Attached, is a patch to fix PR20020, and three test cases.
This patch improves the code generated for structs that
can be represented in a TImode value on an x86_64 target.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20020
The test cases scan the generated RTL and verify
that TImode operations are present.
Note that this patch will uncover a new test
regression, described here:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20020#c9
Index: gcc/config/i386/i386.h
===================================================================
--- gcc/config/i386/i386.h (revision 190336)
+++ gcc/config/i386/i386.h (working copy)
@@ -1820,6 +1820,10 @@ 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)
+
/* 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
Index: gcc/testsuite/gcc.dg/pr20020-1.c
===================================================================
--- gcc/testsuite/gcc.dg/pr20020-1.c (revision 0)
+++ gcc/testsuite/gcc.dg/pr20020-1.c (revision 0)
@@ -0,0 +1,25 @@
+/* Target is restricted to x86_64 type architectures,
+ to check that 128-bit struct's are represented
+ as TImode values. */
+/* { dg-require-effective-target int128 } */
+/* { dg-do compile { target { x86_64-*-* } } } */
+/* { dg-options "-O2 -fdump-rtl-expand" } */
+
+struct shared_ptr_struct
+{
+ unsigned long long phase:48;
+ unsigned short thread:16;
+ void *addr;
+};
+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" } } */
Index: gcc/testsuite/gcc.dg/pr20020-2.c
===================================================================
--- gcc/testsuite/gcc.dg/pr20020-2.c (revision 0)
+++ gcc/testsuite/gcc.dg/pr20020-2.c (revision 0)
@@ -0,0 +1,23 @@
+/* Target is restricted to x86_64 type architectures,
+ to check that 128-bit struct's are represented
+ as TImode values. */
+/* { dg-require-effective-target int128 } */
+/* { dg-do compile { target { x86_64-*-* } } } */
+/* { dg-options "-O2 -fdump-rtl-expand" } */
+
+struct shared_ptr_struct
+{
+ unsigned long long phase:48;
+ unsigned short thread:16;
+ void *addr;
+};
+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" } } */
Index: gcc/testsuite/gcc.dg/pr20020-3.c
===================================================================
--- gcc/testsuite/gcc.dg/pr20020-3.c (revision 0)
+++ gcc/testsuite/gcc.dg/pr20020-3.c (revision 0)
@@ -0,0 +1,26 @@
+/* Target is restricted to x86_64 type architectures,
+ to check that 128-bit struct's are represented
+ as TImode values. */
+/* { dg-require-effective-target int128 } */
+/* { dg-do compile { target { x86_64-*-* } } } */
+/* { dg-options "-O2 -fdump-rtl-expand" } */
+
+struct shared_ptr_struct
+{
+ unsigned long long phase:48;
+ unsigned short thread:16;
+ void *addr;
+};
+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" } } */
