[PATCH 0/2][AArch64] Implement AAPCS64 updates for alignment attribute

[PATCH 0/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Alan Lawrence]

These parallel the updates to ARM
https://gcc.gnu.org/ml/gcc-patches/2015-07/msg00214.html following from Richard
Earnshaw's proposal for updates to the AAPCS and AAPCS64,
 https://gcc.gnu.org/ml/gcc/2015-07/msg00040.html .

On AArch64 we do not have the problem of broken profiledbootstrap (as originally
on ARM), hence I do not propose to backport these to earlier GCC branches.
Rather, the GCC 5 -> 6 transition, seems a better time for any ABI change.
(However, as previously, there should be no changes for types that are naturally
aligned, only those using types with explicit alignment specifiers, which was
not previously sanctioned by the AAPCS.)

Similarly to ARM, I note that Ada is affected. Indeed, with a gcc 4.9 host
compiler, I saw a bootstrap miscompare iff including Ada; however, I was able to
bootstrap Ada successfully, if I first built a GCC including this patch with
--disable-bootstrap, and then used that as host compiler. The best explanation
I can see for this is mismatched host vs built libraries and compiler being used
together, something like Jakub's suggestion
http://gcc.gnu.org/ml/gcc-patches/2015-11/msg00338.html. I don't feel I have the
expertise for this, and am CCing the Ada maintainers in the hope they can help.

Bootstrapped + check-gcc + check-g++ on aarch64-none-linux-gnu and
aarch64_be-none-elf.
Also bootstrapped + check-ada on aarch64-none-linux-gnu with --disable-bootstrap
host compiler, as above.

OK for trunk?

--Alan

[PATCH 2/2][AArch64] Tests of AAPCS64 updates for alignment attribute

[Alan Lawrence]

Here I've added both tests using the abitest.h framework(which verifies values
are passed in the correct registers as specified by the AAPCS64), and separate
tests which verify that called functions read arguments from the same locations
as they are passed. Hence, each test_align-N.c corresponds to rec_align-N.c.

I've tried to stay consistent with the existing naming of e.g. test_10.c,
test_align-1.c, va_arg-10.c, but would be happy to change to another scheme
if preferred! (e.g. func-ret-1.c ?)

Cheers, Alan

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/aapcs64/aapcs64.exp: Also execute rec_*.c
	* gcc.target//aarch64/aapcs64/rec_align-5.c: New.
	* gcc.target//aarch64/aapcs64/rec_align-6.c: New.
	* gcc.target//aarch64/aapcs64/rec_align-7.c: New.
	* gcc.target//aarch64/aapcs64/rec_align-8.c: New.
	* gcc.target//aarch64/aapcs64/rec_align-9.c: New.
	* gcc.target//aarch64/aapcs64/test_align-5.c: New.
	* gcc.target//aarch64/aapcs64/test_align-6.c: New.
	* gcc.target//aarch64/aapcs64/test_align-7.c: New.
	* gcc.target//aarch64/aapcs64/test_align-8.c: New.
	* gcc.target//aarch64/aapcs64/test_align-9.c: New.
	* gcc.target//aarch64/aapcs64/rec_vaarg-1.c: New.
	* gcc.target//aarch64/aapcs64/rec_vaarg-2.c: New.
---
 .../gcc.target/aarch64/aapcs64/aapcs64.exp         | 10 +++++
 .../gcc.target/aarch64/aapcs64/rec_align-5.c       | 44 ++++++++++++++++++++
 .../gcc.target/aarch64/aapcs64/rec_align-6.c       | 45 +++++++++++++++++++++
 .../gcc.target/aarch64/aapcs64/rec_align-7.c       | 47 ++++++++++++++++++++++
 .../gcc.target/aarch64/aapcs64/rec_align-8.c       | 37 +++++++++++++++++
 .../gcc.target/aarch64/aapcs64/rec_align-9.c       | 41 +++++++++++++++++++
 .../gcc.target/aarch64/aapcs64/rec_align_vaarg-1.c | 38 +++++++++++++++++
 .../gcc.target/aarch64/aapcs64/rec_align_vaarg-2.c | 28 +++++++++++++
 .../gcc.target/aarch64/aapcs64/test_align-5.c      | 35 ++++++++++++++++
 .../gcc.target/aarch64/aapcs64/test_align-6.c      | 36 +++++++++++++++++
 .../gcc.target/aarch64/aapcs64/test_align-7.c      | 38 +++++++++++++++++
 .../gcc.target/aarch64/aapcs64/test_align-8.c      | 33 +++++++++++++++
 .../gcc.target/aarch64/aapcs64/test_align-9.c      | 47 ++++++++++++++++++++++
 13 files changed, 479 insertions(+)
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-5.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-6.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-7.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-8.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-9.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-1.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-2.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-5.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-6.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-7.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-8.c
 create mode 100644 gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-9.c

diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp b/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
index ac2f089..eb297c5 100644
--- a/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/aapcs64.exp
@@ -38,6 +38,16 @@ foreach src [lsort [glob -nocomplain $srcdir/$subdir/test_*.c]] {
     }
 }
 
