On Sat, 2 Jan 2016 00:30:58 -0700 Jeff Law <l...@redhat.com> wrote: > > That way gcc will be able to compile glibc's ld: PR/60465 > Egad. PIC on ia64 is a mess. I can kind of see what Richard was trying > to do, but ewww. I don't think it's worth the effort to deep dive into > the PIC support and make ia64 handle things like most other ports -- > it's a dead architecture so ISTM the easiest fix is the right fix. > > A few, relatively minor things.
> > diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
> > index f48cebc..6ea5072 100644
> > --- a/gcc/config/ia64/ia64.c
> > +++ b/gcc/config/ia64/ia64.c
> > @@ -1105,6 +1105,8 @@ ia64_expand_load_address (rtx dest, rtx src)
> > emit_insn (gen_load_fptr (dest, src));
> > else if (sdata_symbolic_operand (src, VOIDmode))
> > emit_insn (gen_load_gprel (dest, src));
> > + else if (local_symbolic_operand64 (src, VOIDmode))
> > + emit_insn (gen_load_gprel64 (dest, src));
> Comment here. Something like
>
> /* We want to use gprel rather than ltoff relocations for
> local symbolic operands. */
Done. Hope not too wordy :)
>
> >
> > +;; True if OP refers to a local symbol +any large offset).
> ;; True if OP refers to a local symbol [+ any offset ]
>
> I haven't dug into the ia64 port (and I'm not planning to) to see if/how
> it MINUS in symbolic expressions. It's been the source of problems in
> various ports trough the years.
>
> Can you take the testcase from your post as well as the one from BZ60465
> comment #37 (from you) and add them to the testsuite?
Added both tests.
> Note you're not running the full testsuite, just a few dozen ia64
> specific tests, which will include your new tests. ANd you're not
> rebuilding the whole compiler between those steps, just ia64.o and
> relinking the compiler. So it ought to be reasonably fast.
>
> So to summarize, I think your patch needs the two trivial comment fixes
> noted above, 2 testcases and the before/after results of running just
> the ia64.exp tests. Repost with that and I'll get it into the tree.
--- ia64-before.log 2016-01-02 11:20:21.000000000 +0000
+++ ia64-after.log 2016-01-02 11:22:37.000000000 +0000
@@ -1 +1 @@
-Test Run By slyfox on Sat Jan 2 11:19:38 2016
+Test Run By slyfox on Sat Jan 2 11:22:16 2016
@@ -26,2 +25,0 @@
-FAIL: gcc.target/ia64/pr60465-gprel64-c37.c scan-assembler-not @ltoffx
-FAIL: gcc.target/ia64/pr60465-gprel64.c scan-assembler-not @ltoffx
@@ -31,2 +29,2 @@
-# of expected passes 147
-# of unexpected failures 11
+# of expected passes 149
+# of unexpected failures 9
I did ran tests only on amd64 host thus the execution failure tests.
Attached updated patch and test runs on a crosscompiler before
and after the change.
Now I'm building on real ia64 hardware as
make bootstrap
make -k check
for both clean and patched trees.
--
Sergei
From 04a34fd97cffae4f40e1c226489129f42f3ceb2a Mon Sep 17 00:00:00 2001
From: Sergei Trofimovich <siarh...@google.com>
Date: Mon, 28 Dec 2015 17:33:43 +0000
Subject: [PATCH] ia64: don't use dynamic relocations for local symbols
Tested on the following example:
void * a[77] __attribute((visibility("hidden")));
void f(long o, void * v) { a[0x6ffffeff - o + 66] = v; }
Before the patch generated code uses .GOT entry:
addl r14 = @ltoffx(a#), r1
ld8.mov r14 = [r14], a#
After the patch generated code uses static gprel relocation:
movl r14 = @gprel(a#)
add r14 = r1, r14
That way gcc will be able to compile glibc's ld: PR/60465
Bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60465
Signed-off-by: Sergei Trofimovich <siarh...@google.com>
---
gcc/config/ia64/ia64.c | 9 ++++++++
gcc/config/ia64/predicates.md | 26 +++++++++++++++++++++
.../gcc.target/ia64/pr60465-gprel64-c37.c | 10 ++++++++
gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c | 27 ++++++++++++++++++++++
4 files changed, 72 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/ia64/pr60465-gprel64-c37.c
create mode 100644 gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c
diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index f48cebc..ccf2bec 100644
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -1105,6 +1105,15 @@ ia64_expand_load_address (rtx dest, rtx src)
emit_insn (gen_load_fptr (dest, src));
else if (sdata_symbolic_operand (src, VOIDmode))
emit_insn (gen_load_gprel (dest, src));
+ else if (local_symbolic_operand64 (src, VOIDmode))
+ {
+ /* We want to use @gprel rather than @ltoff relocations for local
+ symbols:
+ - @gprel does not require dynamic linker
+ - and does not use .sdata section
+ https://gcc.gnu.org/bugzilla/60465 */
+ emit_insn (gen_load_gprel64 (dest, src));
+ }
else
{
HOST_WIDE_INT addend = 0;
diff --git a/gcc/config/ia64/predicates.md b/gcc/config/ia64/predicates.md
index 2aa7a78..1a461ed 100644
--- a/gcc/config/ia64/predicates.md
+++ b/gcc/config/ia64/predicates.md
@@ -97,6 +97,32 @@
}
})
+;; True if OP refers to a local symbol [+any offset].
