This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
deprecate asm memory inputs that don't refer to memories
- From: Richard Henderson <rth at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Sun, 8 Jun 2003 20:27:01 -0700
- Subject: deprecate asm memory inputs that don't refer to memories
As discussed.
r~
* expr.h (EXPAND_MEMORY): New.
* expr.c (expand_expr): Check it.
* stmt.c (expand_asm_operands): Provide it when the constraint
requires a memory. Warn for memory input constraints without
a memory operand.
* gcc.dg/20011029-2.c: Fix the array reference.
* gcc.dg/asm-7.c: New.
Index: expr.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/expr.c,v
retrieving revision 1.546
diff -c -p -d -u -r1.546 expr.c
--- expr.c 3 Jun 2003 17:13:06 -0000 1.546
+++ expr.c 9 Jun 2003 03:03:09 -0000
@@ -7326,7 +7326,9 @@ expand_expr (exp, target, tmode, modifie
Don't fold if this is for wide characters since it's too
difficult to do correctly and this is a very rare case. */
- if (modifier != EXPAND_CONST_ADDRESS && modifier != EXPAND_INITIALIZER
+ if (modifier != EXPAND_CONST_ADDRESS
+ && modifier != EXPAND_INITIALIZER
+ && modifier != EXPAND_MEMORY
&& TREE_CODE (array) == STRING_CST
&& TREE_CODE (index) == INTEGER_CST
&& compare_tree_int (index, TREE_STRING_LENGTH (array)) < 0
@@ -7340,8 +7342,11 @@ expand_expr (exp, target, tmode, modifie
we have an explicit constructor and when our operand is a variable
that was declared const. */
- if (modifier != EXPAND_CONST_ADDRESS && modifier != EXPAND_INITIALIZER
- && TREE_CODE (array) == CONSTRUCTOR && ! TREE_SIDE_EFFECTS (array)
+ if (modifier != EXPAND_CONST_ADDRESS
+ && modifier != EXPAND_INITIALIZER
+ && modifier != EXPAND_MEMORY
+ && TREE_CODE (array) == CONSTRUCTOR
+ && ! TREE_SIDE_EFFECTS (array)
&& TREE_CODE (index) == INTEGER_CST
&& 0 > compare_tree_int (index,
list_length (CONSTRUCTOR_ELTS
@@ -7362,6 +7367,7 @@ expand_expr (exp, target, tmode, modifie
else if (optimize >= 1
&& modifier != EXPAND_CONST_ADDRESS
&& modifier != EXPAND_INITIALIZER
+ && modifier != EXPAND_MEMORY
&& TREE_READONLY (array) && ! TREE_SIDE_EFFECTS (array)
&& TREE_CODE (array) == VAR_DECL && DECL_INITIAL (array)
&& TREE_CODE (DECL_INITIAL (array)) != ERROR_MARK)
Index: expr.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/expr.h,v
retrieving revision 1.139
diff -c -p -d -u -r1.139 expr.h
--- expr.h 3 Jun 2003 11:14:04 -0000 1.139
+++ expr.h 9 Jun 2003 03:03:09 -0000
@@ -51,9 +51,12 @@ Software Foundation, 59 Temple Place - S
EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
is a constant that is not a legitimate address.
- EXPAND_WRITE means we are only going to write to the resulting rtx. */
+ EXPAND_WRITE means we are only going to write to the resulting rtx.