+# Test parameter receiving.
+set additional_flags_for_rec $additional_flags
+append additional_flags_for_rec " -fno-inline"
+foreach src [lsort [glob -nocomplain $srcdir/$subdir/rec_*.c]] {
+    if {[runtest_file_p $runtests $src]} {
+	    c-torture-execute [list $src] \
+				    $additional_flags_for_rec
+    }
+}
+
 # Test unnamed argument retrieval via the va_arg macro.
 foreach src [lsort [glob -nocomplain $srcdir/$subdir/va_arg-*.c]] {
     if {[runtest_file_p $runtests $src]} {
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-5.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-5.c
new file mode 100644
index 0000000..1b42c92
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-5.c
@@ -0,0 +1,44 @@
+/* Test AAPCS layout (alignment) for callee.  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+extern void abort (void);
+
+typedef __attribute__ ((__aligned__ (8))) int alignedint;
+
+alignedint a = 11;
+alignedint b = 13;
+alignedint c = 17;
+alignedint d = 19;
+alignedint e = 23;
+alignedint f = 29;
+alignedint g = 31;
+alignedint h = 37;
+alignedint i = 41;
+alignedint j = 43;
+
+void
+test_passing_many_alignedint (alignedint x0, alignedint x1, alignedint x2,
+			      alignedint x3, alignedint x4, alignedint x5,
+			      alignedint x6, alignedint x7, alignedint stack,
+			      alignedint stack8)
+{
+  if (x0 != a
+      || x1 != b
+      || x2 != c
+      || x3 != d
+      || x4 != e
+      || x5 != f
+      || x6 != g
+      || x7 != h
+      || stack != i
+      || stack8 !=j)
+    abort ();
+}
+
+int
+main (int argc, char **argv)
+{
+  test_passing_many_alignedint (a, b, c, d, e, f, g, h, i, j);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-6.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-6.c
new file mode 100644
index 0000000..a8d8b1b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-6.c
@@ -0,0 +1,45 @@
+/* Test AAPCS layout (alignment) for callee.  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+extern int memcmp (const void *s1, const void *s2, __SIZE_TYPE__ n);
+extern void abort (void);
+
+/* The underlying struct here has alignment 8.  */
+typedef struct __attribute__ ((__aligned__ (16)))
+  {
+    long x;
+    long y;
+  } overaligned;
+
+overaligned a = { 2, 3 };
+overaligned b = { 5, 8 };
+overaligned c = { 13, 21 };
+
+void
+test_passing_overaligned_struct (int x0, overaligned x1, int x3, int x4,
+				 overaligned x5, int x7, int stack,
+				 overaligned stack8)
+{
+  if (x0 != 7 || x3 != 9 || x4 != 11 || x7 != 15 || stack != 10)
+    abort ();
+  if (memcmp ((void *) &x1, (void *)&a, sizeof (overaligned)))
+    abort ();
+  if (memcmp ((void *) &x5, (void *)&b, sizeof (overaligned)))
+    abort ();
+  if (memcmp ((void *)&stack8, (void *)&c, sizeof (overaligned)))
+    abort ();
+  long addr = ((long) &stack8) & 15;
+  if (addr != 0)
+    {
+      __builtin_printf ("Alignment was %d\n", addr);
+      abort ();
+    }
+}
+
+int
+main (int argc, char **argv)
+{
+  test_passing_overaligned_struct (7, a, 9, 11, b, 15, 10, c);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-7.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-7.c
new file mode 100644
index 0000000..61e3c11
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-7.c
@@ -0,0 +1,47 @@
+/* Test AAPCS layout (alignment) for callee.  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+extern int memcmp (const void *s1, const void *s2, __SIZE_TYPE__ n);
+extern void abort (void);
+
+struct s
+  {
+    long x;
+    long y;
+  };
+
+/* This still has size 16, so is still passed by value.  */
+typedef __attribute__ ((__aligned__ (32))) struct s overaligned;
+
+/* A few structs, at 32-byte-aligned memory locations.  */
+overaligned a = { 2, 3 };
+overaligned b = { 5, 8 };
+overaligned c = { 13, 21 };
+
+void
+test_pass_by_value (int x0, overaligned x1, int x3, int x4, overaligned x5,
+		    int x7, int stack, overaligned stack8)
+{
+  if (x0 != 7 || x3 != 9 || x4 != 11 || x7 != 15 || stack != 10)
+    abort ();
+  if (memcmp ((void *) &x1, (void *)&a, sizeof (overaligned)))
+    abort ();
+  if (memcmp ((void *) &x5, (void *)&b, sizeof (overaligned)))
+    abort ();
+  if (memcmp ((void *)&stack8, (void *)&c, sizeof (overaligned)))
+    abort ();
+  long addr = ((long) &stack8) & 15;
+  if (addr != 0)
+    {
+      __builtin_printf ("Alignment was %d\n", addr);
+      abort ();
+    }
+}
+
+int
+main (int argc, char **argv)
+{
+  test_pass_by_value (7, a, 9, 11, b, 15, 10, c);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-8.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-8.c
new file mode 100644
index 0000000..c935180
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-8.c
@@ -0,0 +1,37 @@
+/* Test AAPCS layout (alignment) for callee.  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+extern int memcmp (const void *s1, const void *s2, __SIZE_TYPE__ n);
+extern void abort (void);
+
+/* The alignment also gives this size 32, so will be passed by reference.  */
+typedef struct __attribute__ ((__aligned__ (32)))
+  {
+    long x;
+    long y;
+  } overaligned;
+
+overaligned a = { 2, 3 };
+
+void
+test_pass_by_ref (int x0, overaligned x1, int x2)
+{
+  if (x0 != 7 || x2 != 9)
+    abort ();
+  if (memcmp ((void *) &x1, (void *)&a, sizeof (overaligned)))
+    abort ();
+  long addr = ((long) &x1) & 31;
+  if (addr != 0)
+    {
+      __builtin_printf ("Alignment was %d\n", addr);
+      abort ();
+    }
+}
+
+int
+main (int argc, char **argv)
+{
+  test_pass_by_ref (7, a, 9);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-9.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-9.c
new file mode 100644
index 0000000..81139f5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align-9.c
@@ -0,0 +1,41 @@
+/* Test AAPCS layout (alignment) for callee.  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+extern int memcmp (const void *s1, const void *s2, __SIZE_TYPE__ n);
+extern void abort (void);
+
+struct s
+  {
+    /* This forces the alignment and size of the struct to 16.  */
+    __attribute__ ((__aligned__ (16))) long x;
+    int y;
+    /* 4 bytes padding.  */
+  };
+
+typedef struct s __attribute__ ((__aligned__ (8))) underaligned;
+
+underaligned a = { 1, 4 };
+underaligned b = { 9, 16 };
+underaligned c = { 25, 36 };
+
+void
+test_underaligned_struct (int x0, underaligned x2, int x4, underaligned x6,
+			  int stack, underaligned stack16)
+{
+  if (x0 != 3 || x4 != 5 || stack != 7)
+    abort ();
+  if (memcmp ((void *) &x2, (void *)&a, sizeof (underaligned)))
+    abort ();
+  if (memcmp ((void *)&x6, (void *)&b, sizeof (underaligned)))
+    abort ();
+  if (memcmp ((void *)&stack16, (void *)&c, sizeof (underaligned)))
+    abort ();
+}
+
+int
+main (int argc, char **argv)
+{
+  test_underaligned_struct (3, a, 5, b, 7, c);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-1.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-1.c
new file mode 100644
index 0000000..109ddc2
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-1.c
@@ -0,0 +1,38 @@
+/* Test AAPCS layout (alignment of varargs) for callee.  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+#include <stdarg.h>
