On Wed, Jan 27, 2016 at 11:49 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Wed, Jan 27, 2016 at 8:25 PM, H.J. Lu <hongjiu...@intel.com> wrote:
>>
>> __tls_get_addr must be called with 16-byte aligned stack, which is
>> guaranted by setting preferred_stack_boundary to 128 bits. There
>> is no need to change stack_alignment_needed for __tls_get_addr.
>>
>> Tested on x86-64. OK for trunk?
>
> You know the purpose of these flags better than I, so - OK.
>
> Thanks,
> Uros.
>
>>
>> H.J.
>> --
>> PR target/68986
>> * config/i386/i386.c (ix86_update_stack_boundary): Don't
>> change stack_alignment_needed for __tls_get_addr call.
Here is the backport for GCC 5. Ok for gcc-5-branch?
--
H.J.
From 3c93d02be1e4b41d9116da6262cf083a65439280 Mon Sep 17 00:00:00 2001
From: hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue, 26 Jan 2016 12:51:07 +0000
Subject: [PATCH] Update preferred stack boundary in ix86_update_stack_boundary
__tls_get_addr must be called with 16-byte aligned stack, which is
guaranted by setting preferred_stack_boundary to 128 bits. Preferred
stack boundary adjustment for __tls_get_addr should be done in
ix86_update_stack_boundary, not ix86_compute_frame_layout Also
there is no need to over-align stack for __tls_get_addr and function
with __tls_get_addr call isn't a leaf function.
gcc/
Backport from mainline
PR target/68986
* config/i386/i386.c (ix86_compute_frame_layout): Move stack
alignment adjustment to ...
(ix86_update_stack_boundary): Here. Don't over-align stack nor
change stack_alignment_needed for __tls_get_addr.
(ix86_finalize_stack_realign_flags): Use stack_alignment_needed
if __tls_get_addr is called.
gcc/testsuite/
Backport from mainline
PR target/68986
* gcc.target/i386/pr68986-1.c: New test.
* gcc.target/i386/pr68986-2.c: Likewise.
* gcc.target/i386/pr68986-3.c: Likewise.
---
gcc/config/i386/i386.c | 26 ++++++++++----------------
gcc/testsuite/gcc.target/i386/pr68986-1.c | 11 +++++++++++
gcc/testsuite/gcc.target/i386/pr68986-2.c | 13 +++++++++++++
gcc/testsuite/gcc.target/i386/pr68986-3.c | 13 +++++++++++++
4 files changed, 47 insertions(+), 16 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr68986-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr68986-2.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr68986-3.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 504e8b8..a99d53b 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -10131,18 +10131,6 @@ ix86_compute_frame_layout (struct ix86_frame *frame)
crtl->preferred_stack_boundary = 128;
crtl->stack_alignment_needed = 128;
}
- /* preferred_stack_boundary is never updated for call
- expanded from tls descriptor. Update it here. We don't update it in
- expand stage because according to the comments before
- ix86_current_function_calls_tls_descriptor, tls calls may be optimized
- away. */
- else if (ix86_current_function_calls_tls_descriptor
- && crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
- {
- crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
- if (crtl->stack_alignment_needed < PREFERRED_STACK_BOUNDARY)
- crtl->stack_alignment_needed = PREFERRED_STACK_BOUNDARY;
- }
stack_alignment_needed = crtl->stack_alignment_needed / BITS_PER_UNIT;
preferred_alignment = crtl->preferred_stack_boundary / BITS_PER_UNIT;
@@ -10816,6 +10804,11 @@ ix86_update_stack_boundary (void)
&& cfun->stdarg
&& crtl->stack_alignment_estimated < 128)
crtl->stack_alignment_estimated = 128;
+
+ /* __tls_get_addr needs to be called with 16-byte aligned stack. */
+ if (ix86_tls_descriptor_calls_expanded_in_cfun
+ && crtl->preferred_stack_boundary < 128)
+ crtl->preferred_stack_boundary = 128;
}
/* Handle the TARGET_GET_DRAP_RTX hook. Return NULL if no DRAP is
@@ -11275,10 +11268,11 @@ ix86_finalize_stack_realign_flags (void)
unsigned int incoming_stack_boundary
= (crtl->parm_stack_boundary > ix86_incoming_stack_boundary
? crtl->parm_stack_boundary : ix86_incoming_stack_boundary);
- unsigned int stack_realign = (incoming_stack_boundary
- < (crtl->is_leaf
- ? crtl->max_used_stack_slot_alignment
- : crtl->stack_alignment_needed));
+ unsigned int stack_realign
+ = (incoming_stack_boundary
+ < (crtl->is_leaf && !ix86_current_function_calls_tls_descriptor
+ ? crtl->max_used_stack_slot_alignment
+ : crtl->stack_alignment_needed));
if (crtl->stack_realign_finalized)
{
diff --git a/gcc/testsuite/gcc.target/i386/pr68986-1.c b/gcc/testsuite/gcc.target/i386/pr68986-1.c
new file mode 100644
index 0000000..998f34f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr68986-1.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target tls_native } */
+/* { dg-require-effective-target fpic } */
+/* { dg-options "-fPIC -mno-accumulate-outgoing-args -mpreferred-stack-boundary=5 -mincoming-stack-boundary=4" } */
+
+extern __thread int msgdata;
+int
+foo ()
+{
+ return msgdata;
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr68986-2.c b/gcc/testsuite/gcc.target/i386/pr68986-2.c
new file mode 100644
index 0000000..c3a366c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr68986-2.c
@@ -0,0 +1,13 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-require-effective-target tls_native } */
+/* { dg-require-effective-target fpic } */
+/* { dg-options "-fPIC -mno-accumulate-outgoing-args -mpreferred-stack-boundary=2" } */
+
+extern __thread int msgdata;
+int
+foo ()
+{
+ return msgdata;
+}
+
+/* { dg-final { scan-assembler "andl\[\\t \]*\\$-16,\[\\t \]*%esp" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr68986-3.c b/gcc/testsuite/gcc.target/i386/pr68986-3.c
new file mode 100644
index 0000000..5744cf2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr68986-3.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target tls_native } */
+/* { dg-require-effective-target fpic } */
+/* { dg-options "-fPIC -mno-sse -mpreferred-stack-boundary=3 -mincoming-stack-boundary=3" } */
+
+extern __thread int msgdata;
+int
+foo ()
+{
+ return msgdata;
+}
+
+/* { dg-final { scan-assembler "and\[lq\]\[\\t \]*\\$-16,\[\\t \]*%\[re\]?sp" } } */
--
2.5.0
