From 4da6db51880289f0bf41b39e05cf9bb1c4769c47 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Mon, 23 Jun 2014 20:12:33 +0000 Subject: Fix pow overflow in non-default rounding modes (bug 16315). This patch fixes bug 16315, bad pow handling of overflow/underflow in non-default rounding modes. Tests of pow are duly converted to ALL_RM_TEST to run all tests in all rounding modes. There are two main issues here. First, various implementations compute a negative result by negating a positive result, but this yields inappropriate overflow / underflow values for directed rounding, so either overflow / underflow results need recomputing in the correct sign, or the relevant overflowing / underflowing operation needs to be made to have a result of the correct sign. Second, the dbl-64 implementation sets FE_TONEAREST internally; in the overflow / underflow case, the result needs recomputing in the original rounding mode. Tested x86_64 and x86 and ulps updated accordingly. [BZ #16315] * sysdeps/i386/fpu/e_pow.S (__ieee754_pow): Ensure possibly overflowing or underflowing operations take place with sign of result. * sysdeps/i386/fpu/e_powf.S (__ieee754_powf): Likewise. * sysdeps/i386/fpu/e_powl.S (__ieee754_powl): Likewise. * sysdeps/ieee754/dbl-64/e_pow.c: Include . (__ieee754_pow): Recompute overflowing and underflowing results in original rounding mode. * sysdeps/x86/fpu/powl_helper.c: Include . (__powl_helper): Allow negative argument X and scale negated value as needed. Avoid passing value outside [-1, 1] to f2xm1. * sysdeps/x86_64/fpu/e_powl.S (__ieee754_powl): Ensure possibly overflowing or underflowing operations take place with sign of result. * sysdeps/x86_64/fpu/multiarch/e_pow.c [HAVE_FMA4_SUPPORT]: Include . * math/auto-libm-test-in: Add more tests of pow. * math/auto-libm-test-out: Regenerated. * math/libm-test.inc (pow_test): Use ALL_RM_TEST. (pow_tonearest_test_data): Remove. (pow_test_tonearest): Likewise. (pow_towardzero_test_data): Likewise. (pow_test_towardzero): Likewise. (pow_downward_test_data): Likewise. (pow_test_downward): Likewise. (pow_upward_test_data): Likewise. (pow_test_upward): Likewise. (main): Don't call removed functions. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise. --- math/libm-test.inc | 68 +----------------------------------------------------- 1 file changed, 1 insertion(+), 67 deletions(-) (limited to 'math/libm-test.inc') diff --git a/math/libm-test.inc b/math/libm-test.inc index 0ed1fee..c138778 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -8697,69 +8697,7 @@ static const struct test_ff_f_data pow_test_data[] = static void pow_test (void) { - - START (pow, 0); - RUN_TEST_LOOP_ff_f (pow, pow_test_data, ); - END; -} - - -static const struct test_ff_f_data pow_tonearest_test_data[] = - { - AUTO_TESTS_ff_f (pow), - }; - -static void -pow_test_tonearest (void) -{ - START (pow_tonearest, 0); - RUN_TEST_LOOP_ff_f (pow, pow_tonearest_test_data, FE_TONEAREST); - END; -} - - -static const struct test_ff_f_data pow_towardzero_test_data[] = - { - TEST_ff_f (pow, 1.0625L, 1.125L, 1.070582293028761362162622578677070098674L), - TEST_ff_f (pow, 1.5L, 1.03125L, 1.519127098714743184071644334163037684948L), - }; - -static void -pow_test_towardzero (void) -{ - START (pow_towardzero, 0); - RUN_TEST_LOOP_ff_f (pow, pow_towardzero_test_data, FE_TOWARDZERO); - END; -} - - -static const struct test_ff_f_data pow_downward_test_data[] = - { - TEST_ff_f (pow, 1.0625L, 1.125L, 1.070582293028761362162622578677070098674L), - TEST_ff_f (pow, 1.5L, 1.03125L, 1.519127098714743184071644334163037684948L), - }; - -static void -pow_test_downward (void) -{ - START (pow_downward, 0); - RUN_TEST_LOOP_ff_f (pow, pow_downward_test_data, FE_DOWNWARD); - END; -} - - -static const struct test_ff_f_data pow_upward_test_data[] = - { - TEST_ff_f (pow, 1.0625L, 1.125L, 1.070582293028761362162622578677070098674L), - TEST_ff_f (pow, 1.5L, 1.03125L, 1.519127098714743184071644334163037684948L), - }; - -static void -pow_test_upward (void) -{ - START (pow_upward, 0); - RUN_TEST_LOOP_ff_f (pow, pow_upward_test_data, FE_UPWARD); - END; + ALL_RM_TEST (pow, 0, pow_test_data, RUN_TEST_LOOP_ff_f, END); } @@ -9946,10 +9884,6 @@ main (int argc, char **argv) fabs_test (); hypot_test (); pow_test (); - pow_test_tonearest (); - pow_test_towardzero (); - pow_test_downward (); - pow_test_upward (); sqrt_test (); /* Error and gamma functions: */ -- cgit v1.1