Hi,
this makes sure that stack allocated SSA_NAMEs are
at least MODE_ALIGNED. Also increase the MEM_ALIGN
for the corresponding rtl objects.
Tested on x86_64-pc-linux-gnu and arm-none-eabi.
OK for trunk?
Thanks
Bernd.
From e8f80c0ed18c49e8b8ad4145401a2c1afa50af60 Mon Sep 17 00:00:00 2001
From: Bernd Edlinger <bernd.edlin...@hotmail.de>
Date: Sun, 1 Nov 2020 07:32:20 +0100
Subject: [PATCH] Fix PR97205
This makes sure that stack allocated SSA_NAMEs are
at least MODE_ALIGNED. Also increase the MEM_ALIGN
for the corresponding rtl objects.
gcc:
2020-11-01 Bernd Edlinger <bernd.edlin...@hotmail.de>
PR target/97205
* cfgexpand.c (align_local_variable): Make SSA_NAMEs
at least MODE_ALIGNED.
(expand_one_stack_var_at): Increase MEM_ALIGN for SSA_NAMEs.
testsuite:
2020-11-01 Bernd Edlinger <bernd.edlin...@hotmail.de>
PR target/97205
* gcc.c-torture/compile/pr97205.c: New test.
---
gcc/cfgexpand.c | 26 ++++++++++++++++++++------
gcc/testsuite/gcc.c-torture/compile/pr97205.c | 7 +++++++
2 files changed, 27 insertions(+), 6 deletions(-)
create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr97205.c
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index f3f17d3..3aec250 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -366,7 +366,15 @@ align_local_variable (tree decl, bool really_expand)
unsigned int align;
if (TREE_CODE (decl) == SSA_NAME)
- align = TYPE_ALIGN (TREE_TYPE (decl));
+ {
+ tree type = TREE_TYPE (decl);
+ machine_mode mode = TYPE_MODE (type);
+
+ align = TYPE_ALIGN (type);
+ if (mode != BLKmode
+ && align < GET_MODE_ALIGNMENT (mode))
+ align = GET_MODE_ALIGNMENT (mode);
+ }
else
{
align = LOCAL_DECL_ALIGNMENT (decl);
@@ -1022,6 +1030,14 @@ expand_one_stack_var_at (tree decl, rtx base, unsigned base_align,
}
set_rtl (decl, x);
+
+ if (TREE_CODE (decl) == SSA_NAME
+ && GET_MODE (x) != BLKmode
+ && MEM_ALIGN (x) < GET_MODE_ALIGNMENT (GET_MODE (x)))
+ {
+ gcc_checking_assert (GET_MODE_ALIGNMENT (GET_MODE (x)) <= base_align);
+ set_mem_align (x, GET_MODE_ALIGNMENT (GET_MODE (x)));
+ }
}
class stack_vars_data
@@ -1327,13 +1343,11 @@ expand_one_stack_var_1 (tree var)
{
tree type = TREE_TYPE (var);
size = tree_to_poly_uint64 (TYPE_SIZE_UNIT (type));
- byte_align = TYPE_ALIGN_UNIT (type);
}
else
- {
- size = tree_to_poly_uint64 (DECL_SIZE_UNIT (var));
- byte_align = align_local_variable (var, true);
- }
+ size = tree_to_poly_uint64 (DECL_SIZE_UNIT (var));
+
+ byte_align = align_local_variable (var, true);
/* We handle highly aligned variables in expand_stack_vars. */
gcc_assert (byte_align * BITS_PER_UNIT <= MAX_SUPPORTED_STACK_ALIGNMENT);
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr97205.c b/gcc/testsuite/gcc.c-torture/compile/pr97205.c
new file mode 100644
index 0000000..6600011
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr97205.c
@@ -0,0 +1,7 @@
+int a;
+typedef __attribute__((aligned(2))) int x;
+int f ()
+{
+ x b = a;
+ return b;
+}
--
1.9.1
