s390: Do not warn about vector index register 0 in assembly
Vector index registers are currently only used in the VRV instruction
format. Unlike general purpose index registers an operand value of
zero (e.g. %v0, 0, or omitted) does not imply a zero value:
"For VRV format instructions, a vector element is used in the formation
of the intermediate value. This vector element is an unsigned binary
integer value that is added to the base address and 12-bit displacement
to form a 64-bit intermediate sum. The vector element is designated by
a vector register and an element index. A zero V field accesses the
element in vector register zero and does not imply a zero value." [1]
Therefore when using s390-specific assembler option "-mwarn-areg-zero"
do not warn if vector index register 0 is specified.
[1]: IBM z/Architecture Principles of Operation, SA22-7832-13, IBM z16,
https://publibfp.dhe.ibm.com/epubs/pdf/a227832d.pdf
gas/
* config/tc-s390.c (md_gather_operands): Do not warn about
vector index register 0.
gas/testsuite/
* gas/s390/zarch-warn-areg-zero.l (vgef): Do not expect warning
about vector index register 0.
Signed-off-by: Jens Remus <jremus@linux.ibm.com>
2 files changed
