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[PATCH 4.4] fix PR middle-end/43323 wrong-code for bitfields
- From: Mikael Pettersson <mikpe at it dot uu dot se>
- To: gcc-patches at gcc dot gnu dot org
- Date: Sat, 13 Mar 2010 11:30:36 +0100
- Subject: [PATCH 4.4] fix PR middle-end/43323 wrong-code for bitfields
This patch fixes PR middle-end/43323, wrong-code for bitfields
and type casts. This is a 4.4 regression, 4.3 and 4.5 work.
For 4.5 the bug was fixed by r148631, Adam Nemet's STRIP_NOPS
conversion patch. This patch backports that patch to 4.4, and
adds the new PR43323 test case.
Bootstrapped and regression tested with all default languages
on {i686,x86_64,sparc64,powerpc64}-unknown-linux and
armv5tel-unknown-linux-gnueabi. Both Adam's original test case
and the new PR43323 one pass with this patch but fail without it.
Ok for 4.4? (I don't have svn write access.)
gcc/
2010-03-13 Mikael Pettersson <mikpe@it.uu.se>
PR middle-end/43323
Backport from mainline:
2009-06-17 Adam Nemet <anemet@caviumnetworks.com>
* tree.h (STRIP_NOPS, STRIP_SIGN_NOPS,
STRIP_USELESS_TYPE_CONVERSION): Use tree_strip_nop_conversions,
tree_strip_sign_nop_conversions and
tree_ssa_strip_useless_type_conversions rather than stripping
the operations here.
(tree_strip_nop_conversions, tree_strip_sign_nop_conversions):
Declare them.
* gimple.h (tree_ssa_strip_useless_type_conversions): Declare it.
* tree-ssa.c (tree_ssa_strip_useless_type_conversions): New function.
* tree.c (tree_nop_conversion, tree_sign_nop_conversion,
tree_strip_nop_conversions, tree_strip_sign_nop_conversions): New
functions.
gcc/testsuite/
2010-03-13 Mikael Pettersson <mikpe@it.uu.se>
PR middle-end/43323
* gcc.c-torture/execute/pr43323.c: New test.
Backport from mainline:
2009-06-17 Adam Nemet <anemet@caviumnetworks.com>
* gcc.c-torture/execute/bitfld-5.c: New test.
diff -rupN gcc-4.4-20100309/gcc/gimple.h gcc-4.4-20100309-pr43323/gcc/gimple.h
--- gcc-4.4-20100309/gcc/gimple.h 2009-05-18 12:13:43.000000000 +0200
+++ gcc-4.4-20100309-pr43323/gcc/gimple.h 2010-03-13 10:59:57.000000000 +0100
@@ -1020,6 +1020,7 @@ extern void gimple_add_to_addresses_take
/* In tree-ssa.c */
extern bool tree_ssa_useless_type_conversion (tree);
+extern tree tree_ssa_strip_useless_type_conversions (tree);
extern bool useless_type_conversion_p (tree, tree);
extern bool types_compatible_p (tree, tree);
diff -rupN gcc-4.4-20100309/gcc/testsuite/gcc.c-torture/execute/bitfld-5.c gcc-4.4-20100309-pr43323/gcc/testsuite/gcc.c-torture/execute/bitfld-5.c
--- gcc-4.4-20100309/gcc/testsuite/gcc.c-torture/execute/bitfld-5.c 1970-01-01 01:00:00.000000000 +0100
+++ gcc-4.4-20100309-pr43323/gcc/testsuite/gcc.c-torture/execute/bitfld-5.c 2010-03-13 10:59:57.000000000 +0100
@@ -0,0 +1,35 @@
+/* See http://gcc.gnu.org/ml/gcc/2009-06/msg00072.html. */
+
+extern void abort (void);
+
+struct s
+{
+ unsigned long long a:2;
+ unsigned long long b:40;
+ unsigned long long c:22;
+};
+
+__attribute__ ((noinline)) void
+g (unsigned long long a, unsigned long long b)
+{
+ asm ("");
+ if (a != b)
+ abort ();
+}
+
+__attribute__ ((noinline)) void
+f (struct s s, unsigned long long b)
+{
+ asm ("");
+ g (((unsigned long long) (s.b-8)) + 8, b);
+}
+
+int
+main ()
+{
