On Cortex-A8, we use the NEON v2f32 instructions for f32 arithmetic. For
better latency, we also send D-register copies down the NEON pipeline by
translating them to vorr instructions.
This patch promotes even S-register copies to D-register copies when
possible so they can also go down the NEON pipeline. Example:
vldr.32 s0, LCPI0_0
loop:
vorr d1, d0, d0
loop2:
...
vadd.f32 d1, d1, d16
The vorr instruction looked like this after regalloc:
%S2<def> = COPY %S0, %D1<imp-def>
Copies involving odd S-registers, and copies that don't define the full
D-register are left alone.
llvm-svn: 137182
Frontends(eg. clang) might pass incomplete form of IR, to step off the way beyond iterator end. In the case I had met, it took infinite loop due to meeting bogus PHInode.
Thanks to Jay Foad and John McCall.
llvm-svn: 137175
Assigned symbol addresses get truncated to 32-bits, even on 64-bit platforms.
That's obviously bogus.
For example,
.globl _foo
.equ _foo, 0x987654321ULL
rdar://9922863
llvm-svn: 137158
This new disassembler can correctly decode all the testcases that the old one did, though
some "expected failure" testcases are XFAIL'd for now because it is not (yet) as strict in
operand checking as the old one was.
llvm-svn: 137144
Coalescing can remove copy-like instructions with sub-register operands
that constrained the register class. Examples are:
x86: GR32_ABCD:sub_8bit_hi -> GR32
arm: DPR_VFP2:ssub0 -> DPR
Recompute the register class of any virtual registers that are used by
less instructions after coalescing.
This affects code generation for the Cortex-A8 where we use NEON
instructions for f32 operations, c.f. fp_convert.ll:
vadd.f32 d16, d1, d0
vcvt.s32.f32 d0, d16
The register allocator is now free to use d16 for the temporary, and
that comes first in the allocation order because it doesn't interfere
with any s-registers.
llvm-svn: 137133
This function doesn't have anything to do with spill weights, and MRI
already has functions for manipulating the register class of a virtual
register.
llvm-svn: 137123
When this variable is set, "uname -r" will return its value instead of the
real OS version. Make this affect LLVM's triple for consistency.
<rdar://problem/9919167>
llvm-svn: 137111
The 'unwind' instruction was acting essentially as a placeholder, because it
would be replaced at the end of this function by a branch to the "unwind
handler". The 'unwind' instruction is going away, so use 'unreachable' instead,
which serves the same purpose as a placeholder.
llvm-svn: 137098