+
+extern void abort (void);
+
+typedef __attribute__ ((__aligned__ (16))) long alignedlong;
+
+void
+test_pass_overaligned_long_vaargs (long l, ...)
+{
+  va_list va;
+  va_start (va, l);
+  /* Arguments should be passed in the same registers as if they were ints.  */
+  while (l-- > 0)
+    if (va_arg (va, long) != l)
+      abort ();
+  va_end (va);
+}
+
+int
+main (int argc, char **argv)
+{
+  alignedlong a = 9;
+  alignedlong b = 8;
+  alignedlong c = 7;
+  alignedlong d = 6;
+  alignedlong e = 5;
+  alignedlong f = 4;
+  alignedlong g = 3;
+  alignedlong h = 2;
+  alignedlong i = 1;
+  alignedlong j = 0;
+  test_pass_overaligned_long_vaargs (a, b, c, d, e, f, g, h, i, j);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-2.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-2.c
new file mode 100644
index 0000000..dc4eb2f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/rec_align_vaarg-2.c
@@ -0,0 +1,28 @@
+/* Test AAPCS layout (alignment of varargs) for callee.  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+#include <stdarg.h>
+
+extern void abort (void);
+
+typedef __attribute__ ((__aligned__ (16))) int alignedint;
+
+void
+test_pass_overaligned_int_vaargs (int i, ...)
+{
+  va_list va;
+  va_start (va, i);
+  /* alignedint should be pulled out of regs/stack just like an int.  */
+  while (i-- > 0)
+    if (va_arg (va, alignedint) != i)
+      abort ();
+  va_end (va);
+}
+
+int
+main (int argc, char **argv)
+{
+  test_pass_overaligned_int_vaargs (9, 8, 7, 6, 5, 4, 3, 2, 1, 0);
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-5.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-5.c
new file mode 100644
index 0000000..ac5673e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-5.c
@@ -0,0 +1,35 @@
+/* Test AAPCS layout (alignment).  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+#ifndef IN_FRAMEWORK
+#define TESTFILE "test_align-5.c"
+
+typedef __attribute__ ((__aligned__ (16))) long alignedint;
+
+alignedint a = 11;
+alignedint b = 13;
+alignedint c = 17;
+alignedint d = 19;
+alignedint e = 23;
+alignedint f = 29;
+alignedint g = 31;
+alignedint h = 37;
+alignedint i = 41;
+alignedint j = 43;
+
+#include "abitest.h"
+#else
+  ARG (alignedint, a, X0)
+  /* Attribute suggests R2, but we should use only natural alignment:  */
+  ARG (alignedint, b, X1)
+  ARG (alignedint, c, X2)
+  ARG (alignedint, d, X3)
+  ARG (alignedint, e, X4)
+  ARG (alignedint, f, X5)
+  ARG (alignedint, g, X6)
+  ARG (alignedint, h, X7)
+  ARG (alignedint, i, STACK)
+  /* Attribute would suggest STACK + 16 but should be ignored:  */
+  LAST_ARG (alignedint, j, STACK + 8)
+#endif
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-6.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-6.c
new file mode 100644
index 0000000..20cbd94
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-6.c
@@ -0,0 +1,36 @@
+/* Test AAPCS layout (alignment).  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+#ifndef IN_FRAMEWORK
+#define TESTFILE "test_align-6.c"
+
+/* The underlying struct here has alignment 8.  */
+typedef struct __attribute__ ((__aligned__ (16)))
+  {
+    long x;
+    long y;
+  } overaligned;
+
+/* A couple of instances, at 16-byte-aligned memory locations.  */
+overaligned a = { 2, 3 };
+overaligned b = { 5, 8 };
+overaligned c = { 13, 21 };
+
+#include "abitest.h"
+#else
+  ARG (int, 7, W0)
+  /* Natural alignment should be 8.  */
+  ARG (overaligned, a, X1)
+  ARG (int, 9, W3)
+  ARG (int, 11, W4)
+  ARG (overaligned, b, X5)
+  ARG (int, 15, W7)
+#ifndef __AAPCS64_BIG_ENDIAN__
+  ARG (int, 10, STACK)
+#else
+  ARG (int, 10, STACK + 4)
+#endif
+  /* Natural alignment should be 8.  */
+  LAST_ARG (overaligned, c, STACK + 8)
+#endif
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-7.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-7.c
new file mode 100644
index 0000000..6af422f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-7.c
@@ -0,0 +1,38 @@
+/* Test AAPCS layout (alignment).  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+#ifndef IN_FRAMEWORK
+#define TESTFILE "test_align-7.c"
+
+struct s
+  {
+    long x;
+    long y;
+  };
+
+/* This still has size 16, so is still passed by value.  */
+typedef __attribute__ ((__aligned__ (32))) struct s overaligned;
+
+/* A few structs, at 32-byte-aligned memory locations.  */
+overaligned a = { 2, 3 };
+overaligned b = { 5, 8 };
+overaligned c = { 13, 21 };
+
+#include "abitest.h"
+#else
+  ARG (int, 7, W0)
+  /* Alignment should be 8.  */
+  ARG (overaligned, a, X1)
+  ARG (int, 9, W3)
+  ARG (int, 11, W4)
+  ARG (overaligned, b, X5)
+  ARG (int, 15, W7)
+#ifndef __AAPCS64_BIG_ENDIAN__
+  ARG (int, 10, STACK)
+#else
+  ARG (int, 10, STACK + 4)
+#endif
+  /* Natural alignment should be 8.  */
+  LAST_ARG (overaligned, c, STACK + 8)
+#endif
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-8.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-8.c
new file mode 100644
index 0000000..ad4dfe4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-8.c
@@ -0,0 +1,33 @@
+/* Test AAPCS layout (alignment).  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+#ifndef IN_FRAMEWORK
+#define TESTFILE "test_align-8.c"
+
+/* The alignment also gives this size 32, so will be passed by reference.  */
+typedef struct __attribute__ ((__aligned__ (32)))
+  {
+    long x;
+    long y;
+  } overaligned;
+
+#define EXPECTED_STRUCT_SIZE 32
+extern void link_failure (void);
+int
+foo ()
+{
+  /* Optimization gets rid of this before linking.  */
+  if (sizeof (overaligned) != EXPECTED_STRUCT_SIZE)
+    link_failure ();
+}
+
+overaligned a = { 2, 3 };
+
+#include "abitest.h"
+#else
+  ARG (int, 7, W0)
+  /* Alignment should be 8.  */
+  PTR (overaligned, a, X1)
+  LAST_ARG (int, 9, W2)
+#endif
diff --git a/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-9.c b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-9.c
new file mode 100644
index 0000000..0f5fa35
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/aapcs64/test_align-9.c
@@ -0,0 +1,47 @@
+/* Test AAPCS layout (alignment).  */
+
+/* { dg-do run { target aarch64*-*-* } } */
+
+#ifndef IN_FRAMEWORK
+#define TESTFILE "test_align-9.c"
+
+struct s
+  {
+    /* This forces the alignment and size of the struct to 16.  */
+    __attribute__ ((__aligned__ (16))) long x;
+    int y;
+    /* 4 bytes padding.  */
+  };
+
+typedef struct s __attribute__ ((__aligned__ (8))) underaligned;
+
+#define EXPECTED_STRUCT_SIZE 16
+extern void link_failure (void);
+int
+foo ()
+{
+  /* Optimization gets rid of this before linking.  */
+  if (sizeof (struct s) != EXPECTED_STRUCT_SIZE)
+    link_failure ();
+}
+
+underaligned a = { 1, 4 };
+underaligned b = { 9, 16 };
+underaligned c = { 25, 36 };
+
+#include "abitest.h"
+#else
+  ARG (int, 3, W0)
+  /* Object alignment is 16, so skip X1.  */
+  ARG (underaligned, a, X2)
+  ARG (int, 5, W4)
+  /* Object alignment is 16, so skip X5.  */
+  ARG (underaligned, b, X6)
+#ifndef __AAPCS64_BIG_ENDIAN__
+  ARG (int, 7, STACK)
+#else
+  ARG (int, 7, STACK + 4)
+#endif
+  /* Natural alignment should be 16.  */
+  LAST_ARG (underaligned, c, STACK + 16)
+#endif
-- 
1.9.1

