PATCH: PR target/20020: 128 bit structs not targeted to TImode

[H.J. Lu]

Hi,

My email sent to gcc-patches@gcc.gnu.org was bounced as spam.  I am
resending it.  This patch defines both MAX_FIXED_MODE_SIZE and
MEMBER_TYPE_FORCES_BLK for i386.  MEMBER_TYPE_FORCES_BLK is needed so
that we always put union with XFmode field in BLKmode.  This patch
doesn't change any ABI since both MAX_FIXED_MODE_SIZE and
MEMBER_TYPE_FORCES_BLK aren't ABI macros.  They only change code
quality.  Tested on Linux/x86-64.  OK to install?

Thanks.


H.J.
---
gcc/

2012-08-16  H.J. Lu  <hongjiu.lu@intel.com>
	    Gary Funck <gary@intrepid.com>

	PR target/20020
	* config/i386/i386.h (MAX_FIXED_MODE_SIZE): New macro.
	(MEMBER_TYPE_FORCES_BLK): Likewise.

gcc/testsuite/

2012-08-16  H.J. Lu  <hongjiu.lu@intel.com>
	    Gary Funck <gary@intrepid.com>

	PR target/20020
	* gcc.target/i386/pr20020-1.c: New test.
	* gcc.target/i386/pr20020-2.c: Likewise.
	* gcc.target/i386/pr20020-3.c: Likewise.

diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 5ff82ab..4046a9a 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -1816,6 +1816,16 @@ do {							\
 #define BRANCH_COST(speed_p, predictable_p) \
   (!(speed_p) ? 2 : (predictable_p) ? 0 : ix86_branch_cost)
 
+/* An integer expression for the size in bits of the largest integer machine
+   mode that should actually be used.  We allow pairs of registers.  */
+#define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (TARGET_64BIT ? TImode : DImode)
+
+/* Union with XFmode must be in BLKmode.  */
+#define MEMBER_TYPE_FORCES_BLK(FIELD, MODE)				\
+  ((MODE) == XFmode							\
+   && (TREE_CODE (DECL_FIELD_CONTEXT (FIELD)) == UNION_TYPE		\
+       || TREE_CODE (DECL_FIELD_CONTEXT (FIELD)) == QUAL_UNION_TYPE))
+
 /* Define this macro as a C expression which is nonzero if accessing
    less than a word of memory (i.e. a `char' or a `short') is no
    faster than accessing a word of memory, i.e., if such access
diff --git a/gcc/testsuite/gcc.target/i386/pr20020-1.c b/gcc/testsuite/gcc.target/i386/pr20020-1.c
new file mode 100644
index 0000000..3f10970
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr20020-1.c
@@ -0,0 +1,26 @@
+/* Check that 128-bit struct's are represented as TImode values.  */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O2 -fdump-rtl-expand" } */
+
+struct shared_ptr_struct
+{
+  unsigned long long phase:48;
+  unsigned short thread:16;
+  union
+    {
+      void *addr;
+      unsigned long long pad;
+    };
+};
+typedef struct shared_ptr_struct sptr_t;
+
+sptr_t S;
+
+sptr_t
+sptr_result (void)
+{
+  return S;
+}
+/* { dg-final { scan-rtl-dump "\\\(set \\\(reg:TI \[0-9\]* \\\[ <retval> \\\]\\\)" "expand" } } */
+/* { dg-final { scan-rtl-dump "\\\(set \\\(reg/i:TI 0 ax\\\)" "expand" } } */
+/* { dg-final { cleanup-rtl-dump "expand" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr20020-2.c b/gcc/testsuite/gcc.target/i386/pr20020-2.c
new file mode 100644
index 0000000..e8c5b3d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr20020-2.c
@@ -0,0 +1,24 @@
+/* Check that 128-bit struct's are represented as TImode values.  */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O2 -fdump-rtl-expand" } */
+
+struct shared_ptr_struct
+{
+  unsigned long long phase:48;
+  unsigned short thread:16;
+  union
+    {
+      void *addr;
+      unsigned long long pad;
+    };
+};
+typedef struct shared_ptr_struct sptr_t;
+
+void
+copy_sptr (sptr_t *dest, sptr_t src)
+{
+  *dest = src;
+}
+
+/* { dg-final { scan-rtl-dump "\\\(set \\\(reg:TI \[0-9\]*" "expand" } } */
+/* { dg-final { cleanup-rtl-dump "expand" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr20020-3.c b/gcc/testsuite/gcc.target/i386/pr20020-3.c
new file mode 100644
index 0000000..b1cc926
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr20020-3.c
@@ -0,0 +1,27 @@
+/* Check that 128-bit struct's are represented as TImode values.  */
+/* { dg-do compile { target int128 } } */
+/* { dg-options "-O2 -fdump-rtl-expand" } */
+
+struct shared_ptr_struct
+{
+  unsigned long long phase:48;
+  unsigned short thread:16;
+  union
+    {
+      void *addr;
+      unsigned long long pad;
+    };
+};
+typedef struct shared_ptr_struct sptr_t;
+
+sptr_t sptr_1, sptr_2;
+
+void
+copy_sptr (void)
+{
+  sptr_1 = sptr_2;  
+}
+
+/* { dg-final { scan-rtl-dump "\\\(set \\\(reg:TI \[0-9\]*" "expand" } } */
+/* { dg-final { scan-rtl-dump "\\\(set \\\(mem/c:TI" "expand" } } */
+/* { dg-final { cleanup-rtl-dump "expand" } } */