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Re: [PATCH] Making double precision constants work with -fsingle-precision-constant
On Sun, Dec 11, 2005 at 12:25:26PM -0800, Mark Mitchell wrote:
> Carlos O'Donell wrote:
>
> > +/* Test that double precision constants are correctly handled
> > + when code is compiled with -fsingle-precision-constant */
> > +/* Origin: Carlos O'Donell <carlos@codesourcery.com> */
> > +/* { dg-do run } */
> > +/* { dg-options "-fsingle-precision-constant" } */
> > +#include <stdio.h>
>
> Do we actually need <stdio.h> for the test? If not, please take it out,
> so that the test will still work on freestanding systems.
Removed reference to stdio.h, and made std_limits.h consistent as per
Richard's recommendation.
Tested on x86-pc-linux-gnu with no regressions.
Please commit.
gcc/
2005-12-12 Carlos O'Donell <carlos@codesourcery.com>
* c-cppbuiltin.c (builtin_define_float_constants): Add
fp_cast parameter, pass to builtin_define_with_hex_fp_value.
Define __FLT_HAS_DENORM__, __DBL_HAS_DENORM__, __LDBL_HAS_DENORM__.
(builtin_define_with_hex_fp_value): Use fp_cast when building macro.
(c_cpp_builtins): If flag_single_precision_constant then set fp_cast to
"((double)%sL)" otherwise "%s".
gcc/testsuite/
2005-12-12 Carlos O'Donell <carlos@codesourcery.com>
* gcc.dg/single-precision-constant.c: New test.
libstdc++-v3/
2005-12-12 Carlos O'Donell <carlos@codesourcery.com>
* include/std/std_limits.h (struct numeric_limits):
Use __DBL_HAS_DENORM__, __FLT_HAS_DENORM__, __LDBL_HAS_DENORM__.
Index: gcc/c-cppbuiltin.c
===================================================================
--- gcc/c-cppbuiltin.c (revision 108358)
+++ gcc/c-cppbuiltin.c (working copy)
@@ -53,11 +53,14 @@
static void builtin_define_with_int_value (const char *, HOST_WIDE_INT);
static void builtin_define_with_hex_fp_value (const char *, tree,
int, const char *,
+ const char *,
const char *);
static void builtin_define_stdint_macros (void);
static void builtin_define_type_max (const char *, tree, int);
static void builtin_define_type_precision (const char *, tree);
-static void builtin_define_float_constants (const char *, const char *,
+static void builtin_define_float_constants (const char *,
+ const char *,
+ const char *,
tree);
static void define__GNUC__ (void);
@@ -68,9 +71,13 @@
builtin_define_with_int_value (name, TYPE_PRECISION (type));
}
-/* Define the float.h constants for TYPE using NAME_PREFIX and FP_SUFFIX. */
+/* Define the float.h constants for TYPE using NAME_PREFIX, FP_SUFFIX,
+ and FP_CAST. */
static void
-builtin_define_float_constants (const char *name_prefix, const char *fp_suffix, tree type)
+builtin_define_float_constants (const char *name_prefix,
+ const char *fp_suffix,
+ const char *fp_cast,
+ tree type)
{
/* Used to convert radix-based values to base 10 values in several cases.
@@ -208,13 +215,13 @@
}
}
sprintf (name, "__%s_MAX__", name_prefix);
- builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix);
+ builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
/* The minimum normalized positive floating-point number,
b**(emin-1). */
sprintf (name, "__%s_MIN__", name_prefix);
sprintf (buf, "0x1p%d", (fmt->emin - 1) * fmt->log2_b);
- builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix);
+ builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
/* The difference between 1 and the least value greater than 1 that is
representable in the given floating point type, b**(1-p). */
@@ -225,7 +232,7 @@
sprintf (buf, "0x1p%d", (fmt->emin - fmt->p) * fmt->log2_b);
else
sprintf (buf, "0x1p%d", (1 - fmt->p) * fmt->log2_b);
- builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix);
+ builtin_define_with_hex_fp_value (name, type, decimal_dig, buf, fp_suffix, fp_cast);
/* For C++ std::numeric_limits<T>::denorm_min. The minimum denormalized
positive floating-point number, b**(emin-p). Zero for formats that
@@ -235,7 +242,7 @@
{
sprintf (buf, "0x1p%d", (fmt->emin - fmt->p) * fmt->log2_b);
builtin_define_with_hex_fp_value (name, type, decimal_dig,
- buf, fp_suffix);
+ buf, fp_suffix, fp_cast);
}
else
{
@@ -243,6 +250,9 @@
builtin_define_with_value (name, buf, 0);
}
+ sprintf (name, "__%s_HAS_DENORM__", name_prefix);
+ builtin_define_with_value (name, fmt->has_denorm ? "1" : "0", 0);
