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authorJoseph Myers <joseph@codesourcery.com>2012-09-24 15:38:21 +0000
committerJoseph Myers <joseph@codesourcery.com>2012-09-24 15:38:21 +0000
commita9f8e53a5b14ba481999ded036b025554ea06362 (patch)
treea59b5925b071a62962c3d399bc8758a690f518bd /stdio-common
parenteaf6f205fff7ca8a628869e3bc56800020a70f24 (diff)
downloadglibc-a9f8e53a5b14ba481999ded036b025554ea06362.tar.gz
Make printf respect the rounding mode for hex output (bug 5044).
Diffstat (limited to 'stdio-common')
-rw-r--r--stdio-common/printf_fphex.c40
-rw-r--r--stdio-common/tst-printf-round.c124
2 files changed, 151 insertions, 13 deletions
diff --git a/stdio-common/printf_fphex.c b/stdio-common/printf_fphex.c
index 13491455d1..2224196b24 100644
--- a/stdio-common/printf_fphex.c
+++ b/stdio-common/printf_fphex.c
@@ -28,6 +28,8 @@
#include <_itoa.h>
#include <_itowa.h>
#include <locale/localeinfo.h>
+#include <stdbool.h>
+#include <rounding-mode.h>
/* #define NDEBUG 1*/ /* Undefine this for debugging assertions. */
#include <assert.h>
@@ -343,21 +345,33 @@ __printf_fphex (FILE *fp,
--numend;
}
+ bool do_round_away = false;
+
+ if (precision != -1 && precision < numend - numstr)
+ {
+ char last_digit = precision > 0 ? numstr[precision - 1] : leading;
+ char next_digit = numstr[precision];
+ int last_digit_value = (last_digit >= 'A' && last_digit <= 'F'
+ ? last_digit - 'A' + 10
+ : (last_digit >= 'a' && last_digit <= 'f'
+ ? last_digit - 'a' + 10
+ : last_digit - '0'));
+ int next_digit_value = (next_digit >= 'A' && next_digit <= 'F'
+ ? next_digit - 'A' + 10
+ : (next_digit >= 'a' && next_digit <= 'f'
+ ? next_digit - 'a' + 10
+ : next_digit - '0'));
+ bool more_bits = ((next_digit_value & 7) != 0
+ || precision + 1 < numend - numstr);
+ int rounding_mode = get_rounding_mode ();
+ do_round_away = round_away (negative, last_digit_value & 1,
+ next_digit_value >= 8, more_bits,
+ rounding_mode);
+ }
+
if (precision == -1)
precision = numend - numstr;
- else if (precision < numend - numstr
- && (numstr[precision] > '8'
- || (('A' < '0' || 'a' < '0')
- && numstr[precision] < '0')
- || (numstr[precision] == '8'
- && (precision + 1 < numend - numstr
- /* Round to even. */
- || (precision > 0
- && ((numstr[precision - 1] & 1)
- ^ (isdigit (numstr[precision - 1]) == 0)))
- || (precision == 0
- && ((leading & 1)
- ^ (isdigit (leading) == 0)))))))
+ else if (do_round_away)
{
/* Round up. */
int cnt = precision;
diff --git a/stdio-common/tst-printf-round.c b/stdio-common/tst-printf-round.c
index 2bd46079ac..7cc19c5645 100644
--- a/stdio-common/tst-printf-round.c
+++ b/stdio-common/tst-printf-round.c
@@ -68,6 +68,99 @@ test_dec_in_one_mode (double d, const char *fmt, const char *expected,
}
}
+struct hex_test
+{
+ double d;
+ const char *fmt;
+ const char *rd[4], *rn[4], *rz[4], *ru[4];
+};
+
+static const struct hex_test hex_tests[] =
+ {
+ {
+ 0x1.fffffp+4, "%.1a",
+ { "0x1.fp+4", "0x3.fp+3", "0x7.fp+2", "0xf.fp+1" },
+ { "0x2.0p+4", "0x4.0p+3", "0x8.0p+2", "0x1.0p+5" },
+ { "0x1.fp+4", "0x3.fp+3", "0x7.fp+2", "0xf.fp+1" },
+ { "0x2.0p+4", "0x4.0p+3", "0x8.0p+2", "0x1.0p+5" }
+ },
+ {
+ -0x1.fffffp+4, "%.1a",
+ { "-0x2.0p+4", "-0x4.0p+3", "-0x8.0p+2", "-0x1.0p+5" },
