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Re: [PR47785] COLLECT_AS_OPTIONS
Hi Richard,
Thanks for the review.
On Wed, 23 Oct 2019 at 23:07, Richard Biener <richard.guenther@gmail.com> wrote:
>
> On Mon, Oct 21, 2019 at 10:04 AM Kugan Vivekanandarajah
> <kugan.vivekanandarajah@linaro.org> wrote:
> >
> > Hi Richard,
> >
> > Thanks for the pointers.
> >
> >
> >
> > On Fri, 11 Oct 2019 at 22:33, Richard Biener <richard.guenther@gmail.com> wrote:
> > >
> > > On Fri, Oct 11, 2019 at 6:15 AM Kugan Vivekanandarajah
> > > <kugan.vivekanandarajah@linaro.org> wrote:
> > > >
> > > > Hi Richard,
> > > > Thanks for the review.
> > > >
> > > > On Wed, 2 Oct 2019 at 20:41, Richard Biener <richard.guenther@gmail.com> wrote:
> > > > >
> > > > > On Wed, Oct 2, 2019 at 10:39 AM Kugan Vivekanandarajah
> > > > > <kugan.vivekanandarajah@linaro.org> wrote:
> > > > > >
> > > > > > Hi,
> > > > > >
> > > > > > As mentioned in the PR, attached patch adds COLLECT_AS_OPTIONS for
> > > > > > passing assembler options specified with -Wa, to the link-time driver.
> > > > > >
> > > > > > The proposed solution only works for uniform -Wa options across all
> > > > > > TUs. As mentioned by Richard Biener, supporting non-uniform -Wa flags
> > > > > > would require either adjusting partitioning according to flags or
> > > > > > emitting multiple object files from a single LTRANS CU. We could
> > > > > > consider this as a follow up.
> > > > > >
> > > > > > Bootstrapped and regression tests on arm-linux-gcc. Is this OK for trunk?
> > > > >
> > > > > While it works for your simple cases it is unlikely to work in practice since
> > > > > your implementation needs the assembler options be present at the link
> > > > > command line. I agree that this might be the way for people to go when
> > > > > they face the issue but then it needs to be documented somewhere
> > > > > in the manual.
> > > > >
> > > > > That is, with COLLECT_AS_OPTION (why singular? I'd expected
> > > > > COLLECT_AS_OPTIONS) available to cc1 we could stream this string
> > > > > to lto_options and re-materialize it at link time (and diagnose mismatches
> > > > > even if we like).
> > > > OK. I will try to implement this. So the idea is if we provide
> > > > -Wa,options as part of the lto compile, this should be available
> > > > during link time. Like in:
> > > >
> > > > arm-linux-gnueabihf-gcc -march=armv7-a -mthumb -O2 -flto
> > > > -Wa,-mimplicit-it=always,-mthumb -c test.c
> > > > arm-linux-gnueabihf-gcc -flto test.o
> > > >
> > > > I am not sure where should we stream this. Currently, cl_optimization
> > > > has all the optimization flag provided for compiler and it is
> > > > autogenerated and all the flags are integer values. Do you have any
> > > > preference or example where this should be done.
> > >
> > > In lto_write_options, I'd simply append the contents of COLLECT_AS_OPTIONS
> > > (with -Wa, prepended to each of them), then recover them in lto-wrapper
> > > for each TU and pass them down to the LTRANS compiles (if they agree
> > > for all TUs, otherwise I'd warn and drop them).
> >
> > Attached patch streams it and also make sure that the options are the
> > same for all the TUs. Maybe it is a bit restrictive.
> >
> > What is the best place to document COLLECT_AS_OPTIONS. We don't seem
> > to document COLLECT_GCC_OPTIONS anywhere ?
>
> Nowhere, it's an implementation detail then.
>
> > Attached patch passes regression and also fixes the original ARM
> > kernel build issue with tumb2.
>
> Did you try this with multiple assembler options? I see you stream
> them as -Wa,-mfpu=xyz,-mthumb but then compare the whole
> option strings so a mismatch with -Wa,-mthumb,-mfpu=xyz would be
> diagnosed. If there's a spec induced -Wa option do we get to see
> that as well? I can imagine -march=xyz enabling a -Wa option
> for example.
>
> + *collect_as = XNEWVEC (char, strlen (args_text) + 1);
> + strcpy (*collect_as, args_text);
>
> there's strdup. Btw, I'm not sure why you don't simply leave
> the -Wa option in the merged options [individually] and match
> them up but go the route of comparing strings and carrying that
> along separately. I think that would be much better.
