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authorJoseph Myers <joseph@codesourcery.com>2020-05-04 23:39:39 +0000
committerRichard Henderson <richard.henderson@linaro.org>2020-05-15 11:04:50 -0700
commitbe53fa785ab766d2722628403edee75b3e6ab599 (patch)
tree17bd6e1126e4ce4005f5f70b005f25d6092d1a7c /fpu/softfloat.c
parent41602807766e253ccb6fb761f3ff12767f786e2c (diff)
downloadfocaccia-qemu-be53fa785ab766d2722628403edee75b3e6ab599.tar.gz
focaccia-qemu-be53fa785ab766d2722628403edee75b3e6ab599.zip
softfloat: fix floatx80 pseudo-denormal comparisons
The softfloat floatx80 comparisons fail to allow for pseudo-denormals,
which should compare equal to corresponding values with biased
exponent 1 rather than 0.  Add an adjustment for that case when
comparing numbers with the same sign.

Signed-off-by: Joseph Myers <joseph@codesourcery.com>
Message-Id: <alpine.DEB.2.21.2005042338470.22972@digraph.polyomino.org.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'fpu/softfloat.c')
-rw-r--r--fpu/softfloat.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 6094d267b5..c57f72e3a6 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -7966,6 +7966,13 @@ static inline int floatx80_compare_internal(floatx80 a, floatx80 b,
             return 1 - (2 * aSign);
         }
     } else {
+        /* Normalize pseudo-denormals before comparison.  */
+        if ((a.high & 0x7fff) == 0 && a.low & UINT64_C(0x8000000000000000)) {
+            ++a.high;
+        }
+        if ((b.high & 0x7fff) == 0 && b.low & UINT64_C(0x8000000000000000)) {
+            ++b.high;
+        }
         if (a.low == b.low && a.high == b.high) {
             return float_relation_equal;
         } else {