These instructions are defined as taking a GPR register and a
coprocessor register for ISAs up to MIPS32. MIPS32 extended the
definition to allow a selector--a value from 0 to 32--to access
another register.
These instructions are now internally defined as being MIPS-I
instructions, but are rejected for pre-MIPS32 ISA's if they have
an explicit selector which is non-zero. This deviates slightly from
GAS's behaviour which rejects assembly instructions with an
explicit selector for pre-MIPS32 ISAs.
E.g:
mfc0 $4, $5, 0
is rejected by GAS for MIPS-I to MIPS-V but will be accepted
with this patch for MIPS-I to MIPS-V.
Reviewers: atanasyan
Differential Revision: https://reviews.llvm.org/D41662
llvm-svn: 326890
Permit explicit $fcc<X> operand in c.cond.fmt instruction.
Add c.cond.fmt to the MIPS to microMIPS instruction mapping table.
Check that $fcc1 - $fcc7 are unusable for MIPS-I to MIPS-III for
c.cond.fmt, bc1t, bc1f.
Reviewers: seanbruno, zoran.jovanovic, vkalintiris
Differential Revision: https://reviews.llvm.org/D24510
llvm-svn: 292117
Summary:
Also tightened up the acceptable condition operand for these instructions
on MIPS-I to MIPS-III. Support for $fcc[1-7] was added in MIPS-IV. Prior
to that only $fcc0 is acceptable.
We currently don't optimize (BEQZ (NOT $a), $target) and similar. It's
probably best to do this in InstCombine.
Depends on D4111
Reviewers: jkolek, zoran.jovanovic, vmedic
Reviewed By: vmedic
Differential Revision: http://reviews.llvm.org/D4112
llvm-svn: 210787
Summary:
This required a new instruction group representing the 32-bit subset of
MIPS-3 that was available in MIPS32R2.
To limit the number of tests required, only one 32-bit and one 64-bit ISA
prior to MIPS32/MIPS64 are tested.
rdhwr has been deliberately left without an ISA annotation for now. This is
because the assembler and CodeGen disagree on when the instruction is
available. Strictly speaking, it is only available in MIPS32r2 and
MIPS64r2. However, it is emulated by a kernel trap on earlier ISA's and is
necessary for TLS so CodeGen should emit it on older ISA's too.
Depends on D3696
Reviewers: vmedic
Reviewed By: vmedic
Differential Revision: http://reviews.llvm.org/D3697
llvm-svn: 208690
Simon Dardis