Is attached patch which does this is OK?
Thanks,
Kugan
>
> Thanks and sorry for the delay.
> Richard.
>
> > Thanks,
> > Kugan
> > >
> > > Richard.
> > >
> > > > Thanks,
> > > > Kugan
> > > >
> > > >
> > > >
> > > > >
> > > > > Richard.
> > > > >
> > > > > > Thanks,
> > > > > > Kugan
> > > > > >
> > > > > >
> > > > > > gcc/ChangeLog:
> > > > > >
> > > > > > 2019-10-02 kugan.vivekanandarajah <kugan.vivekanandarajah@linaro.org>
> > > > > >
> > > > > > PR lto/78353
> > > > > > * gcc.c (putenv_COLLECT_AS_OPTION): New to set COLLECT_AS_OPTION in env.
> > > > > > (driver::main): Call putenv_COLLECT_AS_OPTION.
> > > > > > * lto-wrapper.c (run_gcc): use COLLECT_AS_OPTION from env.
> > > > > >
> > > > > > gcc/testsuite/ChangeLog:
> > > > > >
> > > > > > 2019-10-02 kugan.vivekanandarajah <kugan.vivekanandarajah@linaro.org>
> > > > > >
> > > > > > PR lto/78353
> > > > > > * gcc.target/arm/pr78353-1.c: New test.
> > > > > > * gcc.target/arm/pr78353-2.c: New test.
From c74b6f58b7ddb84eece309d28092787590bd130a Mon Sep 17 00:00:00 2001
From: Kugan <kugan.vivekanandarajah@linaro.org>
Date: Sat, 28 Sep 2019 02:11:49 +1000
Subject: [PATCH] COLLECT_AS support
Change-Id: I61689f9c7c8672e4a19461b99932750d8dfc62ae
---
gcc/gcc.c | 29 +++++++++++++++++
gcc/lto-opts.c | 16 ++++++++--
gcc/lto-wrapper.c | 40 ++++++++++++++++++++++++
gcc/testsuite/gcc.target/arm/pr78353-1.c | 9 ++++++
gcc/testsuite/gcc.target/arm/pr78353-2.c | 9 ++++++
5 files changed, 101 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/arm/pr78353-1.c
create mode 100644 gcc/testsuite/gcc.target/arm/pr78353-2.c
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 1216cdd505a..dede47fb055 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -5239,6 +5239,34 @@ do_specs_vec (vec<char_p> vec)
}
}
+/* Store switches specified for as with -Wa in COLLECT_AS_OPTIONS
+ and place that in the environment. */
+static void
+putenv_COLLECT_AS_OPTIONS (vec<char_p> vec)
+{
+ unsigned ix;
+ char *opt;
+ int len = vec.length ();
+
+ if (!len)
+ return;
+
+ obstack_init (&collect_obstack);
+ obstack_grow (&collect_obstack, "COLLECT_AS_OPTIONS=",
+ sizeof ("COLLECT_AS_OPTIONS=") - 1);
+ obstack_grow (&collect_obstack, "-Wa,", strlen ("-Wa,"));
+
+ FOR_EACH_VEC_ELT (vec, ix, opt)
+ {
+ obstack_grow (&collect_obstack, opt, strlen (opt));
+ --len;
+ if (len)
+ obstack_grow (&collect_obstack, ",", strlen (","));
+ }
+
+ xputenv (XOBFINISH (&collect_obstack, char *));
+}
+
/* Process the sub-spec SPEC as a portion of a larger spec.
