The attached patch adds the a target specific attribute via the
new target macro TARGET_BEGIN_TRANSACTION_ATTRIBUTE to the
function begin_transaction(). S/390 uses this to set the
soft-float target attribute which is needed to fix a crash with
-m31.
As there seems to be no place in libitm to document internal macros like
USE_HTM_FASTPATH or the new macro, I've put the documentation in a
comment where the macro is used.
Ciao
Dominik ^_^ ^_^
--
Dominik Vogt
IBM Germany
libitm/ChangeLog
* config/s390/target.h (TARGET_BEGIN_TRANSACTION_ATTRIBUTE): Define
function attribute to disable floating point in begin_transaction() on
S/390.
* beginend.cc (begin_transaction): Use
TARGET_BEGIN_TRANSACTION_ATTRIBUTE.
>From a5c8087753ab1f42082b9ab44d443005ed2c53ba Mon Sep 17 00:00:00 2001
From: Dominik Vogt <v...@linux.vnet.ibm.com>
Date: Mon, 1 Feb 2016 14:07:55 +0100
Subject: [PATCH] libitm: Introduce target macro
TARGET_BEGIN_TRANSACTION_ATTRIBUTE.
The macro can be used to add attributes to the function begin_transaction. Set
it for S/390 to switch of harware floating point.
---
libitm/beginend.cc | 6 ++++++
libitm/config/s390/target.h | 3 +++
2 files changed, 9 insertions(+)
diff --git a/libitm/beginend.cc b/libitm/beginend.cc
index 1a258ad..20b5547 100644
--- a/libitm/beginend.cc
+++ b/libitm/beginend.cc
@@ -149,6 +149,12 @@ choose_code_path(uint32_t prop, abi_dispatch *disp)
return a_runInstrumentedCode;
}
+#ifdef TARGET_BEGIN_TRANSACTION_ATTRIBUTE
+/* This macro can be used to define target specific attributes for this
+ function. For example, S/390 requires floating point to be disabled in
+ begin_transaction. */
+TARGET_BEGIN_TRANSACTION_ATTRIBUTE
+#endif
uint32_t
GTM::gtm_thread::begin_transaction (uint32_t prop, const gtm_jmpbuf *jb)
{
diff --git a/libitm/config/s390/target.h b/libitm/config/s390/target.h
index 44819a4..c9d5203 100644
--- a/libitm/config/s390/target.h
+++ b/libitm/config/s390/target.h
@@ -69,6 +69,9 @@ cpu_relax (void)
/* Number of retries for transient failures. */
#define _HTM_ITM_RETRIES 10
#define USE_HTM_FASTPATH
+#define TARGET_BEGIN_TRANSACTION_ATTRIBUTE \
+ __attribute__ ((target("soft-float")))
+
static inline bool
htm_available ()
--
2.3.0
