o > > whenever -mdaz-ftz is specified. Don't link crtfastmath.o > > when -mno-daz-ftz is specified. > > * config/i386/darwin.h (ENDFILE_SPEC): Ditto. > > * config/i386/gnu-user-common.h > > (GNU_USER_TARGET_MATHFILE_SPEC): Ditto. > > * config/i386/mingw32.h (ENDFILE_SPEC): Ditto. > > * config/i386/i386.opt (mdaz-ftz): New option. > > * doc/invoke.texi (x86 options): Document mftz-daz. > > --- > > gcc/config/i386/cygwin.h | 2 +- > > gcc/config/i386/darwin.h | 4 ++-- > > gcc/config/i386/gnu-user-common.h | 2 +- > > gcc/config/i386/i386.opt | 4 ++++ > > gcc/config/i386/mingw32.h | 2 +- > > gcc/doc/invoke.texi | 11 ++++++++++- > > 6 files changed, 19 insertions(+), 6 deletions(-) > > > > diff --git a/gcc/config/i386/cygwin.h b/gcc/config/i386/cygwin.h > > index d06eda369cf..5412c5d4479 100644 > > --- a/gcc/config/i386/cygwin.h > > +++ b/gcc/config/i386/cygwin.h > > @@ -57,7 +57,7 @@ along with GCC; see the file COPYING3. If not see > > > > #undef ENDFILE_SPEC > > #define ENDFILE_SPEC \ > > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s}\ > > + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > > %{!shared:%:if-exists(default-manifest.o%s)}\ > > %{fvtable-verify=none:%s; \ > > fvtable-verify=preinit:vtv_end.o%s; \ > > diff --git a/gcc/config/i386/darwin.h b/gcc/config/i386/darwin.h > > index a55f6b2b874..2f773924d6e 100644 > > --- a/gcc/config/i386/darwin.h > > +++ b/gcc/config/i386/darwin.h > > @@ -109,8 +109,8 @@ along with GCC; see the file COPYING3. If not see > > "%{!force_cpusubtype_ALL:-force_cpusubtype_ALL} " > > > > #undef ENDFILE_SPEC > > -#define ENDFILE_SPEC \ > > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ > > +#define ENDFILE_SPEC > > +\ "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > > %{mpc32:crtprec32.o%s} \ > > %{mpc64:crtprec64.o%s} \ > > %{mpc80:crtprec80.o%s}" TM_DESTRUCTOR > > diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h > > index 23b54c5be52..3d2a33f1714 100644 > > --- a/gcc/config/i386/gnu-user-common.h > > +++ b/gcc/config/i386/gnu-user-common.h > > @@ -47,7 +47,7 @@ along with GCC; see the file COPYING3. If not see > > > > /* Similar to standard GNU userspace, but adding -ffast-math support. */ > > #define GNU_USER_TARGET_MATHFILE_SPEC \ > > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ > > + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > > %{mpc32:crtprec32.o%s} \ > > %{mpc64:crtprec64.o%s} \ > > %{mpc80:crtprec80.o%s}" > > diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt > > index a3675e515bc..5cfb7cdcbc2 100644 > > --- a/gcc/config/i386/i386.opt > > +++ b/gcc/config/i386/i386.opt > > @@ -420,6 +420,10 @@ mpc80 > > Target RejectNegative > > Set 80387 floating-point precision to 80-bit. > > > > +mdaz-ftz > > +Target > > +Set the FTZ and DAZ Flags. > > + > > mpreferred-stack-boundary= > > Target RejectNegative Joined UInteger Var(ix86_preferred_stack_boundary_arg) > > Attempt to keep stack aligned to this power of 2. > > diff --git a/gcc/config/i386/mingw32.h b/gcc/config/i386/mingw32.h > > index d3ca0cd0279..ddbe6a4054b 100644 > > --- a/gcc/config/i386/mingw32.h > > +++ b/gcc/config/i386/mingw32.h > > @@ -197,7 +197,7 @@ along with GCC; see the file COPYING3. If not see > > > > #undef ENDFILE_SPEC > > #define ENDFILE_SPEC \ > > - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ > > + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ > > %{!shared:%:if-exists(default-manifest.o%s)}\ > > %{fvtable-verify=none:%s; \ > > fvtable-verify=preinit:vtv_end.o%s; \ > > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi > > index cb83dd8a1cc..87eedfffa6c 100644 > > --- a/gcc/doc/invoke.texi > > +++ b/gcc/doc/invoke.texi > > @@ -1434,7 +1434,7 @@ See RS/6000 and PowerPC Options. > > -m96bit-long-double -mlong-double-64 -mlong-double-80 -mlong-double-128 @gol > > -mregparm=@var{num} -msseregparm @gol > > -mveclibabi=@var{type} -mvect8-ret-in-mem @gol > > --mpc32 -mpc64 -mpc80 -mstackrealign @gol > > +-mpc32 -mpc64 -mpc80 -mdaz-ftz -mstackrealign @gol > > -momit-leaf-frame-pointer -mno-red-zone -mno-tls-direct-seg-refs @gol > > -mcmodel=@var{code-model} -mabi=@var{name} -maddress-mode=@var{mode} @gol > > -m32 -m64 -mx32 -m16 -miamcu -mlarge-data-threshold=@var{num} @gol > > @@ -32078,6 +32078,15 @@ are enabled by default; routines in such libraries could suffer significant > > loss of accuracy, typically through so-called ``catastrophic cancellation'', > > when this option is used to set the precision to less than extended precision. > > > > +@item -mdaz-ftz > > +@opindex mdaz-ftz > > + > > +The flush-to-zero (FTZ) and denormals-are-zero (DAZ) flags in the MXCSR register > > +are used to control floating-point calculations.SSE and AVX instructions > > +including scalar and vector instructions could benefit from enabling the FTZ > > +and DAZ flags when @option{-mdaz-ftz} is specified. Don't set FTZ/DAZ flags > > +when @option{-mno-daz-ftz} is specified. > > + > > @item -mstackrealign > > @opindex mstackrealign > > Realign the stack at entry. On the x86, the @option{-mstackrealign} > > -- > > 2.39.1.388.g2fc9e9ca3c > > > > > -- > BR, > Hongtao