This is like processing a whole spec except that we do
not initialize at the beginning and we do not supply a
@@ -7360,6 +7388,7 @@ driver::main (int argc, char **argv)
global_initializations ();
build_multilib_strings ();
set_up_specs ();
+ putenv_COLLECT_AS_OPTIONS (assembler_options);
putenv_COLLECT_GCC (argv[0]);
maybe_putenv_COLLECT_LTO_WRAPPER ();
maybe_putenv_OFFLOAD_TARGETS ();
diff --git a/gcc/lto-opts.c b/gcc/lto-opts.c
index 0e9f24e1189..d89fe5cc4f9 100644
--- a/gcc/lto-opts.c
+++ b/gcc/lto-opts.c
@@ -166,8 +166,20 @@ lto_write_options (void)
obstack_grow (&temporary_obstack, "\0", 1);
args = XOBFINISH (&temporary_obstack, char *);
lto_write_data (args, strlen (args) + 1);
- lto_end_section ();
-
obstack_free (&temporary_obstack, NULL);
+ const char *collect_as_options = getenv ("COLLECT_AS_OPTIONS");
+
+ if (collect_as_options)
+ {
+ obstack_init (&temporary_obstack);
+ append_to_collect_gcc_options (&temporary_obstack, &first_p,
+ collect_as_options);
+ obstack_grow (&temporary_obstack, "\0", 1);
+ args = XOBFINISH (&temporary_obstack, char *);
+ lto_write_data (args, strlen (args) + 1);
+ obstack_free (&temporary_obstack, NULL);
+ }
+
+ lto_end_section ();
free (section_name);
}
diff --git a/gcc/lto-wrapper.c b/gcc/lto-wrapper.c
index 9a7bbd0c022..299d994a507 100644
--- a/gcc/lto-wrapper.c
+++ b/gcc/lto-wrapper.c
@@ -253,6 +253,11 @@ merge_and_complain (struct cl_decoded_option **decoded_options,
break;
default:
+ if (foption->opt_index == OPT_Wa_)
+ {
+ append_option (decoded_options, decoded_options_count, foption);
+ break;
+ }
if (!(cl_options[foption->opt_index].flags & CL_TARGET))
break;
@@ -574,6 +579,37 @@ parse_env_var (const char *str, char ***pvalues, const char *append)
return num;
}
+/* Append options OPTS from -Wa, options to ARGV_OBSTACK. */
+
+static void
+append_compiler_wa_options (obstack *argv_obstack,
+ struct cl_decoded_option *opts,
+ unsigned int count)
+{
+ static const char *collect_as;
+ for (unsigned int j = 1; j < count; ++j)
+ {
+ struct cl_decoded_option *option = &opts[j];
+ if (j == 1)
+ collect_as = NULL;
+ const char *args_text = option->orig_option_with_args_text;
+ switch (option->opt_index)
+ {
+ case OPT_Wa_:
+ break;
+ default:
+ continue;
+ }
+ /* We expect all the -Wa, options to be same. */
+ if (collect_as && strcmp (collect_as, args_text) != 0)
+ fatal_error (input_location, "-Wa, options does not match");
+ if (!collect_as)
+ {
+ obstack_ptr_grow (argv_obstack, args_text);
+ collect_as = args_text;
+ }
+ }
+}
/* Append options OPTS from lto or offload_lto sections to ARGV_OBSTACK. */
static void
@@ -846,6 +882,8 @@ compile_offload_image (const char *target, const char *compiler_path,
/* Append options from offload_lto sections. */
append_compiler_options (&argv_obstack, compiler_opts,
compiler_opt_count);
+ append_compiler_wa_options (&argv_obstack, compiler_opts,
+ compiler_opt_count);
append_diag_options (&argv_obstack, linker_opts, linker_opt_count);
/* Append options specified by -foffload last. In case of conflicting
@@ -1349,6 +1387,8 @@ run_gcc (unsigned argc, char *argv[])
append_compiler_options (&argv_obstack, fdecoded_options,
fdecoded_options_count);
+ append_compiler_wa_options (&argv_obstack, fdecoded_options,
+ fdecoded_options_count);
append_linker_options (&argv_obstack, decoded_options, decoded_options_count);
/* Scan linker driver arguments for things that are of relevance to us. */
diff --git a/gcc/testsuite/gcc.target/arm/pr78353-1.c b/gcc/testsuite/gcc.target/arm/pr78353-1.c
new file mode 100644
index 00000000000..bba81ee50c3
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pr78353-1.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-march=armv7-a -mthumb -O2 -flto -Wa,-mimplicit-it=always" } */
+
+int main(int x)
+{
+ asm("teq %0, #0; addne %0, %0, #1" : "=r" (x));
+ return x;
+}
+
diff --git a/gcc/testsuite/gcc.target/arm/pr78353-2.c b/gcc/testsuite/gcc.target/arm/pr78353-2.c
new file mode 100644
index 00000000000..776eb64b8c7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pr78353-2.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-march=armv7-a -mthumb -O2 -flto -Wa,-mimplicit-it=always,-mthumb" } */
+
+int main(int x)
+{
+ asm("teq %0, #0; addne %0, %0, #1" : "=r" (x));
+ return x;
+}
+
--
2.17.1