On 18.3.19. 19:55, Aleksandar Markovic wrote:
Hi, Mateja,
From: Mateja Marjanovic <mateja.marjano...@rt-rk.com>
Subject: [PATCH] target/mips: Fix minor bug in FPU
From: Mateja Marjanovic <mateja.marjano...@rt-rk.com>
Wrong type of NaN was generated for IEEE754-2008 by maddf and
msubf insturctions when the arguments were inf, zero, nan or
zero, inf, nan respectively.
Signed-off-by: Mateja Marjanovic <mateja.marjano...@rt-rk.com>
---
fpu/softfloat-specialize.h | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index 16c0bcb..56256be 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -495,15 +495,15 @@ static int pickNaNMulAdd(FloatClass a_cls, FloatClass b_cls,
> FloatClass c_cls,
return 1;
}
#elif defined(TARGET_MIPS)
- /* For MIPS, the (inf,zero,qnan) case sets InvalidOp and returns
- * the default NaN
- */
- if (infzero) {
- float_raise(float_flag_invalid, status);
- return 3;
- }
-
if (snan_bit_is_one(status)) {
+ /*
+ * For MIPS systems that conform to IEEE754-1985, the (inf,zero,qnan)
"IEEE754-1985" should be "IEEE 754-1985".
"(inf,zero,qnan)" should be "(inf,zero,nan)" (the "c" can be both kinds of NaN
at
the moment of execution of this block, as it is visible from the code
surrounding
invocations of pickNaNMulAdd()).
It was a copy-paste error. In the previous version I thought the if-else
statement reffers to the snan and qnan.
Later I found out it actually checks if it is IEEE754-1985 or
IEEE754-2008. It will be corrected as soon as possible.
+ * case sets InvalidOp and returns the default NaN
+ */
+ if (infzero) {
+ float_raise(float_flag_invalid, status);
+ return 3;
+ }
/* Prefer sNaN over qNaN, in the a, b, c order. */
if (is_snan(a_cls)) {
return 0;
@@ -519,6 +519,14 @@ static int pickNaNMulAdd(FloatClass a_cls, FloatClass b_cls,
> FloatClass c_cls,
return 2;
}
} else {
+ /*
+ * For MIPS systems that conform to IEEE754-2008, the (inf,zero,qnan)
A similar comment applies, like for the block above.
Same goes for this.
+ * case sets InvalidOp and returns the default NaN
This line is incorrect, and, instead of "the default NaN", there should be "c".
Yes, I noticed that, Peter already wrote me, but thanks anyways.
+ */
+ if (infzero) {
+ float_raise(float_flag_invalid, status);
+ return 2;
+ }
/* Prefer sNaN over qNaN, in the c, a, b order. */
if (is_snan(c_cls)) {
return 2;
--
2.7.4
Reference to the justification in documentation in the commit message would be
useful and nice.
I agree, it will be added.
Thanks,
Aleksandar
Thanks,
Mateja