diff --git a/gcc/config/i386/cygwin.h b/gcc/config/i386/cygwin.h index d06eda369cf..5412c5d4479 100644 --- a/gcc/config/i386/cygwin.h +++ b/gcc/config/i386/cygwin.h @@ -57,7 +57,7 @@ along with GCC; see the file COPYING3. If not see #undef ENDFILE_SPEC #define ENDFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s}\ + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ %{!shared:%:if-exists(default-manifest.o%s)}\ %{fvtable-verify=none:%s; \ fvtable-verify=preinit:vtv_end.o%s; \ diff --git a/gcc/config/i386/darwin.h b/gcc/config/i386/darwin.h index a55f6b2b874..2f773924d6e 100644 --- a/gcc/config/i386/darwin.h +++ b/gcc/config/i386/darwin.h @@ -109,8 +109,8 @@ along with GCC; see the file COPYING3. If not see "%{!force_cpusubtype_ALL:-force_cpusubtype_ALL} " #undef ENDFILE_SPEC -#define ENDFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ +#define ENDFILE_SPEC +\ "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ %{mpc32:crtprec32.o%s} \ %{mpc64:crtprec64.o%s} \ %{mpc80:crtprec80.o%s}" TM_DESTRUCTOR diff --git a/gcc/config/i386/gnu-user-common.h b/gcc/config/i386/gnu-user-common.h index 23b54c5be52..3d2a33f1714 100644 --- a/gcc/config/i386/gnu-user-common.h +++ b/gcc/config/i386/gnu-user-common.h @@ -47,7 +47,7 @@ along with GCC; see the file COPYING3. If not see /* Similar to standard GNU userspace, but adding -ffast-math support. */ #define GNU_USER_TARGET_MATHFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ %{mpc32:crtprec32.o%s} \ %{mpc64:crtprec64.o%s} \ %{mpc80:crtprec80.o%s}" diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt index a3675e515bc..5cfb7cdcbc2 100644 --- a/gcc/config/i386/i386.opt +++ b/gcc/config/i386/i386.opt @@ -420,6 +420,10 @@ mpc80 Target RejectNegative Set 80387 floating-point precision to 80-bit. +mdaz-ftz +Target +Set the FTZ and DAZ Flags. + mpreferred-stack-boundary= Target RejectNegative Joined UInteger Var(ix86_preferred_stack_boundary_arg) Attempt to keep stack aligned to this power of 2. diff --git a/gcc/config/i386/mingw32.h b/gcc/config/i386/mingw32.h index d3ca0cd0279..ddbe6a4054b 100644 --- a/gcc/config/i386/mingw32.h +++ b/gcc/config/i386/mingw32.h @@ -197,7 +197,7 @@ along with GCC; see the file COPYING3. If not see #undef ENDFILE_SPEC #define ENDFILE_SPEC \ - "%{Ofast|ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \ + "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \ %{!shared:%:if-exists(default-manifest.o%s)}\ %{fvtable-verify=none:%s; \ fvtable-verify=preinit:vtv_end.o%s; \ diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index cb83dd8a1cc..87eedfffa6c 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -1434,7 +1434,7 @@ See RS/6000 and PowerPC Options. -m96bit-long-double -mlong-double-64 -mlong-double-80 -mlong-double-128 @gol -mregparm=@var{num} -msseregparm @gol -mveclibabi=@var{type} -mvect8-ret-in-mem @gol --mpc32 -mpc64 -mpc80 -mstackrealign @gol +-mpc32 -mpc64 -mpc80 -mdaz-ftz -mstackrealign @gol -momit-leaf-frame-pointer -mno-red-zone -mno-tls-direct-seg-refs @gol -mcmodel=@var{code-model} -mabi=@var{name} -maddress-mode=@var{mode} @gol -m32 -m64 -mx32 -m16 -miamcu -mlarge-data-threshold=@var{num} @gol @@ -32078,6 +32078,15 @@ are enabled by default; routines in such libraries could suffer significant loss of accuracy, typically through so-called ``catastrophic cancellation'', when this option is used to set the precision to less than extended precision. +@item -mdaz-ftz +@opindex mdaz-ftz + +The flush-to-zero (FTZ) and denormals-are-zero (DAZ) flags in the MXCSR register +are used to control floating-point calculations.SSE and AVX instructions +including scalar and vector instructions could benefit from enabling the FTZ +and DAZ flags when @option{-mdaz-ftz} is specified. Don't set FTZ/DAZ flags +when @option{-mno-daz-ftz} is specified. + @item -mstackrealign @opindex mstackrealign Realign the stack at entry. On the x86, the @option{-mstackrealign}