From e27fcd027cbdc2f13bf440177c0434eb9ec3dd28 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 1 Oct 2015 15:24:54 +0000 Subject: Use type-specific precision when printing results in libm-test.inc. When libm-test.inc prints the results of failing tests, the output can be unhelpful for ldbl-128 and ldbl-128ibm because the precision used is insufficient to distinguish values of those types, resulting in reported values that look identical but differ by a large number of ulps. This patch changes it to use a precision appropriate for the type, for both decimal and hex output (so output for float is more compact, output for ldbl-128 and ldbl-128ibm is substantially wider). The natural precision to use for decimal is given by the C11 macros such as FLT_DECIMAL_DIG. GCC's only defines those in C11 mode, so this patch uses the predefines such as __FLT_DECIMAL_DIG__ (added in GCC 4.6) instead; if we move to building with -std=gnu11 (or -std=gnu1x if we can't get rid of 4.6 support). Tested for powerpc and mips64. * math/libm-test.inc (TYPE_DECIMAL_DIG): New macro. (TYPE_HEX_DIG): Likewise. (print_float): Use TYPE_DECIMAL_DIG - 1 and TYPE_HEX_DIG - 1 as precisions when printing floating-point numbers. (check_float_internal): Likewise. --- ChangeLog | 8 ++++++++ math/libm-test.inc | 19 ++++++++++++++++--- 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/ChangeLog b/ChangeLog index a88defa9f6..6da0652f4e 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2015-10-01 Joseph Myers + + * math/libm-test.inc (TYPE_DECIMAL_DIG): New macro. + (TYPE_HEX_DIG): Likewise. + (print_float): Use TYPE_DECIMAL_DIG - 1 and TYPE_HEX_DIG - 1 as + precisions when printing floating-point numbers. + (check_float_internal): Likewise. + 2015-09-30 Joseph Myers [BZ #16620] diff --git a/math/libm-test.inc b/math/libm-test.inc index 8615957600..f627296d66 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -338,6 +338,18 @@ static FLOAT max_valid_error; (LDBL_MANT_DIG-1), (DBL_MANT_DIG-1), (FLT_MANT_DIG-1)) #define MIN_EXP CHOOSE ((LDBL_MIN_EXP-1), (DBL_MIN_EXP-1), (FLT_MIN_EXP-1), \ (LDBL_MIN_EXP-1), (DBL_MIN_EXP-1), (FLT_MIN_EXP-1)) +/* Sufficient numbers of digits to represent any floating-point value + unambiguously (for any choice of the number of bits in the first + hex digit, in the case of TYPE_HEX_DIG). When used with printf + formats where the precision counts only digits after the point, 1 + is subtracted from these values. */ +#define TYPE_DECIMAL_DIG CHOOSE (__DECIMAL_DIG__, \ + __DBL_DECIMAL_DIG__, \ + __FLT_DECIMAL_DIG__, \ + __DECIMAL_DIG__, \ + __DBL_DECIMAL_DIG__, \ + __FLT_DECIMAL_DIG__) +#define TYPE_HEX_DIG ((MANT_DIG + 7) / 4) /* Compare KEY (a string, with the name of a function) with ULP (a pointer to a struct ulp_data structure), returning a value less @@ -419,7 +431,8 @@ print_float (FLOAT f) else if (isnan (f)) printf ("qNaN\n"); else - printf ("% .20" PRINTF_EXPR " % .20" PRINTF_XEXPR "\n", f, f); + printf ("% .*" PRINTF_EXPR " % .*" PRINTF_XEXPR "\n", + TYPE_DECIMAL_DIG - 1, f, TYPE_HEX_DIG - 1, f); } /* Should the message print to screen? This depends on the verbose flag, @@ -837,8 +850,8 @@ check_float_internal (const char *test_name, FLOAT computed, FLOAT expected, print_float (expected); if (print_diff) { - printf (" difference: % .20" PRINTF_EXPR " % .20" PRINTF_XEXPR - "\n", diff, diff); + printf (" difference: % .*" PRINTF_EXPR " % .*" PRINTF_XEXPR + "\n", TYPE_DECIMAL_DIG - 1, diff, TYPE_HEX_DIG - 1, diff); printf (" ulp : % .4" PRINTF_NEXPR "\n", ulps); printf (" max.ulp : % .4" PRINTF_NEXPR "\n", max_ulp); } -- cgit v1.2.3