+
/* For C++ std::numeric_limits<T>::has_infinity. */
sprintf (name, "__%s_HAS_INFINITY__", name_prefix);
builtin_define_with_int_value (name,
@@ -382,9 +392,16 @@
builtin_define_with_int_value ("__FLT_EVAL_METHOD__",
TARGET_FLT_EVAL_METHOD);
- builtin_define_float_constants ("FLT", "F", float_type_node);
- builtin_define_float_constants ("DBL", "", double_type_node);
- builtin_define_float_constants ("LDBL", "L", long_double_type_node);
+ builtin_define_float_constants ("FLT", "F", "%s", float_type_node);
+ /* Cast the double precision constants when single precision constants are
+ specified. The correct result is computed by the compiler when using
+ macros that include a cast. This has the side-effect of making the value
+ unusable in const expressions. */
+ if (flag_single_precision_constant)
+ builtin_define_float_constants ("DBL", "L", "((double)%s)", double_type_node);
+ else
+ builtin_define_float_constants ("DBL", "", "%s", double_type_node);
+ builtin_define_float_constants ("LDBL", "L", "%s", long_double_type_node);
/* For use in assembly language. */
builtin_define_with_value ("__REGISTER_PREFIX__", REGISTER_PREFIX, 0);
@@ -580,10 +597,12 @@
static void
builtin_define_with_hex_fp_value (const char *macro,
tree type ATTRIBUTE_UNUSED, int digits,
- const char *hex_str, const char *fp_suffix)
+ const char *hex_str,
+ const char *fp_suffix,
+ const char *fp_cast)
{
REAL_VALUE_TYPE real;
- char dec_str[64], buf[256];
+ char dec_str[64], buf1[256], buf2[256];
/* Hex values are really cool and convenient, except that they're
not supported in strict ISO C90 mode. First, the "p-" sequence
@@ -598,8 +617,13 @@
real_from_string (&real, hex_str);
real_to_decimal (dec_str, &real, sizeof (dec_str), digits, 0);
- sprintf (buf, "%s=%s%s", macro, dec_str, fp_suffix);
- cpp_define (parse_in, buf);
+ /* Assemble the macro in the following fashion
+ macro = fp_cast [dec_str fp_suffix] */
+ sprintf (buf1, "%s%s", dec_str, fp_suffix);
+ sprintf (buf2, fp_cast, buf1);
+ sprintf (buf1, "%s=%s", macro, buf2);
+
+ cpp_define (parse_in, buf1);
}
/* Define MAX for TYPE based on the precision of the type. IS_LONG is
Index: libstdc++-v3/include/std/std_limits.h
===================================================================
--- libstdc++-v3/include/std/std_limits.h (revision 108358)
+++ libstdc++-v3/include/std/std_limits.h (working copy)
@@ -1007,7 +1007,7 @@
static const bool has_quiet_NaN = __FLT_HAS_QUIET_NAN__;
static const bool has_signaling_NaN = has_quiet_NaN;
static const float_denorm_style has_denorm
- = bool(__FLT_DENORM_MIN__) ? denorm_present : denorm_absent;
+ = bool(__FLT_HAS_DENORM__) ? denorm_present : denorm_absent;
static const bool has_denorm_loss = __glibcxx_float_has_denorm_loss;
static float infinity() throw()
@@ -1064,7 +1064,7 @@
static const bool has_quiet_NaN = __DBL_HAS_QUIET_NAN__;
static const bool has_signaling_NaN = has_quiet_NaN;
static const float_denorm_style has_denorm
- = bool(__DBL_DENORM_MIN__) ? denorm_present : denorm_absent;
+ = bool(__DBL_HAS_DENORM__) ? denorm_present : denorm_absent;
static const bool has_denorm_loss = __glibcxx_double_has_denorm_loss;
static double infinity() throw()
@@ -1121,7 +1121,7 @@
static const bool has_quiet_NaN = __LDBL_HAS_QUIET_NAN__;
static const bool has_signaling_NaN = has_quiet_NaN;
static const float_denorm_style has_denorm
- = bool(__LDBL_DENORM_MIN__) ? denorm_present : denorm_absent;
+ = bool(__LDBL_HAS_DENORM__) ? denorm_present : denorm_absent;
static const bool has_denorm_loss
= __glibcxx_long_double_has_denorm_loss;
--- /dev/null 2005-09-01 09:08:28.063949816 -0700
+++ gcc/testsuite/gcc.dg/single-precision-constant.c 2005-12-12 14:49:05.995645523 -0800
@@ -0,0 +1,19 @@
+/* Test that double precision constants are correctly handled
+ when code is compiled with -fsingle-precision-constant */
+/* Origin: Carlos O'Donell <carlos@codesourcery.com> */
+/* { dg-do run } */
+/* { dg-options "-fsingle-precision-constant" } */
+#include <math.h>
+#include <float.h>
+
+int main (void)
+{
+ int result = 0;
+ double local_DBL_MAX = DBL_MAX;
+ double local_DBL_MIN = DBL_MIN;
+ if (isinf (local_DBL_MAX))
+ result |= 1;
+ if (local_DBL_MIN <= 0.0)
+ result |= 1;
+ return result;
+}