+ { "-0x2.0p+4", "-0x4.0p+3", "-0x8.0p+2", "-0x1.0p+5" },
+ { "-0x1.fp+4", "-0x3.fp+3", "-0x7.fp+2", "-0xf.fp+1" },
+ { "-0x1.fp+4", "-0x3.fp+3", "-0x7.fp+2", "-0xf.fp+1" }
+ },
+ {
+ 0x1.88p+4, "%.1a",
+ { "0x1.8p+4", "0x3.1p+3", "0x6.2p+2", "0xc.4p+1" },
+ { "0x1.8p+4", "0x3.1p+3", "0x6.2p+2", "0xc.4p+1" },
+ { "0x1.8p+4", "0x3.1p+3", "0x6.2p+2", "0xc.4p+1" },
+ { "0x1.9p+4", "0x3.1p+3", "0x6.2p+2", "0xc.4p+1" }
+ },
+ {
+ -0x1.88p+4, "%.1a",
+ { "-0x1.9p+4", "-0x3.1p+3", "-0x6.2p+2", "-0xc.4p+1" },
+ { "-0x1.8p+4", "-0x3.1p+3", "-0x6.2p+2", "-0xc.4p+1" },
+ { "-0x1.8p+4", "-0x3.1p+3", "-0x6.2p+2", "-0xc.4p+1" },
+ { "-0x1.8p+4", "-0x3.1p+3", "-0x6.2p+2", "-0xc.4p+1" }
+ },
+ {
+ 0x1.78p+4, "%.1a",
+ { "0x1.7p+4", "0x2.fp+3", "0x5.ep+2", "0xb.cp+1" },
+ { "0x1.8p+4", "0x2.fp+3", "0x5.ep+2", "0xb.cp+1" },
+ { "0x1.7p+4", "0x2.fp+3", "0x5.ep+2", "0xb.cp+1" },
+ { "0x1.8p+4", "0x2.fp+3", "0x5.ep+2", "0xb.cp+1" }
+ },
+ {
+ -0x1.78p+4, "%.1a",
+ { "-0x1.8p+4", "-0x2.fp+3", "-0x5.ep+2", "-0xb.cp+1" },
+ { "-0x1.8p+4", "-0x2.fp+3", "-0x5.ep+2", "-0xb.cp+1" },
+ { "-0x1.7p+4", "-0x2.fp+3", "-0x5.ep+2", "-0xb.cp+1" },
+ { "-0x1.7p+4", "-0x2.fp+3", "-0x5.ep+2", "-0xb.cp+1" }
+ },
+ {
+ 64.0 / 3.0, "%.1a",
+ { "0x1.5p+4", "0x2.ap+3", "0x5.5p+2", "0xa.ap+1" },
+ { "0x1.5p+4", "0x2.bp+3", "0x5.5p+2", "0xa.bp+1" },
+ { "0x1.5p+4", "0x2.ap+3", "0x5.5p+2", "0xa.ap+1" },
+ { "0x1.6p+4", "0x2.bp+3", "0x5.6p+2", "0xa.bp+1" }
+ },
+ {
+ -64.0 / 3.0, "%.1a",
+ { "-0x1.6p+4", "-0x2.bp+3", "-0x5.6p+2", "-0xa.bp+1" },
+ { "-0x1.5p+4", "-0x2.bp+3", "-0x5.5p+2", "-0xa.bp+1" },
+ { "-0x1.5p+4", "-0x2.ap+3", "-0x5.5p+2", "-0xa.ap+1" },
+ { "-0x1.5p+4", "-0x2.ap+3", "-0x5.5p+2", "-0xa.ap+1" }
+ },
+ };
+
+static int
+test_hex_in_one_mode (double d, const char *fmt, const char *expected[4],
+ const char *mode_name)
+{
+ char buf[100];
+ int ret = snprintf (buf, sizeof buf, fmt, d);
+ if (ret <= 0 || ret >= (int) sizeof buf)
+ {
+ printf ("snprintf for %a returned %d\n", d, ret);
+ return 1;
+ }
+ if (strcmp (buf, expected[0]) == 0
+ || strcmp (buf, expected[1]) == 0
+ || strcmp (buf, expected[2]) == 0
+ || strcmp (buf, expected[3]) == 0)
+ return 0;
+ else
+ {
+ printf ("snprintf (\"%s\", %a) returned \"%s\" not "
+ "\"%s\" or \"%s\" or \"%s\" or \"%s\" (%s)\n",
+ fmt, d, buf, expected[0], expected[1], expected[2], expected[3],
+ mode_name);
+ return 1;
+ }
+}
+
static int
do_test (void)
{
@@ -103,6 +196,37 @@ do_test (void)
}
#endif
}
+
+ for (size_t i = 0; i < sizeof (hex_tests) / sizeof (hex_tests[0]); i++)
+ {
+ result |= test_hex_in_one_mode (hex_tests[i].d, hex_tests[i].fmt,
+ hex_tests[i].rn, "default rounding mode");
+#ifdef FE_DOWNWARD
+ if (!fesetround (FE_DOWNWARD))
+ {
+ result |= test_hex_in_one_mode (hex_tests[i].d, hex_tests[i].fmt,
+ hex_tests[i].rd, "FE_DOWNWARD");
+ fesetround (save_round_mode);
+ }
+#endif
+#ifdef FE_TOWARDZERO
+ if (!fesetround (FE_TOWARDZERO))
+ {
+ result |= test_hex_in_one_mode (hex_tests[i].d, hex_tests[i].fmt,
+ hex_tests[i].rz, "FE_TOWARDZERO");
+ fesetround (save_round_mode);
+ }
+#endif
+#ifdef FE_UPWARD
+ if (!fesetround (FE_UPWARD))
+ {
+ result |= test_hex_in_one_mode (hex_tests[i].d, hex_tests[i].fmt,
+ hex_tests[i].ru, "FE_UPWARD");
+ fesetround (save_round_mode);
+ }
+#endif
+ }
+
return result;
}