diff options
| author | Sandipan Das <sandipan@linux.vnet.ibm.com> | 2018-03-06 17:38:12 +0530 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2018-03-06 13:02:41 +0000 |
| commit | 69835a3891a5c7d262f244a062783ea1ecc606ea (patch) | |
| tree | 648c89fa79a38ac94ba64d8a653f9bd0f0b7b57d | |
| parent | 0a7b2b5f10883c3320e5afba0156cffe1724ed76 (diff) | |
ppc64.risu: Fix pattern for load qword
The pattern for the Load Quadword (lq) instruction is fixed.
If rtp is 0 or 12, the instruction will overwrite r0, r1 or
r12, r13 respectively. However, r1 is the stack frame pointer
and r13 is the thread pointer. So, overwriting them can cause
a crash. This is avoided by putting a constraint to prevent
rtp from being 0 or 12.
For a given effective address (ea), this instruction loads
two dwords from ea and ea+8. However, if ea is the start
address of the current stack frame, then the value of the
back chain dword from the previous stack frame, which is at
ea+8, is loaded on to one of the registers. This can cause
a mismatch as the addresses may vary across the master and
the apprentice instances. This is avoided by always adding
8 to the offset used for calculating the ea.
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Message-id: 20180306120813.17537-3-sandipan@linux.vnet.ibm.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| -rw-r--r-- | ppc64.risu | 4 |
1 files changed, 2 insertions, 2 deletions
@@ -1050,8 +1050,8 @@ LHZX PPC64LE 011111 rt:5 ra:5 rb:5 01000101110 \ # format:DQ book:I page:59 v2.03 lq Load Qword LQ PPC64LE 111000 rtp:5 ra:5 imm:12 0000 \ -!constraints { $rtp % 2 == 0 && $ra != 1 && $ra != 13 && $ra != 0 && $ra != $rtp && $imm <= 2032; } \ -!memory { reg_plus_imm($ra, $imm << 4); } +!constraints { $rtp % 2 == 0 && $rtp != 0 && $rtp != 12 && $ra != 1 && $ra != 13 && $ra != 0 && $ra != $rtp && $imm <= 2032; } \ +!memory { reg_plus_imm($ra, ($imm << 4) + 8); } # format:X book:I page:65 v:P1 lswi Load String Word Immediate LSWI PPC64LE 011111 rt:5 ra:5 rb:5 10010101010 \ |