Re: [PATCH 2/2][AArch64] Tests of AAPCS64 updates for alignment attribute

[James Greenhalgh]

On Fri, Jan 15, 2016 at 02:17:43PM +0000, Alan Lawrence wrote:
> Here I've added both tests using the abitest.h framework(which verifies values
> are passed in the correct registers as specified by the AAPCS64), and separate
> tests which verify that called functions read arguments from the same locations
> as they are passed. Hence, each test_align-N.c corresponds to rec_align-N.c.
> 
> I've tried to stay consistent with the existing naming of e.g. test_10.c,
> test_align-1.c, va_arg-10.c, but would be happy to change to another scheme
> if preferred! (e.g. func-ret-1.c ?)
> 
> Cheers, Alan

These tests are OK.

I'll commit them alongside patch 1/2 from this series tomorrow.

Thanks,
James

> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.target/aarch64/aapcs64/aapcs64.exp: Also execute rec_*.c
> 	* gcc.target//aarch64/aapcs64/rec_align-5.c: New.
> 	* gcc.target//aarch64/aapcs64/rec_align-6.c: New.
> 	* gcc.target//aarch64/aapcs64/rec_align-7.c: New.
> 	* gcc.target//aarch64/aapcs64/rec_align-8.c: New.
> 	* gcc.target//aarch64/aapcs64/rec_align-9.c: New.
> 	* gcc.target//aarch64/aapcs64/test_align-5.c: New.
> 	* gcc.target//aarch64/aapcs64/test_align-6.c: New.
> 	* gcc.target//aarch64/aapcs64/test_align-7.c: New.
> 	* gcc.target//aarch64/aapcs64/test_align-8.c: New.
> 	* gcc.target//aarch64/aapcs64/test_align-9.c: New.
> 	* gcc.target//aarch64/aapcs64/rec_vaarg-1.c: New.
> 	* gcc.target//aarch64/aapcs64/rec_vaarg-2.c: New.

[PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Alan Lawrence]

gcc/ChangeLog:

	* gcc/config/aarch64/aarch64.c (aarch64_function_arg_alignment):
	Rewrite, looking one level down for records and arrays.
---
 gcc/config/aarch64/aarch64.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index ae4cfb3..8eb8c3e 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1925,22 +1925,24 @@ aarch64_vfp_is_call_candidate (cumulative_args_t pcum_v, machine_mode mode,
 static unsigned int
 aarch64_function_arg_alignment (machine_mode mode, const_tree type)
 {
-  unsigned int alignment;
+  if (!type)
+    return GET_MODE_ALIGNMENT (mode);
+  if (integer_zerop (TYPE_SIZE (type)))
+    return 0;
 
-  if (type)
-    {
-      if (!integer_zerop (TYPE_SIZE (type)))
-	{
-	  if (TYPE_MODE (type) == mode)
-	    alignment = TYPE_ALIGN (type);
-	  else
-	    alignment = GET_MODE_ALIGNMENT (mode);
-	}
-      else
-	alignment = 0;
-    }
-  else
-    alignment = GET_MODE_ALIGNMENT (mode);
+  gcc_assert (TYPE_MODE (type) == mode);
+
+  if (!AGGREGATE_TYPE_P (type))
+    return TYPE_ALIGN (TYPE_MAIN_VARIANT (type));
+
+  if (TREE_CODE (type) == ARRAY_TYPE)
+    return TYPE_ALIGN (TREE_TYPE (type));
+
+  unsigned int alignment = 0;
+  gcc_assert (TYPE_FIELDS (type));
+
+  for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
+    alignment = std::max (alignment, DECL_ALIGN (field));
 
   return alignment;
 }
-- 
1.9.1

Re: [PATCH 0/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Eric Botcazou]

> Similarly to ARM, I note that Ada is affected. Indeed, with a gcc 4.9 host
> compiler, I saw a bootstrap miscompare iff including Ada; however, I was
> able to bootstrap Ada successfully, if I first built a GCC including this
> patch with --disable-bootstrap, and then used that as host compiler. The
> best explanation I can see for this is mismatched host vs built libraries
> and compiler being used together, something like Jakub's suggestion
> http://gcc.gnu.org/ml/gcc-patches/2015-11/msg00338.html. I don't feel I have
> the expertise for this, and am CCing the Ada maintainers in the hope they
> can help.

That's a bit weird though because this should have also occurred for ARM when 
the ABI was broken the same way if the Ada bootstrap is not entirely correct.
Now, as far I know, this didn't occur for ARM during bootstrap but only during 
testing with make -k check.  Or else could this be a parallel compilation bug?

Could you post the list of files that differ?  How do they differ exactly?

-- 
Eric Botcazou

Re: [PATCH 0/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Alan Lawrence]

On 18/01/16 17:10, Eric Botcazou wrote:
>> Similarly to ARM, I note that Ada is affected. Indeed, with a gcc 4.9 host
>> compiler, I saw a bootstrap miscompare iff including Ada; however, I was
>> able to bootstrap Ada successfully, if I first built a GCC including this
>> patch with --disable-bootstrap, and then used that as host compiler. The
>> best explanation I can see for this is mismatched host vs built libraries
>> and compiler being used together, something like Jakub's suggestion
>> http://gcc.gnu.org/ml/gcc-patches/2015-11/msg00338.html. I don't feel I have
>> the expertise for this, and am CCing the Ada maintainers in the hope they
>> can help.
>
> That's a bit weird though because this should have also occurred for ARM when
> the ABI was broken the same way if the Ada bootstrap is not entirely correct.
> Now, as far I know, this didn't occur for ARM during bootstrap but only during
> testing with make -k check.  Or else could this be a parallel compilation bug?
>
> Could you post the list of files that differ?  How do they differ exactly?

Hmmm. Well, I definitely had this failing to bootstrap once. I repeated that, to 
try to identify exactly what the differences were....and it succeeded even with 
my pre-AAPCS64-update host compiler. So, this is probably a false alarm; I'm 
bootstrapping again, after a rebase, to make sure...

--Alan

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Alan Lawrence]

On 21/01/16 17:23, Alan Lawrence wrote:
> On 18/01/16 17:10, Eric Botcazou wrote:
>>
>> Could you post the list of files that differ?  How do they differ exactly?
>
> Hmmm. Well, I definitely had this failing to bootstrap once. I repeated that, to
> try to identify exactly what the differences were....and it succeeded even with
> my pre-AAPCS64-update host compiler. So, this is probably a false alarm; I'm
> bootstrapping again, after a rebase, to make sure...
>
> --Alan

Ok, rebased onto a more recent build, and bootstrapping with Ada posed no
problems. Sorry for the noise.

However, I had to drop the assert that TYPE_FIELDS was non-null because of some
C++ testcases.

Is this version OK for trunk?

--Alan

gcc/ChangeLog:

	* gcc/config/aarch64/aarch64.c (aarch64_function_arg_alignment):
	Rewrite, looking one level down for records and arrays.
---
 gcc/config/aarch64/aarch64.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 9142ac0..b084f83 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1925,22 +1925,23 @@ aarch64_vfp_is_call_candidate (cumulative_args_t pcum_v, machine_mode mode,
 static unsigned int
 aarch64_function_arg_alignment (machine_mode mode, const_tree type)
 {
-  unsigned int alignment;
+  if (!type)
+    return GET_MODE_ALIGNMENT (mode);
+  if (integer_zerop (TYPE_SIZE (type)))
+    return 0;
 
-  if (type)
-    {
-      if (!integer_zerop (TYPE_SIZE (type)))
-	{
-	  if (TYPE_MODE (type) == mode)
-	    alignment = TYPE_ALIGN (type);
-	  else
-	    alignment = GET_MODE_ALIGNMENT (mode);
-	}
-      else
-	alignment = 0;
-    }
-  else
-    alignment = GET_MODE_ALIGNMENT (mode);
+  gcc_assert (TYPE_MODE (type) == mode);
+
+  if (!AGGREGATE_TYPE_P (type))
+    return TYPE_ALIGN (TYPE_MAIN_VARIANT (type));
+
+  if (TREE_CODE (type) == ARRAY_TYPE)
+    return TYPE_ALIGN (TREE_TYPE (type));
+
+  unsigned int alignment = 0;
+
+  for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
+    alignment = std::max (alignment, DECL_ALIGN (field));
 
   return alignment;
 }
-- 
1.9.1

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Eric Botcazou]

> Ok, rebased onto a more recent build, and bootstrapping with Ada posed no
> problems. Sorry for the noise.