+;; To be encoded as:
+;; movl % = @gprel(symbol+offset)
+;; add % = %, gp
+(define_predicate "local_symbolic_operand64"
+ (match_code "symbol_ref,const")
+{
+ switch (GET_CODE (op))
+ {
+ case CONST:
+ op = XEXP (op, 0);
+ if (GET_CODE (op) != PLUS
+ || GET_CODE (XEXP (op, 0)) != SYMBOL_REF
+ || GET_CODE (XEXP (op, 1)) != CONST_INT)
+ return false;
+ op = XEXP (op, 0);
+ /* FALLTHRU */
+
+ case SYMBOL_REF:
+ return SYMBOL_REF_LOCAL_P (op);
+
+ default:
+ gcc_unreachable ();
+ }
+})
+
;; True if OP refers to a symbol in the small address area.
(define_predicate "small_addr_symbolic_operand"
(match_code "symbol_ref,const")
diff --git a/gcc/testsuite/gcc.target/ia64/pr60465-gprel64-c37.c
b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64-c37.c
new file mode 100644
index 0000000..a7e6809
--- /dev/null
+++ b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64-c37.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia64-*-* } } */
+/* { dg-options "-O2 -fpic" } */
+/* { dg-final { scan-assembler-not "@ltoffx" } } */
+
+/* A bit of https://bugzilla.redhat.com/show_bug.cgi?id=33354
+ where many stores to static variables overflow .sdata */
+
+static const char *s90;
+void f() { s90 = "string 90"; }
+const char * g() { return s90; }
diff --git a/gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c
b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c
new file mode 100644
index 0000000..c00ecc9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/ia64/pr60465-gprel64.c
@@ -0,0 +1,27 @@
+/* { dg-do compile { target ia64-*-* } } */
+/* { dg-options "-O2 -fpic" } */
+/* { dg-final { scan-assembler-not "@ltoffx" } } */
+
+/* Test imitates early ld.so setup in glibc
+ where no dynamic relocations must be present. */
+
+struct rtld_global
+{
+ long *p[77];
+};
+
+struct rtld_global _rtld_local __attribute__ ((visibility ("hidden"), section
(".sdata")));
+
+static void __attribute__ ((unused, noinline))
+elf_get_dynamic_info (struct rtld_global * g, long * dyn)
+{
+ long **info = g->p;
+
+ info[(0x6ffffeff - *dyn) + 66] = dyn;
+}
+
+void __attribute__ ((unused, noinline))
+_dl_start (long * dyn)
+{
+ elf_get_dynamic_info(&_rtld_local, dyn);
+}
--
2.6.4
Test Run By slyfox on Sat Jan 2 11:22:16 2016
Target is ia64-unknown-linux-gnu
Host is x86_64-pc-linux-gnu
=== gcc tests ===
Schedule of variations:
unix
Running target unix
Using /usr/share/dejagnu/baseboards/unix.exp as board description file for target.
Using /usr/share/dejagnu/config/unix.exp as generic interface file for target.
Using /home/slyfox/dev/git/gcc/gcc/testsuite/config/default.exp as tool-and-target-specific interface file.
WARNING: Assuming target board is the local machine (which is probably wrong).
You may need to set your DEJAGNU environment variable.
Running /home/slyfox/dev/git/gcc/gcc/testsuite/gcc.target/ia64/ia64.exp ...
FAIL: gcc.target/ia64/20030225-2.c execution test
FAIL: gcc.target/ia64/20040303-1.c execution test
FAIL: gcc.target/ia64/asm-1.c execution test
FAIL: gcc.target/ia64/float80-1.c execution test
FAIL: gcc.target/ia64/float80-2.c execution test
FAIL: gcc.target/ia64/float80-varargs-1.c execution test
FAIL: gcc.target/ia64/pr42542-1.c execution test
FAIL: gcc.target/ia64/pr42542-2.c execution test
FAIL: gcc.target/ia64/pr42542-3.c execution test
=== gcc Summary ===
# of expected passes 149
# of unexpected failures 9
# of unsupported tests 4
/home/slyfox/dev/git/gcc-ia64/gcc/xgcc version 6.0.0 20151228 (experimental) (GCC)
Test Run By slyfox on Sat Jan 2 11:19:38 2016
Target is ia64-unknown-linux-gnu
Host is x86_64-pc-linux-gnu
=== gcc tests ===
Schedule of variations:
unix
Running target unix
Using /usr/share/dejagnu/baseboards/unix.exp as board description file for target.
Using /usr/share/dejagnu/config/unix.exp as generic interface file for target.
Using /home/slyfox/dev/git/gcc/gcc/testsuite/config/default.exp as tool-and-target-specific interface file.
WARNING: Assuming target board is the local machine (which is probably wrong).
You may need to set your DEJAGNU environment variable.
Running /home/slyfox/dev/git/gcc/gcc/testsuite/gcc.target/ia64/ia64.exp ...
FAIL: gcc.target/ia64/20030225-2.c execution test
FAIL: gcc.target/ia64/20040303-1.c execution test
FAIL: gcc.target/ia64/asm-1.c execution test
FAIL: gcc.target/ia64/float80-1.c execution test
FAIL: gcc.target/ia64/float80-2.c execution test
FAIL: gcc.target/ia64/float80-varargs-1.c execution test
FAIL: gcc.target/ia64/pr42542-1.c execution test
FAIL: gcc.target/ia64/pr42542-2.c execution test
FAIL: gcc.target/ia64/pr42542-3.c execution test
FAIL: gcc.target/ia64/pr60465-gprel64-c37.c scan-assembler-not @ltoffx
FAIL: gcc.target/ia64/pr60465-gprel64.c scan-assembler-not @ltoffx
=== gcc Summary ===
# of expected passes 147
# of unexpected failures 11
# of unsupported tests 4
/home/slyfox/dev/git/gcc-ia64/gcc/xgcc version 6.0.0 20151228 (experimental) (GCC)
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