+ EXPAND_MEMORY means we are interested in a memory result, even if
+ the memory is constant and we could have propagated a constant value. */
enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM = 2, EXPAND_SUM,
- EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE};
+ EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
+ EXPAND_MEMORY};
/* Prevent the compiler from deferring stack pops. See
inhibit_defer_pop for more information. */
Index: stmt.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/stmt.c,v
retrieving revision 1.303
diff -c -p -d -u -r1.303 stmt.c
--- stmt.c 6 Jun 2003 17:03:08 -0000 1.303
+++ stmt.c 9 Jun 2003 03:03:11 -0000
@@ -1748,7 +1748,9 @@ expand_asm_operands (string, outputs, in
val = TREE_VALUE (tail);
type = TREE_TYPE (val);
- op = expand_expr (val, NULL_RTX, VOIDmode, 0);
+ op = expand_expr (val, NULL_RTX, VOIDmode,
+ (allows_mem && !allows_reg
+ ? EXPAND_MEMORY : EXPAND_NORMAL));
/* Never pass a CONCAT to an ASM. */
if (GET_CODE (op) == CONCAT)
@@ -1763,38 +1765,35 @@ expand_asm_operands (string, outputs, in
else if (!allows_mem)
warning ("asm operand %d probably doesn't match constraints",
i + noutputs);
- else if (CONSTANT_P (op))
- {
- op = force_const_mem (TYPE_MODE (type), op);
- op = validize_mem (op);
- }
- else if (GET_CODE (op) == REG
- || GET_CODE (op) == SUBREG
- || GET_CODE (op) == ADDRESSOF
- || GET_CODE (op) == CONCAT)
- {
- tree qual_type = build_qualified_type (type,
- (TYPE_QUALS (type)
- | TYPE_QUAL_CONST));
- rtx memloc = assign_temp (qual_type, 1, 1, 1);
- memloc = validize_mem (memloc);
- emit_move_insn (memloc, op);
- op = memloc;
- }
-
else if (GET_CODE (op) == MEM && MEM_VOLATILE_P (op))
{
/* We won't recognize volatile memory as available a
memory_operand at this point. Ignore it. */
}
- else if (queued_subexp_p (op))
- ;
else
- /* ??? Leave this only until we have experience with what
- happens in combine and elsewhere when constraints are
- not satisfied. */
- warning ("asm operand %d probably doesn't match constraints",
- i + noutputs);
+ {
+ warning ("asm operand %d uses deprecated memory input "
+ "without lvalue", i + noutputs);
+
+ if (CONSTANT_P (op))
+ {
+ op = force_const_mem (TYPE_MODE (type), op);
+ op = validize_mem (op);
+ }
+ else if (GET_CODE (op) == REG
+ || GET_CODE (op) == SUBREG
+ || GET_CODE (op) == ADDRESSOF
+ || GET_CODE (op) == CONCAT)
+ {
+ tree qual_type = build_qualified_type (type,
+ (TYPE_QUALS (type)
+ | TYPE_QUAL_CONST));
+ rtx memloc = assign_temp (qual_type, 1, 1, 1);
+ memloc = validize_mem (memloc);
+ emit_move_insn (memloc, op);
+ op = memloc;
+ }
+ }
}
generating_concat_p = old_generating_concat_p;
Index: testsuite/gcc.dg/20011029-2.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/gcc.dg/20011029-2.c,v
retrieving revision 1.2
diff -c -p -d -u -r1.2 20011029-2.c
--- testsuite/gcc.dg/20011029-2.c 6 Feb 2002 20:40:17 -0000 1.2
+++ testsuite/gcc.dg/20011029-2.c 9 Jun 2003 03:03:33 -0000
@@ -16,7 +16,7 @@ int foo (int s)
continue;
else if (({ register char r;
__asm__ __volatile__ ("" : "=q" (r)
- : "r" (0), "m" (a)
+ : "r" (0), "m" (a[0])
: "cc"); r; }))
continue;
}
Index: testsuite/gcc.dg/asm-7.c
===================================================================
RCS file: testsuite/gcc.dg/asm-7.c
diff -N testsuite/gcc.dg/asm-7.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gcc.dg/asm-7.c 9 Jun 2003 03:03:33 -0000
@@ -0,0 +1,26 @@
+/* Gcc 3.3.1 deprecates memory inputs of non-lvalues. */
+/* { dg-do compile } */
+
+void test(void)
+{
+ register int r;
+ register int r2;
+ int i;
+ static int m;
+
+ __asm__ ("" : : "m"(r)); /* { dg-warning "address of register" } */
+ __asm__ ("" : : "m"(i));
+ __asm__ ("" : : "m"(m));
+ __asm__ ("" : : "m"(0)); /* { dg-warning "deprecated memory input" } */
+ __asm__ ("" : : "m"(i+1)); /* { dg-warning "deprecated memory input" } */
+
+ __asm__ ("" : : "g"(r));
+ __asm__ ("" : : "g"(i));
+ __asm__ ("" : : "g"(m));
+ __asm__ ("" : : "g"(0));
+ __asm__ ("" : : "g"(i+1));
+
+ __asm__ ("" : "=m"(r2)); /* { dg-warning "address of register" } */
+ __asm__ ("" : "=m"(i));
+ __asm__ ("" : "=m"(m));
+}