Great, no problem, and thanks for double checking.

-- 
Eric Botcazou

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Alan Lawrence]

On 22/01/16 17:16, Alan Lawrence wrote:
>
> On 21/01/16 17:23, Alan Lawrence wrote:
>> On 18/01/16 17:10, Eric Botcazou wrote:
>>>
>>> Could you post the list of files that differ?  How do they differ exactly?
>>
>> Hmmm. Well, I definitely had this failing to bootstrap once. I repeated that, to
>> try to identify exactly what the differences were....and it succeeded even with
>> my pre-AAPCS64-update host compiler. So, this is probably a false alarm; I'm
>> bootstrapping again, after a rebase, to make sure...
>>
>> --Alan
>
> Ok, rebased onto a more recent build, and bootstrapping with Ada posed no
> problems. Sorry for the noise.
>
> However, I had to drop the assert that TYPE_FIELDS was non-null because of some
> C++ testcases.
>
> Is this version OK for trunk?
>
> --Alan
>
> gcc/ChangeLog:
>
> 	* gcc/config/aarch64/aarch64.c (aarch64_function_arg_alignment):
> 	Rewrite, looking one level down for records and arrays.
> ---
>   gcc/config/aarch64/aarch64.c | 31 ++++++++++++++++---------------
>   1 file changed, 16 insertions(+), 15 deletions(-)
>
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 9142ac0..b084f83 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -1925,22 +1925,23 @@ aarch64_vfp_is_call_candidate (cumulative_args_t pcum_v, machine_mode mode,
>   static unsigned int
>   aarch64_function_arg_alignment (machine_mode mode, const_tree type)
>   {
> -  unsigned int alignment;
> +  if (!type)
> +    return GET_MODE_ALIGNMENT (mode);
> +  if (integer_zerop (TYPE_SIZE (type)))
> +    return 0;
>
> -  if (type)
> -    {
> -      if (!integer_zerop (TYPE_SIZE (type)))
> -	{
> -	  if (TYPE_MODE (type) == mode)
> -	    alignment = TYPE_ALIGN (type);
> -	  else
> -	    alignment = GET_MODE_ALIGNMENT (mode);
> -	}
> -      else
> -	alignment = 0;
> -    }
> -  else
> -    alignment = GET_MODE_ALIGNMENT (mode);
> +  gcc_assert (TYPE_MODE (type) == mode);
> +
> +  if (!AGGREGATE_TYPE_P (type))
> +    return TYPE_ALIGN (TYPE_MAIN_VARIANT (type));
> +
> +  if (TREE_CODE (type) == ARRAY_TYPE)
> +    return TYPE_ALIGN (TREE_TYPE (type));
> +
> +  unsigned int alignment = 0;
> +
> +  for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
> +    alignment = std::max (alignment, DECL_ALIGN (field));
>
>     return alignment;
>   }
>


Ping.

If this is not appropriate for GCC6, then is it OK for Stage 1 of GCC 7?

Thanks, Alan

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[James Greenhalgh]

On Mon, Feb 22, 2016 at 03:07:09PM +0000, Alan Lawrence wrote:
> On 22/01/16 17:16, Alan Lawrence wrote:
> >
> >On 21/01/16 17:23, Alan Lawrence wrote:
> >>On 18/01/16 17:10, Eric Botcazou wrote:
> >>>
> >>>Could you post the list of files that differ?  How do they differ exactly?
> >>
> >>Hmmm. Well, I definitely had this failing to bootstrap once. I repeated that, to
> >>try to identify exactly what the differences were....and it succeeded even with
> >>my pre-AAPCS64-update host compiler. So, this is probably a false alarm; I'm
> >>bootstrapping again, after a rebase, to make sure...
> >>
> >>--Alan
> >
> >Ok, rebased onto a more recent build, and bootstrapping with Ada posed no
> >problems. Sorry for the noise.
> >
> >However, I had to drop the assert that TYPE_FIELDS was non-null because of some
> >C++ testcases.
> >
> >Is this version OK for trunk?
> >
> >--Alan
> >
> >gcc/ChangeLog:
> >
> >	* gcc/config/aarch64/aarch64.c (aarch64_function_arg_alignment):
> >	Rewrite, looking one level down for records and arrays.
> >---
> >  gcc/config/aarch64/aarch64.c | 31 ++++++++++++++++---------------
> >  1 file changed, 16 insertions(+), 15 deletions(-)
> >
> >diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> >index 9142ac0..b084f83 100644
> >--- a/gcc/config/aarch64/aarch64.c
> >+++ b/gcc/config/aarch64/aarch64.c
> >@@ -1925,22 +1925,23 @@ aarch64_vfp_is_call_candidate (cumulative_args_t pcum_v, machine_mode mode,
> >  static unsigned int
> >  aarch64_function_arg_alignment (machine_mode mode, const_tree type)
> >  {
> >-  unsigned int alignment;
> >+  if (!type)
> >+    return GET_MODE_ALIGNMENT (mode);
> >+  if (integer_zerop (TYPE_SIZE (type)))
> >+    return 0;
> >
> >-  if (type)
> >-    {
> >-      if (!integer_zerop (TYPE_SIZE (type)))
> >-	{
> >-	  if (TYPE_MODE (type) == mode)
> >-	    alignment = TYPE_ALIGN (type);
> >-	  else
> >-	    alignment = GET_MODE_ALIGNMENT (mode);
> >-	}
> >-      else
> >-	alignment = 0;
> >-    }
> >-  else
> >-    alignment = GET_MODE_ALIGNMENT (mode);
> >+  gcc_assert (TYPE_MODE (type) == mode);
> >+
> >+  if (!AGGREGATE_TYPE_P (type))
> >+    return TYPE_ALIGN (TYPE_MAIN_VARIANT (type));
> >+
> >+  if (TREE_CODE (type) == ARRAY_TYPE)
> >+    return TYPE_ALIGN (TREE_TYPE (type));
> >+
> >+  unsigned int alignment = 0;
> >+
> >+  for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
> >+    alignment = std::max (alignment, DECL_ALIGN (field));
> >
> >    return alignment;
> >  }
> >
> 
> 
> Ping.
> 
> If this is not appropriate for GCC6, then is it OK for Stage 1 of GCC 7?