+ struct s s = {1, 10, 3};
+ struct s t = {1, 2, 3};
+ f (s, 10);
+ f (t, 0x10000000002);
+ return 0;
+}
diff -rupN gcc-4.4-20100309/gcc/testsuite/gcc.c-torture/execute/pr43323.c gcc-4.4-20100309-pr43323/gcc/testsuite/gcc.c-torture/execute/pr43323.c
--- gcc-4.4-20100309/gcc/testsuite/gcc.c-torture/execute/pr43323.c 1970-01-01 01:00:00.000000000 +0100
+++ gcc-4.4-20100309-pr43323/gcc/testsuite/gcc.c-torture/execute/pr43323.c 2010-03-13 10:59:57.000000000 +0100
@@ -0,0 +1,14 @@
+/* PR middle-end/43323 */
+
+extern void abort (void);
+
+int main()
+{
+ struct { unsigned bar:1; } foo;
+ foo.bar = 0x1;
+ if ((unsigned char)(foo.bar * 0xfe) != 0xfeu)
+ abort ();
+ if ((unsigned char)(foo.bar * 0xff) != 0xffu)
+ abort ();
+ return 0;
+}
diff -rupN gcc-4.4-20100309/gcc/tree-ssa.c gcc-4.4-20100309-pr43323/gcc/tree-ssa.c
--- gcc-4.4-20100309/gcc/tree-ssa.c 2009-08-03 21:27:32.000000000 +0200
+++ gcc-4.4-20100309-pr43323/gcc/tree-ssa.c 2010-03-13 10:59:57.000000000 +0100
@@ -1271,6 +1271,18 @@ tree_ssa_useless_type_conversion (tree e
return false;
}
+/* Strip conversions from EXP according to
+ tree_ssa_useless_type_conversion and return the resulting
+ expression. */
+
+tree
+tree_ssa_strip_useless_type_conversions (tree exp)
+{
+ while (tree_ssa_useless_type_conversion (exp))
+ exp = TREE_OPERAND (exp, 0);
+ return exp;
+}
+
/* Internal helper for walk_use_def_chains. VAR, FN and DATA are as
described in walk_use_def_chains.
diff -rupN gcc-4.4-20100309/gcc/tree.c gcc-4.4-20100309-pr43323/gcc/tree.c
--- gcc-4.4-20100309/gcc/tree.c 2009-07-20 16:39:32.000000000 +0200
+++ gcc-4.4-20100309-pr43323/gcc/tree.c 2010-03-13 10:59:57.000000000 +0100
@@ -9094,6 +9094,79 @@ tree_nonartificial_location (tree exp)
return EXPR_LOCATION (exp);
}
+/* Return true iff conversion in EXP generates no instruction. Mark
+ it inline so that we fully inline into the stripping functions even
+ though we have two uses of this function. */
+
+static inline bool
+tree_nop_conversion (const_tree exp)
+{
+ tree outer_type, inner_type;
+
+ if (!CONVERT_EXPR_P (exp)
+ && TREE_CODE (exp) != NON_LVALUE_EXPR)
+ return false;
+ if (TREE_OPERAND (exp, 0) == error_mark_node)
+ return false;
+
+ outer_type = TREE_TYPE (exp);
+ inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));
+
+ /* Use precision rather then machine mode when we can, which gives
+ the correct answer even for submode (bit-field) types. */
+ if ((INTEGRAL_TYPE_P (outer_type)
+ || POINTER_TYPE_P (outer_type)
+ || TREE_CODE (outer_type) == OFFSET_TYPE)
+ && (INTEGRAL_TYPE_P (inner_type)
+ || POINTER_TYPE_P (inner_type)
+ || TREE_CODE (inner_type) == OFFSET_TYPE))
+ return TYPE_PRECISION (outer_type) == TYPE_PRECISION (inner_type);
+
+ /* Otherwise fall back on comparing machine modes (e.g. for
+ aggregate types, floats). */
+ return TYPE_MODE (outer_type) == TYPE_MODE (inner_type);
+}
+
+/* Return true iff conversion in EXP generates no instruction. Don't
+ consider conversions changing the signedness. */
+
+static bool
+tree_sign_nop_conversion (const_tree exp)
+{
+ tree outer_type, inner_type;
+
+ if (!tree_nop_conversion (exp))
+ return false;
+
+ outer_type = TREE_TYPE (exp);
+ inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));
+
