Shivaprasad G Bhat 1098cc3fcf softfloat: Fix the incorrect computation in float32_exp2 ... The float32_exp2 function is computing wrong exponent of 2. For example, with the following set of values {0.1, 2.0, 2.0, -1.0}, the expected output would be {1.071773, 4.000000, 4.000000, 0.500000}. Instead, the function is computing {1.119102, 3.382044, 3.382044, -0.191022} Looking at the code, the float32_exp2() attempts to do this 2 3 4 5 n x x x x x x x e = 1 + --- + --- + --- + --- + --- + ... + --- + ... 1! 2! 3! 4! 5! n! But because of the typo it ends up doing x x x x x x x e = 1 + --- + --- + --- + --- + --- + ... + --- + ... 1! 2! 3! 4! 5! n! This is because instead of the xnp which holds the numerator, parts_muladd is using the xp which is just 'x'. Commit '572c4d862ff2' refactored this function, and mistakenly used xp instead of xnp. Cc: qemu-stable@nongnu.org Fixes: 572c4d862f "softfloat: Convert float32_exp2 to FloatParts" Partially-Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1623 Reported-By: Luca Barbato (https://gitlab.com/lu-zero) Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com> Message-Id: <168304110865.537992.13059030916325018670.stgit@localhost.localdomain> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>		2023-05-05 16:57:48 +01:00
..
meson.build	meson: Split out fpu/meson.build	2021-06-11 09:26:28 -07:00
softfloat-parts-addsub.c.inc	softfloat: Move addsub_floats to softfloat-parts.c.inc	2021-05-16 07:13:51 -05:00
softfloat-parts.c.inc	softfloat: logB(0) should raise divideByZero exception	2022-10-17 10:28:35 +08:00
softfloat-specialize.c.inc	* Fixes for s390x floating point vector instructions	2022-07-20 14:13:32 +01:00
softfloat.c	softfloat: Fix the incorrect computation in float32_exp2	2023-05-05 16:57:48 +01:00