I think this needs to be a GCC 7 fix at this point.

Additionally, I'd like to fully understand PR69841 before we take this
patch.

In particular, under what circumstances can the C++ front end set DECL_ALIGN
of a type to be wider than we expect. Can we ever end up with 128-bit
alignment of a template parameter when we were expecting 32- or 64-bit
alignment, and if we can what are the implications on this patch?

Thanks,
James

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Alan Lawrence]

On 26/02/16 14:52, James Greenhalgh wrote:

>>> gcc/ChangeLog:
>>>
>>> 	* gcc/config/aarch64/aarch64.c (aarch64_function_arg_alignment):
>>> 	Rewrite, looking one level down for records and arrays.
>>> ---
>>>   gcc/config/aarch64/aarch64.c | 31 ++++++++++++++++---------------
>>>   1 file changed, 16 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
>>> index 9142ac0..b084f83 100644
>>> --- a/gcc/config/aarch64/aarch64.c
>>> +++ b/gcc/config/aarch64/aarch64.c
>>> @@ -1925,22 +1925,23 @@ aarch64_vfp_is_call_candidate (cumulative_args_t pcum_v, machine_mode mode,
>>>   static unsigned int
>>>   aarch64_function_arg_alignment (machine_mode mode, const_tree type)
>>>   {
>>> -  unsigned int alignment;
>>> +  if (!type)
>>> +    return GET_MODE_ALIGNMENT (mode);
>>> +  if (integer_zerop (TYPE_SIZE (type)))
>>> +    return 0;
>>>
>>> -  if (type)
>>> -    {
>>> -      if (!integer_zerop (TYPE_SIZE (type)))
>>> -	{
>>> -	  if (TYPE_MODE (type) == mode)
>>> -	    alignment = TYPE_ALIGN (type);
>>> -	  else
>>> -	    alignment = GET_MODE_ALIGNMENT (mode);
>>> -	}
>>> -      else
>>> -	alignment = 0;
>>> -    }
>>> -  else
>>> -    alignment = GET_MODE_ALIGNMENT (mode);
>>> +  gcc_assert (TYPE_MODE (type) == mode);
>>> +
>>> +  if (!AGGREGATE_TYPE_P (type))
>>> +    return TYPE_ALIGN (TYPE_MAIN_VARIANT (type));
>>> +
>>> +  if (TREE_CODE (type) == ARRAY_TYPE)
>>> +    return TYPE_ALIGN (TREE_TYPE (type));
>>> +
>>> +  unsigned int alignment = 0;
>>> +
>>> +  for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
>>> +    alignment = std::max (alignment, DECL_ALIGN (field));
>>>
>>>     return alignment;
>>>   }
>>>
>>
>>
>> Ping.
>>
>> If this is not appropriate for GCC6, then is it OK for Stage 1 of GCC 7?
>
> I think this needs to be a GCC 7 fix at this point.
>
> Additionally, I'd like to fully understand PR69841 before we take this
> patch.
>
> In particular, under what circumstances can the C++ front end set DECL_ALIGN
> of a type to be wider than we expect. Can we ever end up with 128-bit
> alignment of a template parameter when we were expecting 32- or 64-bit
> alignment, and if we can what are the implications on this patch?

OK, so IIUC, we *should* be able to rely on DECL_ALIGN for the AAPCS64, as 
PR/69841 occurred on gcc-5-branch because a C++ frontend change had not been 
backported.

I'm not proposing to backport these AArch64 changes, hence:

Ping^2.

(For gcc 7 ?)

Also tests https://gcc.gnu.org/ml/gcc-patches/2016-01/msg01073.html .

Thanks,
Alan

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[Alan Lawrence]

On 04/03/16 17:24, Alan Lawrence wrote:
> On 26/02/16 14:52, James Greenhalgh wrote:
>
>>>> gcc/ChangeLog:
>>>>
>>>>     * gcc/config/aarch64/aarch64.c (aarch64_function_arg_alignment):
>>>>     Rewrite, looking one level down for records and arrays.
>>>> ---
>>>>   gcc/config/aarch64/aarch64.c | 31 ++++++++++++++++---------------
>>>>   1 file changed, 16 insertions(+), 15 deletions(-)
>>>>
>>>> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
>>>> index 9142ac0..b084f83 100644
>>>> --- a/gcc/config/aarch64/aarch64.c
>>>> +++ b/gcc/config/aarch64/aarch64.c
>>>> @@ -1925,22 +1925,23 @@ aarch64_vfp_is_call_candidate (cumulative_args_t
>>>> pcum_v, machine_mode mode,
>>>>   static unsigned int
>>>>   aarch64_function_arg_alignment (machine_mode mode, const_tree type)
>>>>   {
>>>> -  unsigned int alignment;
>>>> +  if (!type)
>>>> +    return GET_MODE_ALIGNMENT (mode);
>>>> +  if (integer_zerop (TYPE_SIZE (type)))
>>>> +    return 0;
>>>>
>>>> -  if (type)
>>>> -    {
>>>> -      if (!integer_zerop (TYPE_SIZE (type)))
>>>> -    {
>>>> -      if (TYPE_MODE (type) == mode)
>>>> -        alignment = TYPE_ALIGN (type);
>>>> -      else
>>>> -        alignment = GET_MODE_ALIGNMENT (mode);
>>>> -    }
>>>> -      else
>>>> -    alignment = 0;
>>>> -    }
>>>> -  else
>>>> -    alignment = GET_MODE_ALIGNMENT (mode);
>>>> +  gcc_assert (TYPE_MODE (type) == mode);
>>>> +
>>>> +  if (!AGGREGATE_TYPE_P (type))
>>>> +    return TYPE_ALIGN (TYPE_MAIN_VARIANT (type));
>>>> +
>>>> +  if (TREE_CODE (type) == ARRAY_TYPE)
>>>> +    return TYPE_ALIGN (TREE_TYPE (type));
>>>> +
>>>> +  unsigned int alignment = 0;
>>>> +
>>>> +  for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
>>>> +    alignment = std::max (alignment, DECL_ALIGN (field));
>>>>
>>>>     return alignment;
>>>>   }
>>>>
>>>
>>>
>>> Ping.