+ return (TYPE_UNSIGNED (outer_type) == TYPE_UNSIGNED (inner_type)
+ && POINTER_TYPE_P (outer_type) == POINTER_TYPE_P (inner_type));
+}
+
+/* Strip conversions from EXP according to tree_nop_conversion and
+ return the resulting expression. */
+
+tree
+tree_strip_nop_conversions (tree exp)
+{
+ while (tree_nop_conversion (exp))
+ exp = TREE_OPERAND (exp, 0);
+ return exp;
+}
+
+/* Strip conversions from EXP according to tree_sign_nop_conversion
+ and return the resulting expression. */
+
+tree
+tree_strip_sign_nop_conversions (tree exp)
+{
+ while (tree_sign_nop_conversion (exp))
+ exp = TREE_OPERAND (exp, 0);
+ return exp;
+}
+
/* These are the hash table functions for the hash table of OPTIMIZATION_NODEq
nodes. */
diff -rupN gcc-4.4-20100309/gcc/tree.h gcc-4.4-20100309-pr43323/gcc/tree.h
--- gcc-4.4-20100309/gcc/tree.h 2009-06-02 09:18:16.000000000 +0200
+++ gcc-4.4-20100309-pr43323/gcc/tree.h 2010-03-13 10:59:57.000000000 +0100
@@ -974,30 +974,17 @@ extern void omp_clause_range_check_faile
case NOP_EXPR: \
case CONVERT_EXPR
-/* Given an expression as a tree, strip any NON_LVALUE_EXPRs and NOP_EXPRs
- that don't change the machine mode. */
+/* Given an expression as a tree, strip any conversion that generates
+ no instruction. Accepts both tree and const_tree arguments since
+ we are not modifying the tree itself. */
-#define STRIP_NOPS(EXP) \
- while ((CONVERT_EXPR_P (EXP) \
- || TREE_CODE (EXP) == NON_LVALUE_EXPR) \
- && TREE_OPERAND (EXP, 0) != error_mark_node \
- && (TYPE_MODE (TREE_TYPE (EXP)) \
- == TYPE_MODE (TREE_TYPE (TREE_OPERAND (EXP, 0))))) \
- (EXP) = TREE_OPERAND (EXP, 0)
+#define STRIP_NOPS(EXP) \
+ (EXP) = tree_strip_nop_conversions (CONST_CAST_TREE (EXP))
/* Like STRIP_NOPS, but don't let the signedness change either. */
#define STRIP_SIGN_NOPS(EXP) \
- while ((CONVERT_EXPR_P (EXP) \
- || TREE_CODE (EXP) == NON_LVALUE_EXPR) \
- && TREE_OPERAND (EXP, 0) != error_mark_node \
- && (TYPE_MODE (TREE_TYPE (EXP)) \
- == TYPE_MODE (TREE_TYPE (TREE_OPERAND (EXP, 0)))) \
- && (TYPE_UNSIGNED (TREE_TYPE (EXP)) \
- == TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (EXP, 0)))) \
- && (POINTER_TYPE_P (TREE_TYPE (EXP)) \
- == POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (EXP, 0))))) \
- (EXP) = TREE_OPERAND (EXP, 0)
+ (EXP) = tree_strip_sign_nop_conversions (CONST_CAST_TREE (EXP))
/* Like STRIP_NOPS, but don't alter the TREE_TYPE either. */
@@ -1012,9 +999,8 @@ extern void omp_clause_range_check_faile
/* Remove unnecessary type conversions according to
tree_ssa_useless_type_conversion. */
-#define STRIP_USELESS_TYPE_CONVERSION(EXP) \
- while (tree_ssa_useless_type_conversion (EXP)) \
- EXP = TREE_OPERAND (EXP, 0)
+#define STRIP_USELESS_TYPE_CONVERSION(EXP) \
+ (EXP) = tree_ssa_strip_useless_type_conversions (EXP)
/* Nonzero if TYPE represents an integral type. Note that we do not
include COMPLEX types here. Keep these checks in ascending code
@@ -4702,6 +4688,8 @@ extern bool stdarg_p (tree);
extern bool prototype_p (tree);
extern int function_args_count (tree);
extern bool auto_var_in_fn_p (const_tree, const_tree);
+extern tree tree_strip_nop_conversions (tree);
+extern tree tree_strip_sign_nop_conversions (tree);
/* In gimplify.c */
extern tree unshare_expr (tree);