OpenE2K/qemu-e2k
13
4
Fork 0
Code Issues 4 Pull Requests Projects 2 Releases Activity

target/arm/translate-a64: Fix mishandling of size in FCMLA decode

Browse Source 
In disas_simd_indexed(), for the case of "complex fp", each indexable
element is a complex pair, so the total size is twice that indicated
in the 'size' field in the encoding. We were trying to do this
"double the size" operation with a left shift by 1, but this is
incorrect because the 'size' field is a MO_8/MO_16/MO_32/MO_64
value, and doubling the size should be done by a simple increment.

This meant we were mishandling FCMLA (by element) of values where
the real and imaginary parts are 32-bit floats, and would incorrectly
UNDEF this encoding. (No other insns take this code path, and for
16-bit floats it happens that 1 << 1 and 1 + 1 are both the same).

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190129140411.682-3-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2019-02-01 14:55:45 +00:00
parent 4dfabb6d56
commit eaefb97a8b
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
target/arm/translate-a64.c
View File

@ -12680,7 +12680,7 @@ static void disas_simd_indexed(DisasContext *s, uint32_t insn)
case 2: /* complex fp */
/* Each indexable element is a complex pair. */
size <<= 1;
size += 1;
switch (size) {
case MO_32:
if (h && !is_q) {