The change will skip a whole function from endbr processing by rest_of_insert_endbranch, which inserts endbr not only at the beginning of the function but inside the function's body also. For example, tests with setjmp should fail.
I would suggest to insert the check in rest_of_insert_endbranch function, something like this if (!(lookup_attribute ("nocf_check", TYPE_ATTRIBUTES (TREE_TYPE (cfun->decl))) || cgraph_node::get (fun->decl)->only_called_directly_p ()) Igor > -----Original Message----- > From: Uros Bizjak [mailto:ubiz...@gmail.com] > Sent: Monday, October 23, 2017 9:26 PM > To: H.J. Lu <hjl.to...@gmail.com> > Cc: gcc-patches@gcc.gnu.org; Tsimbalist, Igor V > <igor.v.tsimbal...@intel.com> > Subject: Re: [PATCH] i386: Don't generate ENDBR if function is only called > directly > > On Sun, Oct 22, 2017 at 4:13 PM, H.J. Lu <hjl.to...@gmail.com> wrote: > > There is no need to insert ENDBR instruction if function is only called > > directly. > > > > OK for trunk if there is no regressions? > > Patch needs to be OK'd by Igor first. > > Uros. > > > H.J. > > ---- > > gcc/ > > > > PR target/82659 > > * config/i386/i386.c (pass_insert_endbranch::gate): Return > > false if function is only called directly. > > > > gcc/testsuite/ > > > > PR target/82659 > > * gcc.target/i386/pr82659-1.c: New test. > > * gcc.target/i386/pr82659-2.c: Likewise. > > * gcc.target/i386/pr82659-3.c: Likewise. > > * gcc.target/i386/pr82659-4.c: Likewise. > > * gcc.target/i386/pr82659-5.c: Likewise. > > * gcc.target/i386/pr82659-6.c: Likewise. > > --- > > gcc/config/i386/i386.c | 6 ++++-- > > gcc/testsuite/gcc.target/i386/pr82659-1.c | 19 +++++++++++++++++++ > > gcc/testsuite/gcc.target/i386/pr82659-2.c | 18 ++++++++++++++++++ > > gcc/testsuite/gcc.target/i386/pr82659-3.c | 21 +++++++++++++++++++++ > > gcc/testsuite/gcc.target/i386/pr82659-4.c | 15 +++++++++++++++ > > gcc/testsuite/gcc.target/i386/pr82659-5.c | 10 ++++++++++ > > gcc/testsuite/gcc.target/i386/pr82659-6.c | 19 +++++++++++++++++++ > > 7 files changed, 106 insertions(+), 2 deletions(-) > > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-1.c > > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-2.c > > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-3.c > > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-4.c > > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-5.c > > create mode 100644 gcc/testsuite/gcc.target/i386/pr82659-6.c > > > > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c > > index fb0b7e71469..b86504378ae 100644 > > --- a/gcc/config/i386/i386.c > > +++ b/gcc/config/i386/i386.c > > @@ -2693,9 +2693,11 @@ public: > > {} > > > > /* opt_pass methods: */ > > - virtual bool gate (function *) > > + virtual bool gate (function *fun) > > { > > - return ((flag_cf_protection & CF_BRANCH) && TARGET_IBT); > > + return ((flag_cf_protection & CF_BRANCH) > > + && TARGET_IBT > > + && !cgraph_node::get (fun->decl)->only_called_directly_p ()); > > } > > > > virtual unsigned int execute (function *) > > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-1.c > b/gcc/testsuite/gcc.target/i386/pr82659-1.c > > new file mode 100644 > > index 00000000000..8f0a6906815 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/i386/pr82659-1.c > > @@ -0,0 +1,19 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-O2 -fcf-protection -mcet" } */ > > +/* { dg-final { scan-assembler-times "endbr32" 1 { target ia32 } } } */ > > +/* { dg-final { scan-assembler-times "endbr64" 1 { target { ! ia32 } } } } > > */ > > + > > +extern int x; > > + > > +static void > > +__attribute__ ((noinline, noclone)) > > +test (int i) > > +{ > > + x = i; > > +} > > + > > +void > > +bar (int i) > > +{ > > + test (i); > > +} > > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-2.c > b/gcc/testsuite/gcc.target/i386/pr82659-2.c > > new file mode 100644 > > index 00000000000..228a20006b6 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/i386/pr82659-2.c > > @@ -0,0 +1,18 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-O2 -fcf-protection -mcet" } */ > > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */ > > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } > > */ > > + > > +extern int x; > > + > > +void > > +test (int i) > > +{ > > + x = i; > > +} > > + > > +void > > +bar (int i) > > +{ > > + test (i); > > +} > > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-3.c > b/gcc/testsuite/gcc.target/i386/pr82659-3.c > > new file mode 100644 > > index 00000000000..6ae23e40abc > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/i386/pr82659-3.c > > @@ -0,0 +1,21 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-O2 -fcf-protection -mcet" } */ > > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */ > > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } > > */ > > + > > +extern int x; > > + > > +static void > > +__attribute__ ((noinline, noclone)) > > +test (int i) > > +{ > > + x = i; > > +} > > + > > +extern __typeof (test) foo __attribute__ ((alias ("test"))); > > + > > +void > > +bar (int i) > > +{ > > + test (i); > > +} > > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-4.c > b/gcc/testsuite/gcc.target/i386/pr82659-4.c > > new file mode 100644 > > index 00000000000..ca87264e98b > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/i386/pr82659-4.c > > @@ -0,0 +1,15 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-O2 -fcf-protection -mcet" } */ > > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */ > > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } > > */ > > + > > +static void > > +test (void) > > +{ > > +} > > + > > +void * > > +bar (void) > > +{ > > + return test; > > +} > > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-5.c > b/gcc/testsuite/gcc.target/i386/pr82659-5.c > > new file mode 100644 > > index 00000000000..c34eade0f90 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/i386/pr82659-5.c > > @@ -0,0 +1,10 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-O2 -fcf-protection -mcet" } */ > > +/* { dg-final { scan-assembler-times "endbr32" 1 { target ia32 } } } */ > > +/* { dg-final { scan-assembler-times "endbr64" 1 { target { ! ia32 } } } } > > */ > > +static void > > +test (void) > > +{ > > +} > > + > > +void (*test_p) (void) = test; > > diff --git a/gcc/testsuite/gcc.target/i386/pr82659-6.c > b/gcc/testsuite/gcc.target/i386/pr82659-6.c > > new file mode 100644 > > index 00000000000..b4ffd65c74f > > --- /dev/null > > +++ b/gcc/testsuite/gcc.target/i386/pr82659-6.c > > @@ -0,0 +1,19 @@ > > +/* { dg-do compile } */ > > +/* { dg-options "-O2 -fcf-protection -mcet" } */ > > +/* { dg-final { scan-assembler-times "endbr32" 2 { target ia32 } } } */ > > +/* { dg-final { scan-assembler-times "endbr64" 2 { target { ! ia32 } } } } > > */ > > + > > +extern int x; > > + > > + __attribute__ ((visibility ("hidden"))) > > +void > > +test (int i) > > +{ > > + x = i; > > +} > > + > > +void > > +bar (int i) > > +{ > > + test (i); > > +} > > -- > > 2.13.6 > >