[snip]

>
> I'm not proposing to backport these AArch64 changes, hence:
>
> Ping^2.
>
> (For gcc 7 ?)
>
> Also tests https://gcc.gnu.org/ml/gcc-patches/2016-01/msg01073.html .

Ping^3.

Cheers, Alan

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[James Greenhalgh]

On Fri, Jan 22, 2016 at 05:16:00PM +0000, Alan Lawrence wrote:
> 
> On 21/01/16 17:23, Alan Lawrence wrote:
> > On 18/01/16 17:10, Eric Botcazou wrote:
> >>
> >> Could you post the list of files that differ?  How do they differ exactly?
> >
> > Hmmm. Well, I definitely had this failing to bootstrap once. I repeated that, to
> > try to identify exactly what the differences were....and it succeeded even with
> > my pre-AAPCS64-update host compiler. So, this is probably a false alarm; I'm
> > bootstrapping again, after a rebase, to make sure...
> >
> > --Alan
> 
> Ok, rebased onto a more recent build, and bootstrapping with Ada posed no
> problems. Sorry for the noise.
> 
> However, I had to drop the assert that TYPE_FIELDS was non-null because of some
> C++ testcases.
> 
> Is this version OK for trunk?

Now that we're in GCC7, this version of the patch is OK for trunk.

From my reading of Richard's AAPCS update, this patch implements the
rules as required.

I'll give this a day for any last minute comments from Richard/Marcus,
then commit this on your behalf tomorrow.

Thanks,
James

> gcc/ChangeLog:
> 
> 	* gcc/config/aarch64/aarch64.c (aarch64_function_arg_alignment):
> 	Rewrite, looking one level down for records and arrays.
> ---
>  gcc/config/aarch64/aarch64.c | 31 ++++++++++++++++---------------
>  1 file changed, 16 insertions(+), 15 deletions(-)
> 
> diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
> index 9142ac0..b084f83 100644
> --- a/gcc/config/aarch64/aarch64.c
> +++ b/gcc/config/aarch64/aarch64.c
> @@ -1925,22 +1925,23 @@ aarch64_vfp_is_call_candidate (cumulative_args_t pcum_v, machine_mode mode,
>  static unsigned int
>  aarch64_function_arg_alignment (machine_mode mode, const_tree type)
>  {
> -  unsigned int alignment;
> +  if (!type)
> +    return GET_MODE_ALIGNMENT (mode);
> +  if (integer_zerop (TYPE_SIZE (type)))
> +    return 0;
>  
> -  if (type)
> -    {
> -      if (!integer_zerop (TYPE_SIZE (type)))
> -	{
> -	  if (TYPE_MODE (type) == mode)
> -	    alignment = TYPE_ALIGN (type);
> -	  else
> -	    alignment = GET_MODE_ALIGNMENT (mode);
> -	}
> -      else
> -	alignment = 0;
> -    }
> -  else
> -    alignment = GET_MODE_ALIGNMENT (mode);
> +  gcc_assert (TYPE_MODE (type) == mode);
> +
> +  if (!AGGREGATE_TYPE_P (type))
> +    return TYPE_ALIGN (TYPE_MAIN_VARIANT (type));
> +
> +  if (TREE_CODE (type) == ARRAY_TYPE)
> +    return TYPE_ALIGN (TREE_TYPE (type));
> +
> +  unsigned int alignment = 0;
> +
> +  for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
> +    alignment = std::max (alignment, DECL_ALIGN (field));
>  
>    return alignment;
>  }
> -- 
> 1.9.1
> 

Re: [PATCH 1/2][AArch64] Implement AAPCS64 updates for alignment attribute

[James Greenhalgh]

On Tue, Jun 07, 2016 at 12:07:03PM +0100, James Greenhalgh wrote:
> On Fri, Jan 22, 2016 at 05:16:00PM +0000, Alan Lawrence wrote:
> > 
> > On 21/01/16 17:23, Alan Lawrence wrote:
> > > On 18/01/16 17:10, Eric Botcazou wrote:
> > >>
> > >> Could you post the list of files that differ?  How do they differ exactly?
> > >
> > > Hmmm. Well, I definitely had this failing to bootstrap once. I repeated that, to
> > > try to identify exactly what the differences were....and it succeeded even with
> > > my pre-AAPCS64-update host compiler. So, this is probably a false alarm; I'm
> > > bootstrapping again, after a rebase, to make sure...
> > >
> > > --Alan
> > 
> > Ok, rebased onto a more recent build, and bootstrapping with Ada posed no
> > problems. Sorry for the noise.
> > 
> > However, I had to drop the assert that TYPE_FIELDS was non-null because of some
> > C++ testcases.
> > 
> > Is this version OK for trunk?
> 
> Now that we're in GCC7, this version of the patch is OK for trunk.
> 
> From my reading of Richard's AAPCS update, this patch implements the
> rules as required.
> 
> I'll give this a day for any last minute comments from Richard/Marcus,
> then commit this on your behalf tomorrow.

I've now committed this on Alan's behalf as revisions r237224 (this patch)
and r237225 (the tests) respectively.

Thanks,
James