target-sparc: fix 32-bit truncation in fpackfix

This is reported by Coverity.  The algorithm description at
ftp://ftp.icm.edu.pl/packages/ggi/doc/hw/sparc/Sparc.pdf suggests
that the 32-bit parts of rs2, after the left shift, is treated
as a 64-bit integer.  Bits 32 and above are used to do the
saturating truncation.

Message-Id: <1446473134-4330-1-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2015-11-02 15:05:34 +01:00
parent bfc2a1a1f4
commit 12a3567c40

View File

@ -447,7 +447,7 @@ uint32_t helper_fpackfix(uint64_t gsr, uint64_t rs2)
for (word = 0; word < 2; word++) {
uint32_t val;
int32_t src = rs2 >> (word * 32);
int64_t scaled = src << scale;
int64_t scaled = (int64_t)src << scale;
int64_t from_fixed = scaled >> 16;
val = (from_fixed < -32768